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

namespace AKSRT\Admin;

defined('ABSPATH') || exit;

class MessageController 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 {
        // ── Notifications ──

        // List notifications
        register_rest_route(self::API_NAMESPACE, '/messages', [
            'methods'             => 'GET',
            'callback'            => [$this, 'list_notifications'],
            'permission_callback' => [$this, 'check_logged_in_permission'],
            'args' => [
                'type'     => ['default' => '', 'sanitize_callback' => 'sanitize_text_field'],
                'page'     => ['default' => 1, 'sanitize_callback' => 'absint'],
                'per_page' => ['default' => 20, 'sanitize_callback' => 'absint'],
            ],
        ]);

        // Unread count
        register_rest_route(self::API_NAMESPACE, '/messages/unread', [
            'methods'             => 'GET',
            'callback'            => [$this, 'get_unread_count'],
            'permission_callback' => [$this, 'check_logged_in_permission'],
        ]);

        // Mark one notification read
        register_rest_route(self::API_NAMESPACE, '/messages/(?P<id>\d+)/read', [
            'methods'             => 'POST',
            'callback'            => [$this, 'mark_read'],
            'permission_callback' => [$this, 'check_logged_in_permission'],
        ]);

        // Mark all notifications read
        register_rest_route(self::API_NAMESPACE, '/messages/read-all', [
            'methods'             => 'POST',
            'callback'            => [$this, 'mark_all_read'],
            'permission_callback' => [$this, 'check_logged_in_permission'],
        ]);

        // ── Private Messages / Conversations ──

        // List conversations
        register_rest_route(self::API_NAMESPACE, '/conversations', [
            'methods'             => 'GET',
            'callback'            => [$this, 'list_conversations'],
            'permission_callback' => [$this, 'check_logged_in_permission'],
            'args' => [
                'limit' => ['default' => 20, 'sanitize_callback' => 'absint'],
            ],
        ]);

        // Get thread messages
        register_rest_route(self::API_NAMESPACE, '/conversations/(?P<id>\d+)/messages', [
            'methods'             => 'GET',
            'callback'            => [$this, 'get_thread'],
            'permission_callback' => [$this, 'check_logged_in_permission'],
            'args' => [
                'page'     => ['default' => 1, 'sanitize_callback' => 'absint'],
                'per_page' => ['default' => 30, 'sanitize_callback' => 'absint'],
            ],
        ]);

        // Send message in conversation
        register_rest_route(self::API_NAMESPACE, '/conversations/(?P<id>\d+)/messages', [
            'methods'             => 'POST',
            'callback'            => [$this, 'send_message'],
            'permission_callback' => [$this, 'check_logged_in_permission'],
            'args' => [
                'content' => ['required' => true, 'sanitize_callback' => 'sanitize_textarea_field'],
            ],
        ]);

        // Create or get conversation with a user
        register_rest_route(self::API_NAMESPACE, '/conversations/with/(?P<user_id>\d+)', [
            'methods'             => 'POST',
            'callback'            => [$this, 'get_or_create_conversation'],
            'permission_callback' => [$this, 'check_logged_in_permission'],
        ]);

        // Mark conversation read
        register_rest_route(self::API_NAMESPACE, '/conversations/(?P<id>\d+)/read', [
            'methods'             => 'POST',
            'callback'            => [$this, 'mark_conversation_read'],
            'permission_callback' => [$this, 'check_logged_in_permission'],
        ]);
    }

    // ── Notification handlers ──

    public function list_notifications(\WP_REST_Request $request): \WP_REST_Response {
        $user_id  = get_current_user_id();
        $type     = $request->get_param('type');
        $per_page = min(100, (int) $request->get_param('per_page'));
        $page     = max(1, (int) $request->get_param('page'));

        if (!class_exists('\AKSRT\Messages\Message')) {
            return $this->success(['data' => [], 'total' => 0]);
        }

        $msg = \AKSRT\Messages\Message::get_instance();
        $args = [
            'limit'  => $per_page,
            'offset' => ($page - 1) * $per_page,
        ];
        if ($type) {
            $args['type'] = $type;
        }

        $notifications = $msg->get_notifications($user_id, $args);
        $unread = $msg->get_unread_count($user_id);

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

    public function get_unread_count(\WP_REST_Request $request): \WP_REST_Response {
        $user_id = get_current_user_id();
        if (!class_exists('\AKSRT\Messages\Message')) {
            return $this->success(['data' => ['unread' => 0]]);
        }
        $count = \AKSRT\Messages\Message::get_instance()->get_unread_count($user_id);
        return $this->success(['data' => ['unread' => $count]]);
    }

    public function mark_read(\WP_REST_Request $request): \WP_REST_Response {
        $user_id = get_current_user_id();
        $id      = (string) $request->get_param('id');
        if (!class_exists('\AKSRT\Messages\Message')) {
            return $this->error('not_available', '消息系统未启用。', 501);
        }
        $result = \AKSRT\Messages\Message::get_instance()->mark_read($user_id, $id);
        return $this->success(['data' => ['success' => $result]]);
    }

    public function mark_all_read(\WP_REST_Request $request): \WP_REST_Response {
        $user_id = get_current_user_id();
        if (!class_exists('\AKSRT\Messages\Message')) {
            return $this->error('not_available', '消息系统未启用。', 501);
        }
        $result = \AKSRT\Messages\Message::get_instance()->mark_all_read($user_id);
        return $this->success(['data' => ['success' => $result]]);
    }

    // ── Conversation handlers ──

    public function list_conversations(\WP_REST_Request $request): \WP_REST_Response {
        $user_id = get_current_user_id();
        $limit   = min(50, (int) $request->get_param('limit'));

        if (!class_exists('\AKSRT\Messages\PrivateMessage')) {
            return $this->success(['data' => []]);
        }

        $conversations = \AKSRT\Messages\PrivateMessage::get_instance()->get_conversations($user_id, $limit);
        return $this->success(['data' => $conversations]);
    }

    public function get_thread(\WP_REST_Request $request): \WP_REST_Response {
        $user_id = get_current_user_id();
        $conv_id = (int) $request->get_param('id');
        $page    = max(1, (int) $request->get_param('page'));
        $per_page = min(50, (int) $request->get_param('per_page'));

        if (!class_exists('\AKSRT\Messages\PrivateMessage')) {
            return $this->error('not_available', '私信系统未启用。', 501);
        }

        $result = \AKSRT\Messages\PrivateMessage::get_instance()->get_thread($conv_id, $user_id, $page, $per_page);
        if (is_wp_error($result)) {
            return $this->error('thread_error', $result->get_error_message(), 403);
        }

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

    public function send_message(\WP_REST_Request $request): \WP_REST_Response {
        $user_id = get_current_user_id();
        $conv_id = (int) $request->get_param('id');
        $content = trim((string) $request->get_param('content'));

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

        if (!class_exists('\AKSRT\Messages\PrivateMessage')) {
            return $this->error('not_available', '私信系统未启用。', 501);
        }

        $result = \AKSRT\Messages\PrivateMessage::get_instance()->send($conv_id, $user_id, $content);
        if (!$result['success']) {
            return $this->error('send_failed', $result['message'] ?? '发送失败。', 500);
        }

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

    public function get_or_create_conversation(\WP_REST_Request $request): \WP_REST_Response {
        $user_id  = get_current_user_id();
        $other_id = (int) $request->get_param('user_id');

        if ($user_id === $other_id) {
            return $this->error('self_message', '不能与自己创建对话。', 400);
        }

        if (!class_exists('\AKSRT\Messages\PrivateMessage')) {
            return $this->error('not_available', '私信系统未启用。', 501);
        }

        $conv_id = \AKSRT\Messages\PrivateMessage::get_instance()->get_or_create_conversation($user_id, $other_id);
        if (is_wp_error($conv_id)) {
            return $this->error('create_failed', $conv_id->get_error_message(), 500);
        }

        return $this->success(['data' => ['conversation_id' => $conv_id]]);
    }

    public function mark_conversation_read(\WP_REST_Request $request): \WP_REST_Response {
        $user_id = get_current_user_id();
        $conv_id = (int) $request->get_param('id');

        if (!class_exists('\AKSRT\Messages\PrivateMessage')) {
            return $this->error('not_available', '私信系统未启用。', 501);
        }

        \AKSRT\Messages\PrivateMessage::get_instance()->mark_conversation_read($conv_id, $user_id);
        return $this->success(['data' => ['success' => true]]);
    }

    public function check_logged_in_permission(): bool {
        return is_user_logged_in();
    }
}