{{/*
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 "update" }}
{{ $pkg := base $.Config.Package }}

{{ template "header" $ }}

{{ template "import" $ }}

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

// {{ $builder }} is the builder for updating {{ $.Name }} entities.
type {{ $builder }} struct {
	config
	{{- template "update/fields" $ -}}
	predicates []predicate.{{ $.Name }}
}

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

{{ with extend $ "Builder" $builder }}
	{{ template "setter" . }}
{{ end }}

{{ with extend $ "Builder" $builder }}
	{{ template "update/edges" . }}
{{ end }}

// Save executes the query and returns the number of rows/vertices matched by this operation.
func ({{ $receiver }} *{{ $builder }}) Save(ctx context.Context) (int, error) {
	{{ with extend $ "Receiver" $receiver "Package" $pkg "ZeroValue" 0 -}}
		{{ template "update/save" . }}
	{{- end -}}
	{{- if $.MultiStorage -}}
		switch {{ $receiver }}.driver.Dialect() {
		{{- range $_, $storage := $.Storage }}
		case {{ join $storage.Dialects ", " }}:
			return {{ $receiver }}.{{ $storage }}Save(ctx)
		{{- end }}
		default:
			return 0, errors.New("{{ $pkg }}: unsupported dialect")
		}
	{{- else -}}
		return {{ $receiver }}.{{ index $.Storage 0 }}Save(ctx)
	{{- end }}
}

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

// Exec executes the query.
func ({{ $receiver }} *{{ $builder }}) Exec(ctx context.Context) error {
	_, err := {{ $receiver }}.Save(ctx)
	return err
}

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

{{- range $_, $storage := $.Storage }}
	{{ with extend $ "Builder" $builder "Package" $pkg }}
		{{ $tmpl := printf "dialect/%s/update" $storage }}
		{{ xtemplate $tmpl . }}
	{{ end }}
{{ end }}

{{ $onebuilder := printf "%sOne" $builder }}
{{ $receiver = receiver $onebuilder }}

// {{ $onebuilder }} is the builder for updating a single {{ $.Name }} entity.
type {{ $onebuilder }} struct {
	config
	id {{ $.ID.Type }}
	{{- template "update/fields" $ }}
}

{{ with extend $ "Builder" $onebuilder }}
	{{ template "setter" . }}
{{ end }}


{{ with extend $ "Builder" $onebuilder }}
	{{ template "update/edges" . }}
{{ end }}

// Save executes the query and returns the updated entity.
func ({{ $receiver }} *{{ $onebuilder }} ) Save(ctx context.Context) (*{{ $.Name }}, error) {
	{{ with extend $ "Receiver" $receiver "Package" $pkg "ZeroValue" "nil" -}}
		{{ template "update/save" . }}
	{{- end -}}
	{{- if $.MultiStorage -}}
	switch {{ $receiver }}.driver.Dialect() {
		{{- range $_, $storage := $.Storage }}
		case {{ join $storage.Dialects ", " }}:
			return {{ $receiver }}.{{ $storage }}Save(ctx)
		{{- end }}
		default:
			return nil, errors.New("{{ $pkg }}: unsupported dialect")
		}
	{{- else -}}
		return {{ $receiver }}.{{ index $.Storage 0 }}Save(ctx)
	{{- end }}
}

// SaveX is like Save, but panics if an error occurs.
func ({{ $receiver }} *{{ $onebuilder }}) SaveX(ctx context.Context) *{{ $.Name }} {
	{{ $.Receiver }}, err := {{ $receiver }}.Save(ctx)
	if err != nil {
		panic(err)
	}
	return {{ $.Receiver }}
}

// Exec executes the query on the entity.
func ({{ $receiver }} *{{ $onebuilder }}) Exec(ctx context.Context) error {
	_, err := {{ $receiver }}.Save(ctx)
	return err
}

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

{{- range $_, $storage := $.Storage }}
	{{ with extend $ "Builder" $onebuilder "Package" $pkg }}
		{{ $tmpl := printf "dialect/%s/update" $storage }}
		{{ xtemplate $tmpl . }}
	{{ end }}
{{ end }}

{{ end }}

{{/* shared struct fields between the two updaters */}}
{{ define "update/fields"}}
{{ range $_, $f := $.Fields }}
	{{- if or (not $f.Immutable) $f.UpdateDefault }}
		{{- $f.BuilderField }} *{{ $f.Type }}
		{{- if $f.Type.Numeric }}
			add{{ $f.BuilderField }} *{{ $f.Type }}
		{{- end }}
	{{- end }}
	{{- if $f.Optional }}
		clear{{ $f.BuilderField }} bool
	{{- end }}
{{ end }}
{{- range $_, $e := $.Edges }}
	{{- $e.BuilderField }} map[{{ $.ID.Type }}]struct{}
{{ end }}
{{- range $_, $e := $.Edges }}
	{{- $p := "removed" }}{{ if $e.Unique }}{{ $p = "cleared" }}{{ end }}
	{{- print $p $e.StructField }} {{ if $e.Unique }}bool{{ else }}map[{{ $.ID.Type }}]struct{}{{ end }}
{{ end -}}
{{ end }}

{{/* shared edges removal between the two updaters */}}
{{ define "update/edges" }}
{{ $builder := pascal .Scope.Builder }}
{{ $receiver := receiver $builder }}

{{ range $_, $e := $.Edges }}
	{{ if $e.Unique }}
		{{ $func := print "Clear" $e.StructField }}
		// {{ $func }} clears the {{ $e.Name }} edge to {{ $e.Type.Name }}.
		func ({{ $receiver }} *{{ $builder }}) {{ $func }}() *{{ $builder }} {
			{{ $receiver }}.cleared{{ $e.StructField }} = true
			return {{ $receiver }}
		}
	{{ else }}
		{{ $p := lower (printf "%.1s" $e.Type.Name) }}
		{{/* if the name of the parameter conflicts with the receiver name */}}
		{{ if eq $p $receiver }} {{ $p = "v" }} {{ end }}
		{{ $idsFunc := print "Remove" (singular $e.Name | pascal) "IDs" }}
		// {{ $idsFunc }} removes the {{ $e.Name }} edge to {{ $e.Type.Name }} by ids.
		func ({{ $receiver }} *{{ $builder }}) {{ $idsFunc }}(ids ...{{ $.ID.Type }}) *{{ $builder }} {
			if {{ $receiver }}.removed{{ $e.StructField }} == nil {
				{{ $receiver }}.removed{{ $e.StructField }} = make(map[{{ $.ID.Type }}]struct{})
			}
			for i := range ids {
				{{ $receiver }}.removed{{ $e.StructField }}[ids[i]] = struct{}{}
			}
			return {{ $receiver }}
		}
		{{ $func := print "Remove" $e.StructField }}
		// {{ $func }} removes {{ $e.Name }} edges to {{ $e.Type.Name }}.
		func ({{ $receiver }} *{{ $builder }}) {{ $func }}({{ $p }} ...*{{ $e.Type.Name }}) *{{ $builder }} {
			ids := make([]{{ $.ID.Type }}, len({{ $p }}))
			{{ $i := "i" }}{{ if eq $i $p }}{{ $i = "j" }}{{ end -}}
			for {{ $i }} := range {{ $p }} {
				ids[{{ $i }}] = {{ $p }}[{{ $i }}].ID
			}
			return {{ $receiver }}.{{ $idsFunc }}(ids...)
		}
	{{ end }}
{{ end }}
{{ end }}

{{/* shared template for the save method of the 2 builders */}}
{{ define "update/save" }}
{{- $pkg := .Scope.Package -}}
{{- $zero := .Scope.ZeroValue }}
{{- $receiver := .Scope.Receiver -}}
{{- range $_, $f := $.Fields -}}
	{{- if $f.UpdateDefault -}}
		if {{ $receiver }}.{{ $f.BuilderField }} == nil {{ if $f.Optional }} && !{{ $receiver }}.clear{{ $f.BuilderField }} {{ end }} {
			v := {{ $.Package }}.{{ $f.UpdateDefaultName }}{{ if $f.IsTime }}(){{ end }}
			{{ $receiver }}.{{ $f.BuilderField }} = &v
		}
	{{ end -}}
	{{ with or $f.Validators $f.IsEnum -}}
		if {{ $receiver }}.{{ $f.BuilderField }} != nil {
			if err := {{ $.Package }}.{{ $f.Validator }}(*{{ $receiver }}.{{ $f.BuilderField }}); err != nil {
				return {{ $zero }}, fmt.Errorf("{{ $pkg }}: validator failed for field \"{{ $f.Name }}\": %v", err)
			}
		}
	{{ end -}}
{{ end -}}
{{- range $_, $e := $.Edges }}
	{{- if $e.Unique -}}
		if len({{ $receiver }}.{{ $e.BuilderField }}) > 1 {
			return {{ $zero }}, errors.New("{{ $pkg }}: multiple assignments on a unique edge \"{{ $e.Name }}\"")
		}
		{{ if not $e.Optional -}}
			if {{ $receiver }}.cleared{{ $e.StructField }} && {{ $receiver }}.{{ $e.BuilderField }} == nil {
				return {{ $zero }}, errors.New("{{ $pkg }}: clearing a unique edge \"{{ $e.Name }}\"")
			}
		{{ end -}}
	{{ end -}}
{{ end -}}
{{ end }}