finish rust rewrite, add docker, drop python

crates/xmedia-bot/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "xmedia-bot"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+teloxide = { version = "0.17", features = ["webhooks-axum", "macros"] }
+tokio = { version = "1.40", features = ["rt-multi-thread", "macros"] }
+serde = { version = "1", features = ["derive"] }
+serde_json = "1"
+log = "0.4"
+pretty_env_logger = "0.5"
+dotenv = "0.15"
+url = "2.5.2"
+regex = "1.12"
+html-escape = "0.2"
+rusqlite = { version = "0.32", features = ["bundled"] }
+rand = "0.8"
+tempfile = "3"
+parking_lot = "0.12"
+x-media = { path = "../x-media" }

crates/xmedia-bot/src/config.rs

@@ -0,0 +1,58 @@
+//! Central env handling. The only other places that read env are
+//! `Bot::from_env` (TELOXIDE_TOKEN) and x-media (PIXIV_REFRESH_TOKEN).
+
+use std::env;
+use std::net::IpAddr;
+use std::time::Duration;
+
+pub struct Config {
+    /// BOT_ADMIN: comma-separated ints; empty when unset.
+    pub admin_ids: Vec<i64>,
+    /// EDIT_MESSAGE_TTL_SECONDS, default 86400 (24h).
+    pub edit_message_ttl: Duration,
+    // Webhook settings (moved out of main; names/defaults unchanged).
+    pub webhook_enabled: bool,
+    pub webhook_url: Option<url::Url>,
+    pub webhook_listen: Option<IpAddr>,
+    pub webhook_port: Option<u16>,
+    pub webhook_cert: Option<String>,
+    pub webhook_secret_token: Option<String>,
+}
+
+impl Config {
+    pub fn load() -> Config {
+        let admin_ids = env::var("BOT_ADMIN")
+        .ok()
+        .map(|s| {
+            s.split(',')
+                .filter_map(|part| part.trim().parse::<i64>().ok())
+                .collect()
+        })
+        .unwrap_or_default();
+
+    let edit_message_ttl = env::var("EDIT_MESSAGE_TTL_SECONDS")
+        .ok()
+        .and_then(|s| s.parse::<u64>().ok())
+        .map(Duration::from_secs)
+        .unwrap_or(Duration::from_secs(86400));
+
+    let webhook_enabled = env::var("WEBHOOK")
+        .is_ok_and(|v| matches!(v.to_lowercase().as_str(), "true" | "yes" | "1"));
+    let webhook_url = env::var("WEBHOOK_URL").ok().and_then(|s| s.parse().ok());
+    let webhook_listen = env::var("WEBHOOK_LISTEN").ok().and_then(|s| s.parse().ok());
+    let webhook_port = env::var("WEBHOOK_PORT").ok().and_then(|s| s.parse().ok());
+    let webhook_cert = env::var("WEBHOOK_CERT").ok();
+    let webhook_secret_token = env::var("WEBHOOK_SECRET_TOKEN").ok();
+
+        Config {
+            admin_ids,
+            edit_message_ttl,
+            webhook_enabled,
+            webhook_url,
+            webhook_listen,
+            webhook_port,
+            webhook_cert,
+            webhook_secret_token,
+        }
+    }
+}

crates/xmedia-bot/src/handlers.rs

@@ -0,0 +1,639 @@
+use crate::config::Config;
+use crate::queue::PersistentTaskQueue;
+use crate::send::{self, MediaItemPayload, Task};
+use crate::state::{ChatStore, unix_now};
+use std::collections::HashSet;
+use std::sync::LazyLock;
+use teloxide::prelude::*;
+use teloxide::types::{
+    CallbackQuery, ChatAction, ChatId, ChatKind, InlineQuery, InlineQueryResult,
+    InlineQueryResultMpeg4Gif, InlineQueryResultPhoto, InlineQueryResultVideo, Message,
+    MessageEntityKind, MessageId, ParseMode, Recipient, ReplyParameters,
+};
+use teloxide::utils::command::BotCommands;
+use teloxide::RequestError;
+use x_media::media::Media;
+
+pub static CHAT_STORE: LazyLock<ChatStore> = LazyLock::new(|| {
+    ChatStore::open("data/task_queue.db").expect("failed to open chat store")
+});
+pub static TASK_QUEUE: LazyLock<PersistentTaskQueue> =
+    LazyLock::new(|| PersistentTaskQueue::new("data/task_queue.db"));
+pub static CONFIG: LazyLock<Config> = LazyLock::new(Config::load);
+
+#[derive(BotCommands, Clone)]
+#[command(rename_rule = "snake_case", description = "")]
+enum Command {
+    #[command(description = "")]
+    Start,
+    #[command(description = "")]
+    Help,
+    #[command(description = "", parse_with = "split")]
+    SetForwardChannel(String),
+    #[command(description = "")]
+    RemoveForwardChannel,
+    #[command(description = "")]
+    EditBeforeForward,
+    #[command(description = "", parse_with = "split")]
+    SetTemplate(String),
+    #[command(description = "")]
+    BotDict,
+    #[command(description = "", parse_with = "split")]
+    SetFormat(String),
+}
+
+async fn reply<T>(bot: Bot, message: Message, text: T) -> Result<Message, RequestError>
+where
+    T: Into<String>,
+{
+    bot.send_message(message.chat.id, text)
+        .reply_parameters(ReplyParameters::new(message.id).allow_sending_without_reply())
+        .await
+}
+
+fn now_f64() -> f64 {
+    std::time::SystemTime::now()
+        .duration_since(std::time::UNIX_EPOCH)
+        .map(|d| d.as_secs_f64())
+        .unwrap_or(0.0)
+}
+
+/// Extracts URL and text-link entities (text + caption), deduped in order.
+pub fn extract_urls(message: &Message) -> Vec<String> {
+    let mut urls = Vec::new();
+    for entity in message.parse_entities().into_iter().flatten() {
+        match entity.kind() {
+            MessageEntityKind::Url => urls.push(entity.text().to_string()),
+            MessageEntityKind::TextLink { url } => urls.push(url.to_string()),
+            _ => {}
+        }
+    }
+    for entity in message.parse_caption_entities().into_iter().flatten() {
+        match entity.kind() {
+            MessageEntityKind::Url => urls.push(entity.text().to_string()),
+            MessageEntityKind::TextLink { url } => urls.push(url.to_string()),
+            _ => {}
+        }
+    }
+    let mut seen = HashSet::new();
+    urls.retain(|url| seen.insert(url.clone()));
+    urls
+}
+
+/// Edit-before-forward: a reply to the prompt swaps the caption of the first
+/// forwarded message. Returns true when the message was consumed as an edit.
+async fn edit_message_handler(bot: &Bot, message: &Message) -> bool {
+    let Some(reply) = message.reply_to_message() else {
+        return false;
+    };
+    let chat_id = message.chat.id.0;
+    let Some(text) = message.text() else {
+        return false;
+    };
+    let chat_data = CHAT_STORE.get(chat_id).await;
+    let Some(edit) = chat_data.edit_message.get(&(reply.id.0 as i64)) else {
+        return false;
+    };
+    let Some(first_forward_id) = edit.forward_message_ids.first() else {
+        return false;
+    };
+    let link = format!(
+        "<a href=\"{0}\">{1}</a>",
+        edit.url,
+        html_escape::encode_text(text)
+    );
+    let new_text = if edit.template.is_empty() {
+        link
+    } else {
+        chat_data
+            .template
+            .get(&edit.template)
+            .map(|template| template.replace("[]", &link))
+            .unwrap_or(link)
+    };
+    let result = bot
+        .edit_message_caption(ChatId(chat_id), MessageId(*first_forward_id as i32))
+        .caption(new_text)
+        .parse_mode(ParseMode::Html)
+        .await;
+    match result {
+        Ok(_) => log::info!(
+            "edit-before-forward: caption swapped on message {first_forward_id} for prompt {}",
+            reply.id.0
+        ),
+        Err(e) => log::error!("edit_message_caption failed: {e}"),
+    }
+    true
+}
+
+enum SetForwardChannelError {
+    EmptyParameter,
+    NotChannel,
+    NotAdmin,
+    NotBotAdmin(RequestError),
+    NotBotCanPost,
+}
+
+async fn set_forward_channel_handler(
+    bot: &Bot,
+    message: &Message,
+    channel: String,
+) -> Result<i64, SetForwardChannelError> {
+    if channel.is_empty() {
+        return Err(SetForwardChannelError::EmptyParameter);
+    }
+    let channel = match channel.parse::<i64>() {
+        Ok(id) => Recipient::Id(ChatId(id)),
+        Err(_) => Recipient::ChannelUsername(channel),
+    };
+    if let Some(from) = &message.from {
+        log::info!(
+            "Set forward channel for {} ({}) to {}",
+            from.full_name(),
+            message.chat.id,
+            channel
+        );
+    }
+    let chat = match bot.get_chat(channel.clone()).await {
+        Err(e) => {
+            log::error!("Failed to get channel {}: {}", channel, e);
+            return Err(SetForwardChannelError::NotBotAdmin(e));
+        }
+        Ok(chat) => chat,
+    };
+    if !chat.is_channel() {
+        return Err(SetForwardChannelError::NotChannel);
+    }
+    let channel_id = chat.id.0;
+    match bot.get_chat_administrators(channel.clone()).await {
+        Err(e) => {
+            log::error!("Failed to get channel administrators {}: {}", channel, e);
+            return Err(SetForwardChannelError::NotBotAdmin(e));
+        }
+        Ok(admins) => {
+            if !admins.iter().any(|admin| admin.user.id == message.chat.id) {
+                return Err(SetForwardChannelError::NotAdmin);
+            }
+            let bot_id = bot.get_me().await.expect("Failed get bot id").user.id;
+            if let Some(bot_admin) = admins.iter().find(|admin| admin.user.id == bot_id)
+                && !bot_admin.can_post_messages()
+            {
+                return Err(SetForwardChannelError::NotBotCanPost);
+            }
+        }
+    }
+    Ok(channel_id)
+}
+
+async fn execute_command(bot: &Bot, message: &Message, command: Command) -> Result<(), RequestError> {
+    match command {
+        Command::Start => {
+            bot.send_message(message.chat.id, "Hello!").await?;
+        }
+        Command::Help => {
+            bot.send_message(message.chat.id, Command::descriptions().to_string())
+                .await?;
+        }
+        Command::SetForwardChannel(channel) => {
+            let result = match set_forward_channel_handler(bot, message, channel).await {
+                Ok(channel_id) => {
+                    let mut chat_data = CHAT_STORE.get(message.chat.id.0).await;
+                    chat_data.forward_channel_id = Some(channel_id);
+                    CHAT_STORE.set(message.chat.id.0, &chat_data).await;
+                    "Add successfully.".to_string()
+                }
+                Err(SetForwardChannelError::EmptyParameter) => {
+                    "Receive empty parameter.\nYou should enter a channel id or username".to_string()
+                }
+                Err(SetForwardChannelError::NotChannel) => {
+                    "Given id / username is not a channel".to_string()
+                }
+                Err(SetForwardChannelError::NotAdmin) => {
+                    "You are not an administrator of the channel".to_string()
+                }
+                Err(SetForwardChannelError::NotBotAdmin(e)) => {
+                    e.to_string() + "\nPlease add the bot as an admin to the channel"
+                }
+                Err(SetForwardChannelError::NotBotCanPost) => {
+                    "Bot can't post messages to the channel".to_string()
+                }
+            };
+            reply(bot.clone(), message.clone(), result).await?;
+        }
+        Command::RemoveForwardChannel => {
+            let chat_id = message.chat.id.0;
+            let mut chat_data = CHAT_STORE.get(chat_id).await;
+            let text = if chat_data.forward_channel_id.is_some() {
+                chat_data.forward_channel_id = None;
+                CHAT_STORE.set(chat_id, &chat_data).await;
+                "Remove successfully.".to_string()
+            } else {
+                "No channel to remove.".to_string()
+            };
+            reply(bot.clone(), message.clone(), text).await?;
+        }
+        Command::EditBeforeForward => {
+            let chat_id = message.chat.id.0;
+            let mut chat_data = CHAT_STORE.get(chat_id).await;
+            let text = if chat_data.forward_channel_id.is_none() {
+                "Please enable forward channel first.".to_string()
+            } else if chat_data.edit_before_forward {
+                chat_data.edit_before_forward = false;
+                chat_data.edit_message.clear();
+                CHAT_STORE.set(chat_id, &chat_data).await;
+                "Disable edit before forward.".to_string()
+            } else {
+                chat_data.edit_before_forward = true;
+                CHAT_STORE.set(chat_id, &chat_data).await;
+                "Enable edit before forward.".to_string()
+            };
+            reply(bot.clone(), message.clone(), text).await?;
+        }
+        Command::SetTemplate(name) => {
+            let chat_id = message.chat.id.0;
+            let text = match message.reply_to_message() {
+                None => "Please reply to a message to set as template.".to_string(),
+                Some(reply) => {
+                    let reply_text = reply.text().unwrap_or_default();
+                    if !reply_text.contains("[]") {
+                        "Please reply to a message with [] to set as template.".to_string()
+                    } else if name.is_empty() {
+                        "Please provide a name for the template.".to_string()
+                    } else {
+                        let mut chat_data = CHAT_STORE.get(chat_id).await;
+                        chat_data
+                            .template
+                            .insert(name, html_escape::encode_text(reply_text).into_owned());
+                        CHAT_STORE.set(chat_id, &chat_data).await;
+                        "Template set.".to_string()
+                    }
+                }
+            };
+            reply(bot.clone(), message.clone(), text).await?;
+        }
+        Command::BotDict => {
+            let chat_data = CHAT_STORE.get(message.chat.id.0).await;
+            let debug = format!("{chat_data:?}");
+            let text = html_escape::encode_text(&debug).into_owned();
+            reply(bot.clone(), message.clone(), text).await?;
+        }
+        Command::SetFormat(arg) => {
+            let chat_id = message.chat.id.0;
+            let (site, format) = match arg.split_once(char::is_whitespace) {
+                Some((site, format)) if !format.trim().is_empty() => (site.trim(), format.trim().to_string()),
+                _ => {
+                    reply(
+                        bot.clone(),
+                        message.clone(),
+                        "Usage: /set_format <site> <format>",
+                    )
+                    .await?;
+                    return Ok(());
+                }
+            };
+            if !["twitter", "bsky", "pixiv"].contains(&site) {
+                reply(
+                    bot.clone(),
+                    message.clone(),
+                    "Unknown site. Use twitter, bsky or pixiv.",
+                )
+                .await?;
+                return Ok(());
+            }
+            let mut chat_data = CHAT_STORE.get(chat_id).await;
+            chat_data.message_format.insert(site.to_string(), format);
+            CHAT_STORE.set(chat_id, &chat_data).await;
+            reply(bot.clone(), message.clone(), "Format set.").await?;
+        }
+    }
+    Ok(())
+}
+
+/// For locally produced media (encoded ugoira MP4) the thumbnail URL is a
+/// hotlink-protected remote URL Telegram may not fetch; let Telegram generate
+/// its own thumbnail instead.
+fn thumbnail_for(media: &Media) -> Option<String> {
+    let url = media.url();
+    if url.starts_with("http://") || url.starts_with("https://") {
+        media.thumbnail_url().map(str::to_string)
+    } else {
+        None
+    }
+}
+
+fn media_to_payload(media: &Media, sensitive: bool) -> MediaItemPayload {
+    match media {
+        // A gif inside a group becomes a video item; a lone gif takes the
+        // animation path (see url_media).
+        Media::Illustration { .. } => MediaItemPayload::Photo {
+            media: media.url().to_string(),
+            has_spoiler: sensitive,
+        },
+        Media::Video { .. } => MediaItemPayload::Video {
+            media: media.url().to_string(),
+            has_spoiler: sensitive,
+            thumbnail: thumbnail_for(media),
+        },
+        Media::Animated { .. } => MediaItemPayload::Video {
+            media: media.url().to_string(),
+            has_spoiler: sensitive,
+            thumbnail: thumbnail_for(media),
+        },
+    }
+}
+
+async fn enqueue_retry(task: Task, delay_seconds: f64) {
+    let payload = serde_json::to_value(task).expect("task serializes");
+    let run_after = now_f64() + delay_seconds;
+    if let Err(e) = TASK_QUEUE.enqueue(payload, run_after).await {
+        log::error!("failed to enqueue retry: {e}");
+    }
+}
+
+async fn url_media(bot: Bot, message: &Message, url: &str) {
+    let chat_id = message.chat.id.0;
+    if let Err(e) = bot.send_chat_action(ChatId(chat_id), ChatAction::Typing).await {
+        log::error!("send_chat_action failed: {e}");
+    }
+    log::info!("fetching {url}");
+    match x_media::site::fetch(url).await {
+        // Unsupported links are ignored silently (Python parity).
+        Ok(None) => {
+            log::info!("no site pattern matches {url}; ignoring");
+        }
+        // Retries exhausted: notify the user (Rust-only requirement 3).
+        Err(e) => {
+            log::error!("fetch {url}: {e}");
+            let _ = reply(bot, message.clone(), "Failed to fetch media from this link.").await;
+        }
+        Ok(Some(fetched)) => {
+            if fetched.media.is_empty() {
+                let _ = reply(
+                    bot,
+                    message.clone(),
+                    "No media found or media type is not supported.",
+                )
+                .await;
+                return;
+            }
+            let chat_data = CHAT_STORE.get(chat_id).await;
+            // Per-site caption format override (empty -> built-in caption).
+            let format = chat_data
+                .message_format
+                .get(fetched.site_name())
+                .cloned()
+                .unwrap_or_default();
+            let caption = fetched.caption_with(&format);
+            let task = if fetched.media.len() == 1
+                && matches!(fetched.media[0], Media::Animated { .. })
+            {
+                Task::SendAnimation {
+                    chat_id,
+                    reply_to_message_id: message.id.0 as i64,
+                    caption: caption.clone(),
+                    animation: MediaItemPayload::Animation {
+                        media: fetched.media[0].url().to_string(),
+                        has_spoiler: fetched.sensitive,
+                    },
+                    source_url: fetched.source_url.clone(),
+                    edit_before_forward: chat_data.edit_before_forward,
+                    forward_channel_id: chat_data.forward_channel_id,
+                    notify_chat_id: Some(chat_id),
+                    notify_message_id: Some(message.id.0 as i64),
+                }
+            } else {
+                let items: Vec<MediaItemPayload> = fetched
+                    .media
+                    .iter()
+                    .map(|media| media_to_payload(media, fetched.sensitive))
+                    .collect();
+                Task::SendMediaSequence {
+                    chat_id,
+                    reply_to_message_id: message.id.0 as i64,
+                    caption: caption.clone(),
+                    media_batches: send::chunk_media_items(items),
+                    batch_index: 0,
+                    sent_message_ids: vec![],
+                    source_url: fetched.source_url.clone(),
+                    edit_before_forward: chat_data.edit_before_forward,
+                    forward_channel_id: chat_data.forward_channel_id,
+                    notify_chat_id: Some(chat_id),
+                    notify_message_id: Some(message.id.0 as i64),
+                }
+            };
+            let result = match &task {
+                Task::SendAnimation { .. } => send::send_animation(&bot, &task).await,
+                Task::SendMediaSequence { .. } => send::send_media_sequence(&bot, &task).await,
+                Task::ForwardMessages { .. } => unreachable!(),
+            };
+            match result {
+                Ok(message_ids) => {
+                    log::info!("sent {} message(s) for {url}", message_ids.len());
+                    send::post_send_actions(&bot, &task, message_ids).await;
+                }
+                Err(send::SendError::Retryable { delay_seconds, task }) => {
+                    log::info!("send for {url} failed, queued for retry in {delay_seconds:.1}s");
+                    enqueue_retry(task, delay_seconds).await;
+                    let _ = reply(bot, message.clone(), "Send failed. Task queued for retry.").await;
+                }
+                Err(send::SendError::Permanent {
+                    message: err_message,
+                    ..
+                }) => {
+                    log::error!("send for {url} failed permanently: {err_message}");
+                    let _ = reply(bot, message.clone(), format!("Send failed: {err_message}")).await;
+                }
+            }
+        }
+    }
+}
+
+pub async fn message_handler(bot: Bot, message: Message) -> Result<(), RequestError> {
+    let is_private = matches!(message.chat.kind, ChatKind::Private(_));
+    let sender = message
+        .from
+        .as_ref()
+        .map(|from| from.full_name())
+        .unwrap_or_else(|| "unknown".to_string());
+    let text_preview = message
+        .text()
+        .map(|t| if t.len() > 120 { &t[..120] } else { t })
+        .unwrap_or("<no text>");
+    log::info!("message from {sender} in {} (private={is_private}): {text_preview}", message.chat.id);
+    // URL/edit flows only run in private chats; commands run in any chat.
+    if is_private && edit_message_handler(&bot, &message).await {
+        return respond(());
+    }
+    if let Some(text) = message.text()
+        && let Ok(command) = Command::parse(text, "")
+    {
+        log::info!("command from {}: {text_preview}", message.chat.id);
+        execute_command(&bot, &message, command).await?;
+        return respond(());
+    }
+    if is_private {
+        let urls = extract_urls(&message);
+        if !urls.is_empty() {
+            log::info!("extracted {} URL(s): {urls:?}", urls.len());
+        }
+        for url in urls {
+            url_media(bot.clone(), &message, &url).await;
+        }
+    }
+    respond(())
+}
+
+pub async fn inline_query_handler(bot: Bot, query: InlineQuery) -> Result<(), RequestError> {
+    if query.query.is_empty() {
+        return respond(());
+    }
+    log::info!("inline query: {}", query.query);
+    match x_media::site::fetch(&query.query).await {
+        Ok(Some(fetched)) => {
+            let mut results: Vec<InlineQueryResult> = Vec::new();
+            for (i, media) in fetched.media.iter().enumerate() {
+                let id = format!("{i}");
+                let Some(url) = url::Url::parse(media.url()).ok() else {
+                    continue;
+                };
+                let thumbnail = media
+                    .thumbnail_url()
+                    .and_then(|t| url::Url::parse(t).ok())
+                    .unwrap_or_else(|| url.clone());
+                let caption = fetched.caption.clone();
+                let result = match media {
+                    Media::Illustration { .. } => InlineQueryResult::Photo(
+                        InlineQueryResultPhoto::new(id, url, thumbnail)
+                            .caption(caption)
+                            .parse_mode(ParseMode::Html),
+                    ),
+                    Media::Video { .. } => InlineQueryResult::Video(
+                        InlineQueryResultVideo::new(
+                            id,
+                            url,
+                            "video/mp4".parse().expect("valid mime"),
+                            thumbnail,
+                            fetched.title.clone(),
+                        )
+                            .caption(caption)
+                            .parse_mode(ParseMode::Html),
+                    ),
+                    Media::Animated { .. } => InlineQueryResult::Mpeg4Gif(
+                        InlineQueryResultMpeg4Gif::new(id, url, thumbnail)
+                            .caption(caption)
+                            .parse_mode(ParseMode::Html),
+                    ),
+                };
+                results.push(result);
+            }
+            if !results.is_empty() {
+                bot.answer_inline_query(query.id, results).await?;
+            }
+        }
+        Ok(None) => {}
+        Err(e) => log::error!("inline fetch {}: {e}", query.query),
+    }
+    respond(())
+}
+
+pub async fn callback_query_handler(bot: Bot, query: CallbackQuery) -> Result<(), RequestError> {
+    let callback_query_id = query.id;
+    let data = query.data.clone();
+    let Some(message) = &query.message else {
+        return respond(());
+    };
+    let chat_id = message.chat().id.0;
+    let prompt_message_id = message.id().0 as i64;
+    let ttl_secs = CONFIG.edit_message_ttl.as_secs() as i64;
+    let mut chat_data = CHAT_STORE.get(chat_id).await;
+    let edit = chat_data.edit_message.get(&prompt_message_id).cloned();
+    let Some(edit) = edit else {
+        log::info!("callback from {}: no edit record for prompt {prompt_message_id}", chat_id);
+        bot.answer_callback_query(callback_query_id)
+            .text("Expired")
+            .await?;
+        return respond(());
+    };
+    // Lazy expiry: a stale record (past the TTL, not yet swept) is dropped.
+    if edit.created_at + ttl_secs <= unix_now() {
+        chat_data.edit_message.remove(&prompt_message_id);
+        CHAT_STORE.set(chat_id, &chat_data).await;
+        bot.answer_callback_query(callback_query_id)
+            .text("Expired")
+            .await?;
+        return respond(());
+    }
+
+    let Some(data) = data else {
+        return respond(());
+    };
+    log::info!("callback from {} on prompt {prompt_message_id}: {data}", chat_id);
+    if data == "forward" {
+        match chat_data.forward_channel_id {
+            Some(channel_id) => {
+                let forward_task = Task::ForwardMessages {
+                    from_chat_id: edit.chat_id,
+                    to_chat_id: channel_id,
+                    message_ids: edit.forward_message_ids.clone(),
+                    notify_chat_id: Some(chat_id),
+                    notify_message_id: Some(prompt_message_id),
+                };
+                match send::forward_messages(&bot, &forward_task).await {
+                    Ok(()) => {
+                        log::info!(
+                            "forwarded {} message(s) to channel {channel_id}",
+                            edit.forward_message_ids.len()
+                        );
+                        bot.answer_callback_query(callback_query_id)
+                            .text("✅ Forwarded")
+                            .await?;
+                        let _ = bot
+                            .delete_message(ChatId(chat_id), MessageId(prompt_message_id as i32))
+                            .await;
+                        chat_data.edit_message.remove(&prompt_message_id);
+                        CHAT_STORE.set(chat_id, &chat_data).await;
+                    }
+                    Err(send::SendError::Retryable { delay_seconds, task }) => {
+                        log::info!("forward queued for retry in {delay_seconds:.1}s");
+                        enqueue_retry(task, delay_seconds).await;
+                        bot.answer_callback_query(callback_query_id)
+                            .text("Forward queued for retry.")
+                            .await?;
+                    }
+                    Err(send::SendError::Permanent { message, .. }) => {
+                        log::error!("forward failed permanently: {message}");
+                        bot.answer_callback_query(callback_query_id)
+                            .text(format!("Forward failed: {message}"))
+                            .await?;
+                    }
+                }
+            }
+            None => {
+                log::info!("forward callback without a forward channel set");
+                bot.answer_callback_query(callback_query_id)
+                    .text("No forward channel set.")
+                    .await?;
+            }
+        }
+        return respond(());
+    }
+    if let Some(name) = data.strip_prefix("template|") {
+        if let Some(template_html) = chat_data.template.get(name).cloned()
+            && let Some(first_forward_id) = edit.forward_message_ids.first().copied()
+        {
+            // Raw template including the [] placeholder (Python parity).
+            let _ = bot
+                .edit_message_caption(ChatId(chat_id), MessageId(first_forward_id as i32))
+                .caption(template_html)
+                .parse_mode(ParseMode::Html)
+                .await;
+            if let Some(entry) = chat_data.edit_message.get_mut(&prompt_message_id) {
+                entry.template = name.to_string();
+            }
+            CHAT_STORE.set(chat_id, &chat_data).await;
+            log::info!("template '{name}' applied to prompt {prompt_message_id}");
+        }
+        bot.answer_callback_query(callback_query_id).await?;
+    }
+    respond(())
+}

crates/xmedia-bot/src/main.rs

@@ -0,0 +1,131 @@
+use dotenv::dotenv;
+use teloxide::dptree::endpoint;
+use teloxide::types::{ChatId, InputFile, MessageId};
+use teloxide::update_listeners::webhooks;
+use teloxide::prelude::*;
+use tokio::sync::watch;
+use x_media::site;
+
+mod config;
+mod handlers;
+mod queue;
+mod send;
+mod state;
+
+use handlers::{CHAT_STORE, CONFIG, TASK_QUEUE};
+
+#[tokio::main]
+async fn main() {
+    dotenv().ok();
+    pretty_env_logger::init();
+    log::info!("Starting bot");
+
+    let bot = Bot::from_env();
+
+    log::info!(
+        "config: {} admin(s), edit-message TTL {}s",
+        CONFIG.admin_ids.len(),
+        CONFIG.edit_message_ttl.as_secs()
+    );
+
+    // Queue worker: handles typed tasks, dead-letters failed sends to the
+    // task's chat.
+    TASK_QUEUE
+        .start(send::handle_task, send::dead_letter_notify)
+        .await;
+    log::info!("task queue worker started");
+
+    // Pixiv login validation (user request): a failed login notifies the
+    // admin and disables pixiv for this process.
+    if site::pixiv::enabled() {
+        match site::pixiv::validate().await {
+            Ok(()) => log::info!("pixiv login validated"),
+            Err(e) => {
+                log::error!("pixiv login failed: {e}");
+                if let Some(admin) = CONFIG.admin_ids.first() {
+                    let _ = bot
+                        .send_message(ChatId(*admin), format!("Pixiv login failed: {e}"))
+                        .await;
+                }
+                site::pixiv::disable();
+            }
+        }
+    }
+
+    // Edit-expiry sweep: clears the prompt's buttons once the record expires.
+    log::info!("edit-expiry sweep: every 300s, ttl {}", CONFIG.edit_message_ttl.as_secs());
+    let (stop_tx, stop_rx) = watch::channel(false);
+    {
+        let bot = bot.clone();
+        let mut stop_rx = stop_rx;
+        tokio::spawn(async move {
+            loop {
+                tokio::select! {
+                    _ = stop_rx.changed() => break,
+                    _ = tokio::time::sleep(std::time::Duration::from_secs(300)) => {}
+                }
+                let ttl = CONFIG.edit_message_ttl;
+                let removed = CHAT_STORE.prune_expired(ttl).await;
+                for (chat_id, prompt_message_id) in removed {
+                    // If the prompt was already deleted, this fails with a
+                    // 400 "message to edit not found" — log and ignore.
+                    if let Err(e) = bot
+                        .edit_message_reply_markup(ChatId(chat_id), MessageId(prompt_message_id as i32))
+                        .await
+                    {
+                        log::info!("edit-expiry sweep: prompt message gone: {e}");
+                    }
+                }
+            }
+        });
+    }
+
+    let handler = dptree::entry()
+        .branch(Update::filter_message().branch(endpoint(handlers::message_handler)))
+        .branch(Update::filter_inline_query().branch(endpoint(handlers::inline_query_handler)))
+        .branch(Update::filter_callback_query().branch(endpoint(handlers::callback_query_handler)));
+
+    let mut dispatcher = Dispatcher::builder(bot.clone(), handler)
+        .dependencies(dptree::deps![""])
+        .enable_ctrlc_handler()
+        .build();
+
+    if CONFIG.webhook_enabled {
+        log::info!("running in webhook mode");
+        let url = CONFIG
+            .webhook_url
+            .clone()
+            .expect("WEBHOOK_URL is not set");
+        bot.set_webhook(url.clone()).await.unwrap();
+        let listen = CONFIG.webhook_listen.expect("WEBHOOK_LISTEN is not set");
+        let port = CONFIG.webhook_port.expect("WEBHOOK_PORT is not set");
+        let mut options = webhooks::Options::new((listen, port).into(), url);
+        if let Some(cert) = &CONFIG.webhook_cert {
+            options = options.certificate(InputFile::file(cert));
+        }
+        if let Some(secret) = &CONFIG.webhook_secret_token {
+            options = options.secret_token(secret.clone());
+        }
+
+        dispatcher
+            .dispatch_with_listener(
+                webhooks::axum(bot.clone(), options)
+                    .await
+                    .expect("Failed to create webhook listener"),
+                LoggingErrorHandler::with_custom_text("Error from update listener"),
+            )
+            .await;
+    } else {
+        log::info!("running in polling mode");
+        dispatcher.dispatch().await;
+    }
+
+    // Graceful stop (Ctrl+C): stop the sweep, notify the admin, drain the queue.
+    log::info!("Stopping bot");
+    let _ = stop_tx.send(true);
+    if let Some(admin) = CONFIG.admin_ids.first() {
+        let _ = bot.send_message(ChatId(*admin), "Shutting down...").await;
+    }
+    TASK_QUEUE.stop().await;
+    log::info!("Bot stopped");
+}

crates/xmedia-bot/src/queue.rs

@@ -0,0 +1,488 @@
+//! Generic persistent task queue backed by SQLite (table `tasks`).
+//!
+//! Concepts kept from the Python `utils/task_queue.py` (untrusted, redesigned):
+//! the table schema, the lease/lock/recovery model, and the retry→dead-letter
+//! flow. The Python dict-mutation hack (attempts inside the payload) is
+//! replaced by dedicated columns.
+
+use parking_lot::Mutex;
+use rusqlite::{params, Connection};
+use serde_json::Value;
+use std::pin::Pin;
+use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
+use std::sync::Arc;
+use std::time::{Duration, SystemTime, UNIX_EPOCH};
+use tokio::sync::Notify;
+use tokio::task::JoinHandle;
+
+pub const MAX_RETRIES: u32 = 2;
+pub const LOCK_TTL_SECONDS: f64 = 120.0;
+
+/// What a handler returns instead of throwing. The payload it carries is the
+/// (possibly updated) task state to persist for the next attempt.
+pub enum QueueError {
+    /// Reschedule with the given delay; after `MAX_RETRIES` attempts the task
+    /// is dead-lettered instead.
+    Retryable {
+        delay_seconds: f64,
+        payload: Value,
+    },
+    /// Give up now.
+    Permanent {
+        message: String,
+        payload: Value,
+    },
+}
+
+type BoxFuture<'a, T> = Pin<Box<dyn Future<Output = T> + Send + 'a>>;
+type Handler = dyn Fn(Value) -> BoxFuture<'static, Result<(), QueueError>> + Send + Sync;
+type DeadLetter = dyn Fn(Value, String) -> BoxFuture<'static, ()> + Send + Sync;
+
+pub struct PersistentTaskQueue {
+    db_path: String,
+    notify: Arc<Notify>,
+    stop: Arc<AtomicBool>,
+    worker: Mutex<Option<JoinHandle<()>>>,
+    counter: AtomicU64,
+}
+
+struct LeasedRow {
+    id: String,
+    payload: String,
+    attempts: i32,
+}
+
+/// Owned worker state so the spawned loop does not borrow the queue handle.
+struct QueueWorker {
+    db_path: String,
+    notify: Arc<Notify>,
+    stop: Arc<AtomicBool>,
+    handler: Arc<Handler>,
+    dead_letter: Arc<DeadLetter>,
+}
+
+fn now_f64() -> f64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map(|d| d.as_secs_f64())
+        .unwrap_or(0.0)
+}
+
+fn ensure_schema(conn: &Connection) -> rusqlite::Result<()> {
+    conn.execute_batch(
+        "CREATE TABLE IF NOT EXISTS tasks (id TEXT PRIMARY KEY, payload TEXT NOT NULL, \
+         run_after REAL NOT NULL, attempts INTEGER NOT NULL, status TEXT NOT NULL, \
+         locked_until REAL NOT NULL, created_at REAL NOT NULL);",
+    )
+}
+
+impl PersistentTaskQueue {
+    pub fn new(db_path: &str) -> Self {
+        // Ensure the parent dir and table exist even if only the queue (not
+        // ChatStore) is used — a fresh container without a mounted data dir
+        // must still be able to open the DB.
+        if let Some(parent) = std::path::Path::new(db_path).parent()
+            && !parent.as_os_str().is_empty()
+            && let Err(e) = std::fs::create_dir_all(parent)
+        {
+            log::error!("failed to create queue dir: {e}");
+        }
+        if let Ok(conn) = Connection::open(db_path)
+            && let Err(e) = ensure_schema(&conn)
+        {
+            log::error!("failed to initialize queue schema: {e}");
+        }
+        Self {
+            db_path: db_path.to_string(),
+            notify: Arc::new(Notify::new()),
+            stop: Arc::new(AtomicBool::new(false)),
+            worker: Mutex::new(None),
+            counter: AtomicU64::new(0),
+        }
+    }
+
+    /// Starts the worker loop. Also recovers rows left `in_progress` by a
+    /// previous process (lease expired).
+    pub async fn start<H, F, D, G>(&self, handler: H, dead_letter: D)
+    where
+        H: Fn(Value) -> F + Send + Sync + 'static,
+        F: Future<Output = Result<(), QueueError>> + Send + 'static,
+        D: Fn(Value, String) -> G + Send + Sync + 'static,
+        G: Future<Output = ()> + Send + 'static,
+    {
+        let handler: Arc<Handler> = Arc::new(move |payload| Box::pin(handler(payload)));
+        let dead_letter: Arc<DeadLetter> =
+            Arc::new(move |payload, message| Box::pin(dead_letter(payload, message)));
+        self.recover_stale().await;
+        let worker = QueueWorker {
+            db_path: self.db_path.clone(),
+            notify: Arc::clone(&self.notify),
+            stop: Arc::clone(&self.stop),
+            handler,
+            dead_letter,
+        };
+        let worker = tokio::spawn(worker.run_loop());
+        *self.worker.lock() = Some(worker);
+    }
+
+    pub async fn stop(&self) {
+        self.stop.store(true, Ordering::Relaxed);
+        self.notify.notify_one();
+        if let Some(handle) = self.worker.lock().take() {
+            let _ = handle.await;
+        }
+    }
+
+    /// Persists a task. `run_after` is an absolute unix timestamp (seconds).
+    /// Notifies the worker only after the insert has committed, so the worker
+    /// never wakes to an invisible row.
+    pub async fn enqueue(&self, payload: Value, run_after: f64) -> rusqlite::Result<()> {
+        let id = format!(
+            "task_{}_{}",
+            (now_f64() * 1000.0) as u64,
+            self.counter.fetch_add(1, Ordering::Relaxed)
+        );
+        let payload = payload.to_string();
+        let db_path = self.db_path.clone();
+        log::info!("enqueued {id} (run_after {run_after:.1})");
+        let result = tokio::task::spawn_blocking(move || -> rusqlite::Result<()> {
+            let conn = Connection::open(&db_path)?;
+            conn.execute(
+                "INSERT OR REPLACE INTO tasks (id, payload, run_after, attempts, status, locked_until, created_at) \
+                 VALUES (?1, ?2, ?3, 0, 'pending', 0, ?4)",
+                params![id, payload, run_after, now_f64()],
+            )?;
+            Ok(())
+        })
+        .await
+        .expect("queue insert worker panicked")?;
+        self.notify.notify_one();
+        Ok(result)
+    }
+
+    async fn recover_stale(&self) {
+        let db_path = self.db_path.clone();
+        tokio::task::spawn_blocking(move || -> rusqlite::Result<()> {
+            let conn = Connection::open(&db_path)?;
+            conn.execute(
+                "UPDATE tasks SET status='pending', locked_until=0 WHERE status='in_progress' AND locked_until < ?1",
+                params![now_f64()],
+            )?;
+            Ok(())
+        })
+        .await
+        .expect("queue recovery worker panicked")
+        .unwrap_or_else(|e| log::error!("queue recovery failed: {e}"));
+    }
+}
+
+impl QueueWorker {
+    async fn run_loop(self) {
+        while !self.stop.load(Ordering::Relaxed) {
+            match self.lease_next().await {
+                Some(row) => self.process(row).await,
+                None => {
+                    let wait_until = self.earliest_run_after().await;
+                    let notified = self.notify.notified();
+                    tokio::pin!(notified);
+                    match wait_until {
+                        Some(until) => {
+                            let delay = (until - now_f64()).max(0.0);
+                            tokio::select! {
+                                _ = &mut notified => {}
+                                _ = tokio::time::sleep(Duration::from_secs_f64(delay)) => {}
+                            }
+                        }
+                        None => {
+                            notified.await;
+                        }
+                    }
+                }
+            }
+        }
+    }
+
+    /// Leases the oldest due row (sets it `in_progress` with a lock TTL).
+    async fn lease_next(&self) -> Option<LeasedRow> {
+        let db_path = self.db_path.clone();
+        tokio::task::spawn_blocking(move || -> rusqlite::Result<Option<LeasedRow>> {
+            let mut conn = Connection::open(&db_path)?;
+            let tx = conn.transaction()?;
+            let now = now_f64();
+            let row = tx.query_row(
+                "SELECT id, payload, attempts FROM tasks WHERE status='pending' AND run_after <= ?1 \
+                 ORDER BY run_after LIMIT 1",
+                params![now],
+                |r| {
+                    Ok((
+                        r.get::<_, String>(0)?,
+                        r.get::<_, String>(1)?,
+                        r.get::<_, i32>(2)?,
+                    ))
+                },
+            );
+            let (id, payload, attempts) = match row {
+                Ok(row) => row,
+                Err(rusqlite::Error::QueryReturnedNoRows) => {
+                    tx.commit()?;
+                    return Ok(None);
+                }
+                Err(e) => return Err(e),
+            };
+            tx.execute(
+                "UPDATE tasks SET status='in_progress', locked_until=?1 WHERE id=?2",
+                params![now + LOCK_TTL_SECONDS, id],
+            )?;
+            tx.commit()?;
+            Ok(Some(LeasedRow {
+                id,
+                payload,
+                attempts,
+            }))
+        })
+        .await
+        .expect("queue lease worker panicked")
+        .unwrap_or_else(|e| {
+            log::error!("queue lease failed: {e}");
+            None
+        })
+    }
+
+    async fn earliest_run_after(&self) -> Option<f64> {
+        let db_path = self.db_path.clone();
+        tokio::task::spawn_blocking(move || -> rusqlite::Result<Option<f64>> {
+            let conn = Connection::open(&db_path)?;
+            let mut stmt = conn.prepare("SELECT MIN(run_after) FROM tasks WHERE status='pending'")?;
+            let mut rows = stmt.query([])?;
+            match rows.next()? {
+                Some(row) => Ok(row.get::<_, Option<f64>>(0)?),
+                None => Ok(None),
+            }
+        })
+        .await
+        .expect("queue timing worker panicked")
+        .unwrap_or_else(|e| {
+            log::error!("queue timing query failed: {e}");
+            None
+        })
+    }
+
+    async fn process(&self, row: LeasedRow) {
+        let payload: Value = match serde_json::from_str(&row.payload) {
+            Ok(value) => value,
+            Err(e) => {
+                log::error!("queue: unparseable payload for {}: {e}", row.id);
+                self.delete_row(&row.id).await;
+                (self.dead_letter)(Value::Null, format!("invalid stored payload: {e}")).await;
+                return;
+            }
+        };
+        log::info!("processing {} (attempt {})", row.id, row.attempts + 1);
+        match (self.handler)(payload).await {
+            Ok(()) => {
+                log::info!("task {} completed", row.id);
+                self.delete_row(&row.id).await;
+            }
+            Err(QueueError::Retryable {
+                delay_seconds,
+                payload,
+            }) => {
+                if row.attempts as u32 >= MAX_RETRIES {
+                    let message = format!("task failed after {MAX_RETRIES} retries");
+                    log::error!("dead-lettering {}: {message}", row.id);
+                    self.delete_row(&row.id).await;
+                    (self.dead_letter)(payload, message).await;
+                } else {
+                    log::info!(
+                        "task {} rescheduled in {delay_seconds:.1}s (attempt {})",
+                        row.id,
+                        row.attempts + 1
+                    );
+                    self.reschedule(&row.id, payload, delay_seconds, row.attempts + 1)
+                        .await;
+                }
+            }
+            Err(QueueError::Permanent { message, payload }) => {
+                log::error!("dead-lettering {}: {message}", row.id);
+                self.delete_row(&row.id).await;
+                (self.dead_letter)(payload, message).await;
+            }
+        }
+    }
+
+    async fn delete_row(&self, id: &str) {
+        let db_path = self.db_path.clone();
+        let id = id.to_string();
+        tokio::task::spawn_blocking(move || -> rusqlite::Result<()> {
+            let conn = Connection::open(&db_path)?;
+            conn.execute("DELETE FROM tasks WHERE id = ?1", params![id])?;
+            Ok(())
+        })
+        .await
+        .expect("queue delete worker panicked")
+        .unwrap_or_else(|e| log::error!("queue delete failed: {e}"));
+    }
+
+    async fn reschedule(&self, id: &str, payload: Value, delay_seconds: f64, attempts: i32) {
+        let db_path = self.db_path.clone();
+        let id = id.to_string();
+        let payload = payload.to_string();
+        tokio::task::spawn_blocking(move || -> rusqlite::Result<()> {
+            let conn = Connection::open(&db_path)?;
+            conn.execute(
+                "UPDATE tasks SET payload=?1, run_after=?2, attempts=?3, status='pending', locked_until=0 WHERE id=?4",
+                params![payload, now_f64() + delay_seconds, attempts, id],
+            )?;
+            Ok(())
+        })
+        .await
+        .expect("queue reschedule worker panicked")
+        .unwrap_or_else(|e| log::error!("queue reschedule failed: {e}"));
+        self.notify.notify_one();
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::sync::atomic::{AtomicUsize, Ordering as AtomicOrdering};
+
+    async fn new_queue() -> (PersistentTaskQueue, tempfile::TempDir) {
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("queue.db");
+        let queue = PersistentTaskQueue::new(path.to_str().unwrap());
+        (queue, dir)
+    }
+
+    #[tokio::test]
+    async fn enqueue_runs_handler_once() {
+        let (queue, _dir) = new_queue().await;
+        let calls = Arc::new(AtomicUsize::new(0));
+        let calls_worker = calls.clone();
+        queue
+            .start(
+                move |payload| {
+                    assert_eq!(payload["n"], 42);
+                    calls_worker.fetch_add(1, AtomicOrdering::SeqCst);
+                    async { Ok(()) }
+                },
+                |_payload, _message| async {},
+            )
+            .await;
+        queue
+            .enqueue(serde_json::json!({"n": 42}), now_f64())
+            .await
+            .unwrap();
+        tokio::time::sleep(Duration::from_millis(300)).await;
+        assert_eq!(calls.load(AtomicOrdering::SeqCst), 1);
+        queue.stop().await;
+    }
+
+    #[tokio::test]
+    async fn retryable_reschedules_then_dead_letters() {
+        let (queue, _dir) = new_queue().await;
+        let calls = Arc::new(AtomicUsize::new(0));
+        let dead_calls = Arc::new(AtomicUsize::new(0));
+        let c = calls.clone();
+        let d = dead_calls.clone();
+        queue
+            .start(
+                move |payload| {
+                    c.fetch_add(1, AtomicOrdering::SeqCst);
+                    let payload = payload.clone();
+                    async move {
+                        Err(QueueError::Retryable {
+                            delay_seconds: 0.001,
+                            payload,
+                        })
+                    }
+                },
+                move |_payload, _message| {
+                    d.fetch_add(1, AtomicOrdering::SeqCst);
+                    async {}
+                },
+            )
+            .await;
+        queue
+            .enqueue(serde_json::json!({"a": 1}), now_f64())
+            .await
+            .unwrap();
+        tokio::time::sleep(Duration::from_millis(600)).await;
+        assert_eq!(
+            calls.load(AtomicOrdering::SeqCst),
+            MAX_RETRIES as usize + 1,
+            "handler should run once per attempt"
+        );
+        assert_eq!(dead_calls.load(AtomicOrdering::SeqCst), 1);
+        queue.stop().await;
+    }
+
+    #[tokio::test]
+    async fn permanent_error_dead_letters_immediately() {
+        let (queue, _dir) = new_queue().await;
+        let calls = Arc::new(AtomicUsize::new(0));
+        let dead_calls = Arc::new(AtomicUsize::new(0));
+        let c = calls.clone();
+        let d = dead_calls.clone();
+        queue
+            .start(
+                move |payload| {
+                    c.fetch_add(1, AtomicOrdering::SeqCst);
+                    let payload = payload.clone();
+                    async move {
+                        Err(QueueError::Permanent {
+                            message: "nope".into(),
+                            payload,
+                        })
+                    }
+                },
+                move |_payload, message| {
+                    assert_eq!(message, "nope");
+                    d.fetch_add(1, AtomicOrdering::SeqCst);
+                    async {}
+                },
+            )
+            .await;
+        queue
+            .enqueue(serde_json::json!({"a": 1}), now_f64())
+            .await
+            .unwrap();
+        tokio::time::sleep(Duration::from_millis(300)).await;
+        assert_eq!(calls.load(AtomicOrdering::SeqCst), 1);
+        assert_eq!(dead_calls.load(AtomicOrdering::SeqCst), 1);
+        queue.stop().await;
+    }
+
+    #[tokio::test]
+    async fn stale_in_progress_row_is_recovered_on_start() {
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("queue.db");
+        // Insert a stale leased row directly (lease expired).
+        {
+            let conn = Connection::open(&path).unwrap();
+            ensure_schema(&conn).unwrap();
+            conn.execute(
+                "INSERT INTO tasks (id, payload, run_after, attempts, status, locked_until, created_at) \
+                 VALUES ('task_stale', '{\"s\":1}', 0, 0, 'in_progress', ?1, 0)",
+                params![now_f64() - 10.0],
+            )
+            .unwrap();
+        }
+        let queue = PersistentTaskQueue::new(path.to_str().unwrap());
+        let calls = Arc::new(AtomicUsize::new(0));
+        let c = calls.clone();
+        queue
+            .start(
+                move |payload| {
+                    assert_eq!(payload["s"], 1);
+                    c.fetch_add(1, AtomicOrdering::SeqCst);
+                    async { Ok(()) }
+                },
+                |_payload, _message| async {},
+            )
+            .await;
+        tokio::time::sleep(Duration::from_millis(300)).await;
+        assert_eq!(calls.load(AtomicOrdering::SeqCst), 1);
+        queue.stop().await;
+    }
+}

crates/xmedia-bot/src/send.rs

@@ -0,0 +1,917 @@
+//! Typed task payloads and send/forward executors with retry classification
+//! and the download-and-reupload fallback (Telegram's own fetch of a media
+//! URL is blocked by hotlink protection; the bot downloads the file itself
+//! and uploads it via multipart).
+
+use crate::handlers::{CHAT_STORE, TASK_QUEUE};
+use crate::queue::QueueError;
+use crate::state::{EditMessage, unix_now};
+use rand::Rng;
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+use tempfile::NamedTempFile;
+use teloxide::prelude::*;
+use teloxide::types::{
+    ChatId, InlineKeyboardButton, InlineKeyboardMarkup, InputFile, InputMedia,
+    InputMediaAnimation, InputMediaPhoto, InputMediaVideo, Message, MessageId, ParseMode,
+    ReplyParameters,
+};
+use teloxide::{ApiError, RequestError};
+use x_media::site::FetchError;
+
+#[derive(Serialize, Deserialize, Clone, Debug)]
+#[serde(tag = "kind", rename_all = "snake_case")]
+pub enum MediaItemPayload {
+    Photo {
+        media: String,
+        has_spoiler: bool,
+    },
+    Video {
+        media: String,
+        has_spoiler: bool,
+        thumbnail: Option<String>,
+    },
+    Animation {
+        media: String,
+        has_spoiler: bool,
+    },
+}
+
+#[derive(Serialize, Deserialize, Clone, Debug)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub enum Task {
+    SendMediaSequence {
+        chat_id: i64,
+        reply_to_message_id: i64,
+        caption: String,
+        media_batches: Vec<Vec<MediaItemPayload>>,
+        batch_index: usize,
+        sent_message_ids: Vec<i64>,
+        source_url: String,
+        edit_before_forward: bool,
+        forward_channel_id: Option<i64>,
+        notify_chat_id: Option<i64>,
+        notify_message_id: Option<i64>,
+    },
+    SendAnimation {
+        chat_id: i64,
+        reply_to_message_id: i64,
+        caption: String,
+        animation: MediaItemPayload,
+        source_url: String,
+        edit_before_forward: bool,
+        forward_channel_id: Option<i64>,
+        notify_chat_id: Option<i64>,
+        notify_message_id: Option<i64>,
+    },
+    ForwardMessages {
+        from_chat_id: i64,
+        to_chat_id: i64,
+        message_ids: Vec<i64>,
+        notify_chat_id: Option<i64>,
+        notify_message_id: Option<i64>,
+    },
+}
+
+pub const MAX_MEDIA_GROUP: usize = 9;
+pub const MAX_UPLOAD_BYTES: u64 = 50 * 1024 * 1024; // Telegram Bot API upload cap
+
+/// Splits media into batches of at most [`MAX_MEDIA_GROUP`] items.
+pub fn chunk_media_items<T: Clone>(items: Vec<T>) -> Vec<Vec<T>> {
+    items.chunks(MAX_MEDIA_GROUP).map(|chunk| chunk.to_vec()).collect()
+}
+
+/// Exponential backoff with jitter, capped at 30s.
+pub fn retry_delay_seconds(attempts: u32) -> f64 {
+    let jitter: f64 = rand::thread_rng().gen_range(0.2..0.8);
+    (2f64.powi(attempts as i32) + jitter).min(30.0)
+}
+
+/// Telegram's servers failed to fetch a media URL (hotlink protection etc.):
+/// these errors are handled by the download-and-reupload fallback, NOT by a
+/// queue retry (resending the URL cannot succeed).
+pub fn is_media_fetch_failure(e: &ApiError) -> bool {
+    const MARKERS: [&str; 5] = [
+        "webpage_media_empty",
+        "media_empty",
+        "empty_web_media",
+        "webpage_curl_failed",
+        "timeout",
+    ];
+    let description = e.to_string().to_lowercase();
+    MARKERS.iter().any(|marker| description.contains(marker))
+}
+
+/// Task-free classification of a Telegram request error. The callers attach
+/// the (updated) task when building a [`SendError`].
+pub enum Classification {
+    Retryable { delay_seconds: f64 },
+    Permanent { message: String },
+    /// Handled by the download fallback, not a queue retry.
+    MediaFetchFailure,
+}
+
+pub fn classify_request_error(e: &RequestError) -> Classification {
+    match e {
+        RequestError::RetryAfter(seconds) => {
+            Classification::Retryable { delay_seconds: seconds.seconds() as f64 }
+        }
+        RequestError::Network(_) => Classification::Retryable {
+            delay_seconds: retry_delay_seconds(0),
+        },
+        RequestError::Api(api) if is_media_fetch_failure(api) => Classification::MediaFetchFailure,
+        RequestError::Api(api) => Classification::Permanent { message: api.to_string() },
+        RequestError::MigrateToChatId(_)
+        | RequestError::InvalidJson { .. }
+        | RequestError::Io(_) => Classification::Permanent { message: e.to_string() },
+    }
+}
+
+pub enum SendError {
+    Retryable { delay_seconds: f64, task: Task },
+    Permanent { message: String, task: Task },
+}
+
+fn classify_to_send_error(e: &RequestError, task: Task) -> SendError {
+    match classify_request_error(e) {
+        Classification::Retryable { delay_seconds } => SendError::Retryable {
+            delay_seconds,
+            task,
+        },
+        Classification::Permanent { message } => SendError::Permanent { message, task },
+        Classification::MediaFetchFailure => SendError::Permanent {
+            message: "media fetch failed".into(),
+            task,
+        },
+    }
+}
+
+fn parse_media_url(s: &str) -> Result<url::Url, String> {
+    url::Url::parse(s).map_err(|e| format!("invalid media URL: {e}"))
+}
+
+fn item_url(item: &MediaItemPayload) -> &str {
+    match item {
+        MediaItemPayload::Photo { media, .. }
+        | MediaItemPayload::Video { media, .. }
+        | MediaItemPayload::Animation { media, .. } => media,
+    }
+}
+
+/// Remote http(s) URLs are handed to Telegram to fetch; everything else
+/// (e.g. a locally encoded ugoira MP4) is uploaded directly.
+fn input_file_for(media: &str) -> Result<InputFile, String> {
+    if media.starts_with("http://") || media.starts_with("https://") {
+        Ok(InputFile::url(parse_media_url(media)?))
+    } else {
+        Ok(InputFile::file(media))
+    }
+}
+
+fn photo_media(file: InputFile, caption: Option<&str>, spoiler: bool) -> InputMedia {
+    let mut photo = InputMediaPhoto::new(file).parse_mode(ParseMode::Html);
+    if let Some(caption) = caption {
+        photo = photo.caption(caption);
+    }
+    if spoiler {
+        photo = photo.spoiler();
+    }
+    InputMedia::Photo(photo)
+}
+
+fn video_media(file: InputFile, caption: Option<&str>, spoiler: bool) -> InputMedia {
+    let mut video = InputMediaVideo::new(file).parse_mode(ParseMode::Html);
+    if let Some(caption) = caption {
+        video = video.caption(caption);
+    }
+    if spoiler {
+        video = video.spoiler();
+    }
+    InputMedia::Video(video)
+}
+
+fn animation_media(file: InputFile, caption: Option<&str>, spoiler: bool) -> InputMedia {
+    let mut animation = InputMediaAnimation::new(file).parse_mode(ParseMode::Html);
+    if let Some(caption) = caption {
+        animation = animation.caption(caption);
+    }
+    if spoiler {
+        animation = animation.spoiler();
+    }
+    InputMedia::Animation(animation)
+}
+
+/// Builds a media group from payloads; only the first item of the batch gets
+/// the caption (Telegram rejects captions on later items).
+fn build_media_group(
+    batch: &[MediaItemPayload],
+    caption: Option<&str>,
+) -> Result<Vec<InputMedia>, String> {
+    batch
+        .iter()
+        .enumerate()
+        .map(|(i, item)| {
+            let item_caption = if i == 0 { caption } else { None };
+            Ok(match item {
+                MediaItemPayload::Photo {
+                    media,
+                    has_spoiler,
+                } => photo_media(input_file_for(media)?, item_caption, *has_spoiler),
+                MediaItemPayload::Video {
+                    media,
+                    has_spoiler,
+                    thumbnail,
+                } => {
+                    let mut video = video_media(input_file_for(media)?, item_caption, *has_spoiler);
+                    if let (Some(thumb), InputMedia::Video(v)) = (thumbnail, &mut video) {
+                        *v = v.clone().thumbnail(input_file_for(thumb)?);
+                    }
+                    video
+                }
+                MediaItemPayload::Animation {
+                    media,
+                    has_spoiler,
+                } => animation_media(input_file_for(media)?, item_caption, *has_spoiler),
+            })
+        })
+        .collect()
+}
+
+/// Infers a file extension from magic bytes so Telegram detects the mime type
+/// on multipart uploads.
+fn sniff_ext(bytes: &[u8]) -> &'static str {
+    if bytes.starts_with(&[0xFF, 0xD8]) {
+        "jpg"
+    } else if bytes.starts_with(b"\x89PNG") {
+        "png"
+    } else if bytes.starts_with(b"RIFF") && bytes.len() >= 12 && &bytes[8..12] == b"WEBP" {
+        "webp"
+    } else if bytes.starts_with(b"GIF8") {
+        "gif"
+    } else if bytes.len() >= 12 && &bytes[4..8] == b"ftyp" {
+        "mp4"
+    } else {
+        "bin"
+    }
+}
+
+enum FallbackError {
+    Retryable { delay_seconds: f64 },
+    Permanent { message: String },
+}
+
+/// Downloads one media item to a temp file (deleted on drop). Network errors
+/// are retryable; size over the upload cap and other download errors are not.
+async fn download_to_temp(item: &MediaItemPayload) -> Result<NamedTempFile, FallbackError> {
+    let media_url = match item {
+        MediaItemPayload::Photo { media, .. }
+        | MediaItemPayload::Video { media, .. }
+        | MediaItemPayload::Animation { media, .. } => media,
+    };
+    let bytes = match x_media::site::download_media(media_url).await {
+        Ok(bytes) => bytes,
+        Err(FetchError::Http(_)) => {
+            return Err(FallbackError::Retryable {
+                delay_seconds: retry_delay_seconds(0),
+            });
+        }
+        Err(e) => {
+            return Err(FallbackError::Permanent {
+                message: format!("download failed: {e}"),
+            });
+        }
+    };
+    if bytes.len() as u64 > MAX_UPLOAD_BYTES {
+        return Err(FallbackError::Permanent {
+            message: "media too large".into(),
+        });
+    }
+    let ext = sniff_ext(&bytes);
+    let mut file = tempfile::Builder::new()
+        .suffix(&format!(".{ext}"))
+        .tempfile()
+        .map_err(|e| FallbackError::Permanent {
+            message: format!("temp file failed: {e}"),
+        })?;
+    use std::io::Write;
+    file.as_file_mut()
+        .write_all(&bytes)
+        .map_err(|e| FallbackError::Permanent {
+            message: format!("temp file write failed: {e}"),
+        })?;
+    Ok(file)
+}
+
+/// Download-and-reupload fallback for one media batch.
+async fn send_batch_via_upload(
+    bot: &Bot,
+    chat_id: i64,
+    reply_to: i64,
+    batch: &[MediaItemPayload],
+    caption: Option<&str>,
+) -> Result<Vec<Message>, FallbackError> {
+    let mut files = Vec::new();
+    let mut items = Vec::new();
+    for (i, item) in batch.iter().enumerate() {
+        let file = download_to_temp(item).await?;
+        let path = file.path().to_path_buf();
+        let item_caption = if i == 0 { caption } else { None };
+        let media = match item {
+            MediaItemPayload::Photo { has_spoiler, .. } => {
+                photo_media(InputFile::file(path), item_caption, *has_spoiler)
+            }
+            MediaItemPayload::Video { has_spoiler, .. } => {
+                video_media(InputFile::file(path), item_caption, *has_spoiler)
+            }
+            MediaItemPayload::Animation { has_spoiler, .. } => {
+                animation_media(InputFile::file(path), item_caption, *has_spoiler)
+            }
+        };
+        items.push(media);
+        files.push(file);
+    }
+    let result = bot
+        .send_media_group(ChatId(chat_id), items)
+        .reply_parameters(ReplyParameters::new(MessageId(reply_to as i32)).allow_sending_without_reply())
+        .await;
+    match result {
+        Ok(messages) => Ok(messages),
+        Err(e) => Err(match classify_request_error(&e) {
+            Classification::Retryable { delay_seconds } => FallbackError::Retryable {
+                delay_seconds,
+            },
+            Classification::Permanent { message } => FallbackError::Permanent { message },
+            Classification::MediaFetchFailure => FallbackError::Permanent {
+                message: "upload failed".into(),
+            },
+        }),
+    }
+}
+
+fn updated_sequence_task(task: &Task, batch_index: usize, sent_message_ids: Vec<i64>) -> Task {
+    match task {
+        Task::SendMediaSequence {
+            chat_id,
+            reply_to_message_id,
+            caption,
+            media_batches,
+            source_url,
+            edit_before_forward,
+            forward_channel_id,
+            notify_chat_id,
+            notify_message_id,
+            ..
+        } => Task::SendMediaSequence {
+            chat_id: *chat_id,
+            reply_to_message_id: *reply_to_message_id,
+            caption: caption.clone(),
+            media_batches: media_batches.clone(),
+            batch_index,
+            sent_message_ids,
+            source_url: source_url.clone(),
+            edit_before_forward: *edit_before_forward,
+            forward_channel_id: *forward_channel_id,
+            notify_chat_id: *notify_chat_id,
+            notify_message_id: *notify_message_id,
+        },
+        _ => unreachable!("updated_sequence_task requires a SendMediaSequence task"),
+    }
+}
+
+/// Sends the media batches starting at `task.batch_index`, extending
+/// `sent_message_ids`. Returns all sent message ids on full success; on
+/// failure returns a [`SendError`] whose task carries the resumed state.
+pub async fn send_media_sequence(bot: &Bot, task: &Task) -> Result<Vec<i64>, SendError> {
+    let Task::SendMediaSequence {
+        chat_id,
+        reply_to_message_id,
+        caption,
+        media_batches,
+        batch_index,
+        sent_message_ids,
+        ..
+    } = task
+    else {
+        unreachable!("send_media_sequence requires a SendMediaSequence task")
+    };
+    let chat_id = *chat_id;
+    let reply_to = *reply_to_message_id;
+    let mut sent = sent_message_ids.clone();
+    for idx in *batch_index..media_batches.len() {
+        let batch = &media_batches[idx];
+        let caption = if idx == 0 { Some(caption.as_str()) } else { None };
+        let items = match build_media_group(batch, caption) {
+            Ok(items) => items,
+            Err(message) => {
+                return Err(SendError::Permanent {
+                    message,
+                    task: updated_sequence_task(task, idx, sent),
+                });
+            }
+        };
+        match bot
+            .send_media_group(ChatId(chat_id), items)
+            .reply_parameters(ReplyParameters::new(MessageId(reply_to as i32)).allow_sending_without_reply())
+            .await
+        {
+            Ok(messages) => {
+                log::info!(
+                    "media group batch {idx}/{} sent ({} item(s))",
+                    media_batches.len(),
+                    batch.len()
+                );
+                sent.extend(messages.into_iter().map(|m| m.id.0 as i64));
+            }
+            Err(RequestError::Api(api)) if is_media_fetch_failure(&api) => {
+                log::info!(
+                    "Telegram could not fetch media for batch {idx} ({}), downloading and reuploading",
+                    batch
+                        .first()
+                        .map(|item| item_url(item))
+                        .unwrap_or("?")
+                );
+                match send_batch_via_upload(bot, chat_id, reply_to, batch, caption).await {
+                    Ok(messages) => sent.extend(messages.into_iter().map(|m| m.id.0 as i64)),
+                    Err(FallbackError::Retryable { delay_seconds }) => {
+                        return Err(SendError::Retryable {
+                            delay_seconds,
+                            task: updated_sequence_task(task, idx, sent),
+                        });
+                    }
+                    Err(FallbackError::Permanent { message }) => {
+                        return Err(SendError::Permanent {
+                            message,
+                            task: updated_sequence_task(task, idx, sent),
+                        });
+                    }
+                }
+            }
+            Err(e) => {
+                return Err(classify_to_send_error(
+                    &e,
+                    updated_sequence_task(task, idx, sent),
+                ));
+            }
+        }
+    }
+    Ok(sent)
+}
+
+async fn send_animation_inner(
+    bot: &Bot,
+    chat_id: i64,
+    reply_to: i64,
+    caption: &str,
+    spoiler: bool,
+    file: InputFile,
+) -> Result<Message, RequestError> {
+    let mut request = bot
+        .send_animation(ChatId(chat_id), file)
+        .caption(caption)
+        .parse_mode(ParseMode::Html)
+        .reply_parameters(ReplyParameters::new(MessageId(reply_to as i32)).allow_sending_without_reply());
+    if spoiler {
+        request = request.has_spoiler(true);
+    }
+    request.await
+}
+
+/// Sends a lone animation (gif), URL first with the download fallback.
+pub async fn send_animation(bot: &Bot, task: &Task) -> Result<Vec<i64>, SendError> {
+    let Task::SendAnimation {
+        chat_id,
+        reply_to_message_id,
+        caption,
+        animation,
+        ..
+    } = task
+    else {
+        unreachable!("send_animation requires a SendAnimation task")
+    };
+    let chat_id = *chat_id;
+    let reply_to = *reply_to_message_id;
+    let (media_url, has_spoiler) = match animation {
+        MediaItemPayload::Animation {
+            media,
+            has_spoiler,
+        } => (media, *has_spoiler),
+        MediaItemPayload::Photo { .. } | MediaItemPayload::Video { .. } => {
+            unreachable!("SendAnimation carries an Animation payload")
+        }
+    };
+    let url_file = match input_file_for(media_url) {
+        Ok(file) => file,
+        Err(message) => return Err(SendError::Permanent { message, task: task.clone() }),
+    };
+    match send_animation_inner(bot, chat_id, reply_to, caption, has_spoiler, url_file)
+        .await
+    {
+        Ok(message) => Ok(vec![message.id.0 as i64]),
+        Err(RequestError::Api(api)) if is_media_fetch_failure(&api) => {
+            log::info!(
+                "Telegram could not fetch animation URL, downloading and reuploading: {}",
+                media_url
+            );
+            let file = match download_to_temp(animation).await {
+                Ok(file) => file,
+                Err(FallbackError::Retryable { delay_seconds }) => {
+                    return Err(SendError::Retryable { delay_seconds, task: task.clone() });
+                }
+                Err(FallbackError::Permanent { message }) => {
+                    return Err(SendError::Permanent { message, task: task.clone() });
+                }
+            };
+            let path = file.path().to_path_buf();
+            match send_animation_inner(
+                bot,
+                chat_id,
+                reply_to,
+                caption,
+                has_spoiler,
+                InputFile::file(path),
+            )
+            .await
+            {
+                Ok(message) => Ok(vec![message.id.0 as i64]),
+                Err(e) => Err(classify_to_send_error(&e, task.clone())),
+            }
+        }
+        Err(e) => Err(classify_to_send_error(&e, task.clone())),
+    }
+}
+
+/// Copies already-sent messages to the forward channel. No download fallback:
+/// the files are already on Telegram's servers.
+pub async fn forward_messages(bot: &Bot, task: &Task) -> Result<(), SendError> {
+    let Task::ForwardMessages {
+        from_chat_id,
+        to_chat_id,
+        message_ids,
+        ..
+    } = task
+    else {
+        unreachable!("forward_messages requires a ForwardMessages task")
+    };
+    let message_ids = message_ids
+        .iter()
+        .map(|id| MessageId(*id as i32))
+        .collect::<Vec<_>>();
+    match bot
+        .copy_messages(ChatId(*to_chat_id), ChatId(*from_chat_id), message_ids.clone())
+        .await
+    {
+        Ok(_) => {
+            log::info!(
+                "copied {} message(s) from {} to {}",
+                message_ids.len(),
+                from_chat_id,
+                to_chat_id
+            );
+            Ok(())
+        }
+        Err(e) => Err(classify_to_send_error(&e, task.clone())),
+    }
+}
+
+/// One button per template name (column layout), then the confirm button.
+pub fn build_edit_markup(templates: &HashMap<String, String>) -> InlineKeyboardMarkup {
+    let mut rows = Vec::new();
+    for name in templates.keys() {
+        rows.push(vec![InlineKeyboardButton::callback(
+            name.clone(),
+            format!("template|{name}"),
+        )]);
+    }
+    rows.push(vec![InlineKeyboardButton::callback(
+        "↩️ Confirm",
+        "forward",
+    )]);
+    InlineKeyboardMarkup::new(rows)
+}
+
+/// Notifies a chat about a dead-lettered task (skips when `notify_chat_id` is
+/// absent).
+pub async fn notify_failure(bot: &Bot, chat_id: Option<i64>, message_id: Option<i64>, message: &str) {
+    let Some(chat_id) = chat_id else { return };
+    let mut request = bot.send_message(ChatId(chat_id), message);
+    if let Some(message_id) = message_id {
+        request = request
+            .reply_parameters(ReplyParameters::new(MessageId(message_id as i32)).allow_sending_without_reply());
+    }
+    if let Err(e) = request.await {
+        log::error!("failed to notify about failed task: {e}");
+    }
+}
+
+/// After a successful send: either open the edit-before-forward prompt or
+/// forward to the configured channel (with retry/queue handling).
+pub async fn post_send_actions(bot: &Bot, task: &Task, message_ids: Vec<i64>) {
+    let (chat_id, reply_to, source_url, edit_before_forward, forward_channel_id, notify_chat_id, notify_message_id) =
+        match task {
+            Task::SendMediaSequence {
+                chat_id,
+                reply_to_message_id,
+                source_url,
+                edit_before_forward,
+                forward_channel_id,
+                notify_chat_id,
+                notify_message_id,
+                ..
+            }
+            | Task::SendAnimation {
+                chat_id,
+                reply_to_message_id,
+                source_url,
+                edit_before_forward,
+                forward_channel_id,
+                notify_chat_id,
+                notify_message_id,
+                ..
+            } => (
+                *chat_id,
+                *reply_to_message_id,
+                source_url.clone(),
+                *edit_before_forward,
+                *forward_channel_id,
+                *notify_chat_id,
+                *notify_message_id,
+            ),
+            Task::ForwardMessages { .. } => return,
+        };
+
+    if edit_before_forward {
+        let mut chat_data = CHAT_STORE.get(chat_id).await;
+        let keyboard = build_edit_markup(&chat_data.template);
+        match bot
+            .send_message(ChatId(chat_id), "Reply to edit message.")
+            .reply_markup(keyboard)
+            .reply_parameters(
+                ReplyParameters::new(MessageId(reply_to as i32)).allow_sending_without_reply(),
+            )
+            .await
+        {
+            Ok(prompt) => {
+                log::info!(
+                    "edit-before-forward prompt {} opened for {} message(s)",
+                    prompt.id.0,
+                    message_ids.len()
+                );
+                chat_data.edit_message.insert(
+                    prompt.id.0 as i64,
+                    EditMessage {
+                        url: source_url,
+                        chat_id,
+                        forward_message_ids: message_ids,
+                        template: String::new(),
+                        created_at: unix_now(),
+                    },
+                );
+                CHAT_STORE.set(chat_id, &chat_data).await;
+            }
+            Err(e) => log::error!("failed to send edit prompt: {e}"),
+        }
+        return;
+    }
+
+    if let Some(channel_id) = forward_channel_id {
+        log::info!("forwarding {} message(s) to channel {channel_id}", message_ids.len());
+        let forward_task = Task::ForwardMessages {
+            from_chat_id: chat_id,
+            to_chat_id: channel_id,
+            message_ids,
+            notify_chat_id,
+            notify_message_id,
+        };
+        match forward_messages(bot, &forward_task).await {
+            Ok(()) => {}
+            Err(SendError::Retryable { delay_seconds, task }) => {
+                let payload = serde_json::to_value(task).expect("task serializes");
+                let run_after = std::time::SystemTime::now()
+                    .duration_since(std::time::UNIX_EPOCH)
+                    .map(|d| d.as_secs_f64())
+                    .unwrap_or(0.0)
+                    + delay_seconds;
+                if let Err(e) = TASK_QUEUE.enqueue(payload, run_after).await {
+                    log::error!("failed to enqueue forward retry: {e}");
+                }
+            }
+            Err(SendError::Permanent { message, .. }) => {
+                notify_failure(
+                    bot,
+                    notify_chat_id,
+                    notify_message_id,
+                    &format!("Task failed after retries: {message}"),
+                )
+                .await;
+            }
+        }
+    }
+}
+
+/// Queue entry point: parses the stored task and dispatches.
+pub async fn handle_task(payload: serde_json::Value) -> Result<(), QueueError> {
+    let task: Task = match serde_json::from_value(payload.clone()) {
+        Ok(task) => task,
+        Err(e) => {
+            return Err(QueueError::Permanent {
+                message: format!("invalid task payload: {e}"),
+                payload,
+            });
+        }
+    };
+    let bot = Bot::from_env();
+    match task {
+        Task::SendMediaSequence { .. } | Task::SendAnimation { .. } => {
+            let message_ids = match send_media_or_animation(&bot, &task).await {
+                Ok(ids) => ids,
+                Err(SendError::Retryable { delay_seconds, task }) => {
+                    return Err(QueueError::Retryable {
+                        delay_seconds,
+                        payload: serde_json::to_value(task).expect("task serializes"),
+                    });
+                }
+                Err(SendError::Permanent { message, task }) => {
+                    return Err(QueueError::Permanent {
+                        message,
+                        payload: serde_json::to_value(task).expect("task serializes"),
+                    });
+                }
+            };
+            post_send_actions(&bot, &task, message_ids).await;
+            Ok(())
+        }
+        Task::ForwardMessages { .. } => match forward_messages(&bot, &task).await {
+            Ok(()) => Ok(()),
+            Err(SendError::Retryable { delay_seconds, task }) => Err(QueueError::Retryable {
+                delay_seconds,
+                payload: serde_json::to_value(task).expect("task serializes"),
+            }),
+            Err(SendError::Permanent { message, task }) => Err(QueueError::Permanent {
+                message,
+                payload: serde_json::to_value(task).expect("task serializes"),
+            }),
+        },
+    }
+}
+
+async fn send_media_or_animation(bot: &Bot, task: &Task) -> Result<Vec<i64>, SendError> {
+    match task {
+        Task::SendMediaSequence { .. } => send_media_sequence(bot, task).await,
+        Task::SendAnimation { .. } => send_animation(bot, task).await,
+        Task::ForwardMessages { .. } => unreachable!(),
+    }
+}
+
+/// Dead-letter callback wired to the queue in main: notifies the task's chat.
+pub async fn dead_letter_notify(payload: serde_json::Value, message: String) {
+    let notify_chat_id = payload.get("notify_chat_id").and_then(|v| v.as_i64());
+    let notify_message_id = payload.get("notify_message_id").and_then(|v| v.as_i64());
+    if notify_chat_id.is_some() {
+        let bot = Bot::from_env();
+        notify_failure(
+            &bot,
+            notify_chat_id,
+            notify_message_id,
+            &format!("Task failed after retries: {message}"),
+        )
+        .await;
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn chunk_media_items_sizes() {
+        assert_eq!(chunk_media_items::<i32>(vec![]), Vec::<Vec<i32>>::new());
+        assert_eq!(chunk_media_items((0..9).collect()).len(), 1);
+        assert_eq!(chunk_media_items((0..10).collect()).len(), 2);
+        assert_eq!(chunk_media_items((0..25).collect()).len(), 3);
+        assert_eq!(chunk_media_items((0..25).collect())[2].len(), 7);
+        assert!(chunk_media_items((0..25).collect()).iter().all(|c| c.len() <= 9));
+    }
+
+    #[test]
+    fn retry_delay_seconds_bounds() {
+        for attempts in 0..10 {
+            let delay = retry_delay_seconds(attempts);
+            assert!(delay >= 1.0, "attempts={attempts}: {delay}");
+            assert!(delay <= 30.0, "attempts={attempts}: {delay}");
+        }
+    }
+
+    #[test]
+    fn is_media_fetch_failure_matches_markers() {
+        for description in [
+            "Bad Request: WEBPAGE_MEDIA_EMPTY",
+            "Bad Request: media_empty",
+            "Bad Request: EMPTY_WEB_MEDIA",
+            "Bad Request: webpage_curl_failed",
+            "Bad Request: request timeout",
+        ] {
+            let api = ApiError::Unknown(description.to_string());
+            assert!(is_media_fetch_failure(&api), "{description}");
+        }
+        for description in ["Bad Request: message is not modified", "Forbidden: bot was blocked by the user"] {
+            let api = ApiError::Unknown(description.to_string());
+            assert!(!is_media_fetch_failure(&api), "{description}");
+        }
+    }
+
+    #[test]
+    fn classification_mapping() {
+        use teloxide::types::Seconds;
+        // RetryAfter -> Retryable with its delay
+        let e = RequestError::RetryAfter(Seconds::from_seconds(7));
+        assert!(matches!(
+            classify_request_error(&e),
+            Classification::Retryable { delay_seconds } if delay_seconds == 7.0
+        ));
+        // Api error -> Permanent
+        let e = RequestError::Api(ApiError::Unknown("Bad Request: something".into()));
+        assert!(matches!(
+            classify_request_error(&e),
+            Classification::Permanent { .. }
+        ));
+        // Api media-fetch marker -> MediaFetchFailure
+        let e = RequestError::Api(ApiError::Unknown("Bad Request: WEBPAGE_MEDIA_EMPTY".into()));
+        assert!(matches!(
+            classify_request_error(&e),
+            Classification::MediaFetchFailure
+        ));
+        // MigrateToChatId -> Permanent
+        let e = RequestError::MigrateToChatId(ChatId(123));
+        assert!(matches!(
+            classify_request_error(&e),
+            Classification::Permanent { .. }
+        ));
+    }
+
+    #[test]
+    fn task_serde_round_trip_preserves_resume_state() {
+        let task = Task::SendMediaSequence {
+            chat_id: 111,
+            reply_to_message_id: 222,
+            caption: "cap".into(),
+            media_batches: vec![
+                vec![MediaItemPayload::Photo {
+                    media: "https://a/b.jpg".into(),
+                    has_spoiler: true,
+                }],
+                vec![MediaItemPayload::Video {
+                    media: "https://a/v.mp4".into(),
+                    has_spoiler: false,
+                    thumbnail: Some("https://a/t.jpg".into()),
+                }],
+            ],
+            batch_index: 1,
+            sent_message_ids: vec![11, 12],
+            source_url: "https://x.com/u/status/1".into(),
+            edit_before_forward: true,
+            forward_channel_id: Some(333),
+            notify_chat_id: Some(111),
+            notify_message_id: Some(222),
+        };
+        let json = serde_json::to_value(&task).unwrap();
+        assert_eq!(json["type"], "send_media_sequence");
+        assert_eq!(json["batch_index"], 1);
+        let decoded: Task = serde_json::from_value(json).unwrap();
+        match decoded {
+            Task::SendMediaSequence {
+                batch_index,
+                sent_message_ids,
+                forward_channel_id,
+                media_batches,
+                ..
+            } => {
+                assert_eq!(batch_index, 1);
+                assert_eq!(sent_message_ids, vec![11, 12]);
+                assert_eq!(forward_channel_id, Some(333));
+                assert_eq!(media_batches.len(), 2);
+                assert!(matches!(media_batches[0][0], MediaItemPayload::Photo { has_spoiler: true, .. }));
+            }
+            other => panic!("expected SendMediaSequence, got {other:?}"),
+        }
+    }
+
+    #[test]
+    fn media_item_payload_serde_tags() {
+        let photo = MediaItemPayload::Photo {
+            media: "https://a/b.jpg".into(),
+            has_spoiler: false,
+        };
+        let json = serde_json::to_value(&photo).unwrap();
+        assert_eq!(json["kind"], "photo");
+    }
+
+    #[test]
+    fn sniff_ext_detects_formats() {
+        assert_eq!(sniff_ext(&[0xFF, 0xD8, 0xFF, 0xE0]), "jpg");
+        assert_eq!(sniff_ext(b"\x89PNG\r\n\x1a\n"), "png");
+        assert_eq!(sniff_ext(b"RIFF\x00\x00\x00\x00WEBPVP8 "), "webp");
+        assert_eq!(sniff_ext(b"GIF89a"), "gif");
+        assert_eq!(sniff_ext(b"\x00\x00\x00\x18ftypisom"), "mp4");
+        assert_eq!(sniff_ext(b"something else"), "bin");
+    }
+}

crates/xmedia-bot/src/state.rs

@@ -0,0 +1,151 @@
+//! Per-chat state with SQLite persistence (table `chat_state` in
+//! `data/task_queue.db`, shared with the task queue).
+
+use parking_lot::Mutex;
+use rusqlite::{params, Connection};
+use serde::{Deserialize, Serialize};
+use std::collections::HashMap;
+use std::path::Path;
+use std::time::{Duration, SystemTime, UNIX_EPOCH};
+
+#[derive(Serialize, Deserialize, Default, Clone, Debug)]
+pub struct ChatData {
+    pub forward_channel_id: Option<i64>,
+    pub edit_before_forward: bool,
+    /// Key: prompt message id.
+    pub edit_message: HashMap<i64, EditMessage>,
+    /// name -> HTML template containing "[]"
+    pub template: HashMap<String, String>,
+    /// site name (twitter/bsky/pixiv) -> user-supplied caption format with
+    /// {url} {author} {author_url} {title} {tags} placeholders.
+    pub message_format: HashMap<String, String>,
+}
+
+#[derive(Serialize, Deserialize, Clone, Debug, Default)]
+pub struct EditMessage {
+    pub url: String,
+    pub chat_id: i64,
+    pub forward_message_ids: Vec<i64>,
+    pub template: String,
+    /// Unix seconds at registration; expiry = created_at + ttl.
+    pub created_at: i64,
+}
+
+pub struct ChatStore {
+    /// In-memory cache; the DB is the source of truth on first access.
+    cache: Mutex<HashMap<i64, ChatData>>,
+    db_path: String,
+}
+
+pub fn unix_now() -> i64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map(|d| d.as_secs() as i64)
+        .unwrap_or(0)
+}
+
+impl ChatStore {
+    /// Creates the parent directory and both tables (idempotent).
+    pub fn open(path: &str) -> rusqlite::Result<Self> {
+        if let Some(parent) = Path::new(path).parent()
+            && !parent.as_os_str().is_empty()
+        {
+            std::fs::create_dir_all(parent)
+                .map_err(|e| rusqlite::Error::ToSqlConversionFailure(Box::new(e)))?;
+        }
+        let conn = Connection::open(path)?;
+        conn.execute_batch(
+            "CREATE TABLE IF NOT EXISTS tasks (id TEXT PRIMARY KEY, payload TEXT NOT NULL, \
+             run_after REAL NOT NULL, attempts INTEGER NOT NULL, status TEXT NOT NULL, \
+             locked_until REAL NOT NULL, created_at REAL NOT NULL); \
+             CREATE TABLE IF NOT EXISTS chat_state (chat_id TEXT PRIMARY KEY, payload TEXT NOT NULL);",
+        )?;
+        drop(conn);
+        Ok(ChatStore {
+            cache: Mutex::new(HashMap::new()),
+            db_path: path.to_string(),
+        })
+    }
+
+    pub async fn get(&self, chat_id: i64) -> ChatData {
+        if let Some(data) = self.cache.lock().get(&chat_id) {
+            return data.clone();
+        }
+        let db_path = self.db_path.clone();
+        let payload = tokio::task::spawn_blocking(move || -> rusqlite::Result<Option<String>> {
+            let conn = Connection::open(&db_path)?;
+            let mut stmt = conn.prepare("SELECT payload FROM chat_state WHERE chat_id = ?1")?;
+            let mut rows = stmt.query(params![chat_id.to_string()])?;
+            match rows.next()? {
+                Some(row) => Ok(Some(row.get(0)?)),
+                None => Ok(None),
+            }
+        })
+        .await
+        .expect("chat_state worker panicked")
+        .unwrap_or_else(|e| {
+            log::error!("chat_state read failed: {e}");
+            None
+        })
+        .unwrap_or_default();
+        let data: ChatData = serde_json::from_str(&payload).unwrap_or_default();
+        self.cache.lock().insert(chat_id, data.clone());
+        data
+    }
+
+    /// Write-through: update the cache and the DB.
+    pub async fn set(&self, chat_id: i64, data: &ChatData) {
+        self.cache.lock().insert(chat_id, data.clone());
+        let payload = serde_json::to_string(data).expect("chat state serializes");
+        let db_path = self.db_path.clone();
+        tokio::task::spawn_blocking(move || -> rusqlite::Result<()> {
+            let conn = Connection::open(&db_path)?;
+            conn.execute(
+                "INSERT OR REPLACE INTO chat_state (chat_id, payload) VALUES (?1, ?2)",
+                params![chat_id.to_string(), payload],
+            )?;
+            Ok(())
+        })
+        .await
+        .expect("chat_state worker panicked")
+        .unwrap_or_else(|e| log::error!("chat_state write failed: {e}"));
+    }
+
+    /// Removes edit-before-forward records whose `created_at + ttl` is in the
+    /// past. Returns the removed `(chat_id, prompt_message_id)` pairs so the
+    /// caller can clear the prompt's buttons.
+    pub async fn prune_expired(&self, ttl: Duration) -> Vec<(i64, i64)> {
+        let now = unix_now();
+        let ttl_secs = ttl.as_secs() as i64;
+        let mut removed = Vec::new();
+        let changed: Vec<(i64, ChatData)> = {
+            let mut cache = self.cache.lock();
+            let mut out = Vec::new();
+            for (chat_id, data) in cache.iter_mut() {
+                let keys: Vec<i64> = data.edit_message.keys().copied().collect();
+                let mut kept = HashMap::new();
+                for key in keys {
+                    if let Some(entry) = data.edit_message.get(&key) {
+                        if entry.created_at + ttl_secs > now {
+                            kept.insert(key, entry.clone());
+                        } else {
+                            removed.push((*chat_id, key));
+                        }
+                    }
+                }
+                if kept.len() != data.edit_message.len() {
+                    data.edit_message = kept;
+                    out.push((*chat_id, data.clone()));
+                }
+            }
+            out
+        };
+        for (chat_id, data) in changed {
+            self.set(chat_id, &data).await;
+        }
+        if !removed.is_empty() {
+            log::info!("pruned {} expired edit-before-forward record(s)", removed.len());
+        }
+        removed
+    }
+}