package handler

import (
	"fmt"
	"strconv"
	"time"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"

	"nl-game-api-gin/internal/database"
	"nl-game-api-gin/internal/middleware"
	"nl-game-api-gin/internal/model"
	"nl-game-api-gin/internal/service"
	"nl-game-api-gin/pkg/resp"
)

// vipGameBrief 周免游戏的精简信息（VIP页展示用）
type vipGameBrief struct {
	ID    int    `json:"id"`    // 游戏ID
	Code  string `json:"code"`  // 游戏编码
	Name  string `json:"name"`  // 游戏名称
	Icon  string `json:"icon"`  // emoji 图标
	Price int    `json:"price"` // 原价（积分）
}

// vipLevelItem VIP等级 + 本周周免批次
type vipLevelItem struct {
	model.VipLevel
	WeeklyGames []vipGameBrief `json:"weekly_games"` // 该等级本周的周免游戏
}

// VipInfo VIP中心数据：我的VIP状态、5个等级的权益与本周周免批次、下次刷新时间
func VipInfo(c *gin.Context) {
	uid := middleware.UID(c)
	now := time.Now()
	var user model.User
	if err := database.DB.First(&user, uid).Error; err != nil {
		resp.Fail(c, "用户不存在")
		return
	}
	var levels []model.VipLevel
	database.DB.Order("level").Find(&levels)
	pool := service.VipWeeklyPool(now)
	myLevel := service.UserVipLevel(&user, now)
	list := make([]vipLevelItem, 0, len(levels))
	myName := ""
	for _, l := range levels {
		batch := service.VipWeeklyBatch(pool, levels, l.Level)
		games := make([]vipGameBrief, 0, len(batch))
		for _, g := range batch {
			games = append(games, vipGameBrief{ID: g.ID, Code: g.Code, Name: g.Name, Icon: g.Icon, Price: g.Price})
		}
		list = append(list, vipLevelItem{VipLevel: l, WeeklyGames: games})
		if l.Level == myLevel {
			myName = l.Name
		}
	}
	resp.OK(c, gin.H{
		"my": gin.H{
			"level":      myLevel,        // 当前生效等级（过期后为 0）
			"level_name": myName,         // 等级名称
			"expire":     user.VipExpire, // 到期时间戳（秒）
			"active":     myLevel > 0,    // 是否生效中
		},
		"refresh_at": service.VipNextRefresh(now).Unix(), // 下次周免刷新时间（周五12:00）
		"levels":     list,
	})
}

// vipBuyReq 购买VIP请求体
type vipBuyReq struct {
	Level int `json:"level" binding:"required,min=1,max=5"` // 目标等级（1~5）
}

// VipBuy 开通/续费/升级VIP：扣积分并更新等级与到期时间（30天/次）
// 规则:同等级续费在原到期时间上顺延;升级立即生效、按30天重新计时;不允许降级购买
func VipBuy(c *gin.Context) {
	var req vipBuyReq
	if err := c.ShouldBindJSON(&req); err != nil {
		resp.Fail(c, "参数有误")
		return
	}
	uid := middleware.UID(c)
	var target model.VipLevel
	if err := database.DB.Where("level = ?", req.Level).First(&target).Error; err != nil {
		resp.Fail(c, "VIP等级不存在")
		return
	}
	now := time.Now()
	var newExpire int64
	var balance int
	err := database.DB.Transaction(func(tx *gorm.DB) error {
		var user model.User
		if err := tx.Set("gorm:query_option", "FOR UPDATE").First(&user, uid).Error; err != nil {
			return fmt.Errorf("用户不存在")
		}
		curLevel := service.UserVipLevel(&user, now)
		if curLevel > req.Level {
			return fmt.Errorf("当前已是更高等级（VIP%d），无需降级购买", curLevel)
		}
		// 计算新到期时间：同级续费顺延，升级/新开从现在起算30天
		if curLevel == req.Level {
			newExpire = user.VipExpire + 30*86400
		} else {
			newExpire = now.Unix() + 30*86400
		}
		// 扣积分并记流水（复用事务，余额不足会报错回滚）
		b, err := service.ChangePoints(tx, uid, -target.PricePoints, model.PointTypeVIP, target.ID,
			fmt.Sprintf("开通VIP%d·%s（30天）", target.Level, target.Name))
		if err != nil {
			return err
		}
		balance = b
		return tx.Model(&model.User{}).Where("id = ?", uid).
			Updates(map[string]any{"vip_level": req.Level, "vip_expire": newExpire}).Error
	})
	if err != nil {
		resp.Fail(c, err.Error())
		return
	}
	resp.OK(c, gin.H{"level": req.Level, "expire": newExpire, "balance": balance})
}

// AdminVipLevels 后台：VIP等级配置列表
func AdminVipLevels(c *gin.Context) {
	var levels []model.VipLevel
	database.DB.Order("level").Find(&levels)
	resp.OK(c, levels)
}

// adminUpdateVipReq 后台修改VIP等级配置请求体（nil=不修改）
type adminUpdateVipReq struct {
	Name            *string `json:"name"`              // 等级名称
	PricePoints     *int    `json:"price_points"`      // 30天价格（积分）
	WeeklyFreeQuota *int    `json:"weekly_free_quota"` // 周免游戏数量
	SigninBonus     *int    `json:"signin_bonus"`      // 签到加成积分
	Description     *string `json:"description"`       // 权益描述
}

// AdminUpdateVipLevel 后台：修改某一VIP等级的价格与权益
func AdminUpdateVipLevel(c *gin.Context) {
	id, _ := strconv.Atoi(c.Param("id"))
	var req adminUpdateVipReq
	if err := c.ShouldBindJSON(&req); err != nil {
		resp.Fail(c, "参数有误")
		return
	}
	updates := map[string]any{}
	if req.Name != nil && *req.Name != "" {
		updates["name"] = *req.Name
	}
	if req.PricePoints != nil && *req.PricePoints >= 0 {
		updates["price_points"] = *req.PricePoints
	}
	if req.WeeklyFreeQuota != nil && *req.WeeklyFreeQuota >= 0 {
		updates["weekly_free_quota"] = *req.WeeklyFreeQuota
	}
	if req.SigninBonus != nil && *req.SigninBonus >= 0 {
		updates["signin_bonus"] = *req.SigninBonus
	}
	if req.Description != nil {
		updates["description"] = *req.Description
	}
	if len(updates) == 0 {
		resp.Fail(c, "没有需要修改的内容")
		return
	}
	if err := database.DB.Model(&model.VipLevel{}).Where("id = ?", id).Updates(updates).Error; err != nil {
		resp.Fail(c, "保存失败")
		return
	}
	resp.OK(c, nil)
}