<?php

namespace App\Module\Game\Services;

use App\Module\Game\Models\GameRewardGroup;
use App\Module\Game\Models\GameRewardItem;
use App\Module\Game\Models\GameRewardGroupPityCount;
use Illuminate\Support\Collection;

/**
 * 保底机制服务类
 *
 * 提供奖励组保底机制的核心功能，包括保底计数管理、概率调整、保底触发等。
 */
class PityService
{
    /**
     * 获取用户在指定奖励组的保底计数
     *
     * @param int $userId 用户ID
     * @param int $rewardGroupId 奖励组ID
     * @return Collection
     */
    public static function getUserPityCounts(int $userId, int $rewardGroupId): Collection
    {
        return GameRewardGroupPityCount::where('user_id', $userId)
            ->where('reward_group_id', $rewardGroupId)
            ->with('rewardItem')
            ->get();
    }

    /**
     * 初始化用户的保底计数
     *
     * @param int $userId 用户ID
     * @param int $rewardGroupId 奖励组ID
     * @return void
     */
    public static function initializePityCounts(int $userId, int $rewardGroupId): void
    {
        // 获取奖励组中启用保底的奖励项
        $pityEnabledItems = GameRewardItem::where('group_id', $rewardGroupId)
            ->where('pity_enabled', true)
            ->where('pity_threshold', '>', 0)
            ->get();

        foreach ($pityEnabledItems as $item) {
            // 检查是否已存在保底计数记录
            $existingCount = GameRewardGroupPityCount::where('user_id', $userId)
                ->where('reward_group_id', $rewardGroupId)
                ->where('reward_item_id', $item->id)
                ->first();

            if (!$existingCount) {
                // 创建新的保底计数记录
                GameRewardGroupPityCount::create([
                    'user_id' => $userId,
                    'reward_group_id' => $rewardGroupId,
                    'reward_item_id' => $item->id,
                    'count' => 0,
                    'pity_threshold' => $item->pity_threshold,
                    'last_attempt_at' => now(),
                ]);
            }
        }
    }

    /**
     * 应用保底机制调整奖励权重
     *
     * @param int $userId 用户ID
     * @param Collection $rewardItems 奖励项集合
     * @return Collection 调整后的奖励项集合
     */
    public static function applyPityAdjustments(int $userId, Collection $rewardItems): Collection
    {
        if ($rewardItems->isEmpty()) {
            return $rewardItems;
        }

        $rewardGroupId = $rewardItems->first()->group_id;

        // 初始化保底计数（如果需要）
        self::initializePityCounts($userId, $rewardGroupId);

        // 获取用户的保底计数
        $pityCounts = self::getUserPityCounts($userId, $rewardGroupId);
        $pityCountsMap = $pityCounts->keyBy('reward_item_id');

        // 调整每个奖励项的权重
        return $rewardItems->map(function (GameRewardItem $item) use ($pityCountsMap) {
            $pityCount = $pityCountsMap->get($item->id);

            if ($pityCount && $item->pity_enabled && $item->pity_threshold > 0) {
                // 计算调整后的权重
                $adjustedWeight = $pityCount->getAdjustedWeight(
                    $item->weight,
                    $item->pity_weight_factor
                );

                // 创建一个新的奖励项实例，避免修改原始数据
                $adjustedItem = clone $item;
                $adjustedItem->weight = $adjustedWeight;

                // 添加保底信息到额外数据中
                $extraData = $adjustedItem->extra_data ?: [];
                $extraData['pity_info'] = [
                    'current_count' => $pityCount->count,
                    'threshold' => $pityCount->pity_threshold,
                    'is_at_threshold' => $pityCount->isAtPityThreshold(),
                    'original_weight' => $item->weight,
                    'adjusted_weight' => $adjustedWeight,
                ];
                $adjustedItem->extra_data = $extraData;

                return $adjustedItem;
            }

            return $item;
        });
    }

    /**
     * 更新保底计数
     *
     * @param int $userId 用户ID
     * @param int $rewardGroupId 奖励组ID
     * @param array $obtainedItemIds 获得的奖励项ID数组
     * @return void
     */
    public static function updatePityCounts(int $userId, int $rewardGroupId, array $obtainedItemIds): void
    {
        // 获取用户的保底计数
        $pityCounts = self::getUserPityCounts($userId, $rewardGroupId);

        foreach ($pityCounts as $pityCount) {
            if (in_array($pityCount->reward_item_id, $obtainedItemIds)) {
                // 获得了该奖励项，重置计数
                $pityCount->resetCount();
            } else {
                // 未获得该奖励项，增加计数
                $pityCount->incrementCount();
            }
        }
    }

    /**
     * 检查是否有保底触发
     *
     * @param int $userId 用户ID
     * @param int $rewardGroupId 奖励组ID
     * @return array 触发保底的奖励项ID数组
     */
    public static function checkPityTriggers(int $userId, int $rewardGroupId): array
    {
        $pityCounts = self::getUserPityCounts($userId, $rewardGroupId);
        $triggeredItems = [];

        foreach ($pityCounts as $pityCount) {
            if ($pityCount->isAtPityThreshold()) {
                $triggeredItems[] = $pityCount->reward_item_id;
            }
        }

        return $triggeredItems;
    }

    /**
     * 获取用户保底状态信息
     *
     * @param int $userId 用户ID
     * @param int $rewardGroupId 奖励组ID
     * @return array
     */
    public static function getPityStatus(int $userId, int $rewardGroupId): array
    {
        $pityCounts = self::getUserPityCounts($userId, $rewardGroupId);
        $status = [];

        foreach ($pityCounts as $pityCount) {
            $rewardItem = $pityCount->rewardItem;
            $status[] = [
                'reward_item_id' => $pityCount->reward_item_id,
                'reward_item_name' => $rewardItem ? $rewardItem->getTargetName() : '未知奖励',
                'current_count' => $pityCount->count,
                'threshold' => $pityCount->pity_threshold,
                'progress_percentage' => $pityCount->pity_threshold > 0 
                    ? round(($pityCount->count / $pityCount->pity_threshold) * 100, 2) 
                    : 0,
                'is_at_threshold' => $pityCount->isAtPityThreshold(),
                'last_attempt_at' => $pityCount->last_attempt_at,
                'last_hit_at' => $pityCount->last_hit_at,
            ];
        }

        return $status;
    }

    /**
     * 重置用户的所有保底计数
     *
     * @param int $userId 用户ID
     * @param int $rewardGroupId 奖励组ID
     * @return void
     */
    public static function resetAllPityCounts(int $userId, int $rewardGroupId): void
    {
        GameRewardGroupPityCount::where('user_id', $userId)
            ->where('reward_group_id', $rewardGroupId)
            ->update([
                'count' => 0,
                'last_hit_at' => now(),
            ]);
    }

    /**
     * 清理过期的保底计数记录
     *
     * @param int $daysOld 清理多少天前的记录
     * @return int 清理的记录数量
     */
    public static function cleanupOldPityCounts(int $daysOld = 90): int
    {
        $cutoffDate = now()->subDays($daysOld);

        return GameRewardGroupPityCount::where('last_attempt_at', '<', $cutoffDate)
            ->where('count', 0)
            ->delete();
    }
}