package packagepkg

import (
	"context"

	"github.com/break/junhong_cmp_fiber/internal/model"
	"github.com/break/junhong_cmp_fiber/internal/model/dto"
	"github.com/break/junhong_cmp_fiber/internal/store/postgres"
	"github.com/break/junhong_cmp_fiber/pkg/constants"
	"github.com/break/junhong_cmp_fiber/pkg/errors"
	"github.com/redis/go-redis/v9"
	"go.uber.org/zap"
	"gorm.io/gorm"
)

type CustomerViewService struct {
	db                *gorm.DB
	redis             *redis.Client
	packageUsageStore *postgres.PackageUsageStore
	logger            *zap.Logger
}

func NewCustomerViewService(
	db *gorm.DB,
	redis *redis.Client,
	packageUsageStore *postgres.PackageUsageStore,
	logger *zap.Logger,
) *CustomerViewService {
	return &CustomerViewService{
		db:                db,
		redis:             redis,
		packageUsageStore: packageUsageStore,
		logger:            logger,
	}
}

// GetMyUsage 任务 12.2-12.5: 获取客户套餐使用情况
// 根据载体ID和类型查询生效中的套餐，计算总流量使用情况
func (s *CustomerViewService) GetMyUsage(ctx context.Context, carrierType string, carrierID uint) (*dto.PackageUsageCustomerViewResponse, error) {
	// 任务 12.3: 查询生效套餐（status IN (1,2)）
	var packages []*model.PackageUsage
	query := s.db.WithContext(ctx).
		Where("status IN ?", []int{constants.PackageUsageStatusActive, constants.PackageUsageStatusDepleted})

	if carrierType == "iot_card" {
		query = query.Where("iot_card_id = ?", carrierID)
	} else if carrierType == "device" {
		query = query.Where("device_id = ?", carrierID)
	} else {
		return nil, errors.New(errors.CodeInvalidParam, "无效的载体类型")
	}

	// 按优先级排序：主套餐在前，加油包在后
	if err := query.Order("CASE WHEN master_usage_id IS NULL THEN 0 ELSE 1 END, priority ASC").
		Find(&packages).Error; err != nil {
		return nil, errors.Wrap(errors.CodeDatabaseError, err, "查询套餐使用记录失败")
	}

	if len(packages) == 0 {
		return nil, errors.New(errors.CodeNotFound, "未找到套餐使用记录")
	}

	// 任务 12.4: 区分主套餐和加油包，计算总流量
	var mainPackage *dto.PackageUsageItemResponse
	var addonPackages []dto.PackageUsageItemResponse
	var totalUsedMB int64
	var totalLimitMB int64

	for _, pkg := range packages {
		// 查询套餐信息
		var packageInfo model.Package
		if err := s.db.First(&packageInfo, pkg.PackageID).Error; err != nil {
			s.logger.Warn("查询套餐信息失败",
				zap.Uint("package_id", pkg.PackageID),
				zap.Error(err))
			continue
		}

		// 格式化状态文本
		statusText := getStatusText(pkg.Status)

		// 格式化时间
		activatedAtStr := ""
		if pkg.ActivatedAt.Year() > 1 {
			activatedAtStr = pkg.ActivatedAt.Format("2006-01-02 15:04:05")
		}

		expiresAtStr := ""
		if pkg.ExpiresAt.Year() > 1 {
			expiresAtStr = pkg.ExpiresAt.Format("2006-01-02 15:04:05")
		}

		item := dto.PackageUsageItemResponse{
			PackageUsageID: pkg.ID,
			PackageID:      pkg.PackageID,
			PackageName:    packageInfo.PackageName,
			UsedMB:         pkg.DataUsageMB,
			TotalMB:        pkg.DataLimitMB,
			Status:         pkg.Status,
			StatusText:     statusText,
			ActivatedAt:    activatedAtStr,
			ExpiresAt:      expiresAtStr,
			Priority:       pkg.Priority,
		}

		// 累计总流量
		totalUsedMB += pkg.DataUsageMB
		totalLimitMB += pkg.DataLimitMB

		// 区分主套餐和加油包
		if pkg.MasterUsageID == nil {
			mainPackage = &item
		} else {
			addonPackages = append(addonPackages, item)
		}
	}

	// 任务 12.5: 组装响应 DTO
	response := &dto.PackageUsageCustomerViewResponse{
		MainPackage:   mainPackage,
		AddonPackages: addonPackages,
		Total: dto.PackageUsageTotalInfo{
			UsedMB:  totalUsedMB,
			TotalMB: totalLimitMB,
		},
	}

	return response, nil
}

// getStatusText 获取状态文本
func getStatusText(status int) string {
	switch status {
	case constants.PackageUsageStatusPending:
		return "待生效"
	case constants.PackageUsageStatusActive:
		return "生效中"
	case constants.PackageUsageStatusDepleted:
		return "已用完"
	case constants.PackageUsageStatusExpired:
		return "已过期"
	case constants.PackageUsageStatusInvalidated:
		return "已失效"
	default:
		return "未知"
	}
}