{{/*
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 "dialect/sql/order/signature" -}}
	// OrderFunc applies an ordering on the sql selector.
	type OrderFunc func(*sql.Selector, func(string) bool)
{{- end }}

{{ define "dialect/sql/order/func" -}}
	{{- $f := $.Scope.Func -}}
	func(s *sql.Selector, check func(string) bool) {
		for _, f := range fields {
			if check(f) {
				s.OrderBy(sql.{{ $f }}(f))
			} else {
				s.AddError(&ValidationError{Name: f, err: fmt.Errorf("invalid field %q for ordering", f)})
			}
		}
	}
{{- end }}

{{/* custom signature for group-by function */}}
{{ define "dialect/sql/group/signature" -}}
	type AggregateFunc func(*sql.Selector, func(string) bool) string
{{- end }}

{{ define "dialect/sql/group/as" -}}
	func(s *sql.Selector, check func(string) bool) string {
			return sql.As(fn(s, check), end)
	}
{{- end }}

{{ define "dialect/sql/group/func" -}}
	{{- $fn := $.Scope.Func -}}
	{{- $withField := $.Scope.WithField -}}
	func(s *sql.Selector, {{ if $withField }}check{{ else }}_{{ end }} func(string) bool) string {
		{{- if $withField }}
			if !check(field) {
				s.AddError(&ValidationError{Name: field, err: fmt.Errorf("invalid field %q for grouping", field)})
				return ""
			}
		{{- end }}
		return sql.{{ if eq $fn "Mean" }}Avg{{ else }}{{ $fn }}{{ end }}({{ if $withField }}s.C(field){{ else }}"*"{{ end }})
	}
{{- end }}