<?php
/**
 * User Library class.
 *
 * @package WP_FediStream
 */

namespace WP_FediStream\User;

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

/**
 * Handles user library features (favorites, follows, history).
 */
class Library {

	/**
	 * Constructor.
	 */
	public function __construct() {
		add_action( 'wp_ajax_fedistream_toggle_favorite', array( $this, 'ajax_toggle_favorite' ) );
		add_action( 'wp_ajax_fedistream_toggle_follow', array( $this, 'ajax_toggle_follow' ) );
		add_action( 'wp_ajax_fedistream_get_library', array( $this, 'ajax_get_library' ) );
		add_action( 'wp_ajax_fedistream_get_followed_artists', array( $this, 'ajax_get_followed_artists' ) );
		add_action( 'wp_ajax_fedistream_get_history', array( $this, 'ajax_get_history' ) );
		add_action( 'wp_ajax_fedistream_clear_history', array( $this, 'ajax_clear_history' ) );

		// Add library buttons to content.
		add_filter( 'fedistream_track_actions', array( $this, 'add_favorite_button' ), 10, 2 );
		add_filter( 'fedistream_album_actions', array( $this, 'add_favorite_button' ), 10, 2 );
		add_filter( 'fedistream_artist_actions', array( $this, 'add_follow_button' ), 10, 2 );

		// Record play history.
		add_action( 'fedistream_track_played', array( $this, 'record_play_history' ), 10, 2 );
	}

	/**
	 * Toggle favorite via AJAX.
	 *
	 * @return void
	 */
	public function ajax_toggle_favorite(): void {
		check_ajax_referer( 'fedistream_library', 'nonce' );

		if ( ! is_user_logged_in() ) {
			wp_send_json_error( array( 'message' => __( 'You must be logged in.', 'wp-fedistream' ) ) );
		}

		$content_type = isset( $_POST['content_type'] ) ? sanitize_text_field( wp_unslash( $_POST['content_type'] ) ) : '';
		$content_id   = isset( $_POST['content_id'] ) ? absint( $_POST['content_id'] ) : 0;

		if ( ! in_array( $content_type, array( 'track', 'album', 'playlist' ), true ) || ! $content_id ) {
			wp_send_json_error( array( 'message' => __( 'Invalid request.', 'wp-fedistream' ) ) );
		}

		$user_id      = get_current_user_id();
		$is_favorited = self::is_favorited( $user_id, $content_type, $content_id );

		if ( $is_favorited ) {
			$result = self::remove_favorite( $user_id, $content_type, $content_id );
			$action = 'removed';
		} else {
			$result = self::add_favorite( $user_id, $content_type, $content_id );
			$action = 'added';
		}

		if ( $result ) {
			wp_send_json_success(
				array(
					'action'       => $action,
					'is_favorited' => ! $is_favorited,
					'message'      => 'added' === $action
						? __( 'Added to your library.', 'wp-fedistream' )
						: __( 'Removed from your library.', 'wp-fedistream' ),
				)
			);
		} else {
			wp_send_json_error( array( 'message' => __( 'Failed to update library.', 'wp-fedistream' ) ) );
		}
	}

	/**
	 * Toggle follow via AJAX.
	 *
	 * @return void
	 */
	public function ajax_toggle_follow(): void {
		check_ajax_referer( 'fedistream_library', 'nonce' );

		if ( ! is_user_logged_in() ) {
			wp_send_json_error( array( 'message' => __( 'You must be logged in.', 'wp-fedistream' ) ) );
		}

		$artist_id = isset( $_POST['artist_id'] ) ? absint( $_POST['artist_id'] ) : 0;

		if ( ! $artist_id ) {
			wp_send_json_error( array( 'message' => __( 'Invalid artist.', 'wp-fedistream' ) ) );
		}

		$user_id      = get_current_user_id();
		$is_following = self::is_following( $user_id, $artist_id );

		if ( $is_following ) {
			$result = self::unfollow_artist( $user_id, $artist_id );
			$action = 'unfollowed';
		} else {
			$result = self::follow_artist( $user_id, $artist_id );
			$action = 'followed';
		}

		if ( $result ) {
			wp_send_json_success(
				array(
					'action'       => $action,
					'is_following' => ! $is_following,
					'message'      => 'followed' === $action
						? __( 'You are now following this artist.', 'wp-fedistream' )
						: __( 'You unfollowed this artist.', 'wp-fedistream' ),
				)
			);
		} else {
			wp_send_json_error( array( 'message' => __( 'Failed to update follow status.', 'wp-fedistream' ) ) );
		}
	}

	/**
	 * Get user library via AJAX.
	 *
	 * @return void
	 */
	public function ajax_get_library(): void {
		check_ajax_referer( 'fedistream_library', 'nonce' );

		if ( ! is_user_logged_in() ) {
			wp_send_json_error( array( 'message' => __( 'You must be logged in.', 'wp-fedistream' ) ) );
		}

		$user_id  = get_current_user_id();
		$type     = isset( $_POST['type'] ) ? sanitize_text_field( wp_unslash( $_POST['type'] ) ) : 'all';
		$page     = isset( $_POST['page'] ) ? absint( $_POST['page'] ) : 1;
		$per_page = 20;

		$library = self::get_user_library( $user_id, $type, $page, $per_page );

		wp_send_json_success( $library );
	}

	/**
	 * Get followed artists via AJAX.
	 *
	 * @return void
	 */
	public function ajax_get_followed_artists(): void {
		check_ajax_referer( 'fedistream_library', 'nonce' );

		if ( ! is_user_logged_in() ) {
			wp_send_json_error( array( 'message' => __( 'You must be logged in.', 'wp-fedistream' ) ) );
		}

		$user_id  = get_current_user_id();
		$page     = isset( $_POST['page'] ) ? absint( $_POST['page'] ) : 1;
		$per_page = 20;

		$artists = self::get_followed_artists( $user_id, $page, $per_page );

		wp_send_json_success( $artists );
	}

	/**
	 * Get listening history via AJAX.
	 *
	 * @return void
	 */
	public function ajax_get_history(): void {
		check_ajax_referer( 'fedistream_library', 'nonce' );

		if ( ! is_user_logged_in() ) {
			wp_send_json_error( array( 'message' => __( 'You must be logged in.', 'wp-fedistream' ) ) );
		}

		$user_id  = get_current_user_id();
		$page     = isset( $_POST['page'] ) ? absint( $_POST['page'] ) : 1;
		$per_page = 50;

		$history = self::get_listening_history( $user_id, $page, $per_page );

		wp_send_json_success( $history );
	}

	/**
	 * Clear listening history via AJAX.
	 *
	 * @return void
	 */
	public function ajax_clear_history(): void {
		check_ajax_referer( 'fedistream_library', 'nonce' );

		if ( ! is_user_logged_in() ) {
			wp_send_json_error( array( 'message' => __( 'You must be logged in.', 'wp-fedistream' ) ) );
		}

		$user_id = get_current_user_id();
		$result  = self::clear_listening_history( $user_id );

		if ( $result ) {
			wp_send_json_success( array( 'message' => __( 'History cleared.', 'wp-fedistream' ) ) );
		} else {
			wp_send_json_error( array( 'message' => __( 'Failed to clear history.', 'wp-fedistream' ) ) );
		}
	}

	/**
	 * Add a favorite.
	 *
	 * @param int    $user_id      User ID.
	 * @param string $content_type Content type (track, album, playlist).
	 * @param int    $content_id   Content ID.
	 * @return bool
	 */
	public static function add_favorite( int $user_id, string $content_type, int $content_id ): bool {
		global $wpdb;

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

		$result = $wpdb->insert(
			$table,
			array(
				'user_id'      => $user_id,
				'content_type' => $content_type,
				'content_id'   => $content_id,
				'created_at'   => current_time( 'mysql' ),
			),
			array( '%d', '%s', '%d', '%s' )
		);

		if ( $result ) {
			do_action( 'fedistream_favorite_added', $user_id, $content_type, $content_id );
		}

		return (bool) $result;
	}

	/**
	 * Remove a favorite.
	 *
	 * @param int    $user_id      User ID.
	 * @param string $content_type Content type (track, album, playlist).
	 * @param int    $content_id   Content ID.
	 * @return bool
	 */
	public static function remove_favorite( int $user_id, string $content_type, int $content_id ): bool {
		global $wpdb;

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

		$result = $wpdb->delete(
			$table,
			array(
				'user_id'      => $user_id,
				'content_type' => $content_type,
				'content_id'   => $content_id,
			),
			array( '%d', '%s', '%d' )
		);

		if ( $result ) {
			do_action( 'fedistream_favorite_removed', $user_id, $content_type, $content_id );
		}

		return (bool) $result;
	}

	/**
	 * Check if content is favorited.
	 *
	 * @param int    $user_id      User ID.
	 * @param string $content_type Content type.
	 * @param int    $content_id   Content ID.
	 * @return bool
	 */
	public static function is_favorited( int $user_id, string $content_type, int $content_id ): bool {
		global $wpdb;

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

		$exists = $wpdb->get_var(
			$wpdb->prepare(
				"SELECT id FROM {$table} WHERE user_id = %d AND content_type = %s AND content_id = %d",
				$user_id,
				$content_type,
				$content_id
			)
		);

		return (bool) $exists;
	}

	/**
	 * Follow an artist.
	 *
	 * @param int $user_id   User ID.
	 * @param int $artist_id Artist post ID.
	 * @return bool
	 */
	public static function follow_artist( int $user_id, int $artist_id ): bool {
		global $wpdb;

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

		$result = $wpdb->insert(
			$table,
			array(
				'user_id'    => $user_id,
				'artist_id'  => $artist_id,
				'created_at' => current_time( 'mysql' ),
			),
			array( '%d', '%d', '%s' )
		);

		if ( $result ) {
			do_action( 'fedistream_artist_followed', $user_id, $artist_id );
		}

		return (bool) $result;
	}

	/**
	 * Unfollow an artist.
	 *
	 * @param int $user_id   User ID.
	 * @param int $artist_id Artist post ID.
	 * @return bool
	 */
	public static function unfollow_artist( int $user_id, int $artist_id ): bool {
		global $wpdb;

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

		$result = $wpdb->delete(
			$table,
			array(
				'user_id'   => $user_id,
				'artist_id' => $artist_id,
			),
			array( '%d', '%d' )
		);

		if ( $result ) {
			do_action( 'fedistream_artist_unfollowed', $user_id, $artist_id );
		}

		return (bool) $result;
	}

	/**
	 * Check if user is following an artist.
	 *
	 * @param int $user_id   User ID.
	 * @param int $artist_id Artist post ID.
	 * @return bool
	 */
	public static function is_following( int $user_id, int $artist_id ): bool {
		global $wpdb;

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

		$exists = $wpdb->get_var(
			$wpdb->prepare(
				"SELECT id FROM {$table} WHERE user_id = %d AND artist_id = %d",
				$user_id,
				$artist_id
			)
		);

		return (bool) $exists;
	}

	/**
	 * Record play history.
	 *
	 * @param int $track_id Track post ID.
	 * @param int $user_id  User ID (0 for anonymous).
	 * @return void
	 */
	public function record_play_history( int $track_id, int $user_id ): void {
		if ( ! $user_id ) {
			return;
		}

		global $wpdb;

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

		// Check if recently played (within last 30 seconds) to avoid duplicates.
		$recent = $wpdb->get_var(
			$wpdb->prepare(
				"SELECT id FROM {$table} WHERE user_id = %d AND track_id = %d AND played_at > DATE_SUB(NOW(), INTERVAL 30 SECOND)",
				$user_id,
				$track_id
			)
		);

		if ( $recent ) {
			return;
		}

		$wpdb->insert(
			$table,
			array(
				'user_id'   => $user_id,
				'track_id'  => $track_id,
				'played_at' => current_time( 'mysql' ),
			),
			array( '%d', '%d', '%s' )
		);
	}

	/**
	 * Get user library.
	 *
	 * @param int    $user_id  User ID.
	 * @param string $type     Content type filter (all, tracks, albums, playlists).
	 * @param int    $page     Page number.
	 * @param int    $per_page Items per page.
	 * @return array
	 */
	public static function get_user_library( int $user_id, string $type = 'all', int $page = 1, int $per_page = 20 ): array {
		global $wpdb;

		$table  = $wpdb->prefix . 'fedistream_favorites';
		$offset = ( $page - 1 ) * $per_page;

		$where  = 'WHERE user_id = %d';
		$params = array( $user_id );

		if ( 'all' !== $type && in_array( $type, array( 'track', 'album', 'playlist' ), true ) ) {
			$where   .= ' AND content_type = %s';
			$params[] = $type;
		}

		$total = $wpdb->get_var(
			$wpdb->prepare(
				"SELECT COUNT(*) FROM {$table} {$where}",
				...$params
			)
		);

		$params[] = $per_page;
		$params[] = $offset;

		$favorites = $wpdb->get_results(
			$wpdb->prepare(
				"SELECT content_type, content_id, created_at FROM {$table} {$where} ORDER BY created_at DESC LIMIT %d OFFSET %d",
				...$params
			)
		);

		$items = array();

		foreach ( $favorites as $favorite ) {
			$post = get_post( $favorite->content_id );

			if ( ! $post || 'publish' !== $post->post_status ) {
				continue;
			}

			$item = array(
				'id'        => $post->ID,
				'type'      => $favorite->content_type,
				'title'     => $post->post_title,
				'permalink' => get_permalink( $post ),
				'added_at'  => $favorite->created_at,
				'thumbnail' => get_the_post_thumbnail_url( $post, 'medium' ),
			);

			if ( 'track' === $favorite->content_type ) {
				$item['duration'] = get_post_meta( $post->ID, '_fedistream_duration', true );
				$item['artist']   = self::get_track_artist_name( $post->ID );
			} elseif ( 'album' === $favorite->content_type ) {
				$item['artist']      = self::get_album_artist_name( $post->ID );
				$item['track_count'] = get_post_meta( $post->ID, '_fedistream_total_tracks', true );
			}

			$items[] = $item;
		}

		return array(
			'items'       => $items,
			'total'       => (int) $total,
			'page'        => $page,
			'per_page'    => $per_page,
			'total_pages' => (int) ceil( $total / $per_page ),
		);
	}

	/**
	 * Get followed artists.
	 *
	 * @param int $user_id  User ID.
	 * @param int $page     Page number.
	 * @param int $per_page Items per page.
	 * @return array
	 */
	public static function get_followed_artists( int $user_id, int $page = 1, int $per_page = 20 ): array {
		global $wpdb;

		$table  = $wpdb->prefix . 'fedistream_user_follows';
		$offset = ( $page - 1 ) * $per_page;

		$total = $wpdb->get_var(
			$wpdb->prepare(
				"SELECT COUNT(*) FROM {$table} WHERE user_id = %d",
				$user_id
			)
		);

		$follows = $wpdb->get_results(
			$wpdb->prepare(
				"SELECT artist_id, created_at FROM {$table} WHERE user_id = %d ORDER BY created_at DESC LIMIT %d OFFSET %d",
				$user_id,
				$per_page,
				$offset
			)
		);

		$artists = array();

		foreach ( $follows as $follow ) {
			$post = get_post( $follow->artist_id );

			if ( ! $post || 'publish' !== $post->post_status ) {
				continue;
			}

			$artists[] = array(
				'id'          => $post->ID,
				'name'        => $post->post_title,
				'permalink'   => get_permalink( $post ),
				'followed_at' => $follow->created_at,
				'thumbnail'   => get_the_post_thumbnail_url( $post, 'thumbnail' ),
				'type'        => get_post_meta( $post->ID, '_fedistream_artist_type', true ) ?: 'solo',
			);
		}

		return array(
			'artists'     => $artists,
			'total'       => (int) $total,
			'page'        => $page,
			'per_page'    => $per_page,
			'total_pages' => (int) ceil( $total / $per_page ),
		);
	}

	/**
	 * Get listening history.
	 *
	 * @param int $user_id  User ID.
	 * @param int $page     Page number.
	 * @param int $per_page Items per page.
	 * @return array
	 */
	public static function get_listening_history( int $user_id, int $page = 1, int $per_page = 50 ): array {
		global $wpdb;

		$table  = $wpdb->prefix . 'fedistream_listening_history';
		$offset = ( $page - 1 ) * $per_page;

		$total = $wpdb->get_var(
			$wpdb->prepare(
				"SELECT COUNT(*) FROM {$table} WHERE user_id = %d",
				$user_id
			)
		);

		$history = $wpdb->get_results(
			$wpdb->prepare(
				"SELECT track_id, played_at FROM {$table} WHERE user_id = %d ORDER BY played_at DESC LIMIT %d OFFSET %d",
				$user_id,
				$per_page,
				$offset
			)
		);

		$tracks = array();

		foreach ( $history as $item ) {
			$post = get_post( $item->track_id );

			if ( ! $post || 'publish' !== $post->post_status ) {
				continue;
			}

			$tracks[] = array(
				'id'        => $post->ID,
				'title'     => $post->post_title,
				'permalink' => get_permalink( $post ),
				'played_at' => $item->played_at,
				'thumbnail' => get_the_post_thumbnail_url( $post, 'thumbnail' ),
				'duration'  => get_post_meta( $post->ID, '_fedistream_duration', true ),
				'artist'    => self::get_track_artist_name( $post->ID ),
			);
		}

		return array(
			'tracks'      => $tracks,
			'total'       => (int) $total,
			'page'        => $page,
			'per_page'    => $per_page,
			'total_pages' => (int) ceil( $total / $per_page ),
		);
	}

	/**
	 * Clear listening history.
	 *
	 * @param int $user_id User ID.
	 * @return bool
	 */
	public static function clear_listening_history( int $user_id ): bool {
		global $wpdb;

		$table  = $wpdb->prefix . 'fedistream_listening_history';
		$result = $wpdb->delete( $table, array( 'user_id' => $user_id ), array( '%d' ) );

		return false !== $result;
	}

	/**
	 * Get track artist name.
	 *
	 * @param int $track_id Track post ID.
	 * @return string
	 */
	private static function get_track_artist_name( int $track_id ): string {
		$artist_ids = get_post_meta( $track_id, '_fedistream_artist_ids', true );

		if ( is_array( $artist_ids ) && ! empty( $artist_ids ) ) {
			$names = array();
			foreach ( $artist_ids as $artist_id ) {
				$artist = get_post( $artist_id );
				if ( $artist ) {
					$names[] = $artist->post_title;
				}
			}
			return implode( ', ', $names );
		}

		$album_id  = get_post_meta( $track_id, '_fedistream_album_id', true );
		$artist_id = $album_id ? get_post_meta( $album_id, '_fedistream_album_artist', true ) : 0;

		if ( $artist_id ) {
			$artist = get_post( $artist_id );
			return $artist ? $artist->post_title : '';
		}

		return '';
	}

	/**
	 * Get album artist name.
	 *
	 * @param int $album_id Album post ID.
	 * @return string
	 */
	private static function get_album_artist_name( int $album_id ): string {
		$artist_id = get_post_meta( $album_id, '_fedistream_album_artist', true );

		if ( $artist_id ) {
			$artist = get_post( $artist_id );
			return $artist ? $artist->post_title : '';
		}

		return '';
	}

	/**
	 * Add favorite button to track/album actions.
	 *
	 * @param string $actions HTML actions.
	 * @param int    $post_id Post ID.
	 * @return string
	 */
	public function add_favorite_button( string $actions, int $post_id ): string {
		if ( ! is_user_logged_in() ) {
			return $actions;
		}

		$post = get_post( $post_id );
		if ( ! $post ) {
			return $actions;
		}

		$content_type = str_replace( 'fedistream_', '', $post->post_type );
		$user_id      = get_current_user_id();
		$is_favorited = self::is_favorited( $user_id, $content_type, $post_id );

		$button = sprintf(
			'<button class="fedistream-favorite-btn%s" data-content-type="%s" data-content-id="%d" title="%s">
				<span class="dashicons dashicons-heart"></span>
			</button>',
			$is_favorited ? ' is-favorited' : '',
			esc_attr( $content_type ),
			$post_id,
			$is_favorited ? esc_attr__( 'Remove from library', 'wp-fedistream' ) : esc_attr__( 'Add to library', 'wp-fedistream' )
		);

		return $actions . $button;
	}

	/**
	 * Add follow button to artist actions.
	 *
	 * @param string $actions   HTML actions.
	 * @param int    $artist_id Artist post ID.
	 * @return string
	 */
	public function add_follow_button( string $actions, int $artist_id ): string {
		if ( ! is_user_logged_in() ) {
			return $actions;
		}

		$user_id      = get_current_user_id();
		$is_following = self::is_following( $user_id, $artist_id );

		$button = sprintf(
			'<button class="fedistream-follow-btn%s" data-artist-id="%d">
				<span class="dashicons dashicons-%s"></span>
				<span class="button-text">%s</span>
			</button>',
			$is_following ? ' is-following' : '',
			$artist_id,
			$is_following ? 'yes' : 'plus',
			$is_following ? esc_html__( 'Following', 'wp-fedistream' ) : esc_html__( 'Follow', 'wp-fedistream' )
		);

		return $actions . $button;
	}

	/**
	 * Get user's favorite count.
	 *
	 * @param int    $user_id      User ID.
	 * @param string $content_type Optional content type filter.
	 * @return int
	 */
	public static function get_favorite_count( int $user_id, string $content_type = '' ): int {
		global $wpdb;

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

		if ( $content_type ) {
			$count = $wpdb->get_var(
				$wpdb->prepare(
					"SELECT COUNT(*) FROM {$table} WHERE user_id = %d AND content_type = %s",
					$user_id,
					$content_type
				)
			);
		} else {
			$count = $wpdb->get_var(
				$wpdb->prepare(
					"SELECT COUNT(*) FROM {$table} WHERE user_id = %d",
					$user_id
				)
			);
		}

		return (int) $count;
	}

	/**
	 * Get user's followed artist count.
	 *
	 * @param int $user_id User ID.
	 * @return int
	 */
	public static function get_following_count( int $user_id ): int {
		global $wpdb;

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

		$count = $wpdb->get_var(
			$wpdb->prepare(
				"SELECT COUNT(*) FROM {$table} WHERE user_id = %d",
				$user_id
			)
		);

		return (int) $count;
	}
}