<?php
/**
 * wp h4b-img bulk — walk all image attachments and optimise unprocessed ones.
 *
 * @package H4B\ImageOptim
 */

namespace H4B\ImageOptim;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

final class CLI_Bulk {

	/**
	 * Optimise all image attachments.
	 *
	 * ## OPTIONS
	 *
	 * [--status=<status>]
	 * : unoptimised (default) | all
	 *
	 * [--mime=<mime>]
	 * : Comma-separated MIME types. Default: image/jpeg,image/png
	 *
	 * [--limit=<n>]
	 * : Maximum attachments to process. 0 = no limit.
	 *
	 * [--batch=<n>]
	 * : Batch size for memory hygiene. Default: from settings (10).
	 *
	 * [--pause=<seconds>]
	 * : Sleep between batches. Default: from settings (1).
	 *
	 * [--dry-run]
	 * : Report counts only.
	 *
	 * [--force]
	 * : Re-optimise even if already processed.
	 *
	 * [--id=<id>]
	 * : Process a single attachment (alias for `optimise --id=X`).
	 *
	 * ## EXAMPLES
	 *     wp h4b-img bulk --dry-run
	 *     wp h4b-img bulk --status=unoptimised
	 *     wp h4b-img bulk --status=all --force --limit=50
	 */
	public function __invoke( $args, $assoc ): void {
		$status   = $assoc['status']  ?? 'unoptimised';
		$mime     = isset( $assoc['mime'] )
			? array_map( 'trim', explode( ',', $assoc['mime'] ) )
			: [ 'image/jpeg', 'image/png' ];
		$limit    = (int) ( $assoc['limit'] ?? 0 );
		$batch    = (int) ( $assoc['batch'] ?? Settings::get( 'bulk_batch_size', 10 ) );
		$pause    = (int) ( $assoc['pause'] ?? Settings::get( 'bulk_pause_seconds', 1 ) );
		$dry_run  = ! empty( $assoc['dry-run'] );
		$force    = ! empty( $assoc['force'] );

		$ids = self::find_candidates( $status, $mime, $limit );
		$total = count( $ids );
		\WP_CLI::log( sprintf(
			'Found %d attachment(s) matching status=%s mime=%s',
			$total, $status, implode( ',', $mime )
		) );
		if ( $dry_run ) {
			\WP_CLI::success( 'Dry run only — no changes made.' );
			return;
		}
		if ( $total === 0 ) {
			\WP_CLI::success( 'Nothing to do.' );
			return;
		}

		$progress = \WP_CLI\Utils\make_progress_bar( 'Optimising', $total );
		$summary = [
			'attachments' => 0,
			'sizes'       => 0,
			'skipped'     => 0,
			'errors'      => 0,
			'bytes_before' => 0,
			'bytes_after'  => 0,
		];

		$processed_since_pause = 0;
		foreach ( $ids as $id ) {
			$result = self::process_attachment( (int) $id, $force );
			$summary['attachments']++;
			$summary['sizes']        += $result['sizes_processed'];
			$summary['skipped']      += $result['sizes_skipped'];
			$summary['errors']       += $result['errors'];
			$summary['bytes_before'] += $result['bytes_before'];
			$summary['bytes_after']  += $result['bytes_after'];

			$progress->tick();
			$processed_since_pause++;
			if ( $processed_since_pause >= $batch ) {
				if ( $pause > 0 ) {
					sleep( $pause );
				}
				$processed_since_pause = 0;
				// Free memory accumulated by Imagick + WP postmeta cache
				wp_cache_flush_runtime();
			}
		}
		$progress->finish();

		$saved = $summary['bytes_before'] - $summary['bytes_after'];
		$pct   = $summary['bytes_before'] > 0
			? round( $saved / $summary['bytes_before'] * 100, 1 )
			: 0;
		\WP_CLI::success( sprintf(
			"Bulk done.\n  Attachments: %d\n  Sizes processed: %d\n  Sizes skipped (small): %d\n  Errors: %d\n  Bytes before: %s\n  Bytes after:  %s\n  Saved: %s (%s%%)",
			$summary['attachments'],
			$summary['sizes'],
			$summary['skipped'],
			$summary['errors'],
			size_format( $summary['bytes_before'], 2 ),
			size_format( $summary['bytes_after'], 2 ),
			size_format( $saved, 2 ),
			$pct
		) );
	}

	/**
	 * Find attachment IDs to process.
	 *
	 * @return int[]
	 */
	private static function find_candidates( string $status, array $mime, int $limit ): array {
		global $wpdb;

		$mime_placeholders = implode( ',', array_fill( 0, count( $mime ), '%s' ) );
		$base_query = "SELECT p.ID FROM {$wpdb->posts} p
			WHERE p.post_type = 'attachment'
			AND p.post_mime_type IN ($mime_placeholders)";

		if ( $status === 'unoptimised' ) {
			// LEFT JOIN postmeta; pick rows where our meta is missing or status pending
			$base_query = "SELECT p.ID FROM {$wpdb->posts} p
				LEFT JOIN {$wpdb->postmeta} pm
					ON pm.post_id = p.ID AND pm.meta_key = %s
				WHERE p.post_type = 'attachment'
				AND p.post_mime_type IN ($mime_placeholders)
				AND pm.meta_id IS NULL";
			$query_args = array_merge( [ Attachment_Meta::META_KEY ], $mime );
		} else {
			$query_args = $mime;
		}

		$base_query .= ' ORDER BY p.ID ASC';
		if ( $limit > 0 ) {
			$base_query .= ' LIMIT ' . (int) $limit;
		}

		$sql = $wpdb->prepare( $base_query, ...$query_args );
		return array_map( 'intval', $wpdb->get_col( $sql ) );
	}

	/**
	 * Process one attachment.
	 *
	 * @return array{sizes_processed:int, sizes_skipped:int, errors:int, bytes_before:int, bytes_after:int}
	 */
	private static function process_attachment( int $id, bool $force ): array {
		$summary = [
			'sizes_processed' => 0,
			'sizes_skipped'   => 0,
			'errors'          => 0,
			'bytes_before'    => 0,
			'bytes_after'     => 0,
		];

		if ( ! $force && Attachment_Meta::is_processed( $id ) ) {
			$summary['sizes_skipped']++;
			return $summary;
		}

		$metadata = wp_get_attachment_metadata( $id );
		$relative = get_post_meta( $id, '_wp_attached_file', true );
		if ( ! $metadata || ! $relative ) {
			$summary['errors']++;
			return $summary;
		}
		$uploads = wp_get_upload_dir();
		$basedir = trailingslashit( $uploads['basedir'] );
		$full    = $basedir . $relative;
		if ( ! is_readable( $full ) ) {
			$summary['errors']++;
			return $summary;
		}

		// Process full + every size
		$paths = [ 'full' => $full ];
		$dir   = dirname( $full );
		foreach ( ( $metadata['sizes'] ?? [] ) as $size_key => $size_data ) {
			if ( empty( $size_data['file'] ) ) {
				continue;
			}
			$paths[ (string) $size_key ] = trailingslashit( $dir ) . $size_data['file'];
		}

		foreach ( $paths as $size_key => $path ) {
			if ( ! is_readable( $path ) ) {
				$summary['errors']++;
				continue;
			}
			$before = filesize( $path );
			$summary['bytes_before'] += $before;

			$opt = Optimizer::optimise( $path );
			if ( $opt['status'] === 'done' ) {
				$summary['sizes_processed']++;
			} elseif ( $opt['status'] === 'skipped' ) {
				$summary['sizes_skipped']++;
			} else {
				$summary['errors']++;
			}

			// Siblings
			$webp_size = null;
			$avif_status = 'skipped';
			$avif_size = null;
			if ( in_array( $opt['status'], [ 'done', 'skipped' ], true ) ) {
				if ( Settings::get( 'generate_webp', true ) ) {
					$w = Format_Generator::make_webp( $path );
					if ( $w['status'] === 'done' ) {
						$webp_size = $w['size'];
					}
				}
				if ( Settings::get( 'generate_avif', true ) ) {
					$a = Format_Generator::make_avif( $path );
					$avif_status = $a['status'];
					if ( $a['status'] === 'done' ) {
						$avif_size = $a['size'];
					} elseif ( $a['status'] === 'queued' ) {
						Attachment_Meta::mark_avif_pending( $id, (string) $size_key );
					}
				}
			}

			clearstatcache( true, $path );
			$after = filesize( $path );
			$summary['bytes_after'] += $after;

			Attachment_Meta::record_size( $id, (string) $size_key, [
				'status'        => $opt['status'],
				'before'        => $before,
				'after'         => $after,
				'percent'       => $opt['percent'] ?? 0,
				'icc_preserved' => $opt['icc_preserved'] ?? false,
				'tool_chain'    => $opt['tool_chain'] ?? [],
				'webp'          => $webp_size,
				'avif'          => $avif_size,
				'avif_status'   => $avif_status,
				'backup'        => $opt['backup_path'] ?? null,
				'error'         => $opt['error'] ?? null,
			] );

			// Update WP-core's filesize record so admin "media used" stats stay accurate
			self::refresh_metadata_filesize( $id, (string) $size_key, $after );
		}

		return $summary;
	}

	/**
	 * Update _wp_attachment_metadata.sizes[<key>].filesize so WP admin stays accurate.
	 */
	private static function refresh_metadata_filesize( int $id, string $size_key, int $bytes ): void {
		$meta = wp_get_attachment_metadata( $id );
		if ( ! is_array( $meta ) ) {
			return;
		}
		if ( $size_key === 'full' ) {
			$meta['filesize'] = $bytes;
		} elseif ( isset( $meta['sizes'][ $size_key ] ) ) {
			$meta['sizes'][ $size_key ]['filesize'] = $bytes;
		}
		wp_update_attachment_metadata( $id, $meta );
	}
}