{{/*
Copyright 2019-present Facebook Inc. All rights reserved.
This source code is licensed under the Apache 2.0 license found
in the LICENSE file in the root directory of this source tree.
*/}}

{{/* custom errors and errors handlers from sql dialects */}}
{{ define "dialect/gremlin/errors" }}
{{ $pkg := base $.Config.Package }}

// Code implements the dsl.Node interface.
func (e ErrConstraintFailed) Code() (string, []interface{}) {
	return strconv.Quote(e.prefix() + e.msg), nil
}

func (e *ErrConstraintFailed) UnmarshalGraphson(b []byte) error {
	var v [1]*string
	if err := graphson.Unmarshal(b, &v); err != nil {
		return err
	}
	if v[0] == nil {
		return fmt.Errorf("{{ $pkg }}: missing string value")
	}
	if !strings.HasPrefix(*v[0], e.prefix()) {
		return fmt.Errorf("{{ $pkg }}: invalid string for error: %s", *v[0])
	}
	e.msg = strings.TrimPrefix(*v[0], e.prefix())
	return nil
}

// prefix returns the prefix used for gremlin constants.
func (ErrConstraintFailed) prefix() string { return "Error: " }

// NewErrUniqueField creates a constraint error for unique fields.
func NewErrUniqueField(label, field string, v interface{}) *ErrConstraintFailed {
	return &ErrConstraintFailed{msg: fmt.Sprintf("field %s.%s with value: %#v", label, field, v)}
}

// NewErrUniqueEdge creates a constraint error for unique edges.
func NewErrUniqueEdge(label, edge, id string) *ErrConstraintFailed {
	return &ErrConstraintFailed{msg: fmt.Sprintf("edge %s.%s with id: %#v", label, edge, id)}
}

// isConstantError indicates if the given response holds a gremlin constant containing an error.
func isConstantError(r *gremlin.Response) (*ErrConstraintFailed, bool) {
	e := &ErrConstraintFailed{}
	if err := graphson.Unmarshal(r.Result.Data, e); err != nil {
		return nil, false
	}
	return e, true
}
{{ end }}