<?php
/**
 * @package AKSRT
 */

namespace AKSRT\Admin;

defined('ABSPATH') || exit;

class CommentController extends ControllerBase {

    private static $instance = null;

    public static function get_instance(): self {
        if (null === self::$instance) {
            self::$instance = new self();
        }
        return self::$instance;
    }

    public function register_routes(): void {
        // List comments (admin)
        register_rest_route(self::API_NAMESPACE, '/comments', [
            'methods'             => 'GET',
            'callback'            => [$this, 'list_comments'],
            'permission_callback' => [$this, 'check_permission'],
            'args'                => [
                'page'     => ['default' => 1, 'sanitize_callback' => 'absint'],
                'per_page' => ['default' => 20, 'sanitize_callback' => 'absint'],
                'post_id'  => ['default' => 0, 'sanitize_callback' => 'absint'],
                'status'   => ['default' => '', 'sanitize_callback' => 'sanitize_text_field'],
                'search'   => ['default' => '', 'sanitize_callback' => 'sanitize_text_field'],
            ],
        ]);

        // Create comment (admin or frontend)
        register_rest_route(self::API_NAMESPACE, '/comments', [
            'methods'             => 'POST',
            'callback'            => [$this, 'create_comment'],
            'permission_callback' => [$this, 'check_logged_in_permission'],
            'args'                => [
                'post_id' => ['required' => true, 'sanitize_callback' => 'absint'],
                'content' => ['required' => true, 'sanitize_callback' => 'sanitize_textarea_field'],
                'parent'  => ['default' => 0, 'sanitize_callback' => 'absint'],
            ],
        ]);

        // Update comment status (admin)
        register_rest_route(self::API_NAMESPACE, '/comments/(?P<id>\d+)/status', [
            'methods'             => 'POST',
            'callback'            => [$this, 'update_comment_status'],
            'permission_callback' => [$this, 'check_permission'],
            'args'                => [
                'id'     => ['required' => true, 'sanitize_callback' => 'absint'],
                'status' => ['required' => true, 'sanitize_callback' => 'sanitize_text_field'],
            ],
        ]);

        // Edit comment content (admin)
        register_rest_route(self::API_NAMESPACE, '/comments/(?P<id>\d+)', [
            'methods'             => 'POST',
            'callback'            => [$this, 'update_comment'],
            'permission_callback' => [$this, 'check_permission'],
            'args'                => [
                'id'      => ['required' => true, 'sanitize_callback' => 'absint'],
                'content' => ['required' => true, 'sanitize_callback' => 'sanitize_textarea_field'],
            ],
        ]);

        // Delete comment (admin)
        register_rest_route(self::API_NAMESPACE, '/comments/(?P<id>\d+)', [
            'methods'             => 'DELETE',
            'callback'            => [$this, 'delete_comment'],
            'permission_callback' => [$this, 'check_permission'],
            'args'                => [
                'id' => ['required' => true, 'sanitize_callback' => 'absint'],
            ],
        ]);

        // Bulk action (admin)
        register_rest_route(self::API_NAMESPACE, '/comments/bulk', [
            'methods'             => 'POST',
            'callback'            => [$this, 'bulk_action'],
            'permission_callback' => [$this, 'check_permission'],
        ]);

        // Frontend: list comments for a post (public)
        register_rest_route(self::API_NAMESPACE, '/comments/post/(?P<post_id>\d+)', [
            'methods'             => 'GET',
            'callback'            => [$this, 'get_post_comments'],
            'permission_callback' => '__return_true',
            'args'                => [
                'post_id'  => ['required' => true, 'sanitize_callback' => 'absint'],
                'page'     => ['default' => 1, 'sanitize_callback' => 'absint'],
                'per_page' => ['default' => 10, 'sanitize_callback' => 'absint'],
                'order'    => ['default' => 'DESC', 'sanitize_callback' => 'sanitize_text_field'],
            ],
        ]);
    }

    /**
     * GET /comments — List comments with filtering.
     */
    public function list_comments(\WP_REST_Request $request): \WP_REST_Response {
        $args = [
            'number'  => min(100, (int) $request->get_param('per_page')),
            'offset'  => ((int) $request->get_param('page') - 1) * (int) $request->get_param('per_page'),
            'orderby' => 'comment_date_gmt',
            'order'   => 'DESC',
        ];

        $post_id = (int) $request->get_param('post_id');
        if ($post_id > 0) {
            $args['post_id'] = $post_id;
        }

        $status = $request->get_param('status');
        if ($status !== '') {
            $args['status'] = $status;
        }

        $search = $request->get_param('search');
        if ($search !== '') {
            $args['search'] = $search;
        }

        $query = new \WP_Comment_Query($args);

        // Batch prefetch to avoid N+1 queries
        $user_ids = array_unique(array_filter(array_map(fn($c) => (int) $c->user_id, $query->comments)));
        $post_ids = array_unique(array_map(fn($c) => (int) $c->comment_post_ID, $query->comments));
        $users_map = [];
        $posts_map = [];
        if (!empty($user_ids)) {
            $users = get_users(['include' => $user_ids, 'fields' => ['ID', 'display_name']]);
            foreach ($users as $u) $users_map[$u->ID] = $u;
        }
        if (!empty($post_ids)) {
            global $wpdb;
            $ids_csv = implode(',', array_map('intval', $post_ids));
            $titles = $wpdb->get_results("SELECT ID, post_title FROM {$wpdb->posts} WHERE ID IN ({$ids_csv})", OBJECT_K);
            foreach ($titles as $t) $posts_map[$t->ID] = $t->post_title;
        }

        $comments = [];
        foreach ($query->comments as $comment) {
            $comments[] = $this->format_comment($comment, $users_map, $posts_map);
        }

        // Total count for pagination
        $count_args = $args;
        unset($count_args['number'], $count_args['offset'], $count_args['orderby'], $count_args['order']);
        $count_args['count'] = true;
        $total = (int) (new \WP_Comment_Query($count_args))->get_comments('count');

        return $this->success([
            'data'  => $comments,
            'total' => $total,
            'pages' => ceil($total / (int) $request->get_param('per_page')),
        ]);
    }

    /**
     * POST /comments — Create a comment.
     */
    public function create_comment(\WP_REST_Request $request): \WP_REST_Response {
        $user_id  = get_current_user_id();
        $post_id  = (int) $request->get_param('post_id');
        $content  = trim((string) $request->get_param('content'));
        $parent   = (int) $request->get_param('parent');

        if (!$content) {
            return $this->error('content_required', '评论内容不能为空。', 400);
        }

        $post = get_post($post_id);
        if (!$post || $post->post_status !== 'publish') {
            return $this->error('invalid_post', '文章不存在或未发布。', 400);
        }

        $comment_data = [
            'comment_post_ID' => $post_id,
            'comment_content' => $content,
            'user_id'         => $user_id,
            'comment_parent'  => $parent,
            'comment_approved'=> 1, // Admin-created comments are auto-approved
        ];

        $comment_id = wp_insert_comment($comment_data);
        if (is_wp_error($comment_id)) {
            return $this->error('create_failed', $comment_id->get_error_message(), 500);
        }

        $comment = get_comment($comment_id);
        return $this->success(['data' => $this->format_comment($comment)]);
    }

    /**
     * POST /comments/{id}/status — Approve/unapprove/spam/trash.
     */
    public function update_comment_status(\WP_REST_Request $request): \WP_REST_Response {
        $comment_id = (int) $request->get_param('id');
        $new_status = $request->get_param('status');
        $comment    = get_comment($comment_id);

        if (!$comment) {
            return $this->error('not_found', '评论不存在。', 404);
        }

        $valid_statuses = ['approve', 'hold', 'spam', 'trash'];
        if (!in_array($new_status, $valid_statuses, true)) {
            return $this->error('invalid_status', '无效的状态值。', 400);
        }

        $result = wp_set_comment_status($comment_id, $new_status);
        if (is_wp_error($result)) {
            return $this->error('update_failed', $result->get_error_message(), 500);
        }

        // Handle spam/trash
        if ($new_status === 'spam') {
            wp_spam_comment($comment_id);
        } elseif ($new_status === 'trash') {
            wp_trash_comment($comment_id);
        }

        $comment = get_comment($comment_id);
        return $this->success(['data' => $this->format_comment($comment)]);
    }

    /**
     * POST /comments/{id} — Edit comment content.
     */
    public function update_comment(\WP_REST_Request $request): \WP_REST_Response {
        $comment_id = (int) $request->get_param('id');
        $content    = trim((string) $request->get_param('content'));
        $comment    = get_comment($comment_id);

        if (!$comment) {
            return $this->error('not_found', '评论不存在。', 404);
        }

        if (!$content) {
            return $this->error('content_required', '评论内容不能为空。', 400);
        }

        $result = wp_update_comment(['comment_ID' => $comment_id, 'comment_content' => $content]);
        if (is_wp_error($result)) {
            return $this->error('update_failed', $result->get_error_message(), 500);
        }

        $comment = get_comment($comment_id);
        return $this->success(['data' => $this->format_comment($comment)]);
    }

    /**
     * DELETE /comments/{id} — Delete a comment.
     */
    public function delete_comment(\WP_REST_Request $request): \WP_REST_Response {
        $comment_id = (int) $request->get_param('id');
        $comment    = get_comment($comment_id);

        if (!$comment) {
            return $this->error('not_found', '评论不存在。', 404);
        }

        $result = wp_delete_comment($comment_id, true);
        if (!$result) {
            return $this->error('delete_failed', '删除评论失败。', 500);
        }

        return $this->success(['data' => ['deleted' => true, 'id' => $comment_id]]);
    }

    /**
     * POST /comments/bulk — Bulk action on comments.
     */
    public function bulk_action(\WP_REST_Request $request): \WP_REST_Response {
        $body = $request->get_json_params();
        $ids  = array_map('absint', $body['ids'] ?? []);
        $action = sanitize_text_field($body['action'] ?? '');

        if (empty($ids) || !$action) {
            return $this->error('missing_params', '缺少参数。', 400);
        }

        $success = 0;
        $failed  = 0;

        foreach ($ids as $id) {
            $comment = get_comment($id);
            if (!$comment) { $failed++; continue; }

            switch ($action) {
                case 'approve':
                    wp_set_comment_status($id, 'approve');
                    $success++;
                    break;
                case 'hold':
                    wp_set_comment_status($id, 'hold');
                    $success++;
                    break;
                case 'spam':
                    wp_spam_comment($id);
                    $success++;
                    break;
                case 'trash':
                    wp_trash_comment($id);
                    $success++;
                    break;
                case 'delete':
                    wp_delete_comment($id, true);
                    $success++;
                    break;
                default:
                    $failed++;
            }
        }

        return $this->success(['data' => ['success' => $success, 'failed' => $failed]]);
    }

    /**
     * GET /comments/post/{post_id} — Public: list comments for a post with nesting.
     */
    public function get_post_comments(\WP_REST_Request $request): \WP_REST_Response {
        $post_id  = (int) $request->get_param('post_id');
        $page     = max(1, (int) $request->get_param('page'));
        $per_page = min(50, max(1, (int) $request->get_param('per_page')));
        $order    = in_array(strtoupper((string) $request->get_param('order')), ['ASC', 'DESC'], true)
                    ? strtoupper((string) $request->get_param('order'))
                    : 'DESC';

        $args = [
            'post_id'    => $post_id,
            'status'     => 'approve',
            'number'     => $per_page,
            'offset'     => ($page - 1) * $per_page,
            'orderby'    => 'comment_date_gmt',
            'order'      => $order,
            'hierarchical' => 'threaded',
        ];

        $query    = new \WP_Comment_Query($args);

        // Batch prefetch users
        $user_ids = array_unique(array_filter(array_map(fn($c) => (int) $c->user_id, $query->comments)));
        $users_map = [];
        if (!empty($user_ids)) {
            $users = get_users(['include' => $user_ids, 'fields' => ['ID', 'display_name']]);
            foreach ($users as $u) $users_map[$u->ID] = $u;
        }

        $comments = [];
        foreach ($query->comments as $comment) {
            $comments[] = $this->format_comment_public($comment, $users_map);
        }

        // Total approved comments for this post
        $total = (int) get_comments_number($post_id);
        $total_approved = get_comments([
            'post_id' => $post_id,
            'status'  => 'approve',
            'count'   => true,
        ]);

        return $this->success([
            'data'  => $comments,
            'total' => (int) $total_approved,
            'pages' => ceil((int) $total_approved / $per_page),
        ]);
    }

    /**
     * Format comment for admin views.
     */
    private function format_comment(\WP_Comment $comment, array $users_map = [], array $posts_map = []): array {
        $uid = (int) $comment->user_id;
        $pid = (int) $comment->comment_post_ID;
        $user = $users_map[$uid] ?? ($uid ? get_userdata($uid) : null);
        return [
            'id'           => (int) $comment->comment_ID,
            'post_id'      => $pid,
            'post_title'   => $posts_map[$pid] ?? get_the_title($pid),
            'author'       => $comment->comment_author,
            'author_email' => $comment->comment_author_email,
            'user_id'      => (int) $comment->user_id,
            'user_name'    => $user ? $user->display_name : '',
            'content'      => $comment->comment_content,
            'status'       => $comment->comment_approved,
            'parent'       => (int) $comment->comment_parent,
            'date'         => $comment->comment_date_gmt,
            'author_ip'    => $comment->comment_author_IP,
            'avatar_url'   => get_avatar_url($comment->comment_author_email, ['size' => 48]),
        ];
    }

    /**
     * Format comment for public views (no email/IP).
     */
    private function format_comment_public(\WP_Comment $comment, array $users_map = []): array {
        $uid = (int) $comment->user_id;
        $user = $users_map[$uid] ?? ($uid ? get_userdata($uid) : null);
        return [
            'id'         => (int) $comment->comment_ID,
            'author'     => $comment->comment_author,
            'user_id'    => (int) $comment->user_id,
            'content'    => $comment->comment_content,
            'date'       => $comment->comment_date_gmt,
            'parent'     => (int) $comment->comment_parent,
            'avatar_url' => get_avatar_url($comment->comment_author_email, ['size' => 48]),
            'children'   => [], // Will be populated by JS if threaded
        ];
    }

    /**
     * Helper: check logged-in permission (any authenticated user).
     */
    public function check_logged_in_permission(): bool {
        return is_user_logged_in();
    }
}