feat: implement upload pipeline with compression and SSE

Backend:
- POST /api/v1/upload: multipart file upload with caption + hashtags
  - Validates file size against DB config limits (image/video separate)
  - Checks user ban status and event upload lock
  - Saves original to disk under {media_path}/originals/{slug}/
  - Tracks user total_upload_bytes for quota enforcement
  - Extracts hashtags from caption text and explicit CSV field
  - Upserts hashtags and links them to uploads
- PATCH /api/v1/upload/{id}: edit caption and hashtags (owner only)
- DELETE /api/v1/upload/{id}: soft-delete (owner only)
- GET /api/v1/stream: SSE endpoint with 30s keepalive
  - Broadcasts new-upload events to all connected clients
  - Uses tokio broadcast channel for fan-out

Services:
- CompressionWorker: Tokio semaphore-bounded (concurrency=2) background processor
  - Images: resize to 800px wide JPEG preview via image crate
  - PNG originals: lossless compression via oxipng
  - Videos: ffmpeg thumbnail extraction (1 frame at 1s, scaled to 800px)
  - Updates upload record with preview_path/thumbnail_path on completion

Models:
- Upload with full CRUD (create, find, update caption, soft delete, set paths)
- Hashtag with upsert, link/unlink, extract_hashtags() text parser
- UploadDto for API serialization with like/comment counts

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/Cargo.lock

@@ -894,6 +894,7 @@ dependencies = [
  "bcrypt",
  "chrono",
  "dotenvy",
+ "futures",
  "image",
  "jsonwebtoken",
  "minijinja",
@@ -905,6 +906,7 @@ dependencies = [
  "sqlx",
  "sysinfo",
  "tokio",
+ "tokio-stream",
  "tower",
  "tower-http",
  "tower_governor",
@@ -3253,6 +3255,7 @@ dependencies = [
  "futures-core",
  "pin-project-lite",
  "tokio",
+ "tokio-util",
 ]
 
 [[package]]

backend/Cargo.toml

@@ -16,6 +16,8 @@ jsonwebtoken = "9"
 bcrypt = "0.15"
 uuid = { version = "1", features = ["v4", "serde"] }
 chrono = { version = "0.4", features = ["serde"] }
+tokio-stream = { version = "0.1", features = ["sync"] }
+futures = "0.3"
 sha2 = "0.10"
 rand = "0.9"
 anyhow = "1"

backend/src/handlers/mod.rs

@@ -0,0 +1,2 @@
+pub mod sse;
+pub mod upload;

backend/src/handlers/sse.rs

@@ -0,0 +1,33 @@
+use std::convert::Infallible;
+use std::time::Duration;
+
+use axum::extract::State;
+use axum::response::sse::{Event, KeepAlive, Sse};
+use futures::stream::Stream;
+use tokio_stream::wrappers::BroadcastStream;
+use tokio_stream::StreamExt;
+
+use crate::auth::middleware::AuthUser;
+use crate::error::AppError;
+use crate::state::AppState;
+
+pub async fn stream(
+    State(state): State<AppState>,
+    _auth: AuthUser,
+) -> Result<Sse<impl Stream<Item = Result<Event, Infallible>>>, AppError> {
+    let rx = state.sse_tx.subscribe();
+    let stream = BroadcastStream::new(rx).filter_map(|msg| {
+        match msg {
+            Ok(sse_event) => Some(Ok(Event::default()
+                .event(sse_event.event_type)
+                .data(sse_event.data))),
+            Err(_) => None, // Lagged — skip missed events
+        }
+    });
+
+    Ok(Sse::new(stream).keep_alive(
+        KeepAlive::new()
+            .interval(Duration::from_secs(30))
+            .text("ping"),
+    ))
+}

backend/src/handlers/upload.rs

@@ -0,0 +1,237 @@
+use axum::extract::{Multipart, Path, State};
+use axum::http::StatusCode;
+use axum::Json;
+use serde::Deserialize;
+use uuid::Uuid;
+
+use crate::auth::middleware::AuthUser;
+use crate::error::AppError;
+use crate::models::hashtag::{self, Hashtag};
+use crate::models::upload::{Upload, UploadDto};
+use crate::models::user::User;
+use crate::state::AppState;
+
+pub async fn upload(
+    State(state): State<AppState>,
+    auth: AuthUser,
+    mut multipart: Multipart,
+) -> Result<(StatusCode, Json<UploadDto>), AppError> {
+    // Check if user is banned
+    let user = User::find_by_id(&state.pool, auth.user_id)
+        .await?
+        .ok_or_else(|| AppError::NotFound("Benutzer nicht gefunden.".into()))?;
+    if user.is_banned {
+        return Err(AppError::Forbidden("Du bist gesperrt.".into()));
+    }
+
+    // Check if uploads are locked
+    let event = crate::models::event::Event::find_by_slug(&state.pool, &state.config.event_slug)
+        .await?
+        .ok_or_else(|| AppError::NotFound("Event nicht gefunden.".into()))?;
+    if event.uploads_locked_at.is_some() {
+        return Err(AppError::Forbidden("Uploads sind gesperrt.".into()));
+    }
+
+    // Read config limits from DB
+    let max_image_mb: i64 = get_config_i64(&state.pool, "max_image_size_mb", 20).await;
+    let max_video_mb: i64 = get_config_i64(&state.pool, "max_video_size_mb", 500).await;
+
+    let mut file_data: Option<Vec<u8>> = None;
+    let mut file_name: Option<String> = None;
+    let mut content_type: Option<String> = None;
+    let mut caption: Option<String> = None;
+    let mut hashtags_csv: Option<String> = None;
+
+    while let Some(field) = multipart.next_field().await.map_err(|e| AppError::BadRequest(e.to_string()))? {
+        let name = field.name().unwrap_or_default().to_string();
+        match name.as_str() {
+            "file" => {
+                file_name = field.file_name().map(|s| s.to_string());
+                content_type = field.content_type().map(|s| s.to_string());
+                file_data = Some(
+                    field.bytes().await
+                        .map_err(|e| AppError::BadRequest(format!("Datei konnte nicht gelesen werden: {e}")))?
+                        .to_vec(),
+                );
+            }
+            "caption" => {
+                caption = Some(
+                    field.text().await
+                        .map_err(|e| AppError::BadRequest(e.to_string()))?,
+                );
+            }
+            "hashtags" => {
+                hashtags_csv = Some(
+                    field.text().await
+                        .map_err(|e| AppError::BadRequest(e.to_string()))?,
+                );
+            }
+            _ => {}
+        }
+    }
+
+    let data = file_data.ok_or_else(|| AppError::BadRequest("Keine Datei hochgeladen.".into()))?;
+    let mime = content_type.unwrap_or_else(|| "application/octet-stream".to_string());
+    let size = data.len() as i64;
+
+    // Validate file size
+    let max_bytes = if mime.starts_with("video/") {
+        max_video_mb * 1024 * 1024
+    } else {
+        max_image_mb * 1024 * 1024
+    };
+    if size > max_bytes {
+        return Err(AppError::BadRequest(format!(
+            "Datei ist zu groß. Maximum: {} MB.",
+            max_bytes / (1024 * 1024)
+        )));
+    }
+
+    // Determine file extension
+    let ext = file_name
+        .as_deref()
+        .and_then(|n| n.rsplit('.').next())
+        .unwrap_or(if mime.starts_with("video/") { "mp4" } else { "jpg" });
+
+    let upload_id = Uuid::new_v4();
+    let event_slug = &state.config.event_slug;
+    let relative_path = format!("originals/{event_slug}/{upload_id}.{ext}");
+    let absolute_path = state.config.media_path.join(&relative_path);
+
+    // Ensure directory exists and write file
+    if let Some(parent) = absolute_path.parent() {
+        tokio::fs::create_dir_all(parent).await.map_err(|e| AppError::Internal(e.into()))?;
+    }
+    tokio::fs::write(&absolute_path, &data).await.map_err(|e| AppError::Internal(e.into()))?;
+
+    // Update user's total upload bytes
+    sqlx::query("UPDATE \"user\" SET total_upload_bytes = total_upload_bytes + $2 WHERE id = $1")
+        .bind(auth.user_id)
+        .bind(size)
+        .execute(&state.pool)
+        .await?;
+
+    // Insert upload record
+    let upload = Upload::create(
+        &state.pool,
+        auth.event_id,
+        auth.user_id,
+        &relative_path,
+        &mime,
+        size,
+        caption.as_deref(),
+    )
+    .await?;
+
+    // Process hashtags from caption and explicit CSV
+    let mut tags: Vec<String> = Vec::new();
+    if let Some(ref cap) = caption {
+        tags.extend(hashtag::extract_hashtags(cap));
+    }
+    if let Some(ref csv) = hashtags_csv {
+        for tag in csv.split(',') {
+            let t = tag.trim().trim_start_matches('#').to_lowercase();
+            if !t.is_empty() {
+                tags.push(t);
+            }
+        }
+    }
+    tags.sort();
+    tags.dedup();
+
+    for tag in &tags {
+        let h = Hashtag::upsert(&state.pool, auth.event_id, tag).await?;
+        Hashtag::link_to_upload(&state.pool, upload.id, h.id).await?;
+    }
+
+    // Spawn compression task
+    state
+        .compression
+        .process(upload.id, relative_path, mime.clone());
+
+    // Broadcast SSE event
+    let dto = UploadDto {
+        id: upload.id,
+        user_id: auth.user_id,
+        uploader_name: user.display_name,
+        preview_url: None,
+        thumbnail_url: None,
+        mime_type: mime,
+        caption,
+        hashtags: tags,
+        like_count: 0,
+        comment_count: 0,
+        liked_by_me: false,
+        created_at: upload.created_at,
+    };
+
+    let _ = state.sse_tx.send(crate::state::SseEvent {
+        event_type: "new-upload".to_string(),
+        data: serde_json::to_string(&dto).unwrap_or_default(),
+    });
+
+    Ok((StatusCode::CREATED, Json(dto)))
+}
+
+#[derive(Deserialize)]
+pub struct EditUploadRequest {
+    pub caption: Option<String>,
+    pub hashtags: Option<Vec<String>>,
+}
+
+pub async fn edit_upload(
+    State(state): State<AppState>,
+    auth: AuthUser,
+    Path(upload_id): Path<Uuid>,
+    Json(body): Json<EditUploadRequest>,
+) -> Result<StatusCode, AppError> {
+    let upload = Upload::find_by_id(&state.pool, upload_id)
+        .await?
+        .ok_or_else(|| AppError::NotFound("Upload nicht gefunden.".into()))?;
+
+    if upload.user_id != auth.user_id {
+        return Err(AppError::Forbidden("Nur eigene Uploads bearbeiten.".into()));
+    }
+
+    if let Some(ref caption) = body.caption {
+        Upload::update_caption(&state.pool, upload_id, Some(caption)).await?;
+    }
+
+    if let Some(ref hashtags) = body.hashtags {
+        Hashtag::unlink_all_from_upload(&state.pool, upload_id).await?;
+        for tag in hashtags {
+            let h = Hashtag::upsert(&state.pool, auth.event_id, tag).await?;
+            Hashtag::link_to_upload(&state.pool, upload_id, h.id).await?;
+        }
+    }
+
+    Ok(StatusCode::OK)
+}
+
+pub async fn delete_upload(
+    State(state): State<AppState>,
+    auth: AuthUser,
+    Path(upload_id): Path<Uuid>,
+) -> Result<StatusCode, AppError> {
+    let upload = Upload::find_by_id(&state.pool, upload_id)
+        .await?
+        .ok_or_else(|| AppError::NotFound("Upload nicht gefunden.".into()))?;
+
+    if upload.user_id != auth.user_id {
+        return Err(AppError::Forbidden("Nur eigene Uploads löschen.".into()));
+    }
+
+    Upload::soft_delete(&state.pool, upload_id).await?;
+
+    Ok(StatusCode::NO_CONTENT)
+}
+
+async fn get_config_i64(pool: &sqlx::PgPool, key: &str, default: i64) -> i64 {
+    let row: Option<(String,)> =
+        sqlx::query_as("SELECT value FROM config WHERE key = $1")
+            .bind(key)
+            .fetch_optional(pool)
+            .await
+            .unwrap_or(None);
+    row.and_then(|r| r.0.parse().ok()).unwrap_or(default)
+}

backend/src/main.rs

@@ -1,5 +1,5 @@
 use anyhow::Result;
-use axum::routing::{delete, post};
+use axum::routing::{delete, get, patch, post};
 use axum::Router;
 use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};
 
@@ -7,7 +7,9 @@ mod auth;
 mod config;
 mod db;
 mod error;
+mod handlers;
 mod models;
+mod services;
 mod state;
 
 use config::AppConfig;
@@ -28,14 +30,26 @@ async fn main() -> Result<()> {
     let pool = db::create_pool(&config.database_url).await?;
     let state = AppState::new(pool, config.clone());
 
+    // Ensure media directories exist
+    tokio::fs::create_dir_all(&config.media_path).await.ok();
+
     let api = Router::new()
+        // Auth
         .route("/api/v1/join", post(auth::handlers::join))
         .route("/api/v1/recover", post(auth::handlers::recover))
         .route("/api/v1/admin/login", post(auth::handlers::admin_login))
-        .route("/api/v1/session", delete(auth::handlers::logout));
+        .route("/api/v1/session", delete(auth::handlers::logout))
+        // Upload
+        .route("/api/v1/upload", post(handlers::upload::upload))
+        .route(
+            "/api/v1/upload/{id}",
+            patch(handlers::upload::edit_upload).delete(handlers::upload::delete_upload),
+        )
+        // SSE
+        .route("/api/v1/stream", get(handlers::sse::stream));
 
     let router = Router::new()
-        .route("/health", axum::routing::get(|| async { "ok" }))
+        .route("/health", get(|| async { "ok" }))
         .merge(api)
         .with_state(state);
 

backend/src/models/hashtag.rs

@@ -0,0 +1,77 @@
+use sqlx::PgPool;
+use uuid::Uuid;
+
+#[derive(Debug, sqlx::FromRow)]
+pub struct Hashtag {
+    pub id: Uuid,
+    pub event_id: Uuid,
+    pub tag: String,
+}
+
+impl Hashtag {
+    /// Upsert a hashtag (insert if not exists, return existing if it does).
+    pub async fn upsert(pool: &PgPool, event_id: Uuid, tag: &str) -> Result<Self, sqlx::Error> {
+        let normalized = tag.trim().trim_start_matches('#').to_lowercase();
+        sqlx::query_as::<_, Self>(
+            "INSERT INTO hashtag (event_id, tag) VALUES ($1, $2)
+             ON CONFLICT (event_id, tag) DO UPDATE SET tag = EXCLUDED.tag
+             RETURNING *",
+        )
+        .bind(event_id)
+        .bind(&normalized)
+        .fetch_one(pool)
+        .await
+    }
+
+    pub async fn link_to_upload(
+        pool: &PgPool,
+        upload_id: Uuid,
+        hashtag_id: Uuid,
+    ) -> Result<(), sqlx::Error> {
+        sqlx::query(
+            "INSERT INTO upload_hashtag (upload_id, hashtag_id) VALUES ($1, $2)
+             ON CONFLICT DO NOTHING",
+        )
+        .bind(upload_id)
+        .bind(hashtag_id)
+        .execute(pool)
+        .await?;
+        Ok(())
+    }
+
+    pub async fn unlink_all_from_upload(
+        pool: &PgPool,
+        upload_id: Uuid,
+    ) -> Result<(), sqlx::Error> {
+        sqlx::query("DELETE FROM upload_hashtag WHERE upload_id = $1")
+            .bind(upload_id)
+            .execute(pool)
+            .await?;
+        Ok(())
+    }
+
+    pub async fn tags_for_upload(
+        pool: &PgPool,
+        upload_id: Uuid,
+    ) -> Result<Vec<String>, sqlx::Error> {
+        let rows: Vec<(String,)> = sqlx::query_as(
+            "SELECT h.tag FROM hashtag h
+             JOIN upload_hashtag uh ON uh.hashtag_id = h.id
+             WHERE uh.upload_id = $1
+             ORDER BY h.tag",
+        )
+        .bind(upload_id)
+        .fetch_all(pool)
+        .await?;
+        Ok(rows.into_iter().map(|r| r.0).collect())
+    }
+}
+
+/// Extract #hashtags from text (caption or body).
+pub fn extract_hashtags(text: &str) -> Vec<String> {
+    text.split_whitespace()
+        .filter(|w| w.starts_with('#') && w.len() > 1)
+        .map(|w| w.trim_start_matches('#').to_lowercase())
+        .filter(|t| !t.is_empty())
+        .collect()
+}

backend/src/models/mod.rs

@@ -1,3 +1,5 @@
 pub mod event;
+pub mod hashtag;
 pub mod session;
+pub mod upload;
 pub mod user;

backend/src/models/upload.rs

@@ -0,0 +1,117 @@
+use chrono::{DateTime, Utc};
+use serde::Serialize;
+use sqlx::PgPool;
+use uuid::Uuid;
+
+#[derive(Debug, sqlx::FromRow)]
+pub struct Upload {
+    pub id: Uuid,
+    pub event_id: Uuid,
+    pub user_id: Uuid,
+    pub original_path: String,
+    pub preview_path: Option<String>,
+    pub thumbnail_path: Option<String>,
+    pub mime_type: String,
+    pub original_size_bytes: i64,
+    pub caption: Option<String>,
+    pub created_at: DateTime<Utc>,
+    pub deleted_at: Option<DateTime<Utc>>,
+}
+
+#[derive(Debug, Serialize)]
+pub struct UploadDto {
+    pub id: Uuid,
+    pub user_id: Uuid,
+    pub uploader_name: String,
+    pub preview_url: Option<String>,
+    pub thumbnail_url: Option<String>,
+    pub mime_type: String,
+    pub caption: Option<String>,
+    pub hashtags: Vec<String>,
+    pub like_count: i64,
+    pub comment_count: i64,
+    pub liked_by_me: bool,
+    pub created_at: DateTime<Utc>,
+}
+
+impl Upload {
+    pub async fn create(
+        pool: &PgPool,
+        event_id: Uuid,
+        user_id: Uuid,
+        original_path: &str,
+        mime_type: &str,
+        original_size_bytes: i64,
+        caption: Option<&str>,
+    ) -> Result<Self, sqlx::Error> {
+        sqlx::query_as::<_, Self>(
+            "INSERT INTO upload (event_id, user_id, original_path, mime_type, original_size_bytes, caption)
+             VALUES ($1, $2, $3, $4, $5, $6)
+             RETURNING *",
+        )
+        .bind(event_id)
+        .bind(user_id)
+        .bind(original_path)
+        .bind(mime_type)
+        .bind(original_size_bytes)
+        .bind(caption)
+        .fetch_one(pool)
+        .await
+    }
+
+    pub async fn find_by_id(pool: &PgPool, id: Uuid) -> Result<Option<Self>, sqlx::Error> {
+        sqlx::query_as::<_, Self>(
+            "SELECT * FROM upload WHERE id = $1 AND deleted_at IS NULL",
+        )
+        .bind(id)
+        .fetch_optional(pool)
+        .await
+    }
+
+    pub async fn set_preview_path(
+        pool: &PgPool,
+        id: Uuid,
+        preview_path: &str,
+    ) -> Result<(), sqlx::Error> {
+        sqlx::query("UPDATE upload SET preview_path = $2 WHERE id = $1")
+            .bind(id)
+            .bind(preview_path)
+            .execute(pool)
+            .await?;
+        Ok(())
+    }
+
+    pub async fn set_thumbnail_path(
+        pool: &PgPool,
+        id: Uuid,
+        thumbnail_path: &str,
+    ) -> Result<(), sqlx::Error> {
+        sqlx::query("UPDATE upload SET thumbnail_path = $2 WHERE id = $1")
+            .bind(id)
+            .bind(thumbnail_path)
+            .execute(pool)
+            .await?;
+        Ok(())
+    }
+
+    pub async fn soft_delete(pool: &PgPool, id: Uuid) -> Result<(), sqlx::Error> {
+        sqlx::query("UPDATE upload SET deleted_at = NOW() WHERE id = $1")
+            .bind(id)
+            .execute(pool)
+            .await?;
+        Ok(())
+    }
+
+    pub async fn update_caption(
+        pool: &PgPool,
+        id: Uuid,
+        caption: Option<&str>,
+    ) -> Result<(), sqlx::Error> {
+        sqlx::query("UPDATE upload SET caption = $2 WHERE id = $1")
+            .bind(id)
+            .bind(caption)
+            .execute(pool)
+            .await?;
+        Ok(())
+    }
+}

backend/src/services/compression.rs

@@ -0,0 +1,139 @@
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+
+use anyhow::{Context, Result};
+use sqlx::PgPool;
+use tokio::sync::Semaphore;
+use uuid::Uuid;
+
+use crate::models::upload::Upload;
+
+#[derive(Clone)]
+pub struct CompressionWorker {
+    semaphore: Arc<Semaphore>,
+    pool: PgPool,
+    media_path: PathBuf,
+}
+
+impl CompressionWorker {
+    pub fn new(pool: PgPool, media_path: PathBuf, concurrency: usize) -> Self {
+        Self {
+            semaphore: Arc::new(Semaphore::new(concurrency)),
+            pool,
+            media_path,
+        }
+    }
+
+    /// Spawn a background task to process an uploaded file.
+    pub fn process(&self, upload_id: Uuid, original_path: String, mime_type: String) {
+        let worker = self.clone();
+        tokio::spawn(async move {
+            let _permit = worker.semaphore.acquire().await;
+            if let Err(e) = worker.do_process(upload_id, &original_path, &mime_type).await {
+                tracing::error!("compression failed for upload {upload_id}: {e:#}");
+            }
+        });
+    }
+
+    async fn do_process(
+        &self,
+        upload_id: Uuid,
+        original_path: &str,
+        mime_type: &str,
+    ) -> Result<()> {
+        let original = self.media_path.join(original_path);
+
+        if mime_type.starts_with("image/") {
+            let preview_rel = self.generate_image_preview(upload_id, &original, mime_type).await?;
+            Upload::set_preview_path(&self.pool, upload_id, &preview_rel).await?;
+            tracing::info!("preview generated for upload {upload_id}");
+        } else if mime_type.starts_with("video/") {
+            let thumb_rel = self.generate_video_thumbnail(upload_id, &original).await?;
+            Upload::set_thumbnail_path(&self.pool, upload_id, &thumb_rel).await?;
+            tracing::info!("thumbnail generated for upload {upload_id}");
+        }
+
+        Ok(())
+    }
+
+    async fn generate_image_preview(
+        &self,
+        upload_id: Uuid,
+        original: &Path,
+        mime_type: &str,
+    ) -> Result<String> {
+        let previews_dir = self.media_path.join("previews");
+        tokio::fs::create_dir_all(&previews_dir).await?;
+
+        let preview_filename = format!("{upload_id}.jpg");
+        let preview_path = previews_dir.join(&preview_filename);
+        let original = original.to_path_buf();
+        let preview_path_clone = preview_path.clone();
+        let mime_owned = mime_type.to_string();
+
+        // Run blocking image operations in a spawn_blocking task
+        tokio::task::spawn_blocking(move || -> Result<()> {
+            let img = image::open(&original)
+                .context("failed to open image")?;
+
+            // Resize to max 800px wide, preserving aspect ratio
+            let preview = img.resize(800, 800, image::imageops::FilterType::Lanczos3);
+            preview.save_with_format(&preview_path_clone, image::ImageFormat::Jpeg)
+                .context("failed to save preview")?;
+
+            // If the original is PNG, try lossless compression in-place
+            if mime_owned == "image/png" {
+                let opts = oxipng::Options::from_preset(2);
+                let _ = oxipng::optimize(
+                    &oxipng::InFile::Path(original),
+                    &oxipng::OutFile::Path {
+                        path: None,
+                        preserve_attrs: true,
+                    },
+                    &opts,
+                );
+            }
+
+            Ok(())
+        })
+        .await??;
+
+        Ok(format!("previews/{preview_filename}"))
+    }
+
+    async fn generate_video_thumbnail(
+        &self,
+        upload_id: Uuid,
+        original: &Path,
+    ) -> Result<String> {
+        let thumbs_dir = self.media_path.join("thumbnails");
+        tokio::fs::create_dir_all(&thumbs_dir).await?;
+
+        let thumb_filename = format!("{upload_id}.jpg");
+        let thumb_path = thumbs_dir.join(&thumb_filename);
+
+        let output = tokio::process::Command::new("ffmpeg")
+            .args([
+                "-i",
+                original.to_str().unwrap_or_default(),
+                "-vframes",
+                "1",
+                "-ss",
+                "00:00:01",
+                "-vf",
+                "scale=800:-1",
+                "-y",
+                thumb_path.to_str().unwrap_or_default(),
+            ])
+            .output()
+            .await
+            .context("failed to run ffmpeg")?;
+
+        if !output.status.success() {
+            let stderr = String::from_utf8_lossy(&output.stderr);
+            anyhow::bail!("ffmpeg failed: {stderr}");
+        }
+
+        Ok(format!("thumbnails/{thumb_filename}"))
+    }
+}

backend/src/services/mod.rs

@@ -0,0 +1 @@
+pub mod compression;

backend/src/state.rs

@@ -2,6 +2,7 @@ use sqlx::PgPool;
 use tokio::sync::broadcast;
 
 use crate::config::AppConfig;
+use crate::services::compression::CompressionWorker;
 
 #[derive(Clone, Debug)]
 pub struct SseEvent {
@@ -14,15 +15,19 @@ pub struct AppState {
     pub pool: PgPool,
     pub config: AppConfig,
     pub sse_tx: broadcast::Sender<SseEvent>,
+    pub compression: CompressionWorker,
 }
 
 impl AppState {
     pub fn new(pool: PgPool, config: AppConfig) -> Self {
         let (sse_tx, _) = broadcast::channel(256);
+        let compression =
+            CompressionWorker::new(pool.clone(), config.media_path.clone(), 2);
         Self {
             pool,
             config,
             sse_tx,
+            compression,
         }
     }
 }