<?php
/**
 * Tracks per-attachment optimisation history.
 *
 * Stored as a single postmeta key `_h4b_img_optim` containing:
 *   [
 *     'version'      => '0.1.0',
 *     'processed_at' => 'ISO-8601',
 *     'tool_chain'   => ['imagick','cjpeg','jpegoptim',...],
 *     'sizes'        => [
 *        'full'      => ['before'=>123, 'after'=>78, 'webp'=>45, 'avif'=>30, 'percent'=>37],
 *        '800x524'   => [...],
 *     ],
 *     'backup_path'  => 'wp-content/h4b-img-originals/2026/02/...',
 *     'errors'       => [],
 *   ]
 *
 * @package H4B\ImageOptim
 */

namespace H4B\ImageOptim;

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

final class Attachment_Meta {

	public const META_KEY = '_h4b_img_optim';

	public static function get( int $attachment_id ): array {
		$meta = get_post_meta( $attachment_id, self::META_KEY, true );
		return is_array( $meta ) ? $meta : [];
	}

	public static function set( int $attachment_id, array $meta ): void {
		update_post_meta( $attachment_id, self::META_KEY, $meta );
	}

	public static function is_processed( int $attachment_id ): bool {
		$meta = self::get( $attachment_id );
		return ! empty( $meta['processed_at'] );
	}

	public static function record_size( int $attachment_id, string $size_key, array $stats ): void {
		$meta              = self::get( $attachment_id );
		$meta['sizes']     = $meta['sizes'] ?? [];
		$meta['sizes'][ $size_key ] = $stats;
		$meta['version']      = H4B_IMG_OPTIM_VERSION;
		$meta['processed_at'] = current_time( 'c' );
		self::set( $attachment_id, $meta );
	}

	public static function mark_avif_pending( int $attachment_id, string $size_key ): void {
		$meta = self::get( $attachment_id );
		$meta['avif_pending'] = $meta['avif_pending'] ?? [];
		$meta['avif_pending'][ $size_key ] = current_time( 'c' );
		self::set( $attachment_id, $meta );
	}

	public static function clear_avif_pending( int $attachment_id, string $size_key ): void {
		$meta = self::get( $attachment_id );
		if ( isset( $meta['avif_pending'][ $size_key ] ) ) {
			unset( $meta['avif_pending'][ $size_key ] );
			if ( empty( $meta['avif_pending'] ) ) {
				unset( $meta['avif_pending'] );
			}
			self::set( $attachment_id, $meta );
		}
	}
}