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

{{ template "header" $ }}

{{ template "import" $ }}

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

{{ $builder := $.QueryName }}
{{ $receiver := receiver $builder }}

// {{ $builder }} is the builder for querying {{ $.Name }} entities.
type {{ $builder }} struct {
	config
	limit		*int
	offset		*int
	order		[]OrderFunc
	fields		[]string
	predicates 	[]predicate.{{ $.Name }}
	{{- with $.Edges }}
		// eager-loading edges.
		{{- range $e := . }}
			{{ $e.EagerLoadField }} *{{ $e.Type.QueryName }}
		{{- end }}
	{{- end }}
	{{- /* Additional fields to add to the builder. */}}
	{{- $tmpl := printf "dialect/%s/query/fields" $.Storage }}
	{{- if hasTemplate $tmpl }}
		{{- xtemplate $tmpl . }}
	{{- end }}
	// intermediate query (i.e. traversal path).
	{{ $.Storage }} {{ $.Storage.Builder }}
	path func(context.Context) ({{ $.Storage.Builder }}, error)
}

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

// Limit adds a limit step to the query.
func ({{ $receiver }} *{{ $builder }}) Limit(limit int) *{{ $builder }} {
	{{ $receiver }}.limit = &limit
	return {{ $receiver }}
}

// Offset adds an offset step to the query.
func ({{ $receiver }} *{{ $builder }}) Offset(offset int) *{{ $builder }} {
	{{ $receiver }}.offset = &offset
	return {{ $receiver }}
}

// Order adds an order step to the query.
func ({{ $receiver }} *{{ $builder }}) Order(o ...OrderFunc) *{{ $builder }} {
	{{ $receiver }}.order = append({{ $receiver }}.order, o...)
	return {{ $receiver }}
}

{{/* this code has similarity with edge queries in client.tmpl */}}
{{ range $e := $.Edges }}
	{{ $edge_builder := print (pascal $e.Type.Name) "Query" }}
	// Query{{ pascal $e.Name }} chains the current query on the "{{ $e.Name }}" edge.
	func ({{ $receiver }} *{{ $builder }}) Query{{ pascal $e.Name }}() *{{ $edge_builder }} {
		query := &{{ $edge_builder }}{config: {{ $receiver }}.config}
		query.path = func(ctx context.Context) (fromU {{ $.Storage.Builder }}, err error) {
			if err := {{ $receiver }}.prepareQuery(ctx); err != nil {
				return nil, err
			}
			{{- with extend $ "Receiver" $receiver "Edge" $e "Ident" "fromU" -}}
				{{ $tmpl := printf "dialect/%s/query/path" $.Storage }}
				{{- xtemplate $tmpl . }}
			{{- end -}}
			return fromU, nil
		}
		return query
	}
{{ end }}

// First returns the first {{ $.Name }} entity from the query. 
// Returns a *NotFoundError when no {{ $.Name }} was found.
func ({{ $receiver }} *{{ $builder }}) First(ctx context.Context) (*{{ $.Name }}, error) {
	nodes, err := {{ $receiver }}.Limit(1).All(ctx)
	if err != nil {
		return nil, err
	}
	if len(nodes) == 0 {
		return nil, &NotFoundError{ {{ $.Package }}.Label}
	}
	return nodes[0], nil
}

// FirstX is like First, but panics if an error occurs.
func ({{ $receiver }} *{{ $builder }}) FirstX(ctx context.Context) *{{ $.Name }} {
	node, err := {{ $receiver }}.First(ctx)
	if err != nil && !IsNotFound(err) {
		panic(err)
	}
	return node
}

// FirstID returns the first {{ $.Name }} ID from the query. 
// Returns a *NotFoundError when no {{ $.Name }} ID was found.
func ({{ $receiver }} *{{ $builder }}) FirstID(ctx context.Context) (id {{ $.ID.Type }}, err error) {
	var ids []{{ $.ID.Type }}
	if ids, err = {{ $receiver }}.Limit(1).IDs(ctx); err != nil {
		return
	}
	if len(ids) == 0 {
		err = &NotFoundError{ {{ $.Package }}.Label}
		return
	}
	return ids[0], nil
}

// FirstIDX is like FirstID, but panics if an error occurs.
func ({{ $receiver }} *{{ $builder }}) FirstIDX(ctx context.Context) {{ $.ID.Type }} {
	id, err := {{ $receiver }}.FirstID(ctx)
	if err != nil && !IsNotFound(err) {
		panic(err)
	}
	return id
}

// Only returns a single {{ $.Name }} entity found by the query, ensuring it only returns one.
// Returns a *NotSingularError when exactly one {{ $.Name }} entity is not found.
// Returns a *NotFoundError when no {{ $.Name }} entities are found.
func ({{ $receiver }} *{{ $builder }}) Only(ctx context.Context) (*{{ $.Name }}, error) {
	nodes, err := {{ $receiver }}.Limit(2).All(ctx)
	if err != nil {
		return nil, err
	}
	switch len(nodes) {
	case 1:
		return nodes[0], nil
	case 0:
		return nil, &NotFoundError{ {{ $.Package }}.Label}
	default:
		return nil, &NotSingularError{ {{ $.Package }}.Label}
	}
}

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

// OnlyID is like Only, but returns the only {{ $.Name }} ID in the query.
// Returns a *NotSingularError when exactly one {{ $.Name }} ID is not found.
// Returns a *NotFoundError when no entities are found.
func ({{ $receiver }} *{{ $builder }}) OnlyID(ctx context.Context) (id {{ $.ID.Type }}, err error) {
	var ids []{{ $.ID.Type }}
	if ids, err = {{ $receiver }}.Limit(2).IDs(ctx); err != nil {
		return
	}
	switch len(ids) {
	case 1:
		id = ids[0]
	case 0:
		err = &NotFoundError{ {{ $.Package }}.Label}
	default:
		err = &NotSingularError{ {{ $.Package }}.Label}
	}
	return
}

// OnlyIDX is like OnlyID, but panics if an error occurs.
func ({{ $receiver }} *{{ $builder }}) OnlyIDX(ctx context.Context) {{ $.ID.Type }} {
	id, err := {{ $receiver }}.OnlyID(ctx)
	if err != nil {
		panic(err)
	}
	return id
}

// All executes the query and returns a list of {{ plural $.Name }}.
func ({{ $receiver }} *{{ $builder }}) All(ctx context.Context) ([]*{{ $.Name }}, error) {
	if err := {{ $receiver }}.prepareQuery(ctx); err != nil {
		return nil, err
	}
	return {{ $receiver }}.{{ $.Storage }}All(ctx)
}

// AllX is like All, but panics if an error occurs.
func ({{ $receiver }} *{{ $builder }}) AllX(ctx context.Context) []*{{ $.Name }} {
	nodes, err := {{ $receiver }}.All(ctx)
	if err != nil {
		panic(err)
	}
	return nodes
}

// IDs executes the query and returns a list of {{ $.Name }} IDs.
func ({{ $receiver }} *{{ $builder }}) IDs(ctx context.Context) ([]{{ $.ID.Type }}, error) {
	var ids []{{ $.ID.Type }}
	if err := {{ $receiver }}.Select({{ $.Package }}.FieldID).Scan(ctx, &ids); err != nil {
		return nil, err
	}
	return ids, nil
}

// IDsX is like IDs, but panics if an error occurs.
func ({{ $receiver }} *{{ $builder }}) IDsX(ctx context.Context) []{{ $.ID.Type }} {
	ids, err := {{ $receiver }}.IDs(ctx)
	if err != nil {
		panic(err)
	}
	return ids
}

// Count returns the count of the given query.
func ({{ $receiver }} *{{ $builder }}) Count(ctx context.Context) (int, error) {
	if err := {{ $receiver }}.prepareQuery(ctx); err != nil {
		return 0, err
	}
	return {{ $receiver }}.{{ $.Storage }}Count(ctx)
}

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

// Exist returns true if the query has elements in the graph.
func ({{ $receiver }} *{{ $builder }}) Exist(ctx context.Context) (bool, error) {
	if err := {{ $receiver }}.prepareQuery(ctx); err != nil {
		return false, err
	}
	return {{ $receiver }}.{{ $.Storage }}Exist(ctx)
}

// ExistX is like Exist, but panics if an error occurs.
func ({{ $receiver }} *{{ $builder }}) ExistX(ctx context.Context) bool {
	exist, err := {{ $receiver }}.Exist(ctx)
	if err != nil {
		panic(err)
	}
	return exist
}

// Clone returns a duplicate of the {{ $builder }} builder, including all associated steps. It can be
// used to prepare common query builders and use them differently after the clone is made.
func ({{ $receiver }} *{{ $builder }}) Clone() *{{ $builder }} {
	if {{ $receiver }} == nil {
		return nil
	}
	return &{{ $builder }}{
		config: 	{{ $receiver }}.config,
		limit: 		{{ $receiver }}.limit,
		offset: 	{{ $receiver }}.offset,
		order: 		append([]OrderFunc{}, {{ $receiver }}.order...),
		predicates: append([]predicate.{{ $.Name }}{}, {{ $receiver }}.predicates...),
		{{- range $e := $.Edges }}
			{{ $e.EagerLoadField }}: {{ $receiver }}.{{ $e.EagerLoadField }}.Clone(),
		{{- end }}
		// clone intermediate query.
		{{ $.Storage }}: {{ $receiver }}.{{ $.Storage }}.Clone(),
		path: {{ $receiver }}.path,
	}
}

{{- range $e := $.Edges }}
	{{ $ebuilder := $e.Type.QueryName }}
	// With{{ pascal $e.Name }} tells the query-builder to eager-load the nodes that are connected to
	// the "{{ $e.Name }}" edge. The optional arguments are used to configure the query builder of the edge.
	func ({{ $receiver }} *{{ $builder }}) With{{ pascal $e.Name }}(opts ...func(*{{ $ebuilder }})) *{{ $builder }} {
		query := &{{ $ebuilder }}{config: {{ $receiver }}.config}
		for _, opt := range opts {
			opt(query)
		}
		{{ $receiver }}.{{ $e.EagerLoadField }} = query
		return {{ $receiver }}
	}
{{- end }}

{{ $groupBuilder := pascal $.Name | printf "%sGroupBy" }}

// GroupBy is used to group vertices by one or more fields/columns.
// It is often used with aggregate functions, like: {{ join (keys aggregate) ", " }}.
{{- with len $.Fields }}
{{- $f := index $.Fields 0 }}
//
// Example:
//
//	var v []struct {
//		{{ $f.StructField }} {{ $f.Type }} `{{ $f.StructTag }}`
//		Count int `json:"count,omitempty"`
//	}
//
//	client.{{ pascal $.Name }}.Query().
//		GroupBy({{ $.Package }}.{{ $f.Constant }}).
//		Aggregate({{ $pkg }}.Count()).
//		Scan(ctx, &v)
//
{{- end }}
func ({{ $receiver }} *{{ $builder }}) GroupBy(field string, fields ...string) *{{ $groupBuilder }} {
	group := &{{ $groupBuilder }}{config: {{ $receiver }}.config}
	group.fields = append([]string{field}, fields...)
	group.path = func(ctx context.Context) (prev {{ $.Storage.Builder }}, err error) {
		if err := {{ $receiver }}.prepareQuery(ctx); err != nil {
			return nil, err
		}
		return {{ $receiver }}.{{ $.Storage }}Query(), nil
	}
	return group
}

{{ $selectBuilder := pascal $.Name | printf "%sSelect" }}

// Select allows the selection one or more fields/columns for the given query,
// instead of selecting all fields in the entity.
{{- with len $.Fields }}
{{- $f := index $.Fields 0 }}
//
// Example:
//
//	var v []struct {
//		{{ $f.StructField }} {{ $f.Type }} `{{ $f.StructTag }}`
//	}
//
//	client.{{ pascal $.Name }}.Query().
//		Select({{ $.Package }}.{{ $f.Constant }}).
//		Scan(ctx, &v)
//
{{- end }}
func ({{ $receiver }} *{{ $builder }}) Select(field string, fields ...string) *{{ $selectBuilder }} {
	{{ $receiver }}.fields = append([]string{field}, fields...)
	return &{{ $selectBuilder }}{ {{ $builder }}: {{ $receiver }} }
}

func ({{ $receiver }} *{{ $builder }}) prepareQuery(ctx context.Context) error {
	{{- /* Optional prepare checks per dialect. */}}
	{{- $tmpl = printf "dialect/%s/query/preparecheck" $.Storage }}
	{{- if hasTemplate $tmpl }}
		{{- with extend $ "Receiver" $receiver "Package" $pkg }}
			{{- xtemplate $tmpl . }}
		{{- end }}
	{{- end }}
	if {{ $receiver }}.path != nil {
		prev, err := {{ $receiver }}.path(ctx)
		if err != nil {
			return err
		}
		{{ $receiver }}.{{ $.Storage }} = prev
	}
	{{- if $.NumPolicy }}
		if {{ $.Package }}.Policy == nil {
			return errors.New("{{ $pkg }}: uninitialized {{ $.Package }}.Policy (forgotten import {{ $pkg }}/runtime?)")
		}
		if err := {{ $.Package }}.Policy.EvalQuery(ctx, {{ $receiver }}); err != nil {
			return err
		}
	{{- end }}
	return nil
}

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

{{/* groupby builder */}}

{{ $groupReceiver := receiver $groupBuilder }}

// {{ $groupBuilder }} is the group-by builder for {{ $.Name }} entities.
type {{ $groupBuilder }} struct {
	config
	fields []string
	fns    []AggregateFunc
	// intermediate query (i.e. traversal path).
	{{ $.Storage }} {{ $.Storage.Builder }}
	path func(context.Context) ({{ $.Storage.Builder }}, error)
}

// Aggregate adds the given aggregation functions to the group-by query.
func ({{ $groupReceiver }} *{{ $groupBuilder }}) Aggregate(fns ...AggregateFunc) *{{ $groupBuilder }} {
	{{ $groupReceiver }}.fns = append({{ $groupReceiver }}.fns, fns...)
	return {{ $groupReceiver }}
}

// Scan applies the group-by query and scans the result into the given value.
func ({{ $groupReceiver }} *{{ $groupBuilder }}) Scan(ctx context.Context, v interface{}) error {
	query, err := {{ $groupReceiver }}.path(ctx)
	if err != nil {
		return err
	}
	{{ $groupReceiver }}.{{ $.Storage }} = query
	return {{ $groupReceiver }}.{{ $.Storage }}Scan(ctx, v)
}

// ScanX is like Scan, but panics if an error occurs.
func ({{ $groupReceiver }} *{{ $groupBuilder }}) ScanX(ctx context.Context, v interface{}) {
	if err := {{ $groupReceiver }}.Scan(ctx, v); err != nil {
		panic(err)
	}
}

{{ range $t := primitives }}
	{{ $plural := pascal $t | plural }}
	// {{ $plural }} returns list of {{ plural $t }} from group-by. 
	// It is only allowed when executing a group-by query with one field.
	func ({{ $groupReceiver }} *{{ $groupBuilder }}) {{ $plural }}(ctx context.Context) ([]{{ $t }}, error) {
		if len({{ $groupReceiver }}.fields) > 1 {
			return nil, errors.New("{{ $pkg }}: {{ $groupBuilder }}.{{ $plural }} is not achievable when grouping more than 1 field")
		}
		var v []{{ $t }}
		if err := {{ $groupReceiver }}.Scan(ctx, &v); err != nil {
			return nil, err
		}
		return v, nil
	}

	// {{ $plural }}X is like {{ $plural }}, but panics if an error occurs.
	func ({{ $groupReceiver }} *{{ $groupBuilder }}) {{ $plural }}X(ctx context.Context) []{{ $t }} {
		v, err := {{ $groupReceiver }}.{{ $plural }}(ctx)
		if err != nil {
			panic(err)
		}
		return v
	}

	{{ $singular := pascal $t -}}
	// {{ $singular }} returns a single {{ $t }} from a group-by query.
	// It is only allowed when executing a group-by query with one field.
	func ({{ $groupReceiver }} *{{ $groupBuilder }}) {{ $singular }}(ctx context.Context) (_ {{ $t }}, err error) {
		var v []{{ $t }}
		if v, err = {{ $groupReceiver }}.{{ $plural }}(ctx); err != nil {
			return
		}
		switch len(v) {
		case 1:
			return v[0], nil
		case 0:
			err = &NotFoundError{ {{ $.Package }}.Label}
		default:
			err = fmt.Errorf("{{ $pkg }}: {{ $groupBuilder }}.{{ $plural }} returned %d results when one was expected", len(v))
		}
		return
	}

	// {{ $singular }}X is like {{ $singular }}, but panics if an error occurs.
	func ({{ $groupReceiver }} *{{ $groupBuilder }}) {{ $singular }}X(ctx context.Context) {{ $t }} {
		v, err := {{ $groupReceiver }}.{{ $singular }}(ctx)
		if err != nil {
			panic(err)
		}
		return v
	}
{{ end }}

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

{{/* select builder */}}

{{ $selectReceiver := receiver $selectBuilder }}

// {{ $selectBuilder }} is the builder for selecting fields of {{ pascal $.Name }} entities.
type {{ $selectBuilder }} struct {
	*{{ $builder }}
	// intermediate query (i.e. traversal path).
	{{ $.Storage }} {{ $.Storage.Builder }}
}


// Scan applies the selector query and scans the result into the given value.
func ({{ $selectReceiver }} *{{ $selectBuilder }}) Scan(ctx context.Context, v interface{}) error {
	if err := {{ $selectReceiver }}.prepareQuery(ctx); err != nil {
		return err
	}
	{{ $selectReceiver }}.{{ $.Storage }} = {{ $selectReceiver }}.{{ $builder }}.{{ $.Storage }}Query()
	return {{ $selectReceiver }}.{{ $.Storage }}Scan(ctx, v)
}

// ScanX is like Scan, but panics if an error occurs.
func ({{ $selectReceiver }} *{{ $selectBuilder }}) ScanX(ctx context.Context, v interface{}) {
	if err := {{ $selectReceiver }}.Scan(ctx, v); err != nil {
		panic(err)
	}
}

{{ range $t := primitives }}
	{{ $plural := pascal $t | plural }}
	// {{ $plural }} returns list of {{ plural $t }} from a selector. It is only allowed when selecting one field.
	func ({{ $selectReceiver }} *{{ $selectBuilder }}) {{ $plural }}(ctx context.Context) ([]{{ $t }}, error) {
		if len({{ $selectReceiver }}.fields) > 1 {
			return nil, errors.New("{{ $pkg }}: {{ $selectBuilder }}.{{ $plural }} is not achievable when selecting more than 1 field")
		}
		var v []{{ $t }}
		if err := {{ $selectReceiver }}.Scan(ctx, &v); err != nil {
			return nil, err
		}
		return v, nil
	}

	// {{ $plural }}X is like {{ $plural }}, but panics if an error occurs.
	func ({{ $selectReceiver }} *{{ $selectBuilder }}) {{ $plural }}X(ctx context.Context) []{{ $t }} {
		v, err := {{ $selectReceiver }}.{{ $plural }}(ctx)
		if err != nil {
			panic(err)
		}
		return v
	}

	{{ $singular := pascal $t -}}
	// {{ $singular }} returns a single {{ $t }} from a selector. It is only allowed when selecting one field.
	func ({{ $selectReceiver }} *{{ $selectBuilder }}) {{ $singular }}(ctx context.Context) (_ {{ $t }}, err error) {
		var v []{{ $t }}
		if v, err = {{ $selectReceiver }}.{{ $plural }}(ctx); err != nil {
			return
		}
		switch len(v) {
		case 1:
			return v[0], nil
		case 0:
			err = &NotFoundError{ {{ $.Package }}.Label}
		default:
			err = fmt.Errorf("{{ $pkg }}: {{ $selectBuilder }}.{{ $plural }} returned %d results when one was expected", len(v))
		}
		return
	}

	// {{ $singular }}X is like {{ $singular }}, but panics if an error occurs.
	func ({{ $selectReceiver }} *{{ $selectBuilder }}) {{ $singular }}X(ctx context.Context) {{ $t }} {
		v, err := {{ $selectReceiver }}.{{ $singular }}(ctx)
		if err != nil {
			panic(err)
		}
		return v
	}
{{ end }}

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

{{ end }}