<?php

namespace App\Module\Promotion\Logics;

use App\Module\Promotion\Enums\REFERRAL_LEVEL;
use App\Module\Promotion\Models\PromotionUserReferral;
use App\Module\Promotion\Models\PromotionUserRelationCache;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\Redis;

/**
 * 关系缓存逻辑类
 *
 * 处理用户关系缓存的核心业务逻辑，包括生成关系缓存、清理关系缓存、
 * 重建关系缓存等功能。该类仅供内部使用，不对外提供服务。
 */
class RelationCacheLogic
{
    /**
     * 生成用户的关系缓存
     *
     * @param int $userId 用户ID
     * @return bool
     */
    public function generateUserRelationCache(int $userId): bool
    {
        try {
            // 清除用户的现有关系缓存
            $this->clearUserRelationCache($userId);

            // 获取用户的直接推荐人
            $referral = PromotionUserReferral::where('user_id', $userId)->first();

            if (!$referral) {
                Log::info("用户 {$userId} 没有推荐人，无需生成关系缓存");
                return true;
            }

            $referrerId = $referral->referrer_id;

            // 创建直接关系缓存
            $directRelation = new PromotionUserRelationCache();
            $directRelation->user_id = $userId;
            $directRelation->related_user_id = $referrerId;
            $directRelation->level = REFERRAL_LEVEL::DIRECT;
            $directRelation->path = (string)$referrerId;
            $directRelation->depth = 1;
            $directRelation->save();

            // 获取推荐人的所有上级
            $upperRelations = PromotionUserRelationCache::where('user_id', $referrerId)->get();

            // 创建间接关系缓存
            foreach ($upperRelations as $upperRelation) {
                $indirectRelation = new PromotionUserRelationCache();
                $indirectRelation->user_id = $userId;
                $indirectRelation->related_user_id = $upperRelation->related_user_id;
                $indirectRelation->level = REFERRAL_LEVEL::INDIRECT;
                $indirectRelation->path = $referrerId . ',' . $upperRelation->path;
                $indirectRelation->depth = $upperRelation->depth + 1;
                $indirectRelation->save();
            }

            // 清除Redis缓存
            Redis::del("promotion:user:{$userId}:all_referrers");

            return true;
        } catch (\Exception $e) {
            Log::error("生成用户关系缓存失败: " . $e->getMessage());
            return false;
        }
    }

    /**
     * 清除用户的关系缓存
     *
     * @param int $userId 用户ID
     * @return bool
     */
    public function clearUserRelationCache(int $userId): bool
    {
        try {
            // 删除数据库中的关系缓存
            PromotionUserRelationCache::where('user_id', $userId)->delete();

            // 清除Redis缓存
            Redis::del("promotion:user:{$userId}:all_referrers");

            return true;
        } catch (\Exception $e) {
            Log::error("清除用户关系缓存失败: " . $e->getMessage());
            return false;
        }
    }

    /**
     * 重建所有用户的关系缓存
     *
     * @param int $batchSize 批处理大小
     * @return array 包含成功和失败的数量
     */
    public function rebuildAllRelationCache(int $batchSize = 100): array
    {
        try {
            // 清空关系缓存表
            PromotionUserRelationCache::truncate();

            // 清除所有Redis缓存
            $keys = Redis::keys("promotion:user:*:all_referrers");
            if (!empty($keys)) {
                Redis::del($keys);
            }

            // 获取所有用户ID
            $userIds = PromotionUserReferral::pluck('user_id')->toArray();

            $successCount = 0;
            $failCount = 0;

            // 分批处理
            $chunks = array_chunk($userIds, $batchSize);

            foreach ($chunks as $chunk) {
                foreach ($chunk as $userId) {
                    if ($this->generateUserRelationCache($userId)) {
                        $successCount++;
                    } else {
                        $failCount++;
                    }
                }
            }

            return [
                'success' => $successCount,
                'fail' => $failCount,
                'total' => count($userIds)
            ];
        } catch (\Exception $e) {
            Log::error("重建所有关系缓存失败: " . $e->getMessage());
            return [
                'success' => 0,
                'fail' => 0,
                'total' => 0,
                'error' => $e->getMessage()
            ];
        }
    }

    /**
     * 检查关系缓存的完整性
     *
     * @return array 包含检查结果
     */
    public function checkRelationCacheIntegrity(): array
    {
        try {
            $totalUsers = PromotionUserReferral::count();
            $usersWithCache = PromotionUserRelationCache::distinct('user_id')->count('user_id');
            $missingUsers = $totalUsers - $usersWithCache;

            $circularRelations = DB::select("
                SELECT r1.user_id, r1.referrer_id
                FROM promotion_user_referrals r1
                JOIN promotion_user_referrals r2 ON r1.referrer_id = r2.user_id
                WHERE r2.referrer_id = r1.user_id
            ");

            $orphanedCaches = DB::select("
                SELECT c.user_id
                FROM promotion_user_relation_cache c
                LEFT JOIN promotion_user_referrals r ON c.user_id = r.user_id
                WHERE r.user_id IS NULL
            ");

            return [
                'total_users' => $totalUsers,
                'users_with_cache' => $usersWithCache,
                'missing_users' => $missingUsers,
                'circular_relations' => count($circularRelations),
                'orphaned_caches' => count($orphanedCaches)
            ];
        } catch (\Exception $e) {
            Log::error("检查关系缓存完整性失败: " . $e->getMessage());
            return [
                'error' => $e->getMessage()
            ];
        }
    }

    /**
     * 修复关系缓存问题
     *
     * @return array 包含修复结果
     */
    public function fixRelationCacheIssues(): array
    {
        try {
            // 检查完整性
            $integrity = $this->checkRelationCacheIntegrity();

            $fixed = [
                'missing_users' => 0,
                'orphaned_caches' => 0
            ];

            // 修复缺失的用户缓存
            if ($integrity['missing_users'] > 0) {
                $usersWithCache = PromotionUserRelationCache::distinct('user_id')->pluck('user_id')->toArray();
                $allUsers = PromotionUserReferral::pluck('user_id')->toArray();
                $missingUsers = array_diff($allUsers, $usersWithCache);

                foreach ($missingUsers as $userId) {
                    if ($this->generateUserRelationCache($userId)) {
                        $fixed['missing_users']++;
                    }
                }
            }

            // 清理孤立的缓存
            if ($integrity['orphaned_caches'] > 0) {
                $orphanedCaches = DB::select("
                    SELECT c.user_id
                    FROM promotion_user_relation_cache c
                    LEFT JOIN promotion_user_referrals r ON c.user_id = r.user_id
                    WHERE r.user_id IS NULL
                ");

                foreach ($orphanedCaches as $cache) {
                    if ($this->clearUserRelationCache($cache->user_id)) {
                        $fixed['orphaned_caches']++;
                    }
                }
            }

            return [
                'integrity' => $integrity,
                'fixed' => $fixed
            ];
        } catch (\Exception $e) {
            Log::error("修复关系缓存问题失败: " . $e->getMessage());
            return [
                'error' => $e->getMessage()
            ];
        }
    }
}