use std::{path::PathBuf, sync::Arc};

use anyhow::Result;
use axum::{Router, response::Redirect, routing::any};
use clap::Parser;
use pinakes_core::{config::Config, storage::StorageBackend};
use pinakes_server::{app, state::AppState};
use tokio::sync::RwLock;
use tracing::info;
use tracing_subscriber::EnvFilter;

/// Pinakes media cataloging server
#[derive(Parser)]
#[command(name = "pinakes-server", version, about)]
struct Cli {
  /// Path to configuration file
  #[arg(short, long, env = "PINAKES_CONFIG")]
  config: Option<PathBuf>,

  /// Override listen host
  #[arg(long)]
  host: Option<String>,

  /// Override listen port
  #[arg(short, long)]
  port: Option<u16>,

  /// Set log level (trace, debug, info, warn, error)
  #[arg(long, default_value = "info")]
  log_level: String,

  /// Log output format (compact, full, pretty, json)
  #[arg(long, default_value = "compact")]
  log_format: String,

  /// Run database migrations only, then exit
  #[arg(long)]
  migrate_only: bool,
}

/// Resolve the configuration file path.
/// Returns (path, was_explicit) where was_explicit indicates if the path was
/// explicitly provided by the user (vs discovered).
fn resolve_config_path(explicit: Option<&std::path::Path>) -> (PathBuf, bool) {
  if let Some(path) = explicit {
    return (path.to_path_buf(), true);
  }
  // Check current directory
  let local = PathBuf::from("pinakes.toml");
  if local.exists() {
    return (local, false);
  }
  // XDG default
  (Config::default_config_path(), false)
}

#[tokio::main]
async fn main() -> Result<()> {
  let cli = Cli::parse();

  // Initialize logging
  let env_filter = EnvFilter::try_new(&cli.log_level)
    .unwrap_or_else(|_| EnvFilter::new("info"));

  match cli.log_format.as_str() {
    "json" => {
      tracing_subscriber::fmt()
        .with_env_filter(env_filter)
        .json()
        .init();
    },
    "pretty" => {
      tracing_subscriber::fmt()
        .with_env_filter(env_filter)
        .pretty()
        .init();
    },
    "full" => {
      tracing_subscriber::fmt().with_env_filter(env_filter).init();
    },
    _ => {
      tracing_subscriber::fmt()
        .with_env_filter(env_filter)
        .compact()
        .init();
    },
  }

  let (config_path, was_explicit) = resolve_config_path(cli.config.as_deref());

  let mut config = if config_path.exists() {
    info!(path = %config_path.display(), "loading configuration from file");
    Config::from_file(&config_path)?
  } else if was_explicit {
    // User explicitly provided a config path that doesn't exist - this is an
    // error
    return Err(anyhow::anyhow!(
      "configuration file not found: {}",
      config_path.display()
    ));
  } else {
    info!(
      "using default configuration (no config file found at {})",
      config_path.display()
    );
    Config::default()
  };
  config.ensure_dirs()?;
  config
    .validate()
    .map_err(|e| anyhow::anyhow!("invalid configuration: {e}"))?;

  // Warn about authentication configuration
  if config.server.authentication_disabled {
    tracing::warn!(
      "⚠️  AUTHENTICATION IS DISABLED - All requests will be allowed without \
       authentication!"
    );
    tracing::warn!(
      "⚠️  This is INSECURE and should only be used for development."
    );
  } else {
    let has_api_key = config
      .server
      .api_key
      .as_ref()
      .is_some_and(|k| !k.is_empty());
    let has_accounts = !config.accounts.users.is_empty();
    if !has_api_key && !has_accounts {
      tracing::error!("⚠️  No authentication method configured!");
    }
  }

  // Apply CLI overrides
  if let Some(host) = cli.host {
    config.server.host = host;
  }
  if let Some(port) = cli.port {
    config.server.port = port;
  }

  // Storage backend initialization
  let storage: pinakes_core::storage::DynStorageBackend = match config
    .storage
    .backend
  {
    pinakes_core::config::StorageBackendType::Sqlite => {
      let sqlite_config = config.storage.sqlite.as_ref().ok_or_else(|| {
        anyhow::anyhow!(
          "sqlite storage selected but [storage.sqlite] config section missing"
        )
      })?;
      info!(path = %sqlite_config.path.display(), "initializing sqlite storage");
      let backend =
        pinakes_core::storage::sqlite::SqliteBackend::new(&sqlite_config.path)?;
      backend.run_migrations().await?;
      Arc::new(backend)
    },
    pinakes_core::config::StorageBackendType::Postgres => {
      let pg_config = config.storage.postgres.as_ref().ok_or_else(|| {
        anyhow::anyhow!(
          "postgres storage selected but [storage.postgres] config section \
           missing"
        )
      })?;
      info!(host = %pg_config.host, port = pg_config.port, database = %pg_config.database, "initializing postgres storage");
      let backend =
        pinakes_core::storage::postgres::PostgresBackend::new(pg_config)
          .await?;
      backend.run_migrations().await?;
      Arc::new(backend)
    },
  };

  if cli.migrate_only {
    info!("migrations complete, exiting");
    return Ok(());
  }

  // Register root directories
  for root in &config.directories.roots {
    if root.exists() {
      storage.add_root_dir(root.clone()).await?;
      info!(path = %root.display(), "registered root directory");
    } else {
      tracing::warn!(path = %root.display(), "root directory does not exist, skipping");
    }
  }

  // Start filesystem watcher if configured
  if config.scanning.watch {
    let watch_storage = storage.clone();
    let watch_dirs = config.directories.roots.clone();
    let watch_ignore = config.scanning.ignore_patterns.clone();
    tokio::spawn(async move {
      if let Err(e) = pinakes_core::scan::watch_and_import(
        watch_storage,
        watch_dirs,
        watch_ignore,
      )
      .await
      {
        tracing::error!(error = %e, "filesystem watcher failed");
      }
    });
    info!("filesystem watcher started");
  }

  let addr = format!("{}:{}", config.server.host, config.server.port);

  // Initialize transcode service early so the job queue can reference it
  let transcode_service: Option<
    Arc<pinakes_core::transcode::TranscodeService>,
  > = if config.transcoding.enabled {
    Some(Arc::new(pinakes_core::transcode::TranscodeService::new(
      config.transcoding.clone(),
    )))
  } else {
    None
  };

  // Initialize job queue with executor
  let job_storage = storage.clone();
  let job_config = config.clone();
  let job_transcode = transcode_service.clone();
  let job_queue = pinakes_core::jobs::JobQueue::new(
    config.jobs.worker_count,
    move |job_id, kind, cancel, jobs| {
      let storage = job_storage.clone();
      let config = job_config.clone();
      let transcode_svc = job_transcode.clone();
      tokio::spawn(async move {
        use pinakes_core::jobs::{JobKind, JobQueue};
        match kind {
          JobKind::Scan { path } => {
            let ignore = config.scanning.ignore_patterns.clone();
            let res = if let Some(p) = path {
              pinakes_core::scan::scan_directory(&storage, &p, &ignore).await
            } else {
              pinakes_core::scan::scan_all_roots(&storage, &ignore)
                .await
                .map(|statuses| {
                  let total_found: usize =
                    statuses.iter().map(|s| s.files_found).sum();
                  let total_processed: usize =
                    statuses.iter().map(|s| s.files_processed).sum();
                  let all_errors: Vec<String> =
                    statuses.into_iter().flat_map(|s| s.errors).collect();
                  pinakes_core::scan::ScanStatus {
                    scanning:        false,
                    files_found:     total_found,
                    files_processed: total_processed,
                    files_skipped:   0,
                    errors:          all_errors,
                  }
                })
            };
            match res {
              Ok(status) => {
                JobQueue::complete(
                  &jobs,
                  job_id,
                  serde_json::json!({
                      "files_found": status.files_found,
                      "files_processed": status.files_processed,
                      "errors": status.errors,
                  }),
                )
                .await;
              },
              Err(e) => {
                JobQueue::fail(&jobs, job_id, e.to_string()).await;
              },
            }
          },
          JobKind::GenerateThumbnails { media_ids } => {
            let thumb_dir = pinakes_core::thumbnail::default_thumbnail_dir();
            let thumb_config = config.thumbnails.clone();
            let total = media_ids.len();
            let mut generated = 0usize;
            let mut errors = Vec::new();
            for (i, mid) in media_ids.iter().enumerate() {
              if cancel.is_cancelled() {
                break;
              }
              JobQueue::update_progress(
                &jobs,
                job_id,
                i as f32 / total as f32,
                format!("{}/{}", i, total),
              )
              .await;
              match storage.get_media(*mid).await {
                Ok(item) => {
                  let source = item.path.clone();
                  let mt = item.media_type.clone();
                  let id = item.id;
                  let td = thumb_dir.clone();
                  let tc = thumb_config.clone();
                  let res = tokio::task::spawn_blocking(move || {
                    pinakes_core::thumbnail::generate_thumbnail_with_config(
                      id, &source, mt, &td, &tc,
                    )
                  })
                  .await;
                  match res {
                    Ok(Ok(Some(path))) => {
                      let mut updated = item;
                      updated.thumbnail_path = Some(path);
                      let _ = storage.update_media(&updated).await;
                      generated += 1;
                    },
                    Ok(Ok(None)) => {},
                    Ok(Err(e)) => errors.push(format!("{}: {}", mid, e)),
                    Err(e) => errors.push(format!("{}: {}", mid, e)),
                  }
                },
                Err(e) => errors.push(format!("{}: {}", mid, e)),
              }
            }
            JobQueue::complete(
              &jobs,
              job_id,
              serde_json::json!({
                  "generated": generated, "errors": errors
              }),
            )
            .await;
          },
          JobKind::VerifyIntegrity { media_ids } => {
            let ids = if media_ids.is_empty() {
              None
            } else {
              Some(media_ids.as_slice())
            };
            match pinakes_core::integrity::verify_integrity(&storage, ids).await
            {
              Ok(report) => {
                JobQueue::complete(
                  &jobs,
                  job_id,
                  serde_json::to_value(&report).unwrap_or_default(),
                )
                .await;
              },
              Err(e) => JobQueue::fail(&jobs, job_id, e.to_string()).await,
            }
          },
          JobKind::OrphanDetection => {
            match pinakes_core::integrity::detect_orphans(&storage).await {
              Ok(report) => {
                JobQueue::complete(
                  &jobs,
                  job_id,
                  serde_json::to_value(&report).unwrap_or_default(),
                )
                .await;
              },
              Err(e) => JobQueue::fail(&jobs, job_id, e.to_string()).await,
            }
          },
          JobKind::CleanupThumbnails => {
            let thumb_dir = pinakes_core::thumbnail::default_thumbnail_dir();
            match pinakes_core::integrity::cleanup_orphaned_thumbnails(
              &storage, &thumb_dir,
            )
            .await
            {
              Ok(removed) => {
                JobQueue::complete(
                  &jobs,
                  job_id,
                  serde_json::json!({ "removed": removed }),
                )
                .await;
              },
              Err(e) => JobQueue::fail(&jobs, job_id, e.to_string()).await,
            }
          },
          JobKind::Export {
            format,
            destination,
          } => {
            match pinakes_core::export::export_library(
              &storage,
              &format,
              &destination,
            )
            .await
            {
              Ok(result) => {
                JobQueue::complete(
                  &jobs,
                  job_id,
                  serde_json::to_value(&result).unwrap_or_default(),
                )
                .await;
              },
              Err(e) => JobQueue::fail(&jobs, job_id, e.to_string()).await,
            }
          },
          JobKind::Transcode { media_id, profile } => {
            if let Some(ref svc) = transcode_svc {
              match storage.get_media(media_id).await {
                Ok(item) => {
                  match svc
                    .start_transcode(
                      media_id,
                      &item.path,
                      &profile,
                      item.duration_secs,
                      &storage,
                    )
                    .await
                  {
                    Ok(session_id) => {
                      JobQueue::complete(
                                                &jobs,
                                                job_id,
                                                serde_json::json!({"session_id": session_id.to_string()}),
                                            )
                                            .await;
                    },
                    Err(e) => {
                      JobQueue::fail(&jobs, job_id, e.to_string()).await
                    },
                  }
                },
                Err(e) => JobQueue::fail(&jobs, job_id, e.to_string()).await,
              }
            } else {
              JobQueue::fail(
                &jobs,
                job_id,
                "transcoding is not enabled".to_string(),
              )
              .await;
            }
          },
          JobKind::Enrich { media_ids } => {
            // Enrichment job placeholder
            JobQueue::complete(
                            &jobs,
                            job_id,
                            serde_json::json!({"media_ids": media_ids.len(), "status": "not_implemented"}),
                        )
                        .await;
          },
          JobKind::CleanupAnalytics => {
            let before = chrono::Utc::now() - chrono::Duration::days(90);
            match storage.cleanup_old_events(before).await {
              Ok(count) => {
                JobQueue::complete(
                  &jobs,
                  job_id,
                  serde_json::json!({"cleaned_up": count}),
                )
                .await;
              },
              Err(e) => JobQueue::fail(&jobs, job_id, e.to_string()).await,
            }
          },
        };
        drop(cancel);
      })
    },
  );

  // Initialize cache layer
  let cache = std::sync::Arc::new(pinakes_core::cache::CacheLayer::new(
    config.jobs.cache_ttl_secs,
  ));

  // Initialize plugin manager if plugins are enabled (before moving config into
  // Arc)
  let plugin_manager = if config.plugins.enabled {
    match pinakes_core::plugin::PluginManager::new(
      config.plugins.data_dir.clone(),
      config.plugins.cache_dir.clone(),
      config.plugins.clone().into(),
    ) {
      Ok(pm) => {
        tracing::info!("Plugin manager initialized");
        Some(Arc::new(pm))
      },
      Err(e) => {
        tracing::warn!("Failed to initialize plugin manager: {}", e);
        None
      },
    }
  } else {
    tracing::info!("Plugins disabled in configuration");
    None
  };

  // Initialize scheduler with cancellation support
  let shutdown_token = tokio_util::sync::CancellationToken::new();
  let config_arc = Arc::new(RwLock::new(config));
  let scheduler = pinakes_core::scheduler::TaskScheduler::new(
    job_queue.clone(),
    shutdown_token.clone(),
    config_arc.clone(),
    Some(config_path.clone()),
  );
  let scheduler = Arc::new(scheduler);

  // Restore saved scheduler state from config
  scheduler.restore_state().await;

  // Spawn scheduler background loop
  {
    let scheduler = scheduler.clone();
    tokio::spawn(async move {
      scheduler.run().await;
    });
  }

  // Initialize managed storage service if enabled
  let managed_storage = {
    let config_read = config_arc.read().await;
    if config_read.managed_storage.enabled {
      let service = pinakes_core::managed_storage::ManagedStorageService::new(
        config_read.managed_storage.storage_dir.clone(),
        config_read.managed_storage.max_upload_size,
        config_read.managed_storage.verify_on_read,
      );
      match service.init().await {
        Ok(()) => {
          info!(
              path = %config_read.managed_storage.storage_dir.display(),
              "managed storage initialized"
          );
          Some(Arc::new(service))
        },
        Err(e) => {
          tracing::error!(error = %e, "failed to initialize managed storage");
          None
        },
      }
    } else {
      tracing::info!("managed storage disabled in configuration");
      None
    }
  };

  // Initialize chunked upload manager if sync is enabled
  let chunked_upload_manager = {
    let config_read = config_arc.read().await;
    if config_read.sync.enabled {
      let manager = pinakes_core::sync::ChunkedUploadManager::new(
        config_read.sync.temp_upload_dir.clone(),
      );
      match manager.init().await {
        Ok(()) => {
          info!(
              path = %config_read.sync.temp_upload_dir.display(),
              "chunked upload manager initialized"
          );
          Some(Arc::new(manager))
        },
        Err(e) => {
          tracing::error!(error = %e, "failed to initialize chunked upload manager");
          None
        },
      }
    } else {
      tracing::info!("sync disabled, chunked upload manager not initialized");
      None
    }
  };

  let state = AppState {
    storage: storage.clone(),
    config: config_arc.clone(),
    config_path: Some(config_path),
    scan_progress: pinakes_core::scan::ScanProgress::new(),
    job_queue,
    cache,
    scheduler,
    plugin_manager,
    transcode_service,
    managed_storage,
    chunked_upload_manager,
  };

  // Periodic session cleanup (every 15 minutes)
  {
    let storage_clone = storage.clone();
    let cancel = shutdown_token.clone();
    tokio::spawn(async move {
      let mut interval =
        tokio::time::interval(std::time::Duration::from_secs(15 * 60));
      loop {
        tokio::select! {
            _ = interval.tick() => {
                match storage_clone.delete_expired_sessions().await {
                    Ok(count) if count > 0 => {
                        tracing::info!(count = count, "cleaned up expired sessions");
                    }
                    Err(e) => {
                        tracing::error!(error = %e, "failed to cleanup expired sessions");
                    }
                    _ => {}
                }
            }
            _ = cancel.cancelled() => {
                break;
            }
        }
      }
    });
  }

  // Periodic chunked upload cleanup (every hour)
  if let Some(ref manager) = state.chunked_upload_manager {
    let manager_clone = manager.clone();
    let cancel = shutdown_token.clone();
    tokio::spawn(async move {
      let mut interval =
        tokio::time::interval(std::time::Duration::from_secs(60 * 60));
      loop {
        tokio::select! {
            _ = interval.tick() => {
                match manager_clone.cleanup_expired(48).await {
                    Ok(count) if count > 0 => {
                        tracing::info!(count = count, "cleaned up expired upload temp files");
                    }
                    Err(e) => {
                        tracing::error!(error = %e, "failed to cleanup expired upload temp files");
                    }
                    _ => {}
                }
            }
            _ = cancel.cancelled() => {
                break;
            }
        }
      }
    });
  }

  let config_read = config_arc.read().await;
  let tls_config = config_read.server.tls.clone();
  drop(config_read);

  // Create router with TLS config for HSTS headers
  let router = if tls_config.enabled {
    app::create_router_with_tls(state, Some(&tls_config))
  } else {
    app::create_router(state)
  };

  if tls_config.enabled {
    // TLS/HTTPS mode
    let cert_path = tls_config.cert_path.as_ref().ok_or_else(|| {
      anyhow::anyhow!("TLS enabled but cert_path not specified")
    })?;
    let key_path = tls_config.key_path.as_ref().ok_or_else(|| {
      anyhow::anyhow!("TLS enabled but key_path not specified")
    })?;

    info!(addr = %addr, cert = %cert_path.display(), "server listening with TLS");

    // Configure TLS
    let tls_config_builder =
      axum_server::tls_rustls::RustlsConfig::from_pem_file(cert_path, key_path)
        .await?;

    // Start HTTP redirect server if configured
    if tls_config.redirect_http {
      let http_addr = format!(
        "{}:{}",
        config_arc.read().await.server.host,
        tls_config.http_port
      );
      let https_port = config_arc.read().await.server.port;
      let https_host = config_arc.read().await.server.host.clone();

      let redirect_router =
        create_https_redirect_router(https_host, https_port);
      let shutdown = shutdown_token.clone();

      tokio::spawn(async move {
        let listener = match tokio::net::TcpListener::bind(&http_addr).await {
          Ok(l) => l,
          Err(e) => {
            tracing::warn!(error = %e, addr = %http_addr, "failed to bind HTTP redirect listener");
            return;
          },
        };
        info!(addr = %http_addr, "HTTP redirect server listening");
        let server = axum::serve(
          listener,
          redirect_router
            .into_make_service_with_connect_info::<std::net::SocketAddr>(),
        );
        tokio::select! {
            result = server => {
                if let Err(e) = result {
                    tracing::warn!(error = %e, "HTTP redirect server error");
                }
            }
            _ = shutdown.cancelled() => {
                info!("HTTP redirect server shutting down");
            }
        }
      });
    }

    // Start HTTPS server with graceful shutdown via Handle
    let addr_parsed: std::net::SocketAddr = addr.parse()?;
    let handle = axum_server::Handle::new();
    let shutdown_handle = handle.clone();

    // Spawn a task to trigger graceful shutdown
    tokio::spawn(async move {
      shutdown_signal().await;
      shutdown_handle
        .graceful_shutdown(Some(std::time::Duration::from_secs(30)));
    });

    axum_server::bind_rustls(addr_parsed, tls_config_builder)
      .handle(handle)
      .serve(
        router.into_make_service_with_connect_info::<std::net::SocketAddr>(),
      )
      .await?;
  } else {
    // Plain HTTP mode
    info!(addr = %addr, "server listening");
    let listener = tokio::net::TcpListener::bind(&addr).await?;

    axum::serve(
      listener,
      router.into_make_service_with_connect_info::<std::net::SocketAddr>(),
    )
    .with_graceful_shutdown(shutdown_signal())
    .await?;
  }

  shutdown_token.cancel();
  info!("server shut down");
  Ok(())
}

/// Create a router that redirects all HTTP requests to HTTPS
fn create_https_redirect_router(https_host: String, https_port: u16) -> Router {
  Router::new().fallback(any(move |uri: axum::http::Uri| {
    let https_host = https_host.clone();
    async move {
      let path_and_query =
        uri.path_and_query().map(|pq| pq.as_str()).unwrap_or("/");

      let https_url = if https_port == 443 {
        format!("https://{}{}", https_host, path_and_query)
      } else {
        format!("https://{}:{}{}", https_host, https_port, path_and_query)
      };

      Redirect::permanent(&https_url)
    }
  }))
}

async fn shutdown_signal() {
  let ctrl_c = async {
    match tokio::signal::ctrl_c().await {
      Ok(()) => {},
      Err(e) => {
        tracing::warn!(error = %e, "failed to install Ctrl+C handler");
        std::future::pending::<()>().await;
      },
    }
  };

  #[cfg(unix)]
  let terminate = async {
    match tokio::signal::unix::signal(
      tokio::signal::unix::SignalKind::terminate(),
    ) {
      Ok(mut signal) => {
        signal.recv().await;
      },
      Err(e) => {
        tracing::warn!(error = %e, "failed to install SIGTERM handler");
        std::future::pending::<()>().await;
      },
    }
  };

  #[cfg(not(unix))]
  let terminate = std::future::pending::<()>();

  tokio::select! {
      _ = ctrl_c => info!("received Ctrl+C, shutting down"),
      _ = terminate => info!("received SIGTERM, shutting down"),
  }
}