<?php
if (!defined('ABSPATH')) exit;

class AIWEST_Undo {
    public static function snapshot($post_id, $source = 'ai_action', $note = '') {
        $post_id = intval($post_id);
        $post = get_post($post_id);
        if (!$post || !in_array($post->post_type, ['page', 'post'], true)) {
            return false;
        }

        $snapshots = get_post_meta($post_id, '_aiwest_undo_snapshots', true);
        if (!is_array($snapshots)) $snapshots = [];

        $snapshots[] = [
            'time' => current_time('mysql'),
            'source' => sanitize_key($source),
            'note' => sanitize_text_field($note),
            'post_title' => $post->post_title,
            'post_content' => $post->post_content,
            'post_excerpt' => $post->post_excerpt,
            'post_status' => $post->post_status,
        ];

        if (count($snapshots) > 10) {
            $snapshots = array_slice($snapshots, -10);
        }

        update_post_meta($post_id, '_aiwest_undo_snapshots', $snapshots);
        update_post_meta($post_id, '_aiwest_last_snapshot_at', current_time('mysql'));
        return true;
    }

    public static function can_undo($post_id) {
        $snapshots = get_post_meta(intval($post_id), '_aiwest_undo_snapshots', true);
        return is_array($snapshots) && !empty($snapshots);
    }

    public static function restore_last($post_id) {
        $post_id = intval($post_id);
        $post = get_post($post_id);
        if (!$post || !in_array($post->post_type, ['page', 'post'], true)) {
            return new WP_Error('aiwest_undo_no_post', __('The page or post to restore was not found.', 'ai-webmaster-studio'));
        }

        $snapshots = get_post_meta($post_id, '_aiwest_undo_snapshots', true);
        if (!is_array($snapshots) || empty($snapshots)) {
            return new WP_Error('aiwest_undo_no_snapshot', __('No saved snapshot is available to restore.', 'ai-webmaster-studio'));
        }

        $snapshot = array_pop($snapshots);

        $result = wp_update_post([
            'ID' => $post_id,
            'post_title' => sanitize_text_field($snapshot['post_title'] ?? $post->post_title),
            'post_content' => $snapshot['post_content'] ?? $post->post_content,
            'post_excerpt' => sanitize_textarea_field($snapshot['post_excerpt'] ?? $post->post_excerpt),
            'post_status' => sanitize_key($snapshot['post_status'] ?? $post->post_status),
        ], true);

        if (is_wp_error($result)) return $result;

        update_post_meta($post_id, '_aiwest_undo_snapshots', $snapshots);
        update_post_meta($post_id, '_aiwest_last_undo_at', current_time('mysql'));

        if (class_exists('AIWEST_Logger')) {
            AIWEST_Logger::info('AI Webmaster Studio undo restored last snapshot.', [
                'post_id' => $post_id,
                'snapshot_time' => $snapshot['time'] ?? '',
                'source' => $snapshot['source'] ?? '',
            ]);
        }

        return [
            'post_id' => $post_id,
            'snapshot_time' => $snapshot['time'] ?? '',
            'source' => $snapshot['source'] ?? '',
        ];
    }
}