/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package protomarshal

import (
	"google.golang.org/grpc/encoding"
	// Guarantee that the built-in proto is called registered before this one
	// so that it can be replaced.
	_ "google.golang.org/grpc/encoding/proto" // nolint:revive
	"google.golang.org/grpc/mem"
)

const Name = "proto"

type vtprotoMessage interface {
	MarshalToSizedBufferVTStrict(data []byte) (int, error)
	SizeVT() int
}

type Codec struct {
	fallback encoding.CodecV2
}

func (Codec) Name() string { return Name }

var defaultBufferPool = mem.DefaultBufferPool()

func (c *Codec) Marshal(v any) (mem.BufferSlice, error) {
	if m, ok := v.(vtprotoMessage); ok {
		size := m.SizeVT()
		if mem.IsBelowBufferPoolingThreshold(size) {
			buf := make([]byte, size)
			if _, err := m.MarshalToSizedBufferVTStrict(buf[:size]); err != nil {
				return nil, err
			}
			return mem.BufferSlice{mem.SliceBuffer(buf)}, nil
		}
		buf := defaultBufferPool.Get(size)
		if _, err := m.MarshalToSizedBufferVTStrict((*buf)[:size]); err != nil {
			defaultBufferPool.Put(buf)
			return nil, err
		}
		return mem.BufferSlice{mem.NewBuffer(buf, defaultBufferPool)}, nil
	}

	return c.fallback.Marshal(v)
}

func (c *Codec) Unmarshal(data mem.BufferSlice, v any) error {
	return c.fallback.Unmarshal(data, v)
}
