{{/*
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" $ }}

import (
	{{- range $path := $.SiblingImports }}
		"{{ $path }}"
	{{- end }}
)


{{ $builder := $.UpdateName }}
{{ $receiver := receiver $builder }}
{{ $mutation := print $receiver ".mutation" }}

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

// Where adds a new predicate for the builder.
func ({{ $receiver}} *{{ $builder }}) Where(ps ...predicate.{{ $.Name }}) *{{ $builder }} {
	{{ $mutation }}.predicates = append({{ $mutation }}.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 nodes affected by the update operation.
func ({{ $receiver }} *{{ $builder }}) Save(ctx context.Context) (int, error) {
	var (
		err error
		affected int
	)
	{{- if $.HasUpdateDefault }}
		{{ $receiver }}.defaults()
	{{- end }}
	if len({{ $receiver }}.hooks) == 0 {
		{{- if $.HasUpdateCheckers }}
			if err = {{ $receiver }}.check(); err != nil {
				return 0, err
			}
		{{- end }}
		affected, err = {{ $receiver }}.{{ $.Storage }}Save(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)
			}
			{{- if $.HasUpdateCheckers }}
				if err = {{ $receiver }}.check(); err != nil {
					return 0, err
				}
			{{- end }}
			{{ $mutation }} = mutation
			affected, err = {{ $receiver }}.{{ $.Storage }}Save(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
}

// 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)
	}
}

{{ with extend $ "Receiver" $receiver "Package" $pkg "Builder" $builder }}
	{{ template "update/checks" . }}
{{ end }}

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

{{ $onebuilder := $.UpdateOneName }}
{{ $receiver = receiver $onebuilder }}
{{ $mutation = print $receiver ".mutation" }}

// {{ $onebuilder }} is the builder for updating a single {{ $.Name }} entity.
type {{ $onebuilder }} struct {
	config
	{{- 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) {
	var (
		err error
		node *{{ $.Name }}
	)
	{{- if $.HasUpdateDefault }}
		{{ $receiver }}.defaults()
	{{- end }}
	if len({{ $receiver }}.hooks) == 0 {
		{{- if $.HasUpdateCheckers }}
			if err = {{ $receiver }}.check(); err != nil {
				return nil, err
			}
		{{- end }}
		node, err = {{ $receiver }}.{{ $.Storage }}Save(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)
			}
			{{- if $.HasUpdateCheckers }}
				if err = {{ $receiver }}.check(); err != nil {
					return nil, err
				}
			{{- end }}
			{{ $mutation }} = mutation
			node, err = {{ $receiver }}.{{ $.Storage }}Save(ctx)
			mutation.done = true
			return node, err
		})
		for i := len({{ $receiver }}.hooks) - 1; i >= 0; i-- {
			mut = {{ $receiver }}.hooks[i](mut)
		}
		if _, err := mut.Mutate(ctx, {{ $mutation }}); err != nil {
			return nil, err
		}
	}
	return node, err
}

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

// 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)
	}
}

{{ with extend $ "Receiver" $receiver "Package" $pkg "Builder" $onebuilder }}
	{{ template "update/checks" . }}
{{ end }}

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

{{ end }}

{{/* shared struct fields between the two updaters */}}
{{ define "update/fields"}}
	hooks []Hook
	mutation *{{ $.MutationName }}
{{ end }}

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

{{ range $e := $.Edges }}
	{{ $func := $e.MutationClear }}
	// {{ $func }} clears {{ if $e.Unique }}the "{{ $e.Name }}" edge{{ else }}all "{{ $e.Name }}" edges{{ end }} to type {{ $e.Type.Name }}.
	func ({{ $receiver }} *{{ $builder }}) {{ $func }}() *{{ $builder }} {
		{{ $mutation }}.{{ $func }}()
		return {{ $receiver }}
	}
	{{ if not $e.Unique }}
		{{ $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 ...{{ $e.Type.ID.Type }}) *{{ $builder }} {
			{{ $mutation }}.{{ $idsFunc }}(ids...)
			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([]{{ $e.Type.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 2 update builders */}}
{{ define "update/checks" }}
{{ $pkg := .Scope.Package }}
{{ $receiver := .Scope.Receiver }}
{{ $builder := pascal .Scope.Builder }}
{{ $mutation := print $receiver ".mutation" }}

{{ if $.HasUpdateDefault }}
	// defaults sets the default values of the builder before save.
	func ({{ $receiver }} *{{ $builder }}) defaults() {
		{{- range $f := $.Fields }}
			{{- if $f.UpdateDefault }}
				if _, ok := {{ $mutation }}.{{ $f.MutationGet }}(); !ok {{ if $f.Optional }} && !{{ $mutation }}.{{ $f.StructField }}Cleared() {{ end }} {
					v := {{ $.Package }}.{{ $f.UpdateDefaultName }}{{ if $f.IsTime }}(){{ end }}
					{{ $mutation }}.Set{{ $f.StructField }}(v)
				}
			{{- end }}
		{{- end }}
	}
{{ end }}

{{ if $.HasUpdateCheckers }}
	// check runs all checks and user-defined validators on the builder.
	func ({{ $receiver }} *{{ $builder }}) check() error {
		{{- range $f := $.Fields }}
			{{- with and (or $f.Validators $f.IsEnum) (not $f.Immutable) }}
				if v, ok := {{ $mutation }}.{{ $f.MutationGet }}(); ok {
					{{- $basic := $f.BasicType "v" }}
					if err := {{ $.Package }}.{{ $f.Validator }}({{ $basic }}); err != nil {
						return &ValidationError{Name: "{{ $f.Name }}", err: fmt.Errorf("{{ $pkg }}: validator failed for field \"{{ $f.Name }}\": %w", err)}
					}
				}
			{{- end }}
		{{- end }}
		{{- range $e := $.Edges }}
			{{- if and $e.Unique (not $e.Optional) }}
				if _, ok := {{ $mutation }}.{{ $e.StructField }}ID(); {{ $mutation }}.{{ $e.StructField }}Cleared() && !ok {
					return errors.New("{{ $pkg }}: clearing a required unique edge \"{{ $e.Name }}\"")
				}
			{{- end }}
		{{- end }}
		return nil
	}
{{ end }}

{{ end }}