package logic

import (
	"context"
	"database/sql"
	"fmt"
	"strconv"
	"time"

	"muyu-apiserver/model"
	"muyu-apiserver/pkg/uid"
	"muyu-apiserver/rpc/inventory/internal/svc"
	"muyu-apiserver/rpc/inventory/pb"

	"github.com/zeromicro/go-zero/core/logx"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
)

type CreateStockCheckLogic struct {
	ctx    context.Context
	svcCtx *svc.ServiceContext
	logx.Logger
}

func NewCreateStockCheckLogic(ctx context.Context, svcCtx *svc.ServiceContext) *CreateStockCheckLogic {
	return &CreateStockCheckLogic{
		ctx:    ctx,
		svcCtx: svcCtx,
		Logger: logx.WithContext(ctx),
	}
}

func generateNo(prefix string) string {
	now := time.Now()
	return fmt.Sprintf("%s%s%04d", prefix, now.Format("20060102"), now.UnixNano()%10000)
}

func (l *CreateStockCheckLogic) CreateStockCheck(in *pb.CreateStockCheckReq) (*pb.IdResp, error) {
	checkId := uid.Generate()
	checkNo := generateNo("PD")

	checkDate, err := time.Parse("2006-01-02", in.CheckDate)
	if err != nil {
		return nil, status.Error(codes.InvalidArgument, "invalid check_date format, expected YYYY-MM-DD")
	}

	check := &model.InvStockCheck{
		CheckId:   checkId,
		CheckNo:   checkNo,
		CheckDate: checkDate,
		Checker:   in.Checker,
		Status:    0,
		Remark:    sql.NullString{String: in.Remark, Valid: in.Remark != ""},
	}

	_, err = l.svcCtx.StockCheckModel.Insert(l.ctx, check)
	if err != nil {
		return nil, status.Error(codes.Internal, err.Error())
	}

	details := make([]*model.InvStockCheckDetail, 0, len(in.Details))
	for _, d := range in.Details {
		product, err := l.svcCtx.ProductModel.FindOneByProductId(l.ctx, d.ProductId)
		if err != nil {
			return nil, status.Errorf(codes.NotFound, "product %s not found", d.ProductId)
		}

		actualQty, _ := strconv.ParseFloat(d.ActualQuantity, 64)
		diffQty := actualQty - product.StockQuantity
		diffAmount := diffQty * product.CostPrice

		details = append(details, &model.InvStockCheckDetail{
			DetailId:       uid.Generate(),
			CheckId:        checkId,
			ProductId:      d.ProductId,
			SystemQuantity: product.StockQuantity,
			ActualQuantity: actualQty,
			DiffQuantity:   diffQty,
			DiffAmount:     diffAmount,
			Remark:         sql.NullString{String: d.Remark, Valid: d.Remark != ""},
		})
	}

	err = l.svcCtx.CheckDetailModel.BatchInsert(l.ctx, details)
	if err != nil {
		return nil, status.Error(codes.Internal, err.Error())
	}

	return &pb.IdResp{Id: checkId}, nil
}