// Copyright 2020 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package detectknown provides functionality for detecting well-known types
// and identifying them by name.
package detectknown

import "google.golang.org/protobuf/reflect/protoreflect"

type ProtoFile int

const (
	Unknown ProtoFile = iota
	AnyProto
	TimestampProto
	DurationProto
	WrappersProto
	StructProto
	FieldMaskProto
	ApiProto
	TypeProto
	SourceContextProto
	EmptyProto
)

var wellKnownTypes = map[protoreflect.FullName]ProtoFile{
	"google.protobuf.Any":               AnyProto,
	"google.protobuf.Timestamp":         TimestampProto,
	"google.protobuf.Duration":          DurationProto,
	"google.protobuf.BoolValue":         WrappersProto,
	"google.protobuf.Int32Value":        WrappersProto,
	"google.protobuf.Int64Value":        WrappersProto,
	"google.protobuf.UInt32Value":       WrappersProto,
	"google.protobuf.UInt64Value":       WrappersProto,
	"google.protobuf.FloatValue":        WrappersProto,
	"google.protobuf.DoubleValue":       WrappersProto,
	"google.protobuf.BytesValue":        WrappersProto,
	"google.protobuf.StringValue":       WrappersProto,
	"google.protobuf.Struct":            StructProto,
	"google.protobuf.ListValue":         StructProto,
	"google.protobuf.Value":             StructProto,
	"google.protobuf.NullValue":         StructProto,
	"google.protobuf.FieldMask":         FieldMaskProto,
	"google.protobuf.Api":               ApiProto,
	"google.protobuf.Method":            ApiProto,
	"google.protobuf.Mixin":             ApiProto,
	"google.protobuf.Syntax":            TypeProto,
	"google.protobuf.Type":              TypeProto,
	"google.protobuf.Field":             TypeProto,
	"google.protobuf.Field.Kind":        TypeProto,
	"google.protobuf.Field.Cardinality": TypeProto,
	"google.protobuf.Enum":              TypeProto,
	"google.protobuf.EnumValue":         TypeProto,
	"google.protobuf.Option":            TypeProto,
	"google.protobuf.SourceContext":     SourceContextProto,
	"google.protobuf.Empty":             EmptyProto,
}

// Which identifies the proto file that a well-known type belongs to.
// This identifies both enums and messages.
func Which(s protoreflect.FullName) ProtoFile {
	return wellKnownTypes[s]
}