Added the playlist generator

src/routes/playlists.rs

@@ -0,0 +1,232 @@
+use actix_session::Session;
+use actix_web::{HttpResponse, web};
+use serde::{Deserialize, Serialize};
+
+use shanty_db::queries;
+use shanty_playlist::{self, PlaylistRequest};
+
+use crate::auth;
+use crate::error::ApiError;
+use crate::state::AppState;
+
+pub fn configure(cfg: &mut web::ServiceConfig) {
+    cfg.service(web::resource("/playlists/generate").route(web::post().to(generate_playlist)))
+        .service(
+            web::resource("/playlists")
+                .route(web::get().to(list_playlists))
+                .route(web::post().to(save_playlist)),
+        )
+        .service(
+            web::resource("/playlists/{id}")
+                .route(web::get().to(get_playlist))
+                .route(web::put().to(update_playlist))
+                .route(web::delete().to(delete_playlist)),
+        )
+        .service(web::resource("/playlists/{id}/m3u").route(web::get().to(export_m3u)));
+}
+
+/// POST /api/playlists/generate — generate a playlist without saving.
+async fn generate_playlist(
+    state: web::Data<AppState>,
+    session: Session,
+    body: web::Json<PlaylistRequest>,
+) -> Result<HttpResponse, ApiError> {
+    auth::require_auth(&session)?;
+    let req = body.into_inner();
+    let conn = state.db.conn();
+
+    let config = state.config.read().await;
+    let lastfm_key = config.metadata.lastfm_api_key.clone();
+    drop(config);
+
+    let result = match req.strategy.as_str() {
+        "similar" => {
+            let api_key = lastfm_key.unwrap_or_default();
+            if api_key.is_empty() {
+                return Err(ApiError::BadRequest(
+                    "SHANTY_LASTFM_API_KEY is required for similar-artist playlists".into(),
+                ));
+            }
+            let fetcher = shanty_data::LastFmSimilarFetcher::new(api_key)
+                .map_err(|e| ApiError::Internal(e.to_string()))?;
+            shanty_playlist::similar_artists(
+                conn,
+                &fetcher,
+                req.seed_artists,
+                req.count,
+                req.popularity_bias,
+                &req.ordering,
+            )
+            .await
+            .map_err(|e| ApiError::Internal(e.to_string()))?
+        }
+        "genre" => shanty_playlist::genre_based(conn, req.genres, req.count, &req.ordering)
+            .await
+            .map_err(|e| ApiError::Internal(e.to_string()))?,
+        "random" => shanty_playlist::random(conn, req.count, req.ordering != "random")
+            .await
+            .map_err(|e| ApiError::Internal(e.to_string()))?,
+        "smart" => {
+            let rules = req.rules.unwrap_or_default();
+            shanty_playlist::smart(conn, rules, req.count)
+                .await
+                .map_err(|e| ApiError::Internal(e.to_string()))?
+        }
+        other => {
+            return Err(ApiError::BadRequest(format!("unknown strategy: {other}")));
+        }
+    };
+
+    Ok(HttpResponse::Ok().json(result))
+}
+
+#[derive(Deserialize)]
+struct SavePlaylistRequest {
+    name: String,
+    description: Option<String>,
+    track_ids: Vec<i32>,
+}
+
+/// POST /api/playlists — save a generated playlist.
+async fn save_playlist(
+    state: web::Data<AppState>,
+    session: Session,
+    body: web::Json<SavePlaylistRequest>,
+) -> Result<HttpResponse, ApiError> {
+    let (user_id, _, _) = auth::require_auth(&session)?;
+    let req = body.into_inner();
+    let playlist = queries::playlists::create(
+        state.db.conn(),
+        &req.name,
+        req.description.as_deref(),
+        Some(user_id),
+        &req.track_ids,
+    )
+    .await?;
+
+    Ok(HttpResponse::Created().json(playlist))
+}
+
+/// GET /api/playlists — list saved playlists.
+async fn list_playlists(
+    state: web::Data<AppState>,
+    session: Session,
+) -> Result<HttpResponse, ApiError> {
+    let (user_id, _, _) = auth::require_auth(&session)?;
+    let playlists = queries::playlists::list(state.db.conn(), Some(user_id)).await?;
+
+    #[derive(Serialize)]
+    struct PlaylistSummary {
+        id: i32,
+        name: String,
+        description: Option<String>,
+        track_count: u64,
+        created_at: String,
+    }
+
+    let mut summaries = Vec::new();
+    for p in playlists {
+        let count = queries::playlists::get_track_count(state.db.conn(), p.id).await?;
+        summaries.push(PlaylistSummary {
+            id: p.id,
+            name: p.name,
+            description: p.description,
+            track_count: count,
+            created_at: p.created_at.format("%Y-%m-%d %H:%M").to_string(),
+        });
+    }
+
+    Ok(HttpResponse::Ok().json(summaries))
+}
+
+/// GET /api/playlists/{id} — get playlist with tracks.
+async fn get_playlist(
+    state: web::Data<AppState>,
+    session: Session,
+    path: web::Path<i32>,
+) -> Result<HttpResponse, ApiError> {
+    auth::require_auth(&session)?;
+    let id = path.into_inner();
+    let playlist = queries::playlists::get_by_id(state.db.conn(), id).await?;
+    let tracks = queries::playlists::get_tracks(state.db.conn(), id).await?;
+
+    Ok(HttpResponse::Ok().json(serde_json::json!({
+        "playlist": playlist,
+        "tracks": tracks,
+    })))
+}
+
+#[derive(Deserialize)]
+struct UpdatePlaylistRequest {
+    name: Option<String>,
+    description: Option<String>,
+}
+
+/// PUT /api/playlists/{id} — update playlist name/description.
+async fn update_playlist(
+    state: web::Data<AppState>,
+    session: Session,
+    path: web::Path<i32>,
+    body: web::Json<UpdatePlaylistRequest>,
+) -> Result<HttpResponse, ApiError> {
+    auth::require_auth(&session)?;
+    let id = path.into_inner();
+    let req = body.into_inner();
+    let playlist = queries::playlists::update(
+        state.db.conn(),
+        id,
+        req.name.as_deref(),
+        req.description.as_deref(),
+    )
+    .await?;
+    Ok(HttpResponse::Ok().json(playlist))
+}
+
+/// DELETE /api/playlists/{id} — delete a playlist.
+async fn delete_playlist(
+    state: web::Data<AppState>,
+    session: Session,
+    path: web::Path<i32>,
+) -> Result<HttpResponse, ApiError> {
+    auth::require_auth(&session)?;
+    let id = path.into_inner();
+    queries::playlists::delete(state.db.conn(), id).await?;
+    Ok(HttpResponse::NoContent().finish())
+}
+
+/// GET /api/playlists/{id}/m3u — export as M3U file.
+async fn export_m3u(
+    state: web::Data<AppState>,
+    session: Session,
+    path: web::Path<i32>,
+) -> Result<HttpResponse, ApiError> {
+    auth::require_auth(&session)?;
+    let id = path.into_inner();
+    let playlist = queries::playlists::get_by_id(state.db.conn(), id).await?;
+    let tracks = queries::playlists::get_tracks(state.db.conn(), id).await?;
+
+    // Convert DB tracks to PlaylistTracks for M3U generation
+    let playlist_tracks: Vec<shanty_playlist::PlaylistTrack> = tracks
+        .into_iter()
+        .map(|t| shanty_playlist::PlaylistTrack {
+            track_id: t.id,
+            file_path: t.file_path,
+            title: t.title,
+            artist: t.artist,
+            album: t.album,
+            score: 0.0,
+            duration: t.duration,
+        })
+        .collect();
+
+    let m3u = shanty_playlist::to_m3u(&playlist_tracks);
+    let filename = format!("{}.m3u", playlist.name.replace(' ', "_"));
+
+    Ok(HttpResponse::Ok()
+        .insert_header(("Content-Type", "audio/x-mpegurl"))
+        .insert_header((
+            "Content-Disposition",
+            format!("attachment; filename=\"{filename}\""),
+        ))
+        .body(m3u))
+}