package monthlyusage

import (
	"context"
	"fmt"
	"strings"

	"github.com/gogf/gf/v2/database/gdb"
	"github.com/gogf/gf/v2/os/gtime"

	"git.5iot.com/iotlcm-public/iotlcm-worker-svr/internal/dao"
	"git.5iot.com/iotlcm-public/iotlcm-worker-svr/internal/model/do"
)

// Repository applies the current usage result to the card information table.
// It deliberately does not write TDengine history for this full-sync flow.
type Repository struct{}

type UsageResult struct {
	CardID  int64
	UsageMB float64
}

func NewRepository() *Repository {
	return &Repository{}
}

func (r *Repository) ApplyBatch(ctx context.Context, results []UsageResult) error {
	if len(results) == 0 {
		return nil
	}
	cardIDs := make([]int64, 0, len(results))
	var statement strings.Builder
	statement.WriteString("CASE " + dao.TSimCardInfo.Columns().Id + " ")
	for _, result := range results {
		if result.CardID <= 0 {
			return fmt.Errorf("monthly usage result has invalid cardId %d", result.CardID)
		}
		fmt.Fprintf(&statement, "WHEN %d THEN %f ", result.CardID, result.UsageMB)
		cardIDs = append(cardIDs, result.CardID)
	}
	statement.WriteString("END")
	_, err := dao.TSimCardInfo.Ctx(ctx).
		WhereIn(dao.TSimCardInfo.Columns().Id, cardIDs).
		Data(do.TSimCardInfo{
			UsedFlowMb:   gdb.Raw(statement.String()),
			FlowSyncTime: gtime.Now(),
		}).
		Update()
	return err
}