<?php
/**
 * Class for the widget importer.
 *
 * Code is mostly from the Widget Importer & Exporter plugin.
 *
 * @see https://wordpress.org/plugins/widget-importer-exporter/
 *
 * @package Merlin WP
 */

class Merlin_Widget_Importer {
	/**
	 * Import widgets from WIE or JSON file.
	 *
	 * @param string $widget_import_file_path path to the widget import file.
	 */
	public static function import( $widget_import_file_path ) {
		if ( empty( $widget_import_file_path ) ) {
			return false;
		}

		self::unset_default_widgets();

		$results = self::import_widgets( $widget_import_file_path );

		if ( is_wp_error( $results ) ) {
			Merlin_Logger::get_instance()->error( $results->get_error_message() );

			return false;
		}

		ob_start();
			self::format_results_for_log( $results );
		$message = ob_get_clean();

		Merlin_Logger::get_instance()->debug( $message );

		return true;
	}


	/**
	 * Imports widgets from a json file.
	 *
	 * @param string $data_file path to json file with WordPress widget export data.
	 */
	private static function import_widgets( $data_file ) {
		// Get widgets data from file.
		$data = self::process_import_file( $data_file );

		// Return from this function if there was an error.
		if ( is_wp_error( $data ) ) {
			return $data;
		}

		// Import the widget data and save the results.
		return self::import_data( $data );
	}

	/**
	 * Process import file - this parses the widget data and returns it.
	 *
	 * @param string $file path to json file.
	 * @return WP_Error|object
	 */
	private static function process_import_file( $file ) {
		// File exists?
		if ( ! file_exists( $file ) ) {
			return new \WP_Error(
				'widget_import_file_not_found',
				__( 'Error: Widget import file could not be found.', 'merlin-wp' )
			);
		}

		// Get file contents and decode.
		$data = file_get_contents( $file );

		// Return from this function if there was an error.
		if ( empty( $data ) ) {
			return new \WP_Error(
				'widget_import_file_missing_content',
				__( 'Error: Widget import file does not have any content in it.', 'merlin-wp' )
			);
		}

		return json_decode( $data );
	}


	/**
	 * Import widget JSON data
	 *
	 * @global array $wp_registered_sidebars
	 * @param object $data JSON widget data.
	 * @return array|WP_Error
	 */
	private static function import_data( $data ) {
		global $wp_registered_sidebars;

		// Have valid data? If no data or could not decode.
		if ( empty( $data ) || ! is_object( $data ) ) {
			return new \WP_Error(
				'corrupted_widget_import_data',
				__( 'Error: Widget import data could not be read. Please try a different file.', 'merlin-wp' )
			);
		}

		// Hook before import.
		do_action( 'merlin_widget_importer_before_widgets_import' );
		$data = apply_filters( 'merlin_before_widgets_import_data', $data );

		// Get all available widgets site supports.
		$available_widgets = self::available_widgets();

		// Get all existing widget instances.
		$widget_instances = array();

		foreach ( $available_widgets as $widget_data ) {
			$widget_instances[ $widget_data['id_base'] ] = get_option( 'widget_' . $widget_data['id_base'] );
		}

		// Begin results.
		$results = array();

		// Loop import data's sidebars.
		foreach ( $data as $sidebar_id => $widgets ) {
			// Skip inactive widgets (should not be in export file).
			if ( 'wp_inactive_widgets' == $sidebar_id ) {
				continue;
			}

			// Check if sidebar is available on this site. Otherwise add widgets to inactive, and say so.
			if ( isset( $wp_registered_sidebars[ $sidebar_id ] ) ) {
				$sidebar_available    = true;
				$use_sidebar_id       = $sidebar_id;
				$sidebar_message_type = 'success';
				$sidebar_message      = '';
			}
			else {
				$sidebar_available    = false;
				$use_sidebar_id       = 'wp_inactive_widgets'; // Add to inactive if sidebar does not exist in theme.
				$sidebar_message_type = 'error';
				$sidebar_message      = __( 'Sidebar does not exist in theme (moving widget to Inactive)', 'merlin-wp' );
			}

			// Result for sidebar.
			$results[ $sidebar_id ]['name']         = ! empty( $wp_registered_sidebars[ $sidebar_id ]['name'] ) ? $wp_registered_sidebars[ $sidebar_id ]['name'] : $sidebar_id; // Sidebar name if theme supports it; otherwise ID.
			$results[ $sidebar_id ]['message_type'] = $sidebar_message_type;
			$results[ $sidebar_id ]['message']      = $sidebar_message;
			$results[ $sidebar_id ]['widgets']      = array();

			// Loop widgets.
			foreach ( $widgets as $widget_instance_id => $widget ) {
				$fail = false;

				// Get id_base (remove -# from end) and instance ID number.
				$id_base            = preg_replace( '/-[0-9]+$/', '', $widget_instance_id );
				$instance_id_number = str_replace( $id_base . '-', '', $widget_instance_id );

				// Does site support this widget?
				if ( ! $fail && ! isset( $available_widgets[ $id_base ] ) ) {
					$fail                = true;
					$widget_message_type = 'error';
					$widget_message      = __( 'Site does not support widget', 'merlin-wp' ); // Explain why widget not imported.
				}

				// Filter to modify settings object before conversion to array and import.
				// Leave this filter here for backwards compatibility with manipulating objects (before conversion to array below).
				// Ideally the newer wie_widget_settings_array below will be used instead of this.
				$widget = apply_filters( 'merlin_widget_settings', $widget ); // Object.

				// Convert multidimensional objects to multidimensional arrays.
				// Some plugins like Jetpack Widget Visibility store settings as multidimensional arrays.
				// Without this, they are imported as objects and cause fatal error on Widgets page.
				// If this creates problems for plugins that do actually intend settings in objects then may need to consider other approach: https://wordpress.org/support/topic/problem-with-array-of-arrays.
				// It is probably much more likely that arrays are used than objects, however.
				$widget = json_decode( json_encode( $widget ), true );

				// Filter to modify settings array.
				// This is preferred over the older wie_widget_settings filter above.
				// Do before identical check because changes may make it identical to end result (such as URL replacements).
				$widget = apply_filters( 'merlin_widget_settings_array', $widget );

				// Does widget with identical settings already exist in same sidebar?
				if ( ! $fail && isset( $widget_instances[ $id_base ] ) ) {
					// Get existing widgets in this sidebar.
					$sidebars_widgets = get_option( 'sidebars_widgets' );
					$sidebar_widgets  = isset( $sidebars_widgets[ $use_sidebar_id ] ) ? $sidebars_widgets[ $use_sidebar_id ] : array(); // Check Inactive if that's where will go.

					// Loop widgets with ID base.
					$single_widget_instances = ! empty( $widget_instances[ $id_base ] ) ? $widget_instances[ $id_base ] : array();
					foreach ( $single_widget_instances as $check_id => $check_widget ) {
						// Is widget in same sidebar and has identical settings?
						if ( in_array( "$id_base-$check_id", $sidebar_widgets ) && (array) $widget == $check_widget ) {
							$fail                = true;
							$widget_message_type = 'warning';
							$widget_message      = __( 'Widget already exists', 'merlin-wp' ); // Explain why widget not imported.

							break;
						}
					}
				}

				// No failure.
				if ( ! $fail ) {
					// Add widget instance.
					$single_widget_instances   = get_option( 'widget_' . $id_base ); // All instances for that widget ID base, get fresh every time.
					$single_widget_instances   = ! empty( $single_widget_instances ) ? $single_widget_instances : array( '_multiwidget' => 1 ); // Start fresh if have to.
					$single_widget_instances[] = $widget; // Add it.

					// Get the key it was given.
					end( $single_widget_instances );
					$new_instance_id_number = key( $single_widget_instances );

					// If key is 0, make it 1.
					// When 0, an issue can occur where adding a widget causes data from other widget to load, and the widget doesn't stick (reload wipes it).
					if ( '0' === strval( $new_instance_id_number ) ) {
						$new_instance_id_number                           = 1;
						$single_widget_instances[ $new_instance_id_number ] = $single_widget_instances[0];
						unset( $single_widget_instances[0] );
					}

					// Move _multiwidget to end of array for uniformity.
					if ( isset( $single_widget_instances['_multiwidget'] ) ) {
						$multiwidget = $single_widget_instances['_multiwidget'];
						unset( $single_widget_instances['_multiwidget'] );
						$single_widget_instances['_multiwidget'] = $multiwidget;
					}

					// Update option with new widget.
					update_option( 'widget_' . $id_base, $single_widget_instances );

					// Assign widget instance to sidebar.
					$sidebars_widgets = get_option( 'sidebars_widgets' ); // Which sidebars have which widgets, get fresh every time.
					$new_instance_id = $id_base . '-' . $new_instance_id_number; // Use ID number from new widget instance.
					$sidebars_widgets[ $use_sidebar_id ][] = $new_instance_id; // Add new instance to sidebar.
					update_option( 'sidebars_widgets', $sidebars_widgets ); // Save the amended data.

					// After widget import action.
					$after_widget_import = array(
						'sidebar'           => $use_sidebar_id,
						'sidebar_old'       => $sidebar_id,
						'widget'            => $widget,
						'widget_type'       => $id_base,
						'widget_id'         => $new_instance_id,
						'widget_id_old'     => $widget_instance_id,
						'widget_id_num'     => $new_instance_id_number,
						'widget_id_num_old' => $instance_id_number,
					);
					do_action( 'merlin_widget_importer_after_single_widget_import', $after_widget_import );

					// Success message.
					if ( $sidebar_available ) {
						$widget_message_type = 'success';
						$widget_message      = __( 'Imported', 'merlin-wp' );
					}
					else {
						$widget_message_type = 'warning';
						$widget_message      = __( 'Imported to Inactive', 'merlin-wp' );
					}
				}

				// Result for widget instance.
				$results[ $sidebar_id ]['widgets'][ $widget_instance_id ]['name']         = isset( $available_widgets[ $id_base ]['name'] ) ? $available_widgets[ $id_base ]['name'] : $id_base; // Widget name or ID if name not available (not supported by site).
				$results[ $sidebar_id ]['widgets'][ $widget_instance_id ]['title']        = ! empty( $widget['title'] ) ? $widget['title'] : __( 'No Title', 'merlin-wp' ); // Show "No Title" if widget instance is untitled.
				$results[ $sidebar_id ]['widgets'][ $widget_instance_id ]['message_type'] = $widget_message_type;
				$results[ $sidebar_id ]['widgets'][ $widget_instance_id ]['message']      = $widget_message;

			}
		}

		// Hook after import.
		do_action( 'merlin_widget_importer_after_widgets_import' );

		// Return results.
		return apply_filters( 'merlin_widget_import_results', $results );
	}


	/**
	 * Available widgets.
	 *
	 * Gather site's widgets into array with ID base, name, etc.
	 *
	 * @global array $wp_registered_widget_controls
	 * @return array $available_widgets, Widget information
	 */
	private static function available_widgets() {
		global $wp_registered_widget_controls;

		$widget_controls   = $wp_registered_widget_controls;
		$available_widgets = array();

		foreach ( $widget_controls as $widget ) {
			if ( ! empty( $widget['id_base'] ) && ! isset( $available_widgets[ $widget['id_base'] ] ) ) {
				$available_widgets[ $widget['id_base'] ]['id_base'] = $widget['id_base'];
				$available_widgets[ $widget['id_base'] ]['name']    = $widget['name'];
			}
		}

		return apply_filters( 'merlin_available_widgets', $available_widgets );
	}


	/**
	 * Remove widgets from sidebars.
	 * By default none are removed, but with the filter you can remove them.
	 */
	private static function unset_default_widgets() {
		$widget_areas = apply_filters( 'merlin_unset_default_widgets_args', false );

		if ( empty( $widget_areas ) ) {
			return false;
		}

		update_option( 'sidebars_widgets', $widget_areas );
	}


	/**
	 * Format results for log file
	 *
	 * @param array $results widget import results.
	 */
	private static function format_results_for_log( $results ) {
		if ( empty( $results ) ) {
			esc_html_e( 'No results for widget import!', 'merlin-wp' );
		}

		// Loop sidebars.
		foreach ( $results as $sidebar ) {
			echo esc_html( $sidebar['name'] ) . ' : ' . esc_html( $sidebar['message'] ) . PHP_EOL . PHP_EOL;
			// Loop widgets.
			foreach ( $sidebar['widgets'] as $widget ) {
				echo esc_html( $widget['name'] ) . ' - ' . esc_html( $widget['title'] ) . ' - ' . esc_html( $widget['message'] ) . PHP_EOL;
			}
			echo PHP_EOL;
		}
	}
}
