// Copyright 2026 The frp Authors
//
// Licensed 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 proxy

import (
	"bufio"
	"encoding/binary"
	"net"
	"testing"
	"time"

	"github.com/stretchr/testify/require"

	"kanhole/pkg/msg"
	"kanhole/pkg/proto/wire"
)

func TestWriteNatHoleSidUsesWireV2MessageFrame(t *testing.T) {
	client, server := net.Pipe()
	defer client.Close()
	defer server.Close()
	setPipeDeadline(t, client, server)

	errCh := make(chan error, 1)
	go func() {
		errCh <- writeNatHoleSid(server, wire.ProtocolV2, "sid-v2")
	}()

	frame, err := wire.NewConn(client).ReadFrame()
	require.NoError(t, err)
	require.Equal(t, wire.FrameTypeMessage, frame.Type)
	require.GreaterOrEqual(t, len(frame.Payload), 2)
	require.Equal(t, msg.V2TypeNatHoleSid, binary.BigEndian.Uint16(frame.Payload[:2]))

	var out msg.NatHoleSid
	require.NoError(t, msg.DecodeV2MessageFrameInto(frame, &out))
	require.Equal(t, "sid-v2", out.Sid)
	require.NoError(t, <-errCh)
}

func TestWriteNatHoleSidUsesLegacyCodecForWireV1AndDefault(t *testing.T) {
	for _, tc := range []struct {
		name         string
		wireProtocol string
	}{
		{name: "default", wireProtocol: ""},
		{name: "v1", wireProtocol: wire.ProtocolV1},
	} {
		t.Run(tc.name, func(t *testing.T) {
			client, server := net.Pipe()
			defer client.Close()
			defer server.Close()
			setPipeDeadline(t, client, server)

			errCh := make(chan error, 1)
			go func() {
				errCh <- writeNatHoleSid(server, tc.wireProtocol, "sid-legacy")
			}()

			reader := bufio.NewReader(client)
			typeByte, err := reader.ReadByte()
			require.NoError(t, err)
			require.Equal(t, msg.TypeNatHoleSid, typeByte)
			require.NoError(t, reader.UnreadByte())

			var out msg.NatHoleSid
			require.NoError(t, msg.ReadMsgInto(reader, &out))
			require.Equal(t, "sid-legacy", out.Sid)
			require.NoError(t, <-errCh)
		})
	}
}

func setPipeDeadline(t *testing.T, conns ...net.Conn) {
	t.Helper()

	deadline := time.Now().Add(time.Second)
	for _, conn := range conns {
		require.NoError(t, conn.SetDeadline(deadline))
	}
}