<?php
defined( 'WPINC' ) or die;

/**
 * Downloads and updates images.
 *
 * @since 1.6
 */
class GeneratePress_Sites_Image_Importer {

	/**
	 * Images IDs
	 *
	 * @var array   The Array of already image IDs.
	 * @since 1.6
	 */
	private $already_imported_ids = array();

	/**
	 * Constructor
	 *
	 * @since 1.6
	 */
	public function __construct() {

		if ( ! function_exists( 'WP_Filesystem' ) ) {
			require_once ABSPATH . 'wp-admin/includes/file.php';
		}

		WP_Filesystem();
	}

	/**
	 * Process Image Download
	 *
	 * @since 1.6
	 * @param  array $attachments Attachment array.
	 * @return array              Attachment array.
	 */
	public function process( $attachments ) {

		$downloaded_images = array();

		foreach ( $attachments as $key => $attachment ) {
			$downloaded_images[] = $this->import( $attachment );
		}

		return $downloaded_images;
	}

	/**
	 * Get Hash Image.
	 *
	 * @since 1.6
	 * @param  string $attachment_url Attachment URL.
	 * @return string                 Hash string.
	 */
	private function get_hash_image( $attachment_url ) {
		return sha1( $attachment_url );
	}

	/**
	 * Get Saved Image.
	 *
	 * @since 1.6
	 * @param  string $attachment   Attachment Data.
	 * @return string                 Hash string.
	 */
	private function get_saved_image( $attachment ) {

		global $wpdb;

		// Already imported? Then return!
		if ( isset( $this->already_imported_ids[ $attachment['id'] ] ) ) {
			GeneratePress_Sites_Helper::log( 'Successfully replaced: ' . $attachment['url'] );

			return $this->already_imported_ids[ $attachment['id'] ];
		}

		// 1. Is already imported in Batch Import Process?
		$post_id = $wpdb->get_var(
			$wpdb->prepare(
				'SELECT `post_id` FROM `' . $wpdb->postmeta . '`
					WHERE `meta_key` = \'_generatepress_sites_image_hash\'
						AND `meta_value` = %s
				;',
				$this->get_hash_image( $attachment['url'] )
			)
		);

		// 2. Is image already imported though XML?
		if ( empty( $post_id ) ) {
			// Get file name without extension.
			// To check it exist in attachment.
			$filename = preg_replace( '/\\.[^.\\s]{3,4}$/', '', basename( $attachment['url'] ) );

			$post_id = $wpdb->get_var(
				$wpdb->prepare(
					'SELECT `post_id` FROM `' . $wpdb->postmeta . '`
						WHERE `meta_key` = \'_wp_attached_file\'
						AND `meta_value` LIKE %s
					;',
					'%' . $filename . '%'
				)
			);

			GeneratePress_Sites_Helper::log( 'Successfully replaced: ' . $attachment['url'] );
		}

		if ( $post_id ) {
			$new_attachment = array(
				'id'  => $post_id,
				'url' => wp_get_attachment_url( $post_id ),
			);

			$this->already_imported_ids[ $attachment['id'] ] = $new_attachment;

			return $new_attachment;
		}

		return false;
	}

	/**
	 * Import Image
	 *
	 * @since 1.6
	 * @param  array $attachment Attachment array.
	 * @return array              Attachment array.
	 */
	public function import( $attachment ) {

		$saved_image = $this->get_saved_image( $attachment );

		if ( $saved_image ) {
			return $saved_image;
		}

		$file_content = wp_remote_retrieve_body( wp_safe_remote_get( $attachment['url'] ) );

		// Empty file content?
		if ( empty( $file_content ) ) {
			GeneratePress_Sites_Helper::log( 'Failed to replace: ' . $attachment['url'] );
			GeneratePress_Sites_Helper::log( 'Error: Failed wp_remote_retrieve_body().' );

			return $attachment;
		}

		// Extract the file name and extension from the URL.
		$filename = basename( $attachment['url'] );

		$upload = wp_upload_bits(
			$filename,
			null,
			$file_content
		);

		$post = array(
			'post_title' => $filename,
			'guid'       => $upload['url'],
		);

		$info = wp_check_filetype( $upload['file'] );

		if ( $info ) {
			$post['post_mime_type'] = $info['type'];
		} else {
			// For now just return the origin attachment.
			return $attachment;
		}

		$post_id = wp_insert_attachment( $post, $upload['file'] );

		wp_update_attachment_metadata(
			$post_id,
			wp_generate_attachment_metadata( $post_id, $upload['file'] )
		);

		update_post_meta( $post_id, '_generatepress_sites_image_hash', $this->get_hash_image( $attachment['url'] ) );

		$new_attachment = array(
			'id'  => $post_id,
			'url' => $upload['url'],
		);

		GeneratePress_Sites_Helper::log( 'Successfully replaced: ' . $attachment['url'] );

		$this->already_imported_ids[ $attachment['id'] ] = $new_attachment;

		return $new_attachment;
	}
}
