<?php
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class MetaForge_JSONSyncManager {

	/**
	 * Get the active directory path for local JSON configs.
	 * Filterable so developers can override the save location.
	 */
	public static function get_sync_dir() {
		$theme_dir = get_stylesheet_directory();
		$dir       = $theme_dir . '/metaforge-json';
		return apply_filters( 'metaforge/settings/save_json', $dir );
	}

	/**
	 * Save field group configuration to local JSON.
	 */
	public static function save_group( $post_id, $config ) {
		// Keep group key persistent
		if ( empty( $config['group_key'] ) ) {
			$config['group_key'] = 'group_' . substr( md5( $config['group_name'] ), 0, 12 );
		}
		$config['modified'] = time();

		// Save updated config with key to database meta (always save to database first)
		update_post_meta( $post_id, '_metaforge_group_config', $config );

		$dir = self::get_sync_dir();
		if ( ! file_exists( $dir ) ) {
			wp_mkdir_p( $dir );
		}
		if ( ! is_dir( $dir ) || ! wp_is_writable( $dir ) ) {
			return false;
		}

		$filename = sanitize_file_name( sanitize_title( $config['group_name'] ) . '.json' );
		$file     = trailingslashit( $dir ) . $filename;

		// Path traversal guard: Ensure target file stays strictly inside the sync directory
		$real_dir = realpath( $dir );
		if ( $real_dir === false ) {
			return false;
		}

		$json = wp_json_encode( $config, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES );

		global $wp_filesystem;
		if ( empty( $wp_filesystem ) ) {
			require_once ABSPATH . 'wp-admin/includes/file.php';
			WP_Filesystem();
		}
		if ( ! $wp_filesystem ) {
			return false;
		}
		return $wp_filesystem->put_contents( $file, $json, FS_CHMOD_FILE );
	}

	/**
	 * Delete JSON file when a field group is deleted.
	 */
	public static function delete_group( $post_id ) {
		$config = get_post_meta( $post_id, '_metaforge_group_config', true );
		if ( ! is_array( $config ) || empty( $config['group_name'] ) ) {
			return;
		}
		$dir      = self::get_sync_dir();
		$filename = sanitize_file_name( sanitize_title( $config['group_name'] ) . '.json' );
		$file     = trailingslashit( $dir ) . $filename;

		$real_dir  = realpath( $dir );
		$real_file = realpath( $file );
		if ( $real_dir && $real_file && strpos( $real_file, $real_dir ) === 0 && file_exists( $real_file ) ) {
			wp_delete_file( $real_file );
		}
	}

	/**
	 * Scan directory for pending imports or updates.
	 */
	public static function get_sync_status() {
		$dir = self::get_sync_dir();
		if ( ! file_exists( $dir ) || ! is_dir( $dir ) ) {
			return array();
		}

		$files = glob( $dir . '/*.json' );
		if ( empty( $files ) ) {
			return array();
		}

		// Retrieve existing database groups indexed by group_key
		$db_posts  = get_posts(
			array(
				'post_type'      => 'metaforge_group',
				'posts_per_page' => -1,
				'post_status'    => 'any',
			)
		);
		$db_groups = array();
		foreach ( $db_posts as $post ) {
			$c = get_post_meta( $post->ID, '_metaforge_group_config', true );
			if ( is_array( $c ) ) {
				$key               = $c['group_key'] ?? 'group_' . substr( md5( $c['group_name'] ), 0, 12 );
				$meta_mod          = isset( $c['modified'] ) ? intval( $c['modified'] ) : 0;
				$post_mod          = (int) get_post_modified_time( 'U', false, $post );
				$db_groups[ $key ] = array(
					'id'       => $post->ID,
					'config'   => $c,
					'modified' => max( $meta_mod, $post_mod ),
				);
			}
		}

		global $wp_filesystem;
		if ( empty( $wp_filesystem ) ) {
			require_once ABSPATH . 'wp-admin/includes/file.php';
			WP_Filesystem();
		}

		$pending = array();
		foreach ( $files as $file ) {
			$content = $wp_filesystem ? $wp_filesystem->get_contents( $file ) : false;
			$config  = json_decode( $content, true );
			if ( ! is_array( $config ) || empty( $config['group_name'] ) ) {
				continue;
			}

			$key = $config['group_key'] ?? 'group_' . substr( md5( $config['group_name'] ), 0, 12 );

			if ( ! isset( $db_groups[ $key ] ) ) {
				$pending[ $key ] = array(
					'type'        => 'new',
					'json_config' => $config,
					'filename'    => basename( $file ),
				);
			} else {
				$db_item = $db_groups[ $key ];

				// Sanitize and normalize both configs so data structures match exactly
				$sanitized_json = MetaForge_Loader::sanitize_group_config( $config );
				$sanitized_db   = MetaForge_Loader::sanitize_group_config( $db_item['config'] );

				$json_fields_hash = md5( wp_json_encode( $sanitized_json['fields'] ?? array() ) );
				$db_fields_hash   = md5( wp_json_encode( $sanitized_db['fields'] ?? array() ) );

				$json_rules_hash = md5( wp_json_encode( $sanitized_json['location_rules'] ?? array() ) );
				$db_rules_hash   = md5( wp_json_encode( $sanitized_db['location_rules'] ?? array() ) );

				$title_differs   = ( $sanitized_json['group_name'] ?? '' ) !== ( $sanitized_db['group_name'] ?? '' );
				$content_changed = ( $json_fields_hash !== $db_fields_hash ) || ( $json_rules_hash !== $db_rules_hash ) || $title_differs;

				$json_modified = isset( $config['modified'] ) ? intval( $config['modified'] ) : filemtime( $file );
				$db_modified   = intval( $db_item['modified'] );

				// Only consider it an update if the content has actually changed and json is newer (or content is different)
				if ( $content_changed && ( $json_modified > ( $db_modified + 2 ) || $content_changed ) ) {
					$pending[ $key ] = array(
						'type'        => 'update',
						'db_id'       => $db_item['id'],
						'json_config' => $config,
						'filename'    => basename( $file ),
					);
				}
			}
		}
		return $pending;
	}

	/**
	 * Delete a sync JSON file by group key.
	 */
	public static function delete_sync_file_by_key( $group_key ) {
		$pending = self::get_sync_status();
		if ( ! isset( $pending[ $group_key ] ) ) {
			return false;
		}

		$dir      = self::get_sync_dir();
		$filename = $pending[ $group_key ]['filename'] ?? '';
		if ( empty( $filename ) ) {
			return false;
		}

		$file      = trailingslashit( $dir ) . $filename;
		$real_dir  = realpath( $dir );
		$real_file = realpath( $file );
		if ( $real_dir && $real_file && strpos( $real_file, $real_dir ) === 0 && file_exists( $real_file ) ) {
			$deleted = wp_delete_file( $real_file );
			if ( $deleted ) {
				MetaForge_Loader::clear_cache();
			}
			return $deleted;
		}
		return false;
	}

	/**
	 * Run synchronization on chosen groups.
	 */
	public static function sync_groups( $keys = array() ) {
		$pending = self::get_sync_status();
		if ( empty( $pending ) ) {
			return 0;
		}

		$dir          = self::get_sync_dir();
		$synced_count = 0;
		foreach ( $pending as $key => $item ) {
			if ( ! empty( $keys ) && ! in_array( $key, $keys, true ) ) {
				continue;
			}

			$config    = $item['json_config'];
			$sanitized = MetaForge_Loader::sanitize_group_config( $config );
			if ( ! $sanitized ) {
				continue;
			}
			// Inject persistent key
			$sanitized['group_key'] = $key;
			$title                  = $sanitized['group_name'];
			$now                    = time();
			$sanitized['modified']  = $now;

			// Remove legacy / previous file if the filename changed due to rename
			$old_filename    = $item['filename'] ?? '';
			$target_filename = sanitize_file_name( sanitize_title( $title ) . '.json' );
			if ( ! empty( $old_filename ) && $old_filename !== $target_filename ) {
				$old_file = trailingslashit( $dir ) . $old_filename;
				$real_dir = realpath( $dir );
				$real_old = realpath( $old_file );
				if ( $real_dir && $real_old && strpos( $real_old, $real_dir ) === 0 && file_exists( $real_old ) ) {
					wp_delete_file( $real_old );
				}
			}

			if ( $item['type'] === 'new' ) {
				$pid = wp_insert_post(
					array(
						'post_title'        => $title,
						'post_type'         => 'metaforge_group',
						'post_status'       => 'publish',
						'post_modified'     => current_time( 'mysql' ),
						'post_modified_gmt' => current_time( 'mysql', 1 ),
					)
				);
				if ( $pid && ! is_wp_error( $pid ) ) {
					update_post_meta( $pid, '_metaforge_group_config', $sanitized );
					self::save_group( $pid, $sanitized );
					++$synced_count;
				}
			} else {
				$pid = $item['db_id'];
				wp_update_post(
					array(
						'ID'                => $pid,
						'post_title'        => $title,
						'post_modified'     => current_time( 'mysql' ),
						'post_modified_gmt' => current_time( 'mysql', 1 ),
					)
				);
				update_post_meta( $pid, '_metaforge_group_config', $sanitized );
				self::save_group( $pid, $sanitized );
				++$synced_count;
			}
		}

		wp_cache_delete( 'metaforge_group', 'counts' );
		MetaForge_Loader::clear_cache();
		return $synced_count;
	}

	/**
	 * Count pending sync items.
	 *
	 * @return int
	 */
	public static function count_pending_sync() {
		return count( self::get_sync_status() );
	}
}