<?php
/**
 * Media library scanner.
 */

defined( 'ABSPATH' ) || exit;

class Adbear_Alt_Text_Generator_Scanner {
	protected $suggestion_generator;

	public function __construct( Adbear_Alt_Text_Generator_Suggestion_Generator $suggestion_generator ) {
		$this->suggestion_generator = $suggestion_generator;
	}

	public function get_results() {
		$results = (array) get_option( Adbear_Alt_Text_Generator_Helpers::get_scan_option_key(), array() );
		return $results;
	}

	public function scan_batch( $offset = 0, $limit = 50, $reset = false ) {
		$offset = max( 0, absint( $offset ) );
		$limit  = max( 1, min( 200, absint( $limit ) ) );

		if ( $reset ) {
			update_option( Adbear_Alt_Text_Generator_Helpers::get_scan_option_key(), array(), false );
			update_option( Adbear_Alt_Text_Generator_Helpers::get_scan_report_option_key(), array(), false );
			update_option( Adbear_Alt_Text_Generator_Helpers::get_scan_meta_option_key(), array(), false );
			$offset = 0;
		}

		$total = $this->count_images();
		$ids   = $this->get_image_ids( $offset, $limit );

		$missing_results = (array) get_option( Adbear_Alt_Text_Generator_Helpers::get_scan_option_key(), array() );
		$report_results  = (array) get_option( Adbear_Alt_Text_Generator_Helpers::get_scan_report_option_key(), array() );
		$meta            = (array) get_option( Adbear_Alt_Text_Generator_Helpers::get_scan_meta_option_key(), array() );

		$meta = wp_parse_args(
			$meta,
			array(
				'total_images_scanned' => 0,
				'missing_alt'          => 0,
				'missing_titles'       => 0,
				'elementor_matches'    => 0,
				'acf_matches'          => 0,
				'woocommerce_images'   => 0,
				'last_scan'            => 0,
			)
		);

		foreach ( $ids as $attachment_id ) {
			$row = $this->build_row( $attachment_id );
			if ( empty( $row ) ) {
				continue;
			}

			$report_results[ $attachment_id ] = $row;

			if ( ! empty( $row['missing_alt'] ) || ! empty( $row['missing_title'] ) ) {
				$missing_results[ $attachment_id ] = $row;
			} elseif ( isset( $missing_results[ $attachment_id ] ) ) {
				unset( $missing_results[ $attachment_id ] );
			}
		}

		$processed = min( $total, $offset + count( $ids ) );
		$meta      = $this->calculate_meta( $report_results, $processed );

		update_option( Adbear_Alt_Text_Generator_Helpers::get_scan_option_key(), $missing_results, false );
		update_option( Adbear_Alt_Text_Generator_Helpers::get_scan_report_option_key(), $report_results, false );
		update_option( Adbear_Alt_Text_Generator_Helpers::get_scan_meta_option_key(), $meta, false );

		return array(
			'total'       => $total,
			'processed'   => $processed,
			'is_complete' => $processed >= $total,
		);
	}

	protected function count_images() {
		$query = new WP_Query(
			array(
				'post_type'      => 'attachment',
				'post_status'    => 'inherit',
				'post_mime_type' => 'image',
				'posts_per_page' => 1,
				'fields'         => 'ids',
				'no_found_rows'  => false,
			)
		);

		return (int) $query->found_posts;
	}

	protected function get_image_ids( $offset, $limit ) {
		$query = new WP_Query(
			array(
				'post_type'      => 'attachment',
				'post_status'    => 'inherit',
				'post_mime_type' => 'image',
				'posts_per_page' => $limit,
				'offset'         => $offset,
				'fields'         => 'ids',
				'orderby'        => 'ID',
				'order'          => 'ASC',
				'no_found_rows'  => true,
			)
		);

		return array_map( 'absint', (array) $query->posts );
	}

	protected function build_row( $attachment_id ) {
		$attachment_id = absint( $attachment_id );
		$post          = get_post( $attachment_id );

		if ( ! $post || 'attachment' !== $post->post_type ) {
			return array();
		}

		$current_alt   = (string) get_post_meta( $attachment_id, '_wp_attachment_image_alt', true );
		$current_title = (string) get_the_title( $attachment_id );
		$suggestion    = $this->suggestion_generator->generate( $attachment_id );
		$file          = (string) get_attached_file( $attachment_id );
		$url           = (string) wp_get_attachment_url( $attachment_id );
		$used_in       = $this->detect_usage( $attachment_id, $url );

		return array(
			'attachment_id'    => $attachment_id,
			'filename'         => wp_basename( $file ? $file : $url ),
			'url'              => $url,
			'thumb'            => wp_get_attachment_image_url( $attachment_id, 'thumbnail' ),
			'uploaded_date'    => get_the_date( 'Y-m-d H:i:s', $attachment_id ),
			'current_alt'      => $current_alt,
			'current_title'    => $current_title,
			'missing_alt'      => '' === trim( $current_alt ) ? 1 : 0,
			'missing_title'    => '' === trim( $current_title ) ? 1 : 0,
			'suggested_alt'    => isset( $suggestion['alt'] ) ? sanitize_text_field( $suggestion['alt'] ) : '',
			'suggested_title'  => isset( $suggestion['title'] ) ? sanitize_text_field( $suggestion['title'] ) : '',
			'used_in'          => $used_in,
			'used_in_display'  => $this->format_usage_labels( $used_in ),
			'file_size_human'  => $file && file_exists( $file ) ? size_format( filesize( $file ) ) : '',
			'is_elementor'     => in_array( 'elementor', $used_in, true ) ? 1 : 0,
			'is_acf'           => in_array( 'acf', $used_in, true ) ? 1 : 0,
			'is_woocommerce'   => in_array( 'woocommerce', $used_in, true ) ? 1 : 0,
		);
	}

	protected function format_usage_labels( $usage_keys ) {
		$labels = array();

		foreach ( (array) $usage_keys as $key ) {
			switch ( $key ) {
				case 'featured_image':
					$labels[] = __( 'Featured Image', 'adbear-alt-text-generator' );
					break;
				case 'woocommerce':
					$labels[] = __( 'WooCommerce', 'adbear-alt-text-generator' );
					break;
				case 'elementor':
					$labels[] = __( 'Elementor', 'adbear-alt-text-generator' );
					break;
				case 'acf':
					$labels[] = __( 'ACF', 'adbear-alt-text-generator' );
					break;
				case 'content':
					$labels[] = __( 'Content', 'adbear-alt-text-generator' );
					break;
			}
		}

		return implode( ', ', $labels );
	}

	protected function detect_usage( $attachment_id, $url ) {
		$usage = array();

		if ( (int) get_post_meta( $attachment_id, '_thumbnail_id', true ) > 0 ) {
			$usage[] = 'featured_image';
		}

		if ( class_exists( 'WooCommerce' ) && $this->is_used_in_woocommerce( $attachment_id ) ) {
			$usage[] = 'woocommerce';
		}

		if ( $this->is_used_in_elementor( $attachment_id ) ) {
			$usage[] = 'elementor';
		}

		if ( $this->is_used_in_acf( $attachment_id ) ) {
			$usage[] = 'acf';
		}

		if ( $url && $this->is_used_in_content( $url ) ) {
			$usage[] = 'content';
		}

		return array_values( array_unique( $usage ) );
	}

	protected function is_used_in_content( $url ) {
		global $wpdb;
		$like  = '%' . $wpdb->esc_like( $url ) . '%';
		$count = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(ID) FROM {$wpdb->posts} WHERE post_content LIKE %s", $like ) );
		return $count > 0;
	}

	protected function is_used_in_elementor( $attachment_id ) {
		global $wpdb;
		$like  = '%' . $wpdb->esc_like( '"id":' . absint( $attachment_id ) ) . '%';
		$count = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(post_id) FROM {$wpdb->postmeta} WHERE meta_key = '_elementor_data' AND meta_value LIKE %s", $like ) );
		return $count > 0;
	}

	protected function is_used_in_acf( $attachment_id ) {
		global $wpdb;
		$count = (int) $wpdb->get_var(
			$wpdb->prepare(
				"SELECT COUNT(meta_id) FROM {$wpdb->postmeta} WHERE meta_value = %s OR meta_value LIKE %s",
				(string) absint( $attachment_id ),
				'%' . $wpdb->esc_like( '"' . absint( $attachment_id ) . '"' ) . '%'
			)
		);
		return $count > 0;
	}

	protected function is_used_in_woocommerce( $attachment_id ) {
		global $wpdb;
		$id = absint( $attachment_id );

		$count = (int) $wpdb->get_var(
			$wpdb->prepare(
				"SELECT COUNT(meta_id) FROM {$wpdb->postmeta} WHERE (meta_key = '_thumbnail_id' AND meta_value = %s) OR (meta_key = '_product_image_gallery' AND FIND_IN_SET(%d, meta_value))",
				(string) $id,
				$id
			)
		);

		return $count > 0;
	}

	protected function calculate_meta( $rows, $processed ) {
		$missing_alt        = 0;
		$missing_titles     = 0;
		$elementor_matches  = 0;
		$acf_matches        = 0;
		$woocommerce_images = 0;

		foreach ( (array) $rows as $row ) {
			$missing_alt        += ! empty( $row['missing_alt'] ) ? 1 : 0;
			$missing_titles     += ! empty( $row['missing_title'] ) ? 1 : 0;
			$elementor_matches  += ! empty( $row['is_elementor'] ) ? 1 : 0;
			$acf_matches        += ! empty( $row['is_acf'] ) ? 1 : 0;
			$woocommerce_images += ! empty( $row['is_woocommerce'] ) ? 1 : 0;
		}

		return array(
			'total_images_scanned' => absint( $processed ),
			'missing_alt'          => absint( $missing_alt ),
			'missing_titles'       => absint( $missing_titles ),
			'elementor_matches'    => absint( $elementor_matches ),
			'acf_matches'          => absint( $acf_matches ),
			'woocommerce_images'   => absint( $woocommerce_images ),
			'last_scan'            => time(),
		);
	}
}