//go:build windows

package starssh

import (
	"bytes"
	"errors"
	"io"
	"net"
	"os"
	"path/filepath"
	"strconv"
	"testing"
	"time"
)

func TestParseGPGAssuanSocketInfo(t *testing.T) {
	info, ok := parseGPGAssuanSocketInfo([]byte("7247\n0123456789abcdef"))
	if !ok {
		t.Fatal("expected Assuan socket info to parse")
	}
	if info.port != 7247 || string(info.nonce) != "0123456789abcdef" || info.cygwin {
		t.Fatalf("info=%+v nonce=%x", info, info.nonce)
	}
}

func TestParseGPGCygwinSocketInfo(t *testing.T) {
	info, ok := parseGPGCygwinSocketInfo([]byte("!<socket >7247 s 00000001-02030405-06070809-0a0b0c0d\x00"))
	if !ok {
		t.Fatal("expected Cygwin socket info to parse")
	}
	want := []byte{1, 0, 0, 0, 5, 4, 3, 2, 9, 8, 7, 6, 13, 12, 11, 10}
	if info.port != 7247 || string(info.nonce) != string(want) || !info.cygwin {
		t.Fatalf("info=%+v nonce=%x", info, info.nonce)
	}
}

func TestParseGPGAssuanSocketRedirect(t *testing.T) {
	t.Setenv("STARSSH_TEST_PIPE", `\\.\pipe\openssh-ssh-agent`)
	target, ok := parseGPGAssuanSocketRedirect([]byte("%Assuan%\r\nsocket=${STARSSH_TEST_PIPE}\r\n"))
	if !ok {
		t.Fatal("expected Assuan redirect to parse")
	}
	if target != `\\.\pipe\openssh-ssh-agent` {
		t.Fatalf("target=%q", target)
	}
}

func TestReadInvalidAgentSSHSocketReturnsGPGSocketError(t *testing.T) {
	path := t.TempDir() + "/S.gpg-agent.ssh"
	if err := os.WriteFile(path, []byte("not a socket info file"), 0o600); err != nil {
		t.Fatalf("write socket file: %v", err)
	}

	_, err := dialResolvedSSHAgent(resolvedSSHAgentEndpoint{
		Endpoint: path,
		Source:   "SSH_AUTH_SOCK",
		Network:  defaultSSHAgentNetwork(path),
	}, 0)
	if !errors.Is(err, errInvalidGPGSocketInfo) {
		t.Fatalf("err=%v want errInvalidGPGSocketInfo", err)
	}
}

func TestMissingAgentSSHSocketReturnsReadError(t *testing.T) {
	path := filepath.Join(t.TempDir(), "S.gpg-agent.ssh")

	_, err := dialResolvedSSHAgent(resolvedSSHAgentEndpoint{
		Endpoint: path,
		Source:   "identity-agent",
		Network:  defaultSSHAgentNetwork(path),
	}, 0)
	if err == nil {
		t.Fatal("expected missing GPG socket file error")
	}
	if !errors.Is(err, os.ErrNotExist) {
		t.Fatalf("err=%v want os.ErrNotExist", err)
	}
}

func TestUnreadableAgentSSHSocketReturnsReadError(t *testing.T) {
	path := filepath.Join(t.TempDir(), "S.gpg-agent.ssh")
	if err := os.Mkdir(path, 0o700); err != nil {
		t.Fatalf("mkdir socket path: %v", err)
	}

	_, err := dialResolvedSSHAgent(resolvedSSHAgentEndpoint{
		Endpoint: path,
		Source:   "identity-agent",
		Network:  defaultSSHAgentNetwork(path),
	}, 0)
	if err == nil {
		t.Fatal("expected unreadable GPG socket file error")
	}
	if errors.Is(err, errInvalidGPGSocketInfo) {
		t.Fatalf("err=%v should expose read failure before parse", err)
	}
}

func TestDialWindowsGPGSocketFilePerformsNonceHandshake(t *testing.T) {
	listener, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatalf("listen tcp: %v", err)
	}
	defer listener.Close()

	type handshakeResult struct {
		nonce []byte
		err   error
	}
	resultCh := make(chan handshakeResult, 1)
	go func() {
		conn, err := listener.Accept()
		if err != nil {
			resultCh <- handshakeResult{err: err}
			return
		}
		defer conn.Close()

		nonce := make([]byte, 16)
		if _, err := io.ReadFull(conn, nonce); err != nil {
			resultCh <- handshakeResult{err: err}
			return
		}
		resultCh <- handshakeResult{nonce: append([]byte(nil), nonce...)}
	}()

	socketPath := filepath.Join(t.TempDir(), "S.gpg-agent.ssh")
	if err := os.WriteFile(socketPath, []byte(strconv.Itoa(listener.Addr().(*net.TCPAddr).Port)+"\n0123456789abcdef"), 0o600); err != nil {
		t.Fatalf("write socket file: %v", err)
	}

	conn, err := dialWindowsGPGSocketFile(socketPath, time.Second)
	if err != nil {
		t.Fatalf("dialWindowsGPGSocketFile: %v", err)
	}
	_ = conn.Close()

	var result handshakeResult
	select {
	case result = <-resultCh:
	case <-time.After(time.Second):
		t.Fatal("listener did not accept GPG socket connection")
	}
	if result.err != nil {
		t.Fatalf("listener handshake error: %v", result.err)
	}

	if !bytes.Equal(result.nonce, []byte("0123456789abcdef")) {
		t.Fatalf("nonce=%q", result.nonce)
	}
}