{{/*
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.
*/}}

{{ define "delete" }}
{{ $pkg := base $.Config.Package }}

{{ template "header" $ }}

{{ template "import" $ }}

import (
	"{{ $.Config.Package }}/{{ $.Package }}"
)


{{ $builder := print (pascal $.Name) "Delete" }}
{{ $receiver := receiver $builder }}
{{ $mutation := print $receiver ".mutation" }}

// {{ $builder }} is the builder for deleting a {{ pascal $.Name }} entity.
type {{ $builder }} struct {
	config
	hooks      []Hook
	mutation   *{{ $.MutationName }}
	predicates []predicate.{{ $.Name }}
}


// Where adds a new predicate to the delete builder.
func ({{ $receiver }} *{{ $builder }}) Where(ps ...predicate.{{ $.Name }}) *{{ $builder }} {
	{{ $receiver}}.predicates = append({{ $receiver}}.predicates, ps...)
	return {{ $receiver }}
}

// Exec executes the deletion query and returns how many vertices were deleted.
func ({{ $receiver}} *{{ $builder }}) Exec(ctx context.Context) (int, error) {
	var (
		err error
		affected int
	)
	if len({{ $receiver }}.hooks) == 0 {
		affected, err = {{ $receiver }}.{{ $.Storage }}Exec(ctx)
	} else {
		var mut Mutator = MutateFunc(func(ctx context.Context, m Mutation) (Value, error) {
			mutation, ok := m.(*{{ $.MutationName }})
			if !ok {
				return nil, fmt.Errorf("unexpected mutation type %T", m)
			}
			{{ $mutation }} = mutation
			affected, err = {{ $receiver }}.{{ $.Storage }}Exec(ctx)
			mutation.done = true
			return affected, err
		})
		for i := len({{ $receiver }}.hooks) - 1; i >= 0; i-- {
			mut = {{ $receiver }}.hooks[i](mut)
		}
		if _, err := mut.Mutate(ctx, {{ $mutation }}); err != nil {
			return 0, err
		}
	}
	return affected, err
}

// ExecX is like Exec, but panics if an error occurs.
func ({{ $receiver }} *{{ $builder }}) ExecX(ctx context.Context) int {
	n, err := {{ $receiver }}.Exec(ctx)
	if err != nil {
		panic(err)
	}
	return n
}

{{ with extend $ "Builder" $builder }}
	{{ $tmpl := printf "dialect/%s/delete" $.Storage }}
	{{ xtemplate $tmpl . }}
{{ end }}

{{ $onebuilder := print $builder "One" }}
{{ $oneReceiver := receiver $onebuilder }}

// {{ $onebuilder }} is the builder for deleting a single {{ $.Name }} entity.
type {{ $onebuilder }} struct {
	{{ $receiver }} *{{ $builder }}
}

// Exec executes the deletion query.
func ({{ $oneReceiver }} *{{ $onebuilder }}) Exec(ctx context.Context) error {
	n, err := {{ $oneReceiver }}.{{ $receiver }}.Exec(ctx)
	switch {
	case err != nil:
		return err
	case n == 0:
		return &NotFoundError{ {{ $.Package }}.Label}
	default:
		return nil
	}
}

// ExecX is like Exec, but panics if an error occurs.
func ({{ $oneReceiver }} *{{ $onebuilder }}) ExecX(ctx context.Context) {
	{{ $oneReceiver }}.{{ $receiver }}.ExecX(ctx)
}

{{ end }}