package sqlite

import (
	"database/sql"
	"errors"

	"code.nochebuena.dev/go/xerrors"
)

// coder is the duck-type interface for SQLite extended error codes.
// modernc.org/sqlite errors implement this interface.
type coder interface{ Code() int }

const (
	sqliteConstraintPrimaryKey  = 1555
	sqliteConstraintUnique      = 2067
	sqliteConstraintForeignKey  = 787
)

// HandleError maps SQLite and database/sql errors to xerrors types.
func HandleError(err error) error {
	if err == nil {
		return nil
	}
	if errors.Is(err, sql.ErrNoRows) {
		return xerrors.New(xerrors.ErrNotFound, "record not found").WithError(err)
	}
	var ce coder
	if errors.As(err, &ce) {
		switch ce.Code() {
		case sqliteConstraintUnique, sqliteConstraintPrimaryKey:
			return xerrors.New(xerrors.ErrAlreadyExists, "record already exists").WithError(err)
		case sqliteConstraintForeignKey:
			return xerrors.New(xerrors.ErrInvalidInput, "data integrity violation").WithError(err)
		}
	}
	return xerrors.New(xerrors.ErrInternal, "unexpected database error").WithError(err)
}