use actix_session::Session;
use actix_web::{HttpResponse, web};
use serde::Deserialize;

use shanty_db::entities::download_queue::DownloadStatus;
use shanty_db::queries;

use crate::auth;
use crate::config::AppConfig;
use crate::error::ApiError;
use crate::routes::artists::enrich_all_watched_artists;
use crate::state::AppState;

pub fn configure(cfg: &mut web::ServiceConfig) {
    cfg.service(web::resource("/status").route(web::get().to(get_status)))
        .service(web::resource("/pipeline").route(web::post().to(trigger_pipeline)))
        .service(web::resource("/index").route(web::post().to(trigger_index)))
        .service(web::resource("/tag").route(web::post().to(trigger_tag)))
        .service(web::resource("/organize").route(web::post().to(trigger_organize)))
        .service(web::resource("/tasks/{id}").route(web::get().to(get_task)))
        .service(web::resource("/watchlist").route(web::get().to(list_watchlist)))
        .service(web::resource("/watchlist/{id}").route(web::delete().to(remove_watchlist)))
        .service(
            web::resource("/config")
                .route(web::get().to(get_config))
                .route(web::put().to(save_config)),
        );
}

async fn get_status(
    state: web::Data<AppState>,
    session: Session,
) -> Result<HttpResponse, ApiError> {
    auth::require_auth(&session)?;
    let summary = shanty_watch::library_summary(state.db.conn()).await?;
    let pending_items =
        queries::downloads::list(state.db.conn(), Some(DownloadStatus::Pending)).await?;
    let downloading_items =
        queries::downloads::list(state.db.conn(), Some(DownloadStatus::Downloading)).await?;
    let failed_items =
        queries::downloads::list(state.db.conn(), Some(DownloadStatus::Failed)).await?;
    let tasks = state.tasks.list();

    let mut queue_items = Vec::new();
    queue_items.extend(downloading_items.iter().cloned());
    queue_items.extend(pending_items.iter().cloned());
    queue_items.extend(failed_items.iter().take(5).cloned());

    let needs_tagging = queries::tracks::get_needing_metadata(state.db.conn()).await?;

    Ok(HttpResponse::Ok().json(serde_json::json!({
        "library": summary,
        "queue": {
            "pending": pending_items.len(),
            "downloading": downloading_items.len(),
            "failed": failed_items.len(),
            "items": queue_items,
        },
        "tagging": {
            "needs_tagging": needs_tagging.len(),
            "items": needs_tagging.iter().take(20).collect::<Vec<_>>(),
        },
        "tasks": tasks,
    })))
}

async fn trigger_index(
    state: web::Data<AppState>,
    session: Session,
) -> Result<HttpResponse, ApiError> {
    auth::require_auth(&session)?;
    let task_id = state.tasks.register("index");
    let state = state.clone();
    let tid = task_id.clone();

    tokio::spawn(async move {
        let cfg = state.config.read().await.clone();
        state
            .tasks
            .update_progress(&tid, 0, 0, "Scanning library...");
        let scan_config = shanty_index::ScanConfig {
            root: cfg.library_path.clone(),
            dry_run: false,
            concurrency: cfg.indexing.concurrency,
        };
        match shanty_index::run_scan(state.db.conn(), &scan_config).await {
            Ok(stats) => state.tasks.complete(&tid, format!("{stats}")),
            Err(e) => state.tasks.fail(&tid, e.to_string()),
        }
    });

    Ok(HttpResponse::Accepted().json(serde_json::json!({ "task_id": task_id })))
}

async fn trigger_tag(
    state: web::Data<AppState>,
    session: Session,
) -> Result<HttpResponse, ApiError> {
    auth::require_auth(&session)?;
    let task_id = state.tasks.register("tag");
    let state = state.clone();
    let tid = task_id.clone();

    tokio::spawn(async move {
        let cfg = state.config.read().await.clone();
        state
            .tasks
            .update_progress(&tid, 0, 0, "Preparing tagger...");
        let mb = match shanty_tag::MusicBrainzClient::new() {
            Ok(c) => c,
            Err(e) => {
                state.tasks.fail(&tid, e.to_string());
                return;
            }
        };
        let tag_config = shanty_tag::TagConfig {
            dry_run: false,
            write_tags: cfg.tagging.write_tags,
            confidence: cfg.tagging.confidence,
        };
        state.tasks.update_progress(&tid, 0, 0, "Tagging tracks...");
        match shanty_tag::run_tagging(state.db.conn(), &mb, &tag_config, None).await {
            Ok(stats) => state.tasks.complete(&tid, format!("{stats}")),
            Err(e) => state.tasks.fail(&tid, e.to_string()),
        }
    });

    Ok(HttpResponse::Accepted().json(serde_json::json!({ "task_id": task_id })))
}

async fn trigger_organize(
    state: web::Data<AppState>,
    session: Session,
) -> Result<HttpResponse, ApiError> {
    auth::require_auth(&session)?;
    let task_id = state.tasks.register("organize");
    let state = state.clone();
    let tid = task_id.clone();

    tokio::spawn(async move {
        let cfg = state.config.read().await.clone();
        state
            .tasks
            .update_progress(&tid, 0, 0, "Organizing files...");
        let org_config = shanty_org::OrgConfig {
            target_dir: cfg.library_path.clone(),
            format: cfg.organization_format.clone(),
            dry_run: false,
            copy: false,
        };
        match shanty_org::organize_from_db(state.db.conn(), &org_config).await {
            Ok(stats) => {
                let promoted = queries::wanted::promote_downloaded_to_owned(state.db.conn())
                    .await
                    .unwrap_or(0);
                let msg = if promoted > 0 {
                    format!("{stats} — {promoted} items marked as owned")
                } else {
                    format!("{stats}")
                };
                state.tasks.complete(&tid, msg);
                let _ = enrich_all_watched_artists(&state).await;
            }
            Err(e) => state.tasks.fail(&tid, e.to_string()),
        }
    });

    Ok(HttpResponse::Accepted().json(serde_json::json!({ "task_id": task_id })))
}

async fn trigger_pipeline(
    state: web::Data<AppState>,
    session: Session,
) -> Result<HttpResponse, ApiError> {
    auth::require_auth(&session)?;
    let sync_id = state.tasks.register_pending("sync");
    let download_id = state.tasks.register_pending("download");
    let index_id = state.tasks.register_pending("index");
    let tag_id = state.tasks.register_pending("tag");
    let organize_id = state.tasks.register_pending("organize");
    let enrich_id = state.tasks.register_pending("enrich");

    let task_ids = vec![
        sync_id.clone(),
        download_id.clone(),
        index_id.clone(),
        tag_id.clone(),
        organize_id.clone(),
        enrich_id.clone(),
    ];

    let state = state.clone();

    tokio::spawn(async move {
        let cfg = state.config.read().await.clone();

        // Step 1: Sync
        state.tasks.start(&sync_id);
        state
            .tasks
            .update_progress(&sync_id, 0, 0, "Syncing watchlist to download queue...");
        match shanty_dl::sync_wanted_to_queue(state.db.conn(), false).await {
            Ok(stats) => state.tasks.complete(&sync_id, format!("{stats}")),
            Err(e) => state.tasks.fail(&sync_id, e.to_string()),
        }

        // Step 2: Download
        state.tasks.start(&download_id);
        let cookies = cfg.download.cookies_path.clone();
        let format: shanty_dl::AudioFormat = cfg
            .download
            .format
            .parse()
            .unwrap_or(shanty_dl::AudioFormat::Opus);
        let source: shanty_dl::SearchSource = cfg
            .download
            .search_source
            .parse()
            .unwrap_or(shanty_dl::SearchSource::YouTubeMusic);
        let rate = if cookies.is_some() {
            cfg.download.rate_limit_auth
        } else {
            cfg.download.rate_limit
        };
        let backend = shanty_dl::YtDlpBackend::new(rate, source, cookies.clone());
        let backend_config = shanty_dl::BackendConfig {
            output_dir: cfg.download_path.clone(),
            format,
            cookies_path: cookies,
        };
        let task_state = state.clone();
        let progress_tid = download_id.clone();
        let on_progress: shanty_dl::ProgressFn = Box::new(move |current, total, msg| {
            task_state
                .tasks
                .update_progress(&progress_tid, current, total, msg);
        });
        match shanty_dl::run_queue_with_progress(
            state.db.conn(),
            &backend,
            &backend_config,
            false,
            Some(on_progress),
        )
        .await
        {
            Ok(stats) => {
                let _ = queries::cache::purge_prefix(state.db.conn(), "artist_totals:").await;
                state.tasks.complete(&download_id, format!("{stats}"));
            }
            Err(e) => state.tasks.fail(&download_id, e.to_string()),
        }

        // Step 3: Index
        state.tasks.start(&index_id);
        state
            .tasks
            .update_progress(&index_id, 0, 0, "Scanning library...");
        let scan_config = shanty_index::ScanConfig {
            root: cfg.library_path.clone(),
            dry_run: false,
            concurrency: cfg.indexing.concurrency,
        };
        match shanty_index::run_scan(state.db.conn(), &scan_config).await {
            Ok(stats) => state.tasks.complete(&index_id, format!("{stats}")),
            Err(e) => state.tasks.fail(&index_id, e.to_string()),
        }

        // Step 4: Tag
        state.tasks.start(&tag_id);
        state
            .tasks
            .update_progress(&tag_id, 0, 0, "Tagging tracks...");
        match shanty_tag::MusicBrainzClient::new() {
            Ok(mb) => {
                let tag_config = shanty_tag::TagConfig {
                    dry_run: false,
                    write_tags: cfg.tagging.write_tags,
                    confidence: cfg.tagging.confidence,
                };
                match shanty_tag::run_tagging(state.db.conn(), &mb, &tag_config, None).await {
                    Ok(stats) => state.tasks.complete(&tag_id, format!("{stats}")),
                    Err(e) => state.tasks.fail(&tag_id, e.to_string()),
                }
            }
            Err(e) => state.tasks.fail(&tag_id, e.to_string()),
        }

        // Step 5: Organize
        state.tasks.start(&organize_id);
        state
            .tasks
            .update_progress(&organize_id, 0, 0, "Organizing files...");
        let org_config = shanty_org::OrgConfig {
            target_dir: cfg.library_path.clone(),
            format: cfg.organization_format.clone(),
            dry_run: false,
            copy: false,
        };
        match shanty_org::organize_from_db(state.db.conn(), &org_config).await {
            Ok(stats) => {
                let promoted = queries::wanted::promote_downloaded_to_owned(state.db.conn())
                    .await
                    .unwrap_or(0);
                let msg = if promoted > 0 {
                    format!("{stats} — {promoted} items marked as owned")
                } else {
                    format!("{stats}")
                };
                state.tasks.complete(&organize_id, msg);
            }
            Err(e) => state.tasks.fail(&organize_id, e.to_string()),
        }

        // Step 6: Enrich
        state.tasks.start(&enrich_id);
        state
            .tasks
            .update_progress(&enrich_id, 0, 0, "Refreshing artist data...");
        match enrich_all_watched_artists(&state).await {
            Ok(count) => state
                .tasks
                .complete(&enrich_id, format!("{count} artists refreshed")),
            Err(e) => state.tasks.fail(&enrich_id, e.to_string()),
        }
    });

    Ok(HttpResponse::Accepted().json(serde_json::json!({ "task_ids": task_ids })))
}

async fn get_task(
    state: web::Data<AppState>,
    session: Session,
    path: web::Path<String>,
) -> Result<HttpResponse, ApiError> {
    auth::require_auth(&session)?;
    let id = path.into_inner();
    match state.tasks.get(&id) {
        Some(task) => Ok(HttpResponse::Ok().json(task)),
        None => Err(ApiError::NotFound(format!("task {id}"))),
    }
}

async fn list_watchlist(
    state: web::Data<AppState>,
    session: Session,
) -> Result<HttpResponse, ApiError> {
    let (user_id, _, _) = auth::require_auth(&session)?;
    let items = shanty_watch::list_items(state.db.conn(), None, None, Some(user_id)).await?;
    Ok(HttpResponse::Ok().json(items))
}

async fn remove_watchlist(
    state: web::Data<AppState>,
    session: Session,
    path: web::Path<i32>,
) -> Result<HttpResponse, ApiError> {
    auth::require_auth(&session)?;
    let id = path.into_inner();
    shanty_watch::remove_item(state.db.conn(), id).await?;
    Ok(HttpResponse::NoContent().finish())
}

async fn get_config(
    state: web::Data<AppState>,
    session: Session,
) -> Result<HttpResponse, ApiError> {
    auth::require_auth(&session)?;
    let config = state.config.read().await;
    Ok(HttpResponse::Ok().json(&*config))
}

#[derive(Deserialize)]
struct SaveConfigRequest {
    #[serde(flatten)]
    config: AppConfig,
}

async fn save_config(
    state: web::Data<AppState>,
    session: Session,
    body: web::Json<SaveConfigRequest>,
) -> Result<HttpResponse, ApiError> {
    auth::require_admin(&session)?;
    let new_config = body.into_inner().config;

    // Persist to YAML
    new_config
        .save(state.config_path.as_deref())
        .map_err(ApiError::Internal)?;

    // Update in-memory config
    let mut config = state.config.write().await;
    *config = new_config.clone();

    tracing::info!("config updated via API");
    Ok(HttpResponse::Ok().json(&new_config))
}