kurz/infrastructure/mysql.go

package infrastructure

import (
	"code.osinet.fr/fgm/kurz/domain"
	"database/sql"
)

type MySQLShortURLRepository struct {
	db *sql.DB
}

type MySQLTargetURLRepository struct {
	db *sql.DB
}

func (sr MySQLShortURLRepository) GetTarget(su domain.ShortURL) (domain.TargetURL, error) {
	var tu domain.TargetURL
	row := sr.db.QueryRow(`
SELECT map.url
FROM map
WHERE map.hash = ?
`, su.URL)
	err := row.Scan(&tu.URL)
	switch err {
	case sql.ErrNoRows:
		err = domain.MakeError(domain.ShortNotFound, string(su.URL))
	case nil:
		break
	default:
		err = domain.MakeError(domain.StorageReadError, "")
	}
	return tu, err
}

func (tr MySQLTargetURLRepository) GetShort(tu domain.TargetURL) (su domain.ShortURL, isNew bool, err error) {
	// TODO future versions may have multiple shorts for a target, and choose a
	// specific short based on the domain and Kurz user. For now just ensure we
	// don't get more than one.
	row := tr.db.QueryRow(`
SELECT map.hash
FROM map
LIMIT 1
`)
	err = row.Scan(&su.URL)
	switch err {
	case sql.ErrNoRows:
		// If it doesn't exist, attempt to create it.
		su, err = domain.NewUnspecifiedShortURL(tu)
		if err != nil {
			// Creation failed.
			return su, false, err
		}
		_, err = tr.db.Exec(`
INSERT INTO map(hash, url, date1, date2, date3, refcount)
VALUES (?, ?, CURRENT_TIMESTAMP(), CURRENT_TIMESTAMP(), CURRENT_TIMESTAMP(), 0)
`, su.URL, tu.URL)
		if err != nil {
			err = domain.MakeError(domain.StorageWriteError, "storing new mapping")
		}
		isNew = true

	case nil:
		break

	default:
		err = domain.MakeError(domain.StorageReadError, "looking for mapping")
	}

	return
}