codeword/internal/repository/promocode_repository.go

package repository

import (
	"codeword/internal/models"
	"context"
	"errors"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
	"time"
)

var ErrDuplicateCodeword = errors.New("duplicate codeword")

type PromoCodeRepository struct {
	mdb *mongo.Collection
}

func NewPromoCodeRepository(mdb *mongo.Collection) *PromoCodeRepository {
	indexModel := mongo.IndexModel{
		Keys: bson.D{
			{"codeword", 1},
			{"delete", 1},
		},
		Options: options.Index().SetUnique(true).SetPartialFilterExpression(bson.M{"delete": false}),
	}
	_, err := mdb.Indexes().CreateOne(context.Background(), indexModel)
	if err != nil {
		panic(err)
	}

	return &PromoCodeRepository{mdb: mdb}
}

func (r *PromoCodeRepository) CreatePromoCode(ctx context.Context, promoCode *models.PromoCode) (*models.PromoCode, error) {
	promoCode.CreatedAt = time.Now()
	promoCode.ID = primitive.NewObjectID()

	_, err := r.mdb.InsertOne(ctx, promoCode)
	if err != nil {
		if writeErr, ok := err.(mongo.WriteException); ok {
			for _, writeError := range writeErr.WriteErrors {
				if writeError.Code == 11000 {
					return nil, ErrDuplicateCodeword
				}
			}
		}

		return nil, err
	}

	return promoCode, nil
}