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

namespace AKSRT\Messages;

defined('ABSPATH') || exit;

class ReportCenter {

    private static $instance = null;

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

    private function table(): string {
        return class_exists('\AKSRT\Core\DBMigrator') ? \AKSRT\Core\DBMigrator::table('report') : '';
    }

    /**
     * 提交举报
     *
     * @param int    $reporter_id 举报人 ID
     * @param string $target_type 举报目标类型 (post/comment/user)
     * @param int    $target_id   目标 ID
     * @param string $reason      举报原因
     * @param string $category    举报分类
     * @return int 举报 ID（0 表示失败）
     */
    public function submit(int $reporter_id, string $target_type, int $target_id, string $reason, string $category = ''): int {
        if ($reporter_id <= 0 || $target_id <= 0) return 0;

        $valid_types = ['post', 'comment', 'user'];
        if (!in_array($target_type, $valid_types, true)) return 0;

        $table = $this->table();
        if ($table === '') return 0;

        global $wpdb;
        $wpdb->insert($table, [
            'reporter_id' => $reporter_id,
            'target_type' => sanitize_key($target_type),
            'target_id'   => $target_id,
            'reason'      => sanitize_textarea_field($reason),
            'category'    => sanitize_key($category),
            'status'      => 'pending',
            'created_at'  => current_time('mysql'),
        ], ['%d', '%s', '%d', '%s', '%s', '%s', '%s']);

        $id = $wpdb->insert_id ? (int) $wpdb->insert_id : 0;
        if ($id > 0) {
            do_action('aksrt_report_submitted', $id, [
                'reporter_id' => $reporter_id,
                'target_type' => $target_type,
                'target_id' => $target_id,
                'reason' => $reason,
                'category' => $category,
            ]);
        }
        return $id;
    }

    /**
     * 获取待处理举报数
     */
    public function get_pending_count(): int {
        $table = $this->table();
        if ($table === '') return 0;

        global $wpdb;
        return (int) $wpdb->get_var(
            "SELECT COUNT(*) FROM {$table} WHERE status = 'pending'"
        );
    }

    /**
     * 获取举报列表
     */
    public function get_reports(array $args = []): array {
        $table = $this->table();
        if ($table === '') return [];

        global $wpdb;

        $where  = [];
        $params = [];

        $status = sanitize_key((string) ($args['status'] ?? ''));
        if ($status !== '') {
            $where[]  = 'status = %s';
            $params[] = $status;
        }

        $limit  = max(1, min(100, (int) ($args['limit'] ?? 20)));
        $offset = max(0, (int) ($args['offset'] ?? 0));

        $where_sql = $where ? 'WHERE ' . implode(' AND ', $where) : '';
        $sql = "SELECT * FROM {$table} {$where_sql} ORDER BY created_at DESC LIMIT %d OFFSET %d";
        $params[] = $limit;
        $params[] = $offset;

        $rows = $wpdb->get_results($wpdb->prepare($sql, $params), ARRAY_A);

        // 附加审核备注
        foreach ($rows as &$row) {
            $row['id']         = (int) $row['id'];
            $row['reporter_id'] = (int) $row['reporter_id'];
            $row['target_id']  = (int) $row['target_id'];
            $row['notes']      = isset($row['notes_json']) ? json_decode($row['notes_json'], true) ?? [] : [];
        }

        return $rows;
    }

    /**
     * 更新举报状态
     */
    public function update_status(int $report_id, string $new_status, string $note = ''): bool {
        $valid_statuses = ['pending', 'reviewing', 'resolved', 'dismissed'];
        if (!in_array($new_status, $valid_statuses, true)) return false;

        $table = $this->table();
        if ($table === '') return false;

        global $wpdb;

        $existing = $wpdb->get_row($wpdb->prepare(
            "SELECT id, reporter_id, notes_json FROM {$table} WHERE id = %d",
            $report_id
        ));

        if (!$existing) return false;

        $update_data = [
            'status'     => $new_status,
            'updated_at' => current_time('mysql'),
        ];
        $format = ['%s', '%s'];

        if ($note !== '') {
            $notes = json_decode($existing->notes_json ?? '[]', true) ?? [];
            $notes[] = [
                'note'      => sanitize_textarea_field($note),
                'status'    => $new_status,
                'operator'  => get_current_user_id(),
                'timestamp' => current_time('mysql'),
            ];
            $update_data['notes_json'] = wp_json_encode($notes);
            $format[] = '%s';
        }

        $result = $wpdb->update($table, $update_data, ['id' => $report_id], $format, ['%d']);
        if ($result !== false) {
            do_action('aksrt_report_status_changed', $report_id, (int) ($existing->reporter_id ?? 0), $new_status);
        }
        return $result !== false;
    }

    /**
     * Get status counts for the admin dashboard.
     *
     * @return array{pending: int, reviewing: int, resolved: int, dismissed: int, total: int}
     */
    public function get_status_counts(): array {
        $table = $this->table();
        if ($table === '') {
            return ['pending' => 0, 'reviewing' => 0, 'resolved' => 0, 'dismissed' => 0, 'total' => 0];
        }

        global $wpdb;
        $rows = $wpdb->get_results(
            "SELECT status, COUNT(*) as cnt FROM {$table} GROUP BY status",
            ARRAY_A
        );

        $counts = ['pending' => 0, 'reviewing' => 0, 'resolved' => 0, 'dismissed' => 0];
        $total  = 0;
        foreach ((array) $rows as $row) {
            $s = $row['status'] ?? '';
            if (isset($counts[$s])) {
                $counts[$s] = (int) $row['cnt'];
            }
            $total += (int) $row['cnt'];
        }
        $counts['total'] = $total;
        return $counts;
    }

    /**
     * 一次性迁移：把 option 中的举报数据搬到表中。
     * 幂等 — 已存在的 ID 不会重复插入。
     */
    public function migrate_from_option(): int {
        $table = $this->table();
        if ($table === '') return 0;

        $reports = get_option('aksrt_reports', []);
        if (!is_array($reports) || empty($reports)) return 0;

        global $wpdb;
        $migrated = 0;

        foreach ($reports as $old_id => $report) {
            // 检查是否已迁移（通过 reporter_id + target_type + target_id + created_at 去重）
            $existing = $wpdb->get_var($wpdb->prepare(
                "SELECT id FROM {$table} WHERE reporter_id = %d AND target_type = %s AND target_id = %d AND created_at = %s",
                (int) ($report['reporter_id'] ?? 0),
                sanitize_key((string) ($report['target_type'] ?? '')),
                (int) ($report['target_id'] ?? 0),
                (string) ($report['created_at'] ?? '')
            ));
            if ($existing) continue;

            $notes_json = '';
            if (!empty($report['notes']) && is_array($report['notes'])) {
                $notes_json = wp_json_encode($report['notes']);
            }

            $wpdb->insert($table, [
                'reporter_id' => (int) ($report['reporter_id'] ?? 0),
                'target_type' => sanitize_key((string) ($report['target_type'] ?? '')),
                'target_id'   => (int) ($report['target_id'] ?? 0),
                'reason'      => sanitize_textarea_field((string) ($report['reason'] ?? '')),
                'category'    => sanitize_key((string) ($report['category'] ?? '')),
                'status'      => sanitize_key((string) ($report['status'] ?? 'pending')),
                'created_at'  => (string) ($report['created_at'] ?? current_time('mysql')),
                'updated_at'  => (string) ($report['updated_at'] ?? ''),
                'notes_json'  => $notes_json,
            ], ['%d', '%s', '%d', '%s', '%s', '%s', '%s', '%s', '%s']);

            if ($wpdb->insert_id) $migrated++;
        }

        if ($migrated > 0) {
            update_option('aksrt_report_migrated_to_table', time());
        }

        return $migrated;
    }

    /**
     * Initialize AJAX hooks for admin operations.
     */
    public function init(): void {
        add_action('wp_ajax_aksrt_report_update_status', [$this, 'ajax_update_status']);
        add_action('wp_ajax_aksrt_report_list', [$this, 'ajax_list']);
        add_action('wp_ajax_aksrt_report_counts', [$this, 'ajax_counts']);

        // 一次性迁移钩子
        add_action('admin_init', [$this, 'maybe_migrate'], 20);
    }

    /**
     * 自动迁移旧 option 数据（幂等）
     */
    public function maybe_migrate(): void {
        if (get_option('aksrt_report_migrated_to_table')) return;
        $this->migrate_from_option();
    }

    /**
     * AJAX: Update report status (admin only).
     */
    public function ajax_update_status(): void {
        if (!current_user_can('manage_options')) {
            wp_send_json_error(['message' => __('权限不足', 'aksrt')]);
        }

        check_ajax_referer('aksrt_report', '_nonce');

        $report_id = (int) ($_POST['report_id'] ?? 0);
        $new_status = sanitize_key((string) ($_POST['status'] ?? ''));
        $note = sanitize_textarea_field((string) ($_POST['note'] ?? ''));

        if ($report_id <= 0 || $new_status === '') {
            wp_send_json_error(['message' => __('参数无效', 'aksrt')]);
        }

        $result = $this->update_status($report_id, $new_status, $note);
        if ($result) {
            wp_send_json_success(['message' => __('状态已更新', 'aksrt')]);
        }

        wp_send_json_error(['message' => __('更新失败', 'aksrt')]);
    }

    /**
     * AJAX: Get report list (admin only).
     */
    public function ajax_list(): void {
        if (!current_user_can('manage_options')) {
            wp_send_json_error(['message' => __('权限不足', 'aksrt')]);
        }

        $status = sanitize_key((string) ($_GET['status'] ?? ''));
        $limit = max(1, min(100, (int) ($_GET['limit'] ?? 20)));
        $offset = max(0, (int) ($_GET['offset'] ?? 0));

        $reports = $this->get_reports(['status' => $status, 'limit' => $limit, 'offset' => $offset]);
        $counts = $this->get_status_counts();

        wp_send_json_success(['reports' => $reports, 'counts' => $counts]);
    }

    /**
     * AJAX: Get status counts (admin only).
     */
    public function ajax_counts(): void {
        if (!current_user_can('manage_options')) {
            wp_send_json_error(['message' => __('权限不足', 'aksrt')]);
        }

        wp_send_json_success($this->get_status_counts());
    }
}