apollo-backend/internal/repository/postgres_user.go

package repository

import (
	"context"
	"fmt"
	"strings"

	"github.com/christianselig/apollo-backend/internal/domain"
)

type postgresUserRepository struct {
	conn Connection
}

func NewPostgresUser(conn Connection) domain.UserRepository {
	return &postgresUserRepository{conn: conn}
}

func (p *postgresUserRepository) fetch(ctx context.Context, query string, args ...interface{}) ([]domain.User, error) {
	rows, err := p.conn.Query(ctx, query, args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var uu []domain.User
	for rows.Next() {
		var u domain.User
		if err := rows.Scan(
			&u.ID,
			&u.UserID,
			&u.Name,
			&u.NextCheckAt,
		); err != nil {
			return nil, err
		}
		uu = append(uu, u)
	}
	return uu, nil
}

func (p *postgresUserRepository) GetByID(ctx context.Context, id int64) (domain.User, error) {
	query := `
		SELECT id, user_id, name, next_check_at
		FROM users
		WHERE id = $1`

	srs, err := p.fetch(ctx, query, id)

	if err != nil {
		return domain.User{}, err
	}
	if len(srs) == 0 {
		return domain.User{}, domain.ErrNotFound
	}
	return srs[0], nil
}

func (p *postgresUserRepository) GetByName(ctx context.Context, name string) (domain.User, error) {
	query := `
		SELECT id, user_id, name, next_check_at
		FROM users
		WHERE name = $1`

	name = strings.ToLower(name)

	srs, err := p.fetch(ctx, query, name)

	if err != nil {
		return domain.User{}, err
	}
	if len(srs) == 0 {
		return domain.User{}, domain.ErrNotFound
	}
	return srs[0], nil
}

func (p *postgresUserRepository) CreateOrUpdate(ctx context.Context, u *domain.User) error {
	if err := u.Validate(); err != nil {
		return err
	}

	query := `
		INSERT INTO users (user_id, name, next_check_at)
		VALUES ($1, $2, NOW())
		ON CONFLICT(user_id) DO NOTHING
		RETURNING id`

	return p.conn.QueryRow(
		ctx,
		query,
		u.UserID,
		u.NormalizedName(),
		u.NextCheckAt,
	).Scan(&u.ID)
}

func (p *postgresUserRepository) Delete(ctx context.Context, id int64) error {
	query := `DELETE FROM users WHERE id = $1`
	res, err := p.conn.Exec(ctx, query, id)

	if res.RowsAffected() != 1 {
		return fmt.Errorf("weird behaviour, total rows affected: %d", res.RowsAffected())
	}
	return err
}