<?php
/**
 * ActivityPub integration main class.
 *
 * @package WP_FediStream
 */

namespace WP_FediStream\ActivityPub;

// Prevent direct file access.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Main ActivityPub integration class.
 *
 * Integrates WP FediStream with the WordPress ActivityPub plugin.
 */
class Integration {

	/**
	 * Whether the ActivityPub plugin is active.
	 *
	 * @var bool
	 */
	private bool $activitypub_active = false;

	/**
	 * Constructor.
	 */
	public function __construct() {
		// Check if ActivityPub plugin is available.
		add_action( 'plugins_loaded', array( $this, 'check_activitypub' ), 5 );

		// Initialize integration after ActivityPub is loaded.
		add_action( 'plugins_loaded', array( $this, 'init' ), 20 );
	}

	/**
	 * Check if the ActivityPub plugin is active.
	 *
	 * @return void
	 */
	public function check_activitypub(): void {
		$this->activitypub_active = defined( 'ACTIVITYPUB_PLUGIN_VERSION' )
			|| class_exists( '\Activitypub\Activitypub' );
	}

	/**
	 * Initialize the ActivityPub integration.
	 *
	 * @return void
	 */
	public function init(): void {
		if ( ! $this->activitypub_active ) {
			return;
		}

		// Register custom post types for ActivityPub.
		add_filter( 'activitypub_post_types', array( $this, 'register_post_types' ) );

		// Register custom transformers.
		add_filter( 'activitypub_transformers', array( $this, 'register_transformers' ) );

		// Register artist actors.
		add_action( 'init', array( $this, 'register_artist_actors' ), 20 );

		// Add custom properties to ActivityPub objects.
		add_filter( 'activitypub_activity_object_array', array( $this, 'add_audio_properties' ), 10, 3 );

		// Handle incoming activities.
		add_action( 'activitypub_inbox_like', array( $this, 'handle_like' ), 10, 2 );
		add_action( 'activitypub_inbox_announce', array( $this, 'handle_announce' ), 10, 2 );
		add_action( 'activitypub_inbox_create', array( $this, 'handle_create' ), 10, 2 );

		// Add hooks for publishing.
		add_action( 'publish_fedistream_track', array( $this, 'on_publish_track' ), 10, 2 );
		add_action( 'publish_fedistream_album', array( $this, 'on_publish_album' ), 10, 2 );
	}

	/**
	 * Check if ActivityPub is active.
	 *
	 * @return bool
	 */
	public function is_active(): bool {
		return $this->activitypub_active;
	}

	/**
	 * Register FediStream post types with ActivityPub.
	 *
	 * @param array $post_types The registered post types.
	 * @return array Modified post types.
	 */
	public function register_post_types( array $post_types ): array {
		$post_types[] = 'fedistream_track';
		$post_types[] = 'fedistream_album';
		$post_types[] = 'fedistream_playlist';

		return array_unique( $post_types );
	}

	/**
	 * Register custom transformers for FediStream post types.
	 *
	 * @param array $transformers The registered transformers.
	 * @return array Modified transformers.
	 */
	public function register_transformers( array $transformers ): array {
		$transformers['fedistream_track']    = TrackTransformer::class;
		$transformers['fedistream_album']    = AlbumTransformer::class;
		$transformers['fedistream_playlist'] = PlaylistTransformer::class;

		return $transformers;
	}

	/**
	 * Register artist actors for ActivityPub.
	 *
	 * @return void
	 */
	public function register_artist_actors(): void {
		// Hook into ActivityPub actor discovery.
		add_filter( 'activitypub_actor', array( $this, 'get_artist_actor' ), 10, 2 );

		// Add artist webfinger handler.
		add_filter( 'webfinger_data', array( $this, 'add_artist_webfinger' ), 10, 2 );
	}

	/**
	 * Get artist actor for ActivityPub.
	 *
	 * @param mixed  $actor The current actor.
	 * @param string $id    The actor ID or handle.
	 * @return mixed The actor object or original.
	 */
	public function get_artist_actor( $actor, string $id ) {
		// Check if this is an artist handle.
		if ( strpos( $id, 'artist-' ) === 0 ) {
			$artist_id = absint( str_replace( 'artist-', '', $id ) );
			$artist    = get_post( $artist_id );

			if ( $artist && 'fedistream_artist' === $artist->post_type ) {
				return new ArtistActor( $artist );
			}
		}

		return $actor;
	}

	/**
	 * Add artist to webfinger data.
	 *
	 * @param array  $data   The webfinger data.
	 * @param string $resource The requested resource.
	 * @return array Modified webfinger data.
	 */
	public function add_artist_webfinger( array $data, string $resource ): array {
		// Parse acct: URI.
		if ( preg_match( '/^acct:artist-(\d+)@/', $resource, $matches ) ) {
			$artist_id = absint( $matches[1] );
			$artist    = get_post( $artist_id );

			if ( $artist && 'fedistream_artist' === $artist->post_type ) {
				$actor = new ArtistActor( $artist );
				$data  = $actor->get_webfinger();
			}
		}

		return $data;
	}

	/**
	 * Add audio-specific properties to ActivityPub objects.
	 *
	 * @param array  $array The object array.
	 * @param object $object The ActivityPub object.
	 * @param int    $post_id The post ID.
	 * @return array Modified array.
	 */
	public function add_audio_properties( array $array, $object, int $post_id ): array {
		$post = get_post( $post_id );

		if ( ! $post ) {
			return $array;
		}

		// Add audio-specific properties for tracks.
		if ( 'fedistream_track' === $post->post_type ) {
			$duration = get_post_meta( $post_id, '_fedistream_duration', true );
			if ( $duration ) {
				$array['duration'] = $this->format_duration_iso8601( (int) $duration );
			}

			$audio_id  = get_post_meta( $post_id, '_fedistream_audio_file', true );
			$audio_url = $audio_id ? wp_get_attachment_url( $audio_id ) : '';
			if ( $audio_url ) {
				$array['attachment'][] = array(
					'type'      => 'Audio',
					'mediaType' => 'audio/mpeg',
					'url'       => $audio_url,
					'name'      => $post->post_title,
					'duration'  => $this->format_duration_iso8601( (int) $duration ),
				);
			}
		}

		return $array;
	}

	/**
	 * Handle incoming Like activity.
	 *
	 * @param array $activity The activity data.
	 * @param int   $user_id  The user ID (actor).
	 * @return void
	 */
	public function handle_like( array $activity, int $user_id ): void {
		$object_id = $activity['object'] ?? '';
		if ( ! $object_id ) {
			return;
		}

		// Find local post from object ID.
		$post_id = url_to_postid( $object_id );
		if ( ! $post_id ) {
			return;
		}

		$post = get_post( $post_id );
		if ( ! $post || ! in_array( $post->post_type, array( 'fedistream_track', 'fedistream_album' ), true ) ) {
			return;
		}

		// Record the like.
		$this->record_reaction( $post_id, $activity['actor'] ?? '', 'like', $activity );
	}

	/**
	 * Handle incoming Announce (boost) activity.
	 *
	 * @param array $activity The activity data.
	 * @param int   $user_id  The user ID (actor).
	 * @return void
	 */
	public function handle_announce( array $activity, int $user_id ): void {
		$object_id = $activity['object'] ?? '';
		if ( ! $object_id ) {
			return;
		}

		// Find local post from object ID.
		$post_id = url_to_postid( $object_id );
		if ( ! $post_id ) {
			return;
		}

		$post = get_post( $post_id );
		if ( ! $post || ! in_array( $post->post_type, array( 'fedistream_track', 'fedistream_album' ), true ) ) {
			return;
		}

		// Record the boost.
		$this->record_reaction( $post_id, $activity['actor'] ?? '', 'boost', $activity );
	}

	/**
	 * Handle incoming Create activity (comments/replies).
	 *
	 * @param array $activity The activity data.
	 * @param int   $user_id  The user ID (actor).
	 * @return void
	 */
	public function handle_create( array $activity, int $user_id ): void {
		$object = $activity['object'] ?? array();
		if ( empty( $object ) ) {
			return;
		}

		// Check if this is a reply to our content.
		$in_reply_to = $object['inReplyTo'] ?? '';
		if ( ! $in_reply_to ) {
			return;
		}

		// Find local post from reply target.
		$post_id = url_to_postid( $in_reply_to );
		if ( ! $post_id ) {
			return;
		}

		$post = get_post( $post_id );
		if ( ! $post || ! in_array( $post->post_type, array( 'fedistream_track', 'fedistream_album' ), true ) ) {
			return;
		}

		// Record the reply.
		$this->record_reaction( $post_id, $activity['actor'] ?? '', 'reply', $activity );
	}

	/**
	 * Record a reaction from the Fediverse.
	 *
	 * @param int    $post_id  The post ID.
	 * @param string $actor    The actor URI.
	 * @param string $type     The reaction type (like, boost, reply).
	 * @param array  $activity The full activity data.
	 * @return bool True on success.
	 */
	private function record_reaction( int $post_id, string $actor, string $type, array $activity ): bool {
		global $wpdb;

		$table = $wpdb->prefix . 'fedistream_reactions';

		// Check if table exists.
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
		$table_exists = $wpdb->get_var(
			$wpdb->prepare(
				'SHOW TABLES LIKE %s',
				$table
			)
		);

		if ( ! $table_exists ) {
			$this->create_reactions_table();
		}

		// Insert reaction.
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery
		$result = $wpdb->insert(
			$table,
			array(
				'post_id'       => $post_id,
				'actor_uri'     => $actor,
				'reaction_type' => $type,
				'activity_data' => wp_json_encode( $activity ),
				'created_at'    => current_time( 'mysql' ),
			),
			array( '%d', '%s', '%s', '%s', '%s' )
		);

		// Update reaction count meta.
		if ( $result ) {
			$meta_key = '_fedistream_' . $type . '_count';
			$count    = (int) get_post_meta( $post_id, $meta_key, true );
			update_post_meta( $post_id, $meta_key, $count + 1 );
		}

		return (bool) $result;
	}

	/**
	 * Create the reactions table.
	 *
	 * @return void
	 */
	private function create_reactions_table(): void {
		global $wpdb;

		$table   = $wpdb->prefix . 'fedistream_reactions';
		$charset = $wpdb->get_charset_collate();

		$sql = "CREATE TABLE IF NOT EXISTS {$table} (
			id bigint(20) unsigned NOT NULL AUTO_INCREMENT,
			post_id bigint(20) unsigned NOT NULL,
			actor_uri varchar(2083) NOT NULL,
			reaction_type varchar(50) NOT NULL,
			activity_data longtext,
			created_at datetime NOT NULL,
			PRIMARY KEY (id),
			KEY post_id (post_id),
			KEY actor_uri (actor_uri(191)),
			KEY reaction_type (reaction_type)
		) {$charset};";

		require_once ABSPATH . 'wp-admin/includes/upgrade.php';
		dbDelta( $sql );
	}

	/**
	 * Handle track publishing.
	 *
	 * @param int      $post_id The post ID.
	 * @param \WP_Post $post    The post object.
	 * @return void
	 */
	public function on_publish_track( int $post_id, \WP_Post $post ): void {
		// The ActivityPub plugin will handle the publishing automatically.
		// This hook is for any additional custom logic.
		do_action( 'fedistream_track_published_activitypub', $post_id, $post );
	}

	/**
	 * Handle album publishing.
	 *
	 * @param int      $post_id The post ID.
	 * @param \WP_Post $post    The post object.
	 * @return void
	 */
	public function on_publish_album( int $post_id, \WP_Post $post ): void {
		// The ActivityPub plugin will handle the publishing automatically.
		// This hook is for any additional custom logic.
		do_action( 'fedistream_album_published_activitypub', $post_id, $post );
	}

	/**
	 * Format duration as ISO 8601.
	 *
	 * @param int $seconds The duration in seconds.
	 * @return string ISO 8601 duration.
	 */
	private function format_duration_iso8601( int $seconds ): string {
		$hours   = floor( $seconds / 3600 );
		$minutes = floor( ( $seconds % 3600 ) / 60 );
		$secs    = $seconds % 60;

		$duration = 'PT';
		if ( $hours > 0 ) {
			$duration .= $hours . 'H';
		}
		if ( $minutes > 0 ) {
			$duration .= $minutes . 'M';
		}
		if ( $secs > 0 || ( $hours === 0 && $minutes === 0 ) ) {
			$duration .= $secs . 'S';
		}

		return $duration;
	}

	/**
	 * Get reactions for a post.
	 *
	 * @param int    $post_id The post ID.
	 * @param string $type    Optional reaction type filter.
	 * @return array The reactions.
	 */
	public function get_reactions( int $post_id, string $type = '' ): array {
		global $wpdb;

		$table = $wpdb->prefix . 'fedistream_reactions';

		if ( $type ) {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
			$results = $wpdb->get_results(
				$wpdb->prepare(
					"SELECT * FROM {$table} WHERE post_id = %d AND reaction_type = %s ORDER BY created_at DESC",
					$post_id,
					$type
				)
			);
		} else {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching
			$results = $wpdb->get_results(
				$wpdb->prepare(
					"SELECT * FROM {$table} WHERE post_id = %d ORDER BY created_at DESC",
					$post_id
				)
			);
		}

		return $results ?: array();
	}

	/**
	 * Get reaction counts for a post.
	 *
	 * @param int $post_id The post ID.
	 * @return array The reaction counts.
	 */
	public function get_reaction_counts( int $post_id ): array {
		return array(
			'likes'   => (int) get_post_meta( $post_id, '_fedistream_like_count', true ),
			'boosts'  => (int) get_post_meta( $post_id, '_fedistream_boost_count', true ),
			'replies' => (int) get_post_meta( $post_id, '_fedistream_reply_count', true ),
		);
	}
}