package db

import "errors"

var ErrInviteUsed = errors.New("db: the requested invite has already been used")

func GetInviteOwner(inviteCode string) (string, error) {
	rows, err := db.Query("SELECT owner, used FROM invite WHERE code=?", inviteCode)
	if err != nil {
		return "", err
	}
	defer rows.Close()
	if rows.Next() {
		var owner string
		var used bool
		err := rows.Scan(&owner, &used)
		if err != nil {
			return "", err
		}
		if used {
			return "", ErrInviteUsed
		}
		return owner, nil
	}
	return "", ErrNotFound
}

func SetInviteOwner(inviteCode, owner string) error {
	_, err := GetInviteOwner(inviteCode)
	if err == nil {
		return ErrAlreadyExists
	}
	if err != ErrNotFound {
		return err
	}
	_, err = db.Exec("INSERT INTO invite(code, owner, used) VALUES(?,?,?)", inviteCode, owner, false)
	return err
}

func UseInvite(inviteCode string) error {
	owner, err := GetInviteOwner(inviteCode)
	if err != nil {
		return err
	}
	_, err = db.Exec("REPLACE INTO invite(code, owner, used) VALUES(?,?,?)", inviteCode, owner, true)
	return err
}