<?php

namespace App\Module\Team\Logics;

use App\Module\Team\Enums\REFERRAL_CODE_STATUS;
use App\Module\Team\Models\TeamReferralCode;
use App\Module\Team\Models\TeamReferralCodeUsage;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Str;

/**
 * 推荐码逻辑类
 *
 * 处理推荐码的核心业务逻辑，包括生成推荐码、验证推荐码、
 * 使用推荐码等功能。该类仅供内部使用，不对外提供服务。
 */
class ReferralCodeLogic
{
    /**
     * @var ReferralLogic
     */
    protected $referralLogic;

    /**
     * 构造函数
     *
     * @param ReferralLogic $referralLogic
     */
    public function __construct(ReferralLogic $referralLogic)
    {
        $this->referralLogic = $referralLogic;
    }

    /**
     * 生成推荐码
     *
     * @param int $userId 用户ID
     * @param \DateTime|null $expireTime 过期时间
     * @return string|null
     */
    public function generateReferralCode(int $userId, ?\DateTime $expireTime = null): ?string
    {
        try {
            // 检查用户是否已有有效的推荐码
            $existingCode = $this->getUserActiveCode($userId);

            if ($existingCode) {
                return $existingCode->code;
            }

            // 生成唯一的推荐码
            $code = $this->generateUniqueCode();

            // 创建推荐码记录
            $referralCode = new TeamReferralCode();
            $referralCode->user_id = $userId;
            $referralCode->code = $code;
            $referralCode->usage_count = 0;
            $referralCode->status = REFERRAL_CODE_STATUS::ACTIVE;
            $referralCode->expire_time = $expireTime;

            if ($referralCode->save()) {
                return $code;
            }

            return null;
        } catch (\Exception $e) {
            Log::error("生成推荐码失败: " . $e->getMessage());
            return null;
        }
    }

    /**
     * 生成唯一的推荐码
     *
     * @param int $length 推荐码长度
     * @return string
     */
    private function generateUniqueCode(int $length = 8): string
    {
        $attempts = 0;
        $maxAttempts = 10;

        do {
            // 生成随机字符串
            $code = strtoupper(Str::random($length));

            // 检查是否已存在
            $exists = TeamReferralCode::where('code', $code)->exists();

            $attempts++;
        } while ($exists && $attempts < $maxAttempts);

        // 如果多次尝试后仍然存在冲突，添加时间戳确保唯一性
        if ($exists) {
            $code = strtoupper(substr(Str::random($length - 4), 0, $length - 4) . substr(time(), -4));
        }

        return $code;
    }

    /**
     * 获取用户的有效推荐码
     *
     * @param int $userId 用户ID
     * @return TeamReferralCode|null
     */
    public function getUserActiveCode(int $userId): ?TeamReferralCode
    {
        $code = TeamReferralCode::where('user_id', $userId)
            ->where('status', REFERRAL_CODE_STATUS::ACTIVE)
            ->where(function ($query) {
                $query->whereNull('expire_time')
                    ->orWhere('expire_time', '>', now());
            })
            ->first();

        return $code;
    }

    /**
     * 验证推荐码
     *
     * @param string $code 推荐码
     * @return array 包含验证结果和推荐码信息
     */
    public function validateReferralCode(string $code): array
    {
        try {
            // 查找推荐码
            $referralCode = TeamReferralCode::where('code', $code)->first();

            if (!$referralCode) {
                return [
                    'valid' => false,
                    'message' => '推荐码不存在',
                    'code' => null
                ];
            }

            // 检查状态
            if ($referralCode->status != REFERRAL_CODE_STATUS::ACTIVE) {
                return [
                    'valid' => false,
                    'message' => '推荐码已禁用',
                    'code' => $referralCode
                ];
            }

            // 检查过期时间
            if ($referralCode->expire_time && $referralCode->expire_time->isPast()) {
                return [
                    'valid' => false,
                    'message' => '推荐码已过期',
                    'code' => $referralCode
                ];
            }

            return [
                'valid' => true,
                'message' => '推荐码有效',
                'code' => $referralCode
            ];
        } catch (\Exception $e) {
            Log::error("验证推荐码失败: " . $e->getMessage());
            return [
                'valid' => false,
                'message' => '验证推荐码时发生错误',
                'code' => null
            ];
        }
    }

    /**
     * 使用推荐码
     *
     * @param string $code 推荐码
     * @param int $userId 使用者ID
     * @param string $ipAddress IP地址
     * @param string $userAgent 用户代理
     * @return array 包含使用结果和信息
     */
    public function useReferralCode(string $code, int $userId, string $ipAddress, string $userAgent): array
    {
        try {
            // 验证推荐码
            $validation = $this->validateReferralCode($code);

            if (!$validation['valid']) {
                return [
                    'success' => false,
                    'message' => $validation['message']
                ];
            }

            $referralCode = $validation['code'];

            // 检查用户是否使用自己的推荐码
            if ($referralCode->user_id == $userId) {
                return [
                    'success' => false,
                    'message' => '不能使用自己的推荐码'
                ];
            }

            // 检查用户是否已有推荐人
            if ($this->referralLogic->hasReferrer($userId)) {
                return [
                    'success' => false,
                    'message' => '用户已有推荐人，不能使用推荐码'
                ];
            }

            // 检查是否形成循环推荐
            if ($this->referralLogic->checkCircularReferral($userId, $referralCode->user_id)) {
                return [
                    'success' => false,
                    'message' => '使用此推荐码会形成循环推荐关系'
                ];
            }

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

            // 记录使用记录
            $usage = new TeamReferralCodeUsage();
            $usage->code = $code;
            $usage->code_owner_id = $referralCode->user_id;
            $usage->user_id = $userId;
            $usage->ip_address = $ipAddress;
            $usage->user_agent = $userAgent;
            $usage->status = TeamReferralCodeUsage::STATUS_SUCCESS;
            $usage->result = '成功使用推荐码';
            $usage->save();

            // 更新推荐码使用次数
            $referralCode->usage_count += 1;
            $referralCode->save();

            // 建立推荐关系
            $result = $this->referralLogic->createReferralRelation($userId, $referralCode->user_id);

            if (!$result) {
                // 如果建立推荐关系失败，更新使用记录状态
                $usage->status = TeamReferralCodeUsage::STATUS_FAILED;
                $usage->result = '建立推荐关系失败';
                $usage->save();

                return [
                    'success' => false,
                    'message' => '建立推荐关系失败'
                ];
            }

            return [
                'success' => true,
                'message' => '成功使用推荐码并建立推荐关系',
                'referrer_id' => $referralCode->user_id
            ];
        } catch (\Exception $e) {
            Log::error("使用推荐码失败: " . $e->getMessage());
            return [
                'success' => false,
                'message' => '使用推荐码时发生错误'
            ];
        }
    }

    /**
     * 禁用推荐码
     *
     * @param string $code 推荐码
     * @return bool
     */
    public function disableReferralCode(string $code): bool
    {
        try {
            $referralCode = TeamReferralCode::where('code', $code)->first();

            if (!$referralCode) {
                return false;
            }

            $referralCode->status = REFERRAL_CODE_STATUS::DISABLED;
            return $referralCode->save();
        } catch (\Exception $e) {
            Log::error("禁用推荐码失败: " . $e->getMessage());
            return false;
        }
    }

    /**
     * 清理过期的推荐码
     *
     * @return int 清理的数量
     */
    public function cleanExpiredReferralCodes(): int
    {
        try {
            return TeamReferralCode::where('status', REFERRAL_CODE_STATUS::ACTIVE)
                ->whereNotNull('expire_time')
                ->where('expire_time', '<', now())
                ->update(['status' => REFERRAL_CODE_STATUS::DISABLED]);
        } catch (\Exception $e) {
            Log::error("清理过期推荐码失败: " . $e->getMessage());
            return 0;
        }
    }
}