From 55c93ad4e2464ebf4be933a47c56501bb9ac5b78 Mon Sep 17 00:00:00 2001
From: Erik Brakkee <erik@brakkee.org>
Date: Mon, 22 Jul 2024 23:55:37 +0200
Subject: [PATCH] Windows terminal support using the termtest library. Should
 even support resizing. Fully untested.

---
 go.mod                      |  2 ++
 go.sum                      |  5 +++
 pkg/iowrappers/io.go        | 12 +++++++
 pkg/terminal/pty_windows.go | 71 +++++++++++++++++++++++++++++++++----
 4 files changed, 83 insertions(+), 7 deletions(-)

diff --git a/go.mod b/go.mod
index 9f65ada..33d0529 100755
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module converge
 go 1.21
 
 require (
+	github.com/ActiveState/termtest/conpty v0.5.0
 	github.com/creack/pty v1.1.21
 	github.com/gliderlabs/ssh v0.3.7
 	github.com/gorilla/websocket v1.5.3
@@ -13,6 +14,7 @@ require (
 )
 
 require (
+	github.com/Azure/go-ansiterm v0.0.0-20170929234023-d6e3b3328b78 // indirect
 	github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be // indirect
 	github.com/kr/fs v0.1.0 // indirect
 	golang.org/x/sys v0.22.0 // indirect
diff --git a/go.sum b/go.sum
index b17c2df..1dcbe17 100755
--- a/go.sum
+++ b/go.sum
@@ -1,3 +1,7 @@
+github.com/ActiveState/termtest/conpty v0.5.0 h1:JLUe6YDs4Jw4xNPCU+8VwTpniYOGeKzQg4SM2YHQNA8=
+github.com/ActiveState/termtest/conpty v0.5.0/go.mod h1:LO4208FLsxw6DcNZ1UtuGUMW+ga9PFtX4ntv8Ymg9og=
+github.com/Azure/go-ansiterm v0.0.0-20170929234023-d6e3b3328b78 h1:w+iIsaOQNcT7OZ575w+acHgRric5iCyQh+xv+KJ4HB8=
+github.com/Azure/go-ansiterm v0.0.0-20170929234023-d6e3b3328b78/go.mod h1:LmzpDX56iTiv29bbRTIsUNlaFfuhWRQBWjQdVyAevI8=
 github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be h1:9AeTilPcZAjCFIImctFaOjnTIavg87rW78vTPkQqLI8=
 github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be/go.mod h1:ySMOLuWl6zY27l47sB3qLNK6tF2fkHG55UZxx8oIVo4=
 github.com/creack/pty v1.1.21 h1:1/QdRyBaHHJP61QkWMXlOIBfsgdDeeKfK8SYVUWJKf0=
@@ -36,6 +40,7 @@ golang.org/x/net v0.1.0/go.mod h1:Cx3nUiGt4eDBEyega/BKRp+/AlGL8hYe7U9odMt2Cco=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20200428200454-593003d681fa/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
diff --git a/pkg/iowrappers/io.go b/pkg/iowrappers/io.go
index a215521..67620f0 100644
--- a/pkg/iowrappers/io.go
+++ b/pkg/iowrappers/io.go
@@ -10,3 +10,15 @@ type ReadWriteAddrCloser interface {
 
 	RemoteAddr() net.Addr
 }
+
+type ReadWriterCombiner struct {
+	io.Reader
+	io.Writer
+}
+
+func (rw *ReadWriterCombiner) Read(p []byte) (n int, err error) {
+	return rw.Reader.Read(p)
+}
+func (rw *ReadWriterCombiner) Write(p []byte) (n int, err error) {
+	return rw.Writer.Write(p)
+}
diff --git a/pkg/terminal/pty_windows.go b/pkg/terminal/pty_windows.go
index bdf8b73..8b534c2 100644
--- a/pkg/terminal/pty_windows.go
+++ b/pkg/terminal/pty_windows.go
@@ -1,24 +1,81 @@
 package terminal
 
 import (
+	"fmt"
+	"github.com/ActiveState/termtest/conpty"
 	"github.com/gliderlabs/ssh"
 	"io"
+	"log"
 	"os"
-	"os/exec"
+	"syscall"
 )
 
-var PtySpawner = Spawner(func(sshSession ssh.Session, env []string, name string, arg ...string) (Process, error) {
-	return nil, nil
+var PtySpawner = Spawner(func(sshSession ssh.Session, env []string, name string, args ...string) (Process, error) {
+	_, winCh, isPty := sshSession.Pty()
+	if !isPty {
+		return nil, fmt.Errorf("ssh session is not a pty")
+	}
+
+	cpty, err := conpty.New(80, 25)
+	if err != nil {
+		return nil, err
+	}
+	pid, _, err := cpty.Spawn(
+		"cmd.exe",
+		args,
+		&syscall.ProcAttr{
+			Env: env,
+		},
+	)
+	if err != nil {
+		cpty.Close()
+		return nil, err
+	}
+	fmt.Printf("New process with pid %d spawned\n", pid)
+	process, err := os.FindProcess(pid)
+	if err != nil {
+		cpty.Close()
+		return nil, fmt.Errorf("Failed to find process: %v", err)
+	}
+
+	go func() {
+		for win := range winCh {
+			err = cpty.Resize(uint16(win.Width), uint16(win.Height))
+			if err != nil {
+				log.Printf("Feiled to resize terminal to %d x %d", win.Width, win.Height)
+			}
+		}
+	}()
+	return ptyProcess{
+		cpty:    cpty,
+		process: process,
+	}, nil
 })
 
 type ptyProcess struct {
-	cmd *exec.Cmd
-	f   *os.File
+	cpty    *conpty.ConPty
+	process *os.Process
+}
+
+func (proc ptyProcess) Read(p []byte) (n int, err error) {
+	return proc.cpty.OutPipe().Read(p)
+}
+func (proc ptyProcess) Write(p []byte) (n int, err error) {
+	return proc.Write(p)
 }
 
 func (p ptyProcess) Pipe() io.ReadWriter {
-	return p.f
+	return p
 }
+
 func (p ptyProcess) Wait() error {
-	return p.cmd.Wait()
+	defer p.cpty.Close()
+	ps, err := p.process.Wait()
+	if err != nil {
+		return fmt.Errorf("Error waiting for process: %v", err)
+	}
+	if ps.ExitCode() != 0 {
+		return fmt.Errorf("exit code was: %d\n", ps.ExitCode())
+	}
+	return nil
 }