<?php

namespace app\common\Service;

use think\Db;
use think\Model;
use app\common\Enum\StatusEnum;
use app\common\Enum\ActivityEnum;
use app\common\Enum\GoodsEnum;
/**
 * 折扣活动服务类
 * 
 * 外层折扣字段说明：
 * - has_discount: 是否有折扣活动
 * - discount_price: 折扣价格（单规格商品直接使用，多规格商品显示最低价）
 * - discount: 折扣率（单规格商品直接使用，多规格商品显示最低折扣）
 * - discount_amount: 折扣金额（原价-折扣价，仅单规格商品）
 * - min_discount_price: 最低折扣价格
 * - max_discount_price: 最高折扣价格
 * - min_discount: 最低折扣率
 * - max_discount: 最高折扣率
 * - price_range: 价格区间文本（如：¥99 或 ¥99-199）
 */
class DiscountService
{
    /**
     * 查询当前时间段内的商品折扣信息
     * @param array $goodsIds 商品ID数组，为空则查询所有参与折扣的商品
     * @param int $limit 限制数量
     * @return array
     */
    public static function getCurrentDiscountGoods($goodsIds = [], $limit = 0)
    {
        // 第一步：查询当前时间有效的活动ID
        $activeActivityIds = self::getActiveActivityIds();
        if (empty($activeActivityIds)) {
            return [];
        }
        
        // 第二步：查询这些活动的SKU数据
        $query = Db::table('shop_activity_sku')
            ->alias('sku')
            ->join('shop_goods goods', 'sku.goods_id = goods.id')
            ->join('shop_goods_sku spec', 'sku.sku_id = spec.id', 'left')
            ->join(['shop_activity'=> 'activity'], 'sku.activity_id = activity.id')
            ->where('sku.activity_id', 'in', $activeActivityIds)
            ->where('goods.status', GoodsEnum::STATUS_ON_SALE) // 已上架的商品
            ->where('sku.stocks', '>', 0) // 有折扣库存的商品
            ->field([
                'goods.id as goods_id',
                'goods.title',
                'goods.sub_title',
                'goods.image',
                'goods.price as original_price',
                'goods.market_price',
                'goods.stocks as goods_stocks',
                'goods.sales',
                'goods.spec_type',
                'sku.id as activity_sku_id',
                'sku.sku_id',
                'sku.discount',
                'sku.discount_price',
                'sku.stocks as discount_stocks',
                'sku.sale_quantity',
                'activity.id as activity_id',
                'activity.name as activity_name',
                'activity.start_time',
                'activity.end_time',
                'spec.price as sku_price',
                'spec.image as sku_image',
                // 'spec.specs as sku_specs'
            ]);
        
        // 如果指定了商品ID，则添加条件
        if (!empty($goodsIds)) {
            $query->where('sku.goods_id', 'in', $goodsIds);
        }
        
        // 如果设置了限制数量
        if ($limit > 0) {
            $query->limit($limit);
        }
        
        // 按折扣力度排序，折扣越大越靠前
        $query->order('sku.discount', 'asc');
        
        $result = $query->select();
        // 处理返回数据
        $processedData = [];
        foreach ($result as $item) {
            $goodsId = $item['goods_id'];
            $skuId = $item['sku_id'];
            
            // 如果商品还没有在结果中，初始化
            if (!isset($processedData[$goodsId])) {
                $processedData[$goodsId] = self::initGoodsDiscountStructure($item);
            }
            
            // 添加折扣信息
            $discountInfo = [
                'activity_sku_id' => $item['activity_sku_id'],
                'sku_id' => $skuId,
                'discount' => $item['discount'],
                'discount_price' => $item['discount_price'],
                'discount_stocks' => $item['discount_stocks'],
                'sale_quantity' => $item['sale_quantity']
            ];
            
            // 如果是多规格商品，添加规格信息
            if ($skuId > 0) {
                $discountInfo['sku_price'] = $item['sku_price'];
                $discountInfo['sku_image'] = $item['sku_image'];
                // $discountInfo['sku_specs'] = $item['sku_specs'];
            }
            
            $processedData[$goodsId]['discount_info'][] = $discountInfo;
        }
        
        // 处理外层折扣价格字段
        $processedData = self::processGoodsDiscountData($processedData);
        
        return array_values($processedData);
    }

    /**
     * 查询单个商品的折扣信息和对应的SKU折扣信息
     * @param int $goodsId 商品ID
     * @return array|null 商品折扣信息，包含所有SKU的折扣详情，如果没有折扣则返回null
     */
    public static function getGoodsDiscountDetail($goodsId)
    {
        // 第一步：查询当前时间有效的活动ID
        $activeActivityIds = self::getActiveActivityIds();
        if (empty($activeActivityIds)) {
            return null;
        }
        
        // 第二步：查询该商品的SKU折扣数据
        $result = Db::table('shop_activity_sku')
            ->alias('sku')
            ->join('shop_goods goods', 'sku.goods_id = goods.id')
            ->join('shop_goods_sku spec', 'sku.sku_id = spec.id', 'left')
            ->join(['shop_activity'=> 'activity'], 'sku.activity_id = activity.id')
            ->where('sku.goods_id', $goodsId)
            ->where('sku.activity_id', 'in', $activeActivityIds)
            ->where('goods.status', GoodsEnum::STATUS_ON_SALE) // 已上架的商品
            ->where('sku.stocks', '>', 0) // 有折扣库存的商品
            ->field([
                'goods.id as goods_id',
                'goods.title',
                'goods.sub_title',
                'goods.image',
                'goods.price as original_price',
                'goods.market_price',
                'goods.stocks as goods_stocks',
                'goods.sales',
                'goods.spec_type',
                'sku.id as activity_sku_id',
                'sku.sku_id',
                'sku.discount',
                'sku.discount_price',
                'sku.stocks as discount_stocks',
                'sku.sale_quantity',
                'activity.id as activity_id',
                'activity.name as activity_name',
                'activity.start_time',
                'activity.end_time',
                'spec.price as sku_price',
                'spec.image as sku_image',
                // 'spec.specs as sku_specs'
            ])
            ->order('sku.discount', 'asc') // 按折扣力度排序，折扣越大越靠前
            ->select();
        
        if (empty($result)) {
            return null;
        }
        
        // 初始化商品折扣结构
        $goodsDiscountData = self::initGoodsDiscountStructure($result[0]);
        
        // 处理所有SKU的折扣信息
        foreach ($result as $item) {
            $skuId = $item['sku_id'];
            
            // 添加折扣信息
            $discountInfo = [
                'activity_sku_id' => $item['activity_sku_id'],
                'sku_id' => $skuId,
                'discount' => $item['discount'],
                'discount_price' => $item['discount_price'],
                'discount_stocks' => $item['discount_stocks'],
                'sale_quantity' => $item['sale_quantity']
            ];
            
            // 如果是多规格商品，添加规格信息
            if ($skuId > 0) {
                $discountInfo['sku_price'] = $item['sku_price'];
                $discountInfo['sku_image'] = $item['sku_image'];
                // $discountInfo['sku_specs'] = $item['sku_specs'];
            }
            
            $goodsDiscountData['discount_info'][] = $discountInfo;
        }
        
        // 处理外层折扣价格字段
        $discountPrices = [];
        $discounts = [];
        
        // 收集所有折扣价格和折扣率
        foreach ($goodsDiscountData['discount_info'] as $discount) {
            $discountPrices[] = $discount['discount_price'];
            $discounts[] = $discount['discount'];
        }
        
        if (!empty($discountPrices)) {
            // 计算最低和最高折扣价格
            $goodsDiscountData['min_discount_price'] = min($discountPrices);
            $goodsDiscountData['max_discount_price'] = max($discountPrices);
            $goodsDiscountData['min_discount'] = min($discounts);
            $goodsDiscountData['max_discount'] = max($discounts);
            
            // 单规格商品处理
            if ($goodsDiscountData['spec_type'] == 0) {
                $goodsDiscountData['discount_price'] = $goodsDiscountData['min_discount_price'];
                $goodsDiscountData['discount'] = $goodsDiscountData['min_discount'];
                $goodsDiscountData['discount_amount'] = round($goodsDiscountData['original_price'] - $goodsDiscountData['discount_price'], 2);
                $goodsDiscountData['price_range'] = '¥' . $goodsDiscountData['discount_price'];
            } 
            // 多规格商品处理
            else {
                // 设置价格区间
                if ($goodsDiscountData['min_discount_price'] == $goodsDiscountData['max_discount_price']) {
                    $goodsDiscountData['price_range'] = '¥' . $goodsDiscountData['min_discount_price'];
                } else {
                    $goodsDiscountData['price_range'] = '¥' . $goodsDiscountData['min_discount_price'] . '-' . $goodsDiscountData['max_discount_price'];
                }
                
                // 对于多规格，使用最低价格作为主要显示价格
                $goodsDiscountData['discount_price'] = $goodsDiscountData['min_discount_price'];
                $goodsDiscountData['discount'] = $goodsDiscountData['min_discount'];
            }
        }

        $goodsDiscountData['remaining_time'] = self::formatRemainingTime($goodsDiscountData['end_time']);
        
        return $goodsDiscountData;
    }
    
    /**
     * 限时查询一个当前活动的信息和商品信息 活动信息直接加一个商品数组字段
     * @param mixed $activityId
     * @return array|bool|Model|string|\PDOStatement|null
     */
    public static function getCurrentActivity()
    {
        $currentTime = time();
        
        // 查询活动信息
        $activity = Db::table('shop_activity')
            // ->where('id', $activityId)
            ->where('start_time', '<=', $currentTime)
            ->where('end_time', '>=', $currentTime)
            ->where('activity_status', ActivityEnum::ACTIVITY_STATUS_ONGOING)
            ->where('status', StatusEnum::ENABLED)
            ->find();
            
        if (!$activity) {
            return null;
        }
        
        // 查询该活动下的商品信息
        $goods = Db::table('shop_activity_sku')
            ->alias('sku')
            ->join('shop_goods goods', 'sku.goods_id = goods.id')
            ->join('shop_goods_sku spec', 'sku.sku_id = spec.id', 'left')
            ->where('sku.activity_id', $activity['id'])
            ->where('goods.status', GoodsEnum::STATUS_ON_SALE)
            ->where('sku.stocks', '>', 0)
            ->field([
                'goods.id as goods_id',
                'goods.title',
                'goods.sub_title',
                'goods.image',
                'goods.price as original_price',
                'goods.market_price',
                'goods.stocks as goods_stocks',
                'goods.sales',
                'goods.spec_type',
                'sku.id as activity_sku_id',
                'sku.sku_id',
                'sku.discount',
                'sku.discount_price',
                'sku.stocks as discount_stocks',
                'sku.sale_quantity',
                'spec.price as sku_price',
                'spec.image as sku_image'
            ])
            ->order('sku.discount', 'asc')
            ->select();
            
        // 处理商品数据
        $processedGoods = [];
        foreach ($goods as $item) {
            $goodsId = $item['goods_id'];
            
            if (!isset($processedGoods[$goodsId])) {
                $processedGoods[$goodsId] = self::initGoodsDiscountStructure($item);
            }
            
            $discountInfo = [
                'activity_sku_id' => $item['activity_sku_id'],
                'sku_id' => $item['sku_id'],
                'discount' => $item['discount'],
                'discount_price' => $item['discount_price'],
                'discount_stocks' => $item['discount_stocks'],
                'sale_quantity' => $item['sale_quantity']
            ];
            
            if ($item['sku_id'] > 0) {
                $discountInfo['sku_price'] = $item['sku_price'];
                $discountInfo['sku_image'] = $item['sku_image'];
            }
            
            $processedGoods[$goodsId]['discount_info'][] = $discountInfo;
        }
        
        // 处理外层折扣价格字段
        foreach ($processedGoods as &$goodsItem) {
            $discountPrices = [];
            $discounts = [];
            
            // 收集所有折扣价格和折扣率
            foreach ($goodsItem['discount_info'] as $discount) {
                $discountPrices[] = $discount['discount_price'];
                $discounts[] = $discount['discount'];
            }
            
            if (!empty($discountPrices)) {
                // 计算最低和最高折扣价格
                $goodsItem['min_discount_price'] = min($discountPrices);
                $goodsItem['max_discount_price'] = max($discountPrices);
                $goodsItem['min_discount'] = min($discounts);
                $goodsItem['max_discount'] = max($discounts);
                
                // 单规格商品处理
                if ($goodsItem['spec_type'] == 0) {
                    $goodsItem['discount_price'] = $goodsItem['min_discount_price'];
                    $goodsItem['discount'] = $goodsItem['min_discount'];
                    $goodsItem['discount_amount'] = round($goodsItem['original_price'] - $goodsItem['discount_price'], 2);
                    $goodsItem['price_range'] = '¥' . $goodsItem['discount_price'];
                } 
                // 多规格商品处理
                else {
                    // 设置价格区间
                    if ($goodsItem['min_discount_price'] == $goodsItem['max_discount_price']) {
                        $goodsItem['price_range'] = '¥' . $goodsItem['min_discount_price'];
                    } else {
                        $goodsItem['price_range'] = '¥' . $goodsItem['min_discount_price'] . '-' . $goodsItem['max_discount_price'];
                    }
                    
                    // 对于多规格，使用最低价格作为主要显示价格
                    $goodsItem['discount_price'] = $goodsItem['min_discount_price'];
                    $goodsItem['discount'] = $goodsItem['min_discount'];
                }
            }
        }
        
        // 在活动信息中添加商品数组字段
        $activity['goods'] = array_values($processedGoods);
        
        return $activity;
    }

    // 限时zhe'kou一个当前活动的信息和商品信息 活动信息直接加一个商品数组字段
    public static function getCurrentActivityInfoAndPrize($activityId)
    {
        $activity = Db::table('shop_activity')->where('id', $activityId)->find();
        $prize = Db::table('shop_activity_sku_prize')->where('activity_id', $activityId)->find();
        return ['activity' => $activity, 'prize' => $prize];
    }
    
    /**
     * 根据商品ID和SKU ID获取折扣信息
     * @param int $goodsId 商品ID
     * @param int $skuId SKU ID，单规格商品传0
     * @return array|null
     */
    public static function getGoodsDiscountInfo($goodsId, $skuId = 0)
    {
        $currentTime = time();
        
        // 第一步：查询当前时间有效的活动ID
        $activeActivityIds = Db::table('shop_activity')
            ->where('start_time', '<=', $currentTime)
            ->where('end_time', '>=', $currentTime)
            ->where('activity_status', ActivityEnum::ACTIVITY_STATUS_ONGOING)
            ->where('status', 'normal')
            ->column('id');
        
        if (empty($activeActivityIds)) {
            return null;
        }
        
        // 第二步：查询指定商品的折扣信息
        $discountInfo = Db::table('shop_activity_sku_prize')
            ->alias('sku')
            ->join('shop_activity activity', 'sku.activity_id = activity.id')
            ->where('sku.goods_id', $goodsId)
            ->where('sku.sku_id', $skuId)
            ->where('sku.activity_id', 'in', $activeActivityIds)
            ->where('sku.status', 1)
            ->where('sku.stocks', '>', 0)
            ->field([
                'sku.id as activity_sku_id',
                'sku.discount',
                'sku.discount_price',
                'sku.stocks as discount_stocks',
                'sku.sale_quantity',
                'activity.id as activity_id',
                'activity.name as activity_name',
                'activity.start_time',
                'activity.end_time'
            ])
            ->find();
        
        return $discountInfo ?: null;
    }
    
    /**
     * 批量获取商品的折扣信息
     * @param array $goodsIds 商品ID数组
     * @return array 键为商品ID，值为折扣信息数组
     */
    public static function getBatchGoodsDiscountInfo($goodsIds)
    {
        if (empty($goodsIds)) {
            return [];
        }
        
        $currentTime = time();
        
        // 第一步：查询当前时间有效的活动ID
        $activeActivityIds = Db::table('shop_activity')
            ->where('start_time', '<=', $currentTime)
            ->where('end_time', '>=', $currentTime)
            ->where('activity_status', ActivityEnum::ACTIVITY_STATUS_ONGOING)
            ->where('status', 'normal')
            ->column('id');
        
        if (empty($activeActivityIds)) {
            return [];
        }
        
        // 第二步：查询指定商品的折扣信息
        $result = Db::table('shop_activity_sku_prize')
            ->alias('sku')
            ->join('shop_activity activity', 'sku.activity_id = activity.id')
            ->where('sku.goods_id', 'in', $goodsIds)
            ->where('sku.activity_id', 'in', $activeActivityIds)
            ->where('sku.status', 1)
            ->where('sku.stocks', '>', 0)
            ->field([
                'sku.goods_id',
                'sku.sku_id',
                'sku.id as activity_sku_id',
                'sku.discount',
                'sku.discount_price',
                'sku.stocks as discount_stocks',
                'sku.sale_quantity',
                'activity.id as activity_id',
                'activity.name as activity_name'
            ])
            ->order('sku.discount', 'asc')
            ->select();
        
        // 按商品ID分组
        $discountData = [];
        foreach ($result as $item) {
            $goodsId = $item['goods_id'];
            if (!isset($discountData[$goodsId])) {
                $discountData[$goodsId] = [];
            }
            $discountData[$goodsId][] = $item;
        }
        
        return $discountData;
    }
    
    /**
     * 检查商品是否参与当前折扣活动
     * @param int $goodsId 商品ID
     * @param int $skuId SKU ID
     * @return bool
     */
    public static function hasActiveDiscount($goodsId, $skuId = 0)
    {
        $discountInfo = self::getGoodsDiscountInfo($goodsId, $skuId);
        return !empty($discountInfo);
    }
    
    /**
     * 计算折扣后的价格
     * @param float $originalPrice 原价
     * @param float $discount 折扣（如9.0表示9折）
     * @return float
     */
    public static function calculateDiscountPrice($originalPrice, $discount)
    {
        return round($originalPrice * $discount / 10, 2);
    }
    
    /**
     * 获取活动剩余时间（秒）
     * @param int $endTime 活动结束时间戳
     * @return int
     */
    public static function getActivityRemainingTime($endTime)
    {
        return max(0, $endTime - time());
    }
    
    /**
     * 格式化活动剩余时间
     * @param int $endTime 活动结束时间戳
     * @return array
     */
    public static function formatRemainingTime($endTime)
    {
        $remaining = self::getActivityRemainingTime($endTime);
        
        if ($remaining <= 0) {
            return ['days' => 0, 'hours' => 0, 'minutes' => 0, 'seconds' => 0];
        }
        
        $days = floor($remaining / 86400);
        $hours = floor(($remaining % 86400) / 3600);
        $minutes = floor(($remaining % 3600) / 60);
        $seconds = $remaining % 60;
        
        return [
            'days' => $days,
            'hours' => $hours,
            'minutes' => $minutes,
            'seconds' => $seconds
        ];
    }

    /**
     * 处理商品的折扣价格信息（公共方法）
     * @param array $goodsData 商品数据数组
     * @return array 处理后的商品数据
     */
    private static function processGoodsDiscountData($goodsData)
    {
        foreach ($goodsData as &$goods) {
            $discountPrices = [];
            $discounts = [];
            
            // 收集所有折扣价格和折扣率
            foreach ($goods['discount_info'] as $discount) {
                $discountPrices[] = $discount['discount_price'];
                $discounts[] = $discount['discount'];
            }
            
            if (!empty($discountPrices)) {
                // 计算最低和最高折扣价格
                $goods['min_discount_price'] = min($discountPrices);
                $goods['max_discount_price'] = max($discountPrices);
                $goods['min_discount'] = min($discounts);
                $goods['max_discount'] = max($discounts);
                
                // 单规格商品处理
                if ($goods['spec_type'] == 0) {
                    $goods['discount_price'] = $goods['min_discount_price'];
                    $goods['discount'] = $goods['min_discount'];
                    $goods['discount_amount'] = round($goods['original_price'] - $goods['discount_price'], 2);
                    $goods['price_range'] = '¥' . $goods['discount_price'];
                } 
                // 多规格商品处理
                else {
                    // 设置价格区间
                    if ($goods['min_discount_price'] == $goods['max_discount_price']) {
                        $goods['price_range'] = '¥' . $goods['min_discount_price'];
                    } else {
                        $goods['price_range'] = '¥' . $goods['min_discount_price'] . '-' . $goods['max_discount_price'];
                    }
                    
                    // 对于多规格，使用最低价格作为主要显示价格
                    $goods['discount_price'] = $goods['min_discount_price'];
                    $goods['discount'] = $goods['min_discount'];
                }
            }
        }
        
        return $goodsData;
    }

    /**
     * 获取当前有效的活动ID列表
     * @return array
     */
    private static function getActiveActivityIds()
    {
        $currentTime = time();
        
        return Db::table('shop_activity')
            ->where('start_time', '<=', $currentTime)
            ->where('end_time', '>=', $currentTime)
            ->where('activity_status', ActivityEnum::ACTIVITY_STATUS_ONGOING)
            ->where('status', StatusEnum::ENABLED)
            ->column('id');
    }

    /**
     * 初始化商品折扣数据结构
     * @param array $item 商品数据
     * @return array
     */
    private static function initGoodsDiscountStructure($item)
    {
        return [
            'goods_id' => $item['goods_id'],
            'title' => $item['title'],
            'sub_title' => $item['sub_title'],
            'image' => $item['image'],
            'original_price' => $item['original_price'],
            'market_price' => $item['market_price'],
            'goods_stocks' => $item['goods_stocks'],
            'sales' => $item['sales'],
            'spec_type' => $item['spec_type'],
            'activity_id' => $item['activity_id'] ?? null,
            'activity_name' => $item['activity_name'] ?? null,
            'start_time' => $item['start_time'] ?? null,
            'end_time' => $item['end_time'] ?? null,
            'has_discount' => true,
            'discount_info' => [],
            // 初始化折扣价格相关字段
            'min_discount_price' => null,
            'max_discount_price' => null,
            'min_discount' => null,
            'max_discount' => null,
            'discount_price' => null,
            'discount' => null,
            'discount_amount' => null,
            'price_range' => ''
        ];
    }
}