<?php

namespace App\Module\Friend\Logics;

use App\Module\Friend\Enums\ERROR_CODE;
use App\Module\Friend\Enums\FRIEND_STATUS;
use App\Module\Friend\Models\FriendRelation;
use App\Module\User\Models\User;
use App\Module\User\Services\UserService;
use Illuminate\Pagination\LengthAwarePaginator;
use Illuminate\Support\Facades\Log;

/**
 * 好友逻辑类
 *
 * 实现好友关系的核心业务逻辑，包括好友添加、删除、查询等功能。
 * 该类仅供内部使用，不对外提供服务。
 */
class FriendLogic
{
    /**
     * 好友数量上限
     *
     * @var int
     */
    protected $friendLimit = 100;

    /**
     * 获取用户的好友列表
     *
     * @param int $userId 用户ID
     * @param int $page 页码
     * @param int $limit 每页数量
     * @param array $filters 过滤条件
     * @return array 好友列表数据
     */
    public function getFriendList(int $userId, int $page = 1, int $limit = 20, array $filters = []): array
    {
        // 构建查询条件
        $where = [
            'user_id' => $userId,
            'status' => $filters['status'] ?? FRIEND_STATUS::NORMAL
        ];

        if (isset($filters['group_id'])) {
            $where['group_id'] = $filters['group_id'];
        }

        // 设置排序
        if (isset($filters['sort_by']) && isset($filters['sort_order'])) {
            $where['_sort_field'] = $filters['sort_by'];
            $where['_sort_order'] = $filters['sort_order'];
        } else {
            $where['_sort_field'] = 'intimacy';
            $where['_sort_order'] = 'desc';
        }

        // 查询好友关系
        $relations = FriendRelation::where($where)
            ->with('friend')
            ->paginate($limit, ['*'], 'page', $page);

        // 格式化数据
        $items = [];
        foreach ($relations as $relation) {
            if (!$relation->friend) {
                continue;
            }

            $items[] = [
                'user_id' => $relation->friend_id,
                'nickname' => $relation->friend->nickname ?? '',
                'avatar' => $relation->friend->avatar ?? '',
                'level' => $relation->friend->level ?? 1,
                'status' => $this->getUserOnlineStatus($relation->friend_id),
                'last_login' => $relation->friend->last_login_at ?? 0,
                'remark' => $relation->remark,
                'intimacy' => $relation->intimacy,
            ];
        }

        return [
            'total' => $relations->total(),
            'per_page' => $relations->perPage(),
            'current_page' => $relations->currentPage(),
            'last_page' => $relations->lastPage(),
            'items' => $items
        ];
    }

    /**
     * 搜索可添加为好友的用户
     *
     * @param int $userId 当前用户ID
     * @param string $keyword 搜索关键词
     * @param int $page 页码
     * @param int $limit 每页数量
     * @return array 搜索结果
     */
    public function searchUsers(int $userId, string $keyword, int $page = 1, int $limit = 20): array
    {
        // 构建查询条件
        $query = User::query();

        // 排除当前用户
        $query->where('id', '!=', $userId);

        // 根据关键词搜索
        if (is_numeric($keyword)) {
            // 如果是数字，则按ID搜索
            $query->where('id', $keyword);
        } else {
            // 否则按昵称搜索
            $query->where('nickname', 'like', "%{$keyword}%");
        }

        // 执行分页查询
        $users = $query->paginate($limit, ['id', 'nickname', 'avatar', 'level'], 'page', $page);

        // 获取当前用户的好友ID列表
        $friendIds = FriendRelation::where('user_id', $userId)
            ->where('status', FRIEND_STATUS::NORMAL)
            ->pluck('friend_id')
            ->toArray();

        // 获取当前用户已发送申请的用户ID列表
        $requestLogic = new RequestLogic();
        $requestedIds = $requestLogic->getSentRequestUserIds($userId);

        // 格式化数据
        $items = [];
        foreach ($users as $user) {
            $relation = 0; // 0:无关系, 1:已是好友, 2:已申请

            if (in_array($user->id, $friendIds)) {
                $relation = 1;
            } elseif (in_array($user->id, $requestedIds)) {
                $relation = 2;
            }

            $items[] = [
                'user_id' => $user->id,
                'nickname' => $user->nickname ?? '',
                'avatar' => $user->avatar ?? '',
                'level' => $user->level ?? 1,
                'relation' => $relation
            ];
        }

        return [
            'total' => $users->total(),
            'per_page' => $users->perPage(),
            'current_page' => $users->currentPage(),
            'last_page' => $users->lastPage(),
            'items' => $items
        ];
    }

    /**
     * 创建好友关系
     *
     * @param int $userId 用户ID
     * @param int $friendId 好友ID
     * @param string|null $remark 备注名
     * @return array 操作结果
     */
    public function createFriendRelation(int $userId, int $friendId, ?string $remark = null): array
    {
        try {
            // 检查是否已经是好友
            $existingRelation = FriendRelation::where('user_id', $userId)
                ->where('friend_id', $friendId)
                ->first();

            if ($existingRelation) {
                if ($existingRelation->status == FRIEND_STATUS::NORMAL) {
                    return [
                        'success' => false,
                        'code' => ERROR_CODE::ALREADY_FRIEND,
                        'message' => '已经是好友关系'
                    ];
                } else {
                    // 如果是黑名单状态，则更新为正常状态
                    $existingRelation->status = FRIEND_STATUS::NORMAL;
                    $existingRelation->save();

                    return [
                        'success' => true,
                        'data' => $existingRelation
                    ];
                }
            }

            // 检查好友数量是否达到上限
            $friendCount = FriendRelation::where('user_id', $userId)
                ->where('status', FRIEND_STATUS::NORMAL)
                ->count();

            if ($friendCount >= $this->friendLimit) {
                return [
                    'success' => false,
                    'code' => ERROR_CODE::FRIEND_LIMIT_REACHED,
                    'message' => '好友数量已达上限'
                ];
            }

            // 检查事务是否已开启
            \UCore\Db\Helper::check_tr();

            // 创建A->B的关系
            $relationAB = FriendRelation::create([
                'user_id' => $userId,
                'friend_id' => $friendId,
                'remark' => $remark,
                'group_id' => 0,
                'intimacy' => 0,
                'status' => FRIEND_STATUS::NORMAL,
            ]);

            // 创建B->A的关系
            $relationBA = FriendRelation::create([
                'user_id' => $friendId,
                'friend_id' => $userId,
                'remark' => null,
                'group_id' => 0,
                'intimacy' => 0,
                'status' => FRIEND_STATUS::NORMAL,
            ]);

            return [
                'success' => true,
                'data' => $relationAB
            ];
        } catch (\Exception $e) {
            Log::error('创建好友关系失败: ' . $e->getMessage());

            return [
                'success' => false,
                'code' => ERROR_CODE::PARAM_ERROR,
                'message' => '创建好友关系失败'
            ];
        }
    }

    /**
     * 删除好友关系
     *
     * @param int $userId 用户ID
     * @param int $friendId 好友ID
     * @return array 操作结果
     */
    public function deleteFriend(int $userId, int $friendId): array
    {
        try {
            // 检查是否存在好友关系
            $relation = FriendRelation::where('user_id', $userId)
                ->where('friend_id', $friendId)
                ->where('status', FRIEND_STATUS::NORMAL)
                ->first();

            if (!$relation) {
                return [
                    'success' => false,
                    'code' => ERROR_CODE::RELATION_NOT_EXIST,
                    'message' => '好友关系不存在'
                ];
            }

            // 检查事务是否已开启
            \UCore\Db\Helper::check_tr();

            // 删除A->B的关系
            FriendRelation::where('user_id', $userId)
                ->where('friend_id', $friendId)
                ->delete();

            // 删除B->A的关系
            FriendRelation::where('user_id', $friendId)
                ->where('friend_id', $userId)
                ->delete();

            return [
                'success' => true
            ];
        } catch (\Exception $e) {
            Log::error('删除好友关系失败: ' . $e->getMessage());

            return [
                'success' => false,
                'code' => ERROR_CODE::PARAM_ERROR,
                'message' => '删除好友关系失败'
            ];
        }
    }

    /**
     * 更新好友备注
     *
     * @param int $userId 用户ID
     * @param int $friendId 好友ID
     * @param string $remark 备注名
     * @return array 操作结果
     */
    public function updateFriendRemark(int $userId, int $friendId, string $remark): array
    {
        try {
            // 检查是否存在好友关系
            $relation = FriendRelation::where('user_id', $userId)
                ->where('friend_id', $friendId)
                ->where('status', FRIEND_STATUS::NORMAL)
                ->first();

            if (!$relation) {
                return [
                    'success' => false,
                    'code' => ERROR_CODE::RELATION_NOT_EXIST,
                    'message' => '好友关系不存在'
                ];
            }

            // 更新备注
            $relation->remark = $remark;
            $relation->save();

            return [
                'success' => true
            ];
        } catch (\Exception $e) {
            Log::error('更新好友备注失败: ' . $e->getMessage());

            return [
                'success' => false,
                'code' => ERROR_CODE::PARAM_ERROR,
                'message' => '更新好友备注失败'
            ];
        }
    }

    /**
     * 获取用户在线状态
     *
     * @param int $userId 用户ID
     * @return int 状态：1在线，2离线
     */
    protected function getUserOnlineStatus(int $userId): int
    {
        // TODO: 实现获取用户在线状态的逻辑
        // 这里可以调用用户模块的相关服务或者查询缓存
        return 2; // 默认离线
    }
}