<?php

use ISC\Image_Sources\Image_Sources;
use ISC\Image_Sources\Post_Meta;
use ISC\indexer;

/**
 * Logic to get and store sources
 */
class ISC_Model {
	/**
	 * Instance of ISC_Model
	 *
	 * @var ISC_Model
	 */
	protected static $instance;

	/**
	 * Maximum number of entries in custom queries
	 */
	const MAX_POSTS = 100;

	/**
	 * Setup registers filters and actions.
	 */
	public function __construct() {
		add_filter( 'attachment_fields_to_save', [ $this, 'isc_fields_save' ], 10, 2 );
	}

	/**
	 * Get instance of ISC_Model
	 *
	 * @return ISC_Model
	 */
	public static function get_instance() {
		return self::$instance;
	}

	/**
	 * Update the isc_image_posts and isc_post_images indexes
	 *
	 * @depecated since October 2024
	 *
	 * @param integer $post_id ID of the target post.
	 * @param string  $content content of the target post.
	 */
	public static function update_indexes( $post_id, $content ) {

		ISC_Log::log( 'function removed. Use \ISC\Indexer::update_indexes' );

		ISC\Indexer::update_indexes( $content );
	}

	/**
	 * Update isc_image_posts meta field with includes IDs of all posts that have the image in its content
	 * the function should be used to push a post ID to the (maybe) existing meta field
	 *
	 * @removed since April 2025
	 *
	 * @param integer $post_id ID of the target post.
	 * @param array   $image_ids IDs of the attachments in the content.
	 */
	public static function update_image_posts_meta( $post_id, $image_ids ) {

		ISC_Log::log( 'function removed. \ISC\Indexer::update_indexes covers most of it now' );
	}

	/**
	 * Save image source to post_meta
	 * Used as a filter function. See save_field() it you are looking for a direct method to store post meta values
	 *
	 * @updated 1.5 added field for url
	 *
	 * @param array $post post data.
	 * @param array $attachment attachment data.
	 * @return array $post updated post data
	 */
	public function isc_fields_save( $post, $attachment ) {
		if ( isset( $attachment['isc_image_source'] ) ) {
			self::save_field( $post['ID'], 'isc_image_source', Image_Sources::sanitize_source_html( $attachment['isc_image_source'] ) );
		}
		if ( isset( $attachment['isc_image_source_url'] ) ) {
			self::save_field( $post['ID'], 'isc_image_source_url', $this->sanitize_source_url( $attachment['isc_image_source_url'] ) );
		}
		$own = ( isset( $attachment['isc_image_source_own'] ) ) ? $attachment['isc_image_source_own'] : '';
		self::save_field( $post['ID'], 'isc_image_source_own', $own );

		if ( isset( $attachment['isc_ai_label'] ) ) {
			self::save_field( $post['ID'], \ISC\Image_Sources\Ai_Labels::META_KEY, \ISC\Image_Sources\Ai_Labels::sanitize_label( $attachment['isc_ai_label'] ) );
		}

		if ( isset( $attachment['isc_image_licence'] ) ) {
			self::save_field( $post['ID'], 'isc_image_licence', sanitize_text_field( $attachment['isc_image_licence'] ) );
		}

		return $post;
	}

	/**
	 * Sanitize source URL string by removing any HTML tags
	 *
	 * @param string $source_url source URL string.
	 *
	 * @return string sanitized source URL
	 */
	public function sanitize_source_url( string $source_url ): string {
		return wp_kses( $source_url, [] );
	}

	/**
	 * Store attachment-related post meta values
	 *
	 * @param int    $att_id WP_Post ID of the attachment.
	 * @param string $key post meta key.
	 * @param mixed  $value post meta value.
	 */
	public static function save_field( $att_id, $key, $value ) {
		if ( is_string( $value ) ) {
			$value = trim( $value );
		}

		self::update_post_meta( $att_id, $key, $value );
	}

	/**
	 * Update image-post index attached to attachments when a post is updated
	 *
	 * @removed since April 2025
	 *
	 * @param int     $post_ID      Post ID.
	 * @param WP_Post $post_after   Post object following the update.
	 * @param WP_Post $post_before  Post object before the update.
	 *
	 * @return void
	 */
	public static function update_image_post_meta( $post_ID, $post_after, $post_before ) {
		ISC_Log::log( 'function removed without a replacement.' );
	}

	/**
	 * Remove the post_images index from a single post
	 * namely the post meta field `isc_post_images`
	 *
	 * @moved since April 2025
	 *
	 * @param int $post_id Post ID.
	 */
	public static function clear_single_post_images_index( $post_id ) {
		ISC_Log::log( 'function moved. \ISC\Image_Sources\Post_Meta\Post_Images_Meta::delete' );

		Post_Meta\Post_Images_Meta::delete( $post_id );
	}

	/**
	 * Remove post_images index
	 * namely the post meta field `isc_post_images`
	 *
	 * @moved since April 2025
	 *
	 * @return int|false The number of rows updated, or false on error.
	 */
	public static function clear_post_images_index() {
		ISC_Log::log( 'function moved. \ISC\Image_Sources\Post_Images_Meta::delete_all' );

		return Post_Meta\Post_Images_Meta::delete_all();
	}

	/**
	 * Remove image_posts index
	 * namely the post meta field `isc_image_posts`
	 *
	 * @moved since April 2025
	 *
	 * @return int|false The number of rows updated, or false on error.
	 */
	public static function clear_image_posts_index() {
		ISC_Log::log( 'function moved. \ISC\Image_Sources\Image_Posts_Meta::delete_all' );

		return Post_Meta\Image_Posts_Meta::delete_all();
	}

	/**
	 * Remove all image-post relations
	 * this concerns the post meta fields `isc_image_posts` and `isc_post_images`
	 *
	 * @deprecated since April 2025
	 *
	 * @return bool True if the option was removed
	 */
	public static function clear_index(): bool {
		ISC_Log::log( 'function moved. \ISC\Indexer::clear_index' );

		return Indexer::clear_index();
	}

	/**
	 * Checks if there are image with missing sources
	 * this includes attachments that were not indexed yet (don’t have the appropriate meta values)
	 *
	 * @return int number of images with missing sources
	 */
	public static function count_missing_sources(): int {

		// get known and used attachments without sources
		return count( self::get_attachments_with_empty_sources() );
	}

	/**
	 * Get attachments.
	 * Allows to be called with custom arguments.
	 *
	 * @param array $args arguments for the query.
	 * @return array with attachments. Returns all attachments in the Media Library if called without additional arguments.
	 */
	public static function get_attachments( $args ) {
		$args = wp_parse_args(
			$args,
			[
				'post_type'   => 'attachment',
				'numberposts' => -1,
				'post_status' => null,
				'post_parent' => null,
			]
		);

		return get_posts( $args );
	}

	/**
	 * Get all attachments with empty sources options.
	 *
	 * @return array with attachments.
	 */
	public static function get_attachments_with_empty_sources() {
		global $wpdb;

		$where_clause = "wp_posts.post_type = 'attachment' AND wp_posts.post_status = 'inherit'";

		// Add image type check if images_only is enabled
		if ( \ISC\Media_Type_Checker::enabled_images_only_option() ) {
			$where_clause .= " AND wp_posts.post_mime_type LIKE 'image/%'";
		}

		/**
		 * Filters the WHERE clause for the query that finds attachments with empty sources.
		 *
		 * @param string $where_clause The WHERE clause conditions for the attachments query.
		 * @return string The filtered WHERE clause.
		 */
		$where_clause = apply_filters( 'isc_image_sources_attachments_with_empty_sources_where_clause', $where_clause );

		/**
		 * Using EXISTS instead of LEFT JOINs resulted in much faster queries and helped caching the results.
		 */
		$query = "SELECT wp_posts.ID, wp_posts.post_title, wp_posts.post_parent
	        FROM {$wpdb->posts} AS wp_posts
	        WHERE {$where_clause}
	          AND NOT EXISTS (
	                SELECT 1
	                FROM {$wpdb->postmeta} AS mt1
	                WHERE mt1.post_id = wp_posts.ID
	                  AND mt1.meta_key = 'isc_image_source_own'
	                  AND mt1.meta_value = '1'
	              )
	          AND NOT EXISTS (
	                SELECT 1
	                FROM {$wpdb->postmeta} AS mt_ai
	                WHERE mt_ai.post_id = wp_posts.ID
	                  AND mt_ai.meta_key = 'isc_ai_label'
	                  AND mt_ai.meta_value IN ('ai', 'ai-modified', 'ai-generated')
	              )
	          AND (
	              EXISTS (
	                SELECT 1
	                FROM {$wpdb->postmeta} AS wp_postmeta
	                WHERE wp_postmeta.post_id = wp_posts.ID
	                  AND wp_postmeta.meta_key = 'isc_image_source'
	                  AND wp_postmeta.meta_value = ''
	              )
	            OR NOT EXISTS (
	              SELECT 1
	              FROM {$wpdb->postmeta} AS mt2
	              WHERE mt2.post_id = wp_posts.ID
	                AND mt2.meta_key = 'isc_image_source'
	            )
	          )
	        ORDER BY wp_posts.ID DESC
	        LIMIT %d, %d
	    ";

		// The result of the query is already cached for a day, or until an image is added or removed.
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared
		$attachments = $wpdb->get_results( $wpdb->prepare( $query, 0, self::MAX_POSTS ) );

		$count = count( $attachments );

		// update the transient if the number of results differ
		if ( $count !== (int) get_transient( 'isc-show-missing-sources-warning' ) ) {
			set_transient( 'isc-show-missing-sources-warning', $count, DAY_IN_SECONDS );
		}

		return $attachments;
	}

	/**
	 * Update the transient we set for missing sources to not check them for another day
	 * running each time we are writing the `isc_image_source` post meta key
	 *
	 * @return int number of missing sources.
	 */
	public static function update_missing_sources_transient() {
		$missing_sources = self::count_missing_sources();
		set_transient( 'isc-show-missing-sources-warning', $missing_sources, DAY_IN_SECONDS );
		return $missing_sources;
	}

	/**
	 * Filter image ids from content
	 *
	 * @param string $content post content.
	 * @return string[] with image ids => image src uri-s
	 */
	public static function filter_image_ids( $content = '' ) {
		$srcs = [];

		ISC_Log::log( 'enter looking for image IDs within the content' );

		if ( empty( $content ) ) {
			ISC_Log::log( 'exit due to missing content' );
			return $srcs;
		}

		// parse HTML with DOM
		$dom = new DOMDocument();

		libxml_use_internal_errors( true );
		if ( version_compare( PHP_VERSION, '8.2', '<' ) && function_exists( 'mb_convert_encoding' ) ) {
			$content = mb_convert_encoding( $content, 'HTML-ENTITIES', 'UTF-8' );
		}
		$dom->loadHTML( $content );

		// Prevents from sending E_WARNINGs notice (Outputs are forbidden during activation)
		libxml_clear_errors();

		/**
		 * Handle multiple tags at once
		 * the original use case is checking AMP pages generated in reader mode in the AMP plugin and in AMPforWP
		 * for IMG and AMP-IMG tags
		 */
		$tags = apply_filters( 'isc_filter_image_ids_tags', [ 'img' ] );

		if ( ! is_array( $tags ) ) {
			return [];
		}

		// I am keeping the original $dom->getElementsByTagName as well as the new DOMXpath solution for multiple elements for now
		// since I am not 100% sure about the implications of the latter on existing features
		if ( count( $tags ) === 1 ) {
			$nodes = $dom->getElementsByTagName( 'img' );
		} else {
			$xpath       = new DOMXpath( $dom );
			$tags_string = '//' . implode( '|//', $tags );
			$nodes       = $xpath->query( $tags_string );
		}

		$nodes_count = count( $nodes );

		ISC_Log::log( sprintf( 'found %d img tags', $nodes_count ) );

		if ( ISC_Log::is_type( 'content' ) ) {
			ISC_Log::log( sprintf( 'looked in content: %s', $content ) );
		}

		foreach ( $nodes as $node ) {
			if ( isset( $node->attributes ) ) {
				$matched = false;
				if ( $node->attributes->getNamedItem( 'class' ) !== null ) {
					ISC_Log::log( sprintf( 'found class attribute "%s"', $node->attributes->getNamedItem( 'class' )->textContent ) );

					if ( preg_match( '#.*wp-image-(\d+?).*#U', $node->attributes->getNamedItem( 'class' )->textContent, $matches ) ) {
						// check if a src attribute exists
						if ( $node->attributes->getNamedItem( 'src' ) !== null ) {
							$srcs[ intval( $matches[1] ) ] = $node->attributes->getNamedItem( 'src' )->textContent;
							$matched                       = true;

							ISC_Log::log( sprintf( 'found image ID "%d" with src "%s"', intval( $matches[1] ), $srcs[ intval( $matches[1] ) ] ) );
						} else {
							ISC_Log::log( sprintf( 'no src attribute found for image ID "%d"', intval( $matches[1] ) ) );
						}
					}
				}
				if ( ! $matched ) {
					if ( $node->attributes->getNamedItem( 'src' ) !== null ) {
						$url = $node->attributes->getNamedItem( 'src' )->textContent;
						ISC_Log::log( sprintf( 'found src "%s"', $url ) );
						// get ID of images by url
						$id = self::get_image_by_url( $url );
						if ( $id ) {
							$srcs[ $id ] = $url;
						}
					}
				}
			}
		}

		/**
		 * Filter image IDs found in HTML content, or add new ones based on other rules.
		 *
		 * @since 2.9.0
		 *
		 * @param string[] $srcs image sources with image ids => image src uri
		 * @param string $content any HTML document
		 */
		return apply_filters( 'isc_filter_image_ids_from_content', $srcs, $content );
	}

	/**
	 * Get image ID by URL accessing the database directly
	 *
	 * @param string $url URL of the image.
	 *
	 * @return integer ID of the image.
	 */
	public static function get_image_by_url( string $url = '' ): ?int {
		global $wpdb;

		ISC_Log::log( 'enter get_image_by_url() to look for URL ' . $url );

		$original_url = $url;
		$url          = apply_filters( 'isc_filter_url_pre_get_image_by_url', $url );

		// replace certain characters that WordPress accepts in file names only to test if the URL is valid
		$url_to_check = esc_url( $url, [ 'http', 'https' ] );

		if ( empty( $url ) || $url_to_check !== $url ) {
			return 0;
		}

		// ignore src strings with more than 1000 characters; these could be base24 images not hosted in WordPress
		if ( strlen( $url ) > 1000 ) {
			ISC_Log::log( 'exit due to URL length' );
			return 0;
		}

		// get the file extension, e.g. "jpg"
		$ext = pathinfo( $url, PATHINFO_EXTENSION );
		if ( ! $ext ) {
			ISC_Log::log( 'exit get_image_by_url() no extension found' );
			if ( apply_filters( 'isc_allow_empty_file_extension', __return_false() ) ) {
				ISC_Log::log( "get_image_by_url() didn’t find an extension for $url but continues." );
			} else {
				return 0;
			}
		} elseif ( ! in_array( $ext, Image_Sources::get_allowed_extensions(), true ) ) {
			// a valid image extension is required, if an extension is given
			ISC_Log::log( 'exit get_image_by_url() due to invalid image extension' );
			return 0;
		}

		/**
		 * Check for the format 'image-title-(e12452112-)300x200.jpg(?query…)' and removes
		 * - the image size
		 * - edit marks
		 * - "scaled" or "rotated"
		 * - additional query vars
		 */
		// this is how WordPress core is detecting changed image URLs
		$newurl  = esc_url( preg_replace( "/-(?:\d+x\d+|scaled|rotated)\.{$ext}(.*)/i", '.' . $ext, $url ) );
		$storage = new ISC_Storage_Model();

		// check if the URL is already in storage and if so, take it from there
		if ( $storage->is_image_url_in_storage( $newurl ) ) {
			$id_from_storage = absint( $storage->get_image_id_from_storage( $newurl ) );
			ISC_Log::log( "found $newurl in storage with attachment ID $id_from_storage" );
			return $id_from_storage;
		}

		/**
		 * Attachment_url_to_postid needs the URL including protocol, but cannot handle sizes, so it needs to be at exactly this position
		 * this function finds images based on the _wp_attached_file post meta value that includes the image path followed after the upload dir
		 * it therefore also works when the domain changed
		 * since _wp_attached_file contains "scaled" or "rotated" as well, we keep them, but only remove sizes
		 */
		$id = attachment_url_to_postid( esc_url( preg_replace( "/-\d+x\d+\.{$ext}(.*)/i", '.' . $ext, $url ) ) );
		if ( $id ) {
			// store attachment ID in storage
			$storage->update_post_id( $newurl, $id );
			ISC_Log::log( '_attachment_url_to_postid found image ID ' . $id );
			return $id;
		}

		// remove protocol (http or https)
		$url    = str_ireplace( [ 'http:', 'https:' ], '', $url );
		$newurl = str_ireplace( [ 'http:', 'https:' ], '', $newurl );

		// gather different URLs formats
		$urls = [
			'http:' . $url,
			'https:' . $url,
			'http:' . $newurl,
			'https:' . $newurl,
		];

		// remove duplicates
		$urls = array_unique( $urls );

		$url_queries = [];
		foreach ( $urls as $_url ) {
			// return if any of the URLs is already in storage
			if ( $storage->is_image_url_in_storage( $_url ) ) {
				$id_from_storage = absint( $storage->get_image_id_from_storage( $_url ) );
				ISC_Log::log( "found $newurl in storage with attachment ID $id_from_storage" );
				return $id_from_storage;
			}

			$url_queries[] = 'guid = "' . esc_url( $_url ) . '"';
		}
		$url_query_string = implode( ' OR ', $url_queries );
		ISC_Log::log( sprintf( 'SQL query looking for anything with %s', implode( ', ', array_unique( [ $url, $newurl ] ) ) ) );

		// not escaped, because escaping already happened above
		$raw_query = "SELECT ID, guid FROM `$wpdb->posts` WHERE post_type='attachment' AND {$url_query_string} LIMIT 1";

		$query = apply_filters( 'isc_get_image_by_url_query', $raw_query, $newurl );
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.NotPrepared
		$results = $wpdb->get_results( $query );

		$id   = isset( $results[0]->ID ) ? absint( $results[0]->ID ) : 0;
		$guid = $results[0]->guid ?? null;

		/**
		 * Filter the image ID found by ISC
		 *
		 * Especially useful for compatibility with plugins that manipulate the image URL or meta data so that our checks don’t work
		 *
		 * @param int   $id     attachment ID or null
		 * @param array $params array with additional, optional parameters
		 */
		$id = apply_filters(
			'isc_filter_final_id_get_image_by_url',
			$id,
			[
				'original_url' => $original_url,
				'newurl'       => $newurl,
				'url'          => $url,
			]
		);

		if ( $id ) {
			// if no $guid is found, we store one of the earlier URLs
			$storage->update_post_id( $guid ?? $url, $id );
			ISC_Log::log( 'found image ID ' . $id );
		} else {
			// this should ideally only apply to image URLs that are not in the media library
			// ISC also stores the URL to prevent too many database requests
			// using $newurl, because it is already stripped by potential parameters and stuff
			$storage->update( $newurl, [ 'post_id' => null ] );
			ISC_Log::log( 'no image ID found' );
		}

		return $id;
	}

	/**
	 * Store post meta information.
	 * Use this function instead of core’s update_post_meta() to allow debugging
	 *
	 * @param int    $post_id post ID of the attachment.
	 * @param string $key     post meta key.
	 * @param mixed  $value   value of the post meta information.
	 *
	 * @return bool|int
	 */
	public static function update_post_meta( int $post_id, string $key, $value ) {
		/**
		 * Run when any post meta information is stored by ISC
		 *
		 * @since 2.9.0
		 *
		 * @param int    $post_id post ID of the attachment.
		 * @param string $key     post meta key.
		 * @param mixed  $value   value of the post meta information.
		 */
		do_action( 'isc_update_post_meta', $post_id, $key, $value );

		return update_post_meta( $post_id, $key, $value );
	}

	/**
	 * Get an array of all posts that have the isc_post_images meta field set
	 * and the number of them not having it
	 * list each post type separately
	 *
	 * @return array
	 */
	public static function get_posts_with_image_index(): array {
		$post_types = get_post_types( [ 'public' => true ] );
		// remove the attachment post type
		$post_types = array_diff( $post_types, [ 'attachment' ] );
		$results    = [];

		foreach ( $post_types as $post_type ) {
			$count_posts = wp_count_posts( $post_type );
			$total_posts = $count_posts->publish;

			$args                     = [
				'post_type'      => $post_type,
				'posts_per_page' => self::MAX_POSTS,
				'post_status'    => 'publish',
				'fields'         => 'ids',
				// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
				'meta_query'     => [
					[
						'key'     => 'isc_post_images',
						'compare' => 'NOT EXISTS',
					],
				],
			];
			$query_without            = new WP_Query( $args );
			$posts_without_meta_field = $query_without->post_count;

			$results[ $post_type ] = [
				'total_posts'        => $total_posts,
				'without_meta_field' => $posts_without_meta_field,
				'with_meta_field'    => $total_posts - $posts_without_meta_field,
			];
		}

		return $results;
	}

	/**
	 * Get the attachment’s file URL from the database
	 *
	 * @param int $image_id Attachment ID.
	 *
	 * @return string
	 */
	public function get_base_file_url( int $image_id ): string {
		// load the attachment post
		$file = get_post_meta( $image_id, '_wp_attached_file', true );
		// get guid as fallback, e.g., _wp_attached_file can be empty for external images
		if ( empty( $file ) ) {
			$attachment = get_post( $image_id );
			$file       = $attachment->guid;
		}

		return $file;
	}

	/**
	 * Remove all plugin meta from non-image attachments
	 *
	 * @return void
	 */
	public static function remove_plugin_meta_from_non_images() {
		// The meta keys used by ISC that should be removed from non-images
		$isc_meta_keys = [
			'isc_image_source',
			'isc_image_source_url',
			'isc_image_license',
			'isc_image_source_own',
			\ISC\Image_Sources\Ai_Labels::META_KEY,
			'isc_image_posts',
			'isc_possible_usages',
			'isc_possible_usages_last_check',
		];

		/**
		 * Filter the meta keys to be removed from non-image attachments
		 *
		 * @param array $isc_meta_keys The meta keys to be removed from non-image attachments.
		 */
		apply_filters( 'isc_cleanup_non_image_meta_keys', $isc_meta_keys );

		$attachments = get_posts(
			[
				'post_type'      => 'attachment',
				'post_status'    => 'inherit',
				'posts_per_page' => -1,
			]
		);

		if ( empty( $attachments ) ) {
			return;
		}

		foreach ( $attachments as $attachment ) {
			if ( ! \ISC\Media_Type_Checker::is_image( $attachment ) ) {
				foreach ( $isc_meta_keys as $meta_key ) {
					delete_post_meta( $attachment->ID, $meta_key );
				}
			}
		}
	}
}