<?php
/**
 * Export Functions
 *
 * @package    Widget_Importer_Exporter
 * @subpackage Functions
 * @copyright  Copyright (c) 2013 - 2017, ChurchThemes.com
 * @link       https://churchthemes.com/plugins/widget-importer-exporter/
 * @license    GPLv2 or later
 * @since      0.1
 */

// No direct access.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Generate export data
 *
 * @since 0.1
 * @return string Export file contents
 */
function wie_generate_export_data() {

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

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

	// Loop widgets.
	foreach ( $available_widgets as $widget_data ) {

		// Get all instances for this ID base.
		$instances = get_option( 'widget_' . $widget_data['id_base'] );

		// Have instances.
		if ( ! empty( $instances ) ) {

			// Loop instances.
			foreach ( $instances as $instance_id => $instance_data ) {

				// Key is ID (not _multiwidget).
				if ( is_numeric( $instance_id ) ) {
					$unique_instance_id = $widget_data['id_base'] . '-' . $instance_id;
					$widget_instances[ $unique_instance_id ] = $instance_data;
				}

			}

		}

	}

	// Gather sidebars with their widget instances.
	$sidebars_widgets = get_option( 'sidebars_widgets' );
	$sidebars_widget_instances = array();
	foreach ( $sidebars_widgets as $sidebar_id => $widget_ids ) {

		// Skip inactive widgets.
		if ( 'wp_inactive_widgets' === $sidebar_id ) {
			continue;
		}

		// Skip if no data or not an array (array_version).
		if ( ! is_array( $widget_ids ) || empty( $widget_ids ) ) {
			continue;
		}

		// Loop widget IDs for this sidebar.
		foreach ( $widget_ids as $widget_id ) {

			// Is there an instance for this widget ID?
			if ( isset( $widget_instances[ $widget_id ] ) ) {

				// Add to array.
				$sidebars_widget_instances[ $sidebar_id ][ $widget_id ] = $widget_instances[ $widget_id ];

			}

		}

	}

	// Filter pre-encoded data.
	$data = apply_filters( 'wie_unencoded_export_data', $sidebars_widget_instances );

	// Encode the data for file contents.
	$encoded_data = wp_json_encode( $data );

	// Return contents.
	return apply_filters( 'wie_generate_export_data', $encoded_data );

}

/**
 * Send export file to user
 *
 * Triggered by URL like /wp-admin/tools.php?page=widget-importer-exporter&export=1
 *
 * The data is JSON with .wie extension in order not to confuse export files with other plugins.
 *
 * @since 0.1
 */
function wie_send_export_file() {

	// Export requested.
	if ( ! empty( $_GET['export'] ) ) {

		// Check referer before doing anything else.
		check_admin_referer( 'wie_export', 'wie_export_nonce' );

		// Build filename
		// Single Site: yoursite.com-widgets.wie
		// Multisite: site.multisite.com-widgets.wie or multisite.com-site-widgets.wie.
		$site_url = site_url( '', 'http' );
		$site_url = trim( $site_url, '/\\' ); // Remove trailing slash.
		$filename = str_replace( 'http://', '', $site_url ); // Remove http://.
		$filename = str_replace( array( '/', '\\' ), '-', $filename ); // Replace slashes with - .
		$filename .= '-widgets.wie'; // Append.
		$filename = apply_filters( 'wie_export_filename', $filename );

		// Generate export file contents.
		$file_contents = wie_generate_export_data();
		$filesize = strlen( $file_contents );

		// Headers to prompt "Save As".
		header( 'Content-Type: application/octet-stream' );
		header( 'Content-Disposition: attachment; filename=' . $filename );
		header( 'Expires: 0' );
		header( 'Cache-Control: must-revalidate' );
		header( 'Pragma: public' );
		header( 'Content-Length: ' . $filesize );

		// Clear buffering just in case.
		// @codingStandardsIgnoreLine
		@ob_end_clean();
		flush();

		// Output file contents.
		// @todo export or verify the output data. Or simply ignore the line.
		echo $file_contents;

		// Stop execution.
		exit;

	}

}

add_action( 'load-tools_page_widget-importer-exporter', 'wie_send_export_file' );