//go:build windows
// +build windows

package wsl

import (
	"bufio"
	"encoding/json"
	"fmt"
	"io"
	"io/fs"
	"io/ioutil"
	"net/url"
	"os"
	"os/exec"
	"path/filepath"
	"strconv"
	"strings"
	"time"

	"github.com/containers/podman/v4/pkg/machine"
	"github.com/containers/podman/v4/utils"
	"github.com/containers/storage/pkg/homedir"
	"github.com/pkg/errors"
	"github.com/sirupsen/logrus"
	"golang.org/x/text/encoding/unicode"
	"golang.org/x/text/transform"
)

var (
	wslProvider = &Provider{}
	// vmtype refers to qemu (vs libvirt, krun, etc)
	vmtype = "wsl"
)

const (
	ErrorSuccessRebootInitiated = 1641
	ErrorSuccessRebootRequired  = 3010
	currentMachineVersion       = 2
)

const containersConf = `[containers]

[engine]
cgroup_manager = "cgroupfs"
events_logger = "file"
`

const appendPort = `grep -q Port\ %d /etc/ssh/sshd_config || echo Port %d >> /etc/ssh/sshd_config`

const configServices = `ln -fs /usr/lib/systemd/system/sshd.service /etc/systemd/system/multi-user.target.wants/sshd.service
ln -fs /usr/lib/systemd/system/podman.socket /etc/systemd/system/sockets.target.wants/podman.socket
rm -f /etc/systemd/system/getty.target.wants/console-getty.service
rm -f /etc/systemd/system/getty.target.wants/getty@tty1.service
rm -f /etc/systemd/system/multi-user.target.wants/systemd-resolved.service
rm -f /etc/systemd/system/dbus-org.freedesktop.resolve1.service
ln -fs /dev/null /etc/systemd/system/console-getty.service
mkdir -p /etc/systemd/system/systemd-sysusers.service.d/
adduser -m [USER] -G wheel
mkdir -p /home/[USER]/.config/systemd/[USER]/
chown [USER]:[USER] /home/[USER]/.config
`

const sudoers = `%wheel        ALL=(ALL)       NOPASSWD: ALL
`

const bootstrap = `#!/bin/bash
ps -ef | grep -v grep | grep -q systemd && exit 0
nohup unshare --kill-child --fork --pid --mount --mount-proc --propagation shared /lib/systemd/systemd >/dev/null 2>&1 &
sleep 0.1
`

const wslmotd = `
You will be automatically entered into a nested process namespace where
systemd is running. If you need to access the parent namespace, hit ctrl-d
or type exit. This also means to log out you need to exit twice.

`

const sysdpid = "SYSDPID=`ps -eo cmd,pid | grep -m 1 ^/lib/systemd/systemd | awk '{print $2}'`"

const profile = sysdpid + `
if [ ! -z "$SYSDPID" ] && [ "$SYSDPID" != "1" ]; then
    cat /etc/wslmotd
	/usr/local/bin/enterns
fi
`

const enterns = "#!/bin/bash\n" + sysdpid + `
if [ ! -z "$SYSDPID" ] && [ "$SYSDPID" != "1" ]; then
	nsenter -m -p -t $SYSDPID "$@"
fi
`

const waitTerm = sysdpid + `
if [ ! -z "$SYSDPID" ]; then
	timeout 60 tail -f /dev/null --pid $SYSDPID
fi
`

// WSL kernel does not have sg and crypto_user modules
const overrideSysusers = `[Service]
LoadCredential=
`

const lingerService = `[Unit]
Description=A systemd user unit demo
After=network-online.target
Wants=network-online.target podman.socket
[Service]
ExecStart=/usr/bin/sleep infinity
`

const lingerSetup = `mkdir -p /home/[USER]/.config/systemd/[USER]/default.target.wants
ln -fs /home/[USER]/.config/systemd/[USER]/linger-example.service \
       /home/[USER]/.config/systemd/[USER]/default.target.wants/linger-example.service
`

const wslInstallError = `Could not %s. See previous output for any potential failure details.
If you can not resolve the issue, and rerunning fails, try the "wsl --install" process
outlined in the following article:

http://docs.microsoft.com/en-us/windows/wsl/install

`

const wslKernelError = `Could not %s. See previous output for any potential failure details.
If you can not resolve the issue, try rerunning the "podman machine init command". If that fails
try the "wsl --update" command and then rerun "podman machine init". Finally, if all else fails,
try following the steps outlined in the following article:

http://docs.microsoft.com/en-us/windows/wsl/install

`

const wslInstallKernel = "install the WSL Kernel"

const wslOldVersion = `Automatic installation of WSL can not be performed on this version of Windows
Either update to Build 19041 (or later), or perform the manual installation steps
outlined in the following article:

http://docs.microsoft.com/en-us/windows/wsl/install\

`

const (
	winSShProxy    = "win-sshproxy.exe"
	winSshProxyTid = "win-sshproxy.tid"
	pipePrefix     = "npipe:////./pipe/"
	globalPipe     = "docker_engine"
)

type Provider struct{}

type MachineVM struct {
	// ConfigPath is the path to the configuration file
	ConfigPath string
	// Created contains the original created time instead of querying the file mod time
	Created time.Time
	// ImageStream is the version of fcos being used
	ImageStream string
	// ImagePath is the fq path to
	ImagePath string
	// LastUp contains the last recorded uptime
	LastUp time.Time
	// Name of the vm
	Name string
	// Whether this machine should run in a rootful or rootless manner
	Rootful bool
	// SSH identity, username, etc
	machine.SSHConfig
	// machine version
	Version int
}

type ExitCodeError struct {
	code uint
}

func (e *ExitCodeError) Error() string {
	return fmt.Sprintf("Process failed with exit code: %d", e.code)
}

func GetWSLProvider() machine.Provider {
	return wslProvider
}

// NewMachine initializes an instance of a wsl machine
func (p *Provider) NewMachine(opts machine.InitOptions) (machine.VM, error) {
	vm := new(MachineVM)
	if len(opts.Name) > 0 {
		vm.Name = opts.Name
	}
	configPath, err := getConfigPath(opts.Name)
	if err != nil {
		return vm, err
	}

	vm.ConfigPath = configPath
	vm.ImagePath = opts.ImagePath
	vm.RemoteUsername = opts.Username
	vm.Created = time.Now()
	vm.LastUp = vm.Created

	// Add a random port for ssh
	port, err := utils.GetRandomPort()
	if err != nil {
		return nil, err
	}
	vm.Port = port

	return vm, nil
}

func getConfigPath(name string) (string, error) {
	vmConfigDir, err := machine.GetConfDir(vmtype)
	if err != nil {
		return "", err
	}
	return filepath.Join(vmConfigDir, name+".json"), nil
}

// LoadByName reads a json file that describes a known qemu vm
// and returns a vm instance
func (p *Provider) LoadVMByName(name string) (machine.VM, error) {
	configPath, err := getConfigPath(name)
	if err != nil {
		return nil, err
	}

	vm, err := readAndMigrate(configPath, name)
	return vm, err
}

// readAndMigrate returns the content of the VM's
// configuration file in json
func readAndMigrate(configPath string, name string) (*MachineVM, error) {
	vm := new(MachineVM)
	b, err := os.ReadFile(configPath)
	if err != nil {
		if errors.Is(err, os.ErrNotExist) {
			return nil, errors.Wrap(machine.ErrNoSuchVM, name)
		}
		return vm, err
	}
	err = json.Unmarshal(b, vm)
	if err == nil && vm.Version < currentMachineVersion {
		err = vm.migrateMachine(configPath)
	}

	return vm, err
}

func (v *MachineVM) migrateMachine(configPath string) error {
	if v.Created.IsZero() {
		if err := v.migrate40(configPath); err != nil {
			return err
		}
	}

	// Update older machines to use lingering
	if err := enableUserLinger(v, toDist(v.Name)); err != nil {
		return err
	}

	v.Version = currentMachineVersion
	return v.writeConfig()
}

func (v *MachineVM) migrate40(configPath string) error {
	v.ConfigPath = configPath
	fi, err := os.Stat(configPath)
	if err != nil {
		return err
	}
	v.Created = fi.ModTime()
	v.LastUp = getLegacyLastStart(v)
	return nil
}

func getLegacyLastStart(vm *MachineVM) time.Time {
	vmDataDir, err := machine.GetDataDir(vmtype)
	if err != nil {
		return vm.Created
	}
	distDir := filepath.Join(vmDataDir, "wsldist")
	start := filepath.Join(distDir, vm.Name, "laststart")
	info, err := os.Stat(start)
	if err != nil {
		return vm.Created
	}
	return info.ModTime()
}

// Init writes the json configuration file to the filesystem for
// other verbs (start, stop)
func (v *MachineVM) Init(opts machine.InitOptions) (bool, error) {
	if cont, err := checkAndInstallWSL(opts); !cont {
		appendOutputIfError(opts.ReExec, err)
		return cont, err
	}

	homeDir := homedir.Get()
	sshDir := filepath.Join(homeDir, ".ssh")
	v.IdentityPath = filepath.Join(sshDir, v.Name)
	v.Rootful = opts.Rootful
	v.Version = currentMachineVersion

	if err := downloadDistro(v, opts); err != nil {
		return false, err
	}

	if err := v.writeConfig(); err != nil {
		return false, err
	}

	if err := setupConnections(v, opts, sshDir); err != nil {
		return false, err
	}

	dist, err := provisionWSLDist(v)
	if err != nil {
		return false, err
	}

	fmt.Println("Configuring system...")
	if err = configureSystem(v, dist); err != nil {
		return false, err
	}

	if err = installScripts(dist); err != nil {
		return false, err
	}

	if err = createKeys(v, dist, sshDir); err != nil {
		return false, err
	}

	return true, nil
}

func downloadDistro(v *MachineVM, opts machine.InitOptions) error {
	var (
		dd  machine.DistributionDownload
		err error
	)

	if _, e := strconv.Atoi(opts.ImagePath); e == nil {
		v.ImageStream = opts.ImagePath
		dd, err = machine.NewFedoraDownloader(vmtype, v.Name, v.ImageStream)
	} else {
		v.ImageStream = "custom"
		dd, err = machine.NewGenericDownloader(vmtype, v.Name, opts.ImagePath)
	}
	if err != nil {
		return err
	}

	v.ImagePath = dd.Get().LocalUncompressedFile
	return machine.DownloadImage(dd)
}

func (v *MachineVM) writeConfig() error {
	jsonFile := v.ConfigPath

	b, err := json.MarshalIndent(v, "", " ")
	if err != nil {
		return err
	}
	if err := ioutil.WriteFile(jsonFile, b, 0644); err != nil {
		return errors.Wrap(err, "could not write machine json config")
	}

	return nil
}

func setupConnections(v *MachineVM, opts machine.InitOptions, sshDir string) error {
	uri := machine.SSHRemoteConnection.MakeSSHURL("localhost", "/run/user/1000/podman/podman.sock", strconv.Itoa(v.Port), v.RemoteUsername)
	uriRoot := machine.SSHRemoteConnection.MakeSSHURL("localhost", "/run/podman/podman.sock", strconv.Itoa(v.Port), "root")
	identity := filepath.Join(sshDir, v.Name)

	uris := []url.URL{uri, uriRoot}
	names := []string{v.Name, v.Name + "-root"}

	// The first connection defined when connections is empty will become the default
	// regardless of IsDefault, so order according to rootful
	if opts.Rootful {
		uris[0], names[0], uris[1], names[1] = uris[1], names[1], uris[0], names[0]
	}

	for i := 0; i < 2; i++ {
		if err := machine.AddConnection(&uris[i], names[i], identity, opts.IsDefault && i == 0); err != nil {
			return err
		}
	}

	return nil
}

func provisionWSLDist(v *MachineVM) (string, error) {
	vmDataDir, err := machine.GetDataDir(vmtype)
	if err != nil {
		return "", err
	}

	distDir := filepath.Join(vmDataDir, "wsldist")
	distTarget := filepath.Join(distDir, v.Name)
	if err := os.MkdirAll(distDir, 0755); err != nil {
		return "", errors.Wrap(err, "could not create wsldist directory")
	}

	dist := toDist(v.Name)
	fmt.Println("Importing operating system into WSL (this may take 5+ minutes on a new WSL install)...")
	if err = runCmdPassThrough("wsl", "--import", dist, distTarget, v.ImagePath); err != nil {
		return "", errors.Wrap(err, "WSL import of guest OS failed")
	}

	fmt.Println("Installing packages (this will take awhile)...")
	if err = runCmdPassThrough("wsl", "-d", dist, "dnf", "upgrade", "-y"); err != nil {
		return "", errors.Wrap(err, "package upgrade on guest OS failed")
	}

	fmt.Println("Enabling Copr")
	if err = runCmdPassThrough("wsl", "-d", dist, "dnf", "install", "-y", "'dnf-command(copr)'"); err != nil {
		return "", errors.Wrap(err, "enabling copr failed")
	}

	fmt.Println("Enabling podman4 repo")
	if err = runCmdPassThrough("wsl", "-d", dist, "dnf", "-y", "copr", "enable", "rhcontainerbot/podman4"); err != nil {
		return "", errors.Wrap(err, "enabling copr failed")
	}

	if err = runCmdPassThrough("wsl", "-d", dist, "dnf", "install",
		"podman", "podman-docker", "openssh-server", "procps-ng", "-y"); err != nil {
		return "", errors.Wrap(err, "package installation on guest OS failed")
	}

	// Fixes newuidmap
	if err = runCmdPassThrough("wsl", "-d", dist, "dnf", "reinstall", "shadow-utils", "-y"); err != nil {
		return "", errors.Wrap(err, "package reinstallation of shadow-utils on guest OS failed")
	}

	// Windows 11 (NT Version = 10, Build 22000) generates harmless but scary messages on every
	// operation when mount was not present on the initial start. Force a cycle so that it won't
	// repeatedly complain.
	if winVersionAtLeast(10, 0, 22000) {
		if err := runCmdPassThrough("wsl", "--terminate", dist); err != nil {
			logrus.Warnf("could not cycle WSL dist: %s", err.Error())
		}
	}

	return dist, nil
}

func createKeys(v *MachineVM, dist string, sshDir string) error {
	user := v.RemoteUsername

	if err := os.MkdirAll(sshDir, 0700); err != nil {
		return errors.Wrap(err, "could not create ssh directory")
	}

	if err := runCmdPassThrough("wsl", "--terminate", dist); err != nil {
		return errors.Wrap(err, "could not cycle WSL dist")
	}

	key, err := machine.CreateSSHKeysPrefix(sshDir, v.Name, true, true, "wsl", "-d", dist)
	if err != nil {
		return errors.Wrap(err, "could not create ssh keys")
	}

	if err := pipeCmdPassThrough("wsl", key+"\n", "-d", dist, "sh", "-c", "mkdir -p /root/.ssh;"+
		"cat >> /root/.ssh/authorized_keys; chmod 600 /root/.ssh/authorized_keys"); err != nil {
		return errors.Wrap(err, "could not create root authorized keys on guest OS")
	}

	userAuthCmd := withUser("mkdir -p /home/[USER]/.ssh;"+
		"cat >> /home/[USER]/.ssh/authorized_keys; chown -R [USER]:[USER] /home/[USER]/.ssh;"+
		"chmod 600 /home/[USER]/.ssh/authorized_keys", user)
	if err := pipeCmdPassThrough("wsl", key+"\n", "-d", dist, "sh", "-c", userAuthCmd); err != nil {
		return errors.Wrapf(err, "could not create '%s' authorized keys on guest OS", v.RemoteUsername)
	}

	return nil
}

func configureSystem(v *MachineVM, dist string) error {
	user := v.RemoteUsername
	if err := runCmdPassThrough("wsl", "-d", dist, "sh", "-c", fmt.Sprintf(appendPort, v.Port, v.Port)); err != nil {
		return errors.Wrap(err, "could not configure SSH port for guest OS")
	}

	if err := pipeCmdPassThrough("wsl", withUser(configServices, user), "-d", dist, "sh"); err != nil {
		return errors.Wrap(err, "could not configure systemd settings for guest OS")
	}

	if err := pipeCmdPassThrough("wsl", sudoers, "-d", dist, "sh", "-c", "cat >> /etc/sudoers"); err != nil {
		return errors.Wrap(err, "could not add wheel to sudoers")
	}

	if err := pipeCmdPassThrough("wsl", overrideSysusers, "-d", dist, "sh", "-c",
		"cat > /etc/systemd/system/systemd-sysusers.service.d/override.conf"); err != nil {
		return errors.Wrap(err, "could not generate systemd-sysusers override for guest OS")
	}

	lingerCmd := withUser("cat > /home/[USER]/.config/systemd/[USER]/linger-example.service", user)
	if err := pipeCmdPassThrough("wsl", lingerService, "-d", dist, "sh", "-c", lingerCmd); err != nil {
		return errors.Wrap(err, "could not generate linger service for guest OS")
	}

	if err := enableUserLinger(v, dist); err != nil {
		return err
	}

	if err := pipeCmdPassThrough("wsl", withUser(lingerSetup, user), "-d", dist, "sh"); err != nil {
		return errors.Wrap(err, "could not configure systemd settomgs for guest OS")
	}

	if err := pipeCmdPassThrough("wsl", containersConf, "-d", dist, "sh", "-c", "cat > /etc/containers/containers.conf"); err != nil {
		return errors.Wrap(err, "could not create containers.conf for guest OS")
	}

	if err := runCmdPassThrough("wsl", "-d", dist, "sh", "-c", "echo wsl > /etc/containers/podman-machine"); err != nil {
		return errors.Wrap(err, "could not create podman-machine file for guest OS")
	}

	return nil
}

func enableUserLinger(v *MachineVM, dist string) error {
	lingerCmd := "mkdir -p /var/lib/systemd/linger; touch /var/lib/systemd/linger/" + v.RemoteUsername
	if err := runCmdPassThrough("wsl", "-d", dist, "sh", "-c", lingerCmd); err != nil {
		return errors.Wrap(err, "could not enable linger for remote user on guest OS")
	}

	return nil
}

func installScripts(dist string) error {
	if err := pipeCmdPassThrough("wsl", enterns, "-d", dist, "sh", "-c",
		"cat > /usr/local/bin/enterns; chmod 755 /usr/local/bin/enterns"); err != nil {
		return errors.Wrap(err, "could not create enterns script for guest OS")
	}

	if err := pipeCmdPassThrough("wsl", profile, "-d", dist, "sh", "-c",
		"cat > /etc/profile.d/enterns.sh"); err != nil {
		return errors.Wrap(err, "could not create motd profile script for guest OS")
	}

	if err := pipeCmdPassThrough("wsl", wslmotd, "-d", dist, "sh", "-c", "cat > /etc/wslmotd"); err != nil {
		return errors.Wrap(err, "could not create a WSL MOTD for guest OS")
	}

	if err := pipeCmdPassThrough("wsl", bootstrap, "-d", dist, "sh", "-c",
		"cat > /root/bootstrap; chmod 755 /root/bootstrap"); err != nil {
		return errors.Wrap(err, "could not create bootstrap script for guest OS")
	}

	return nil
}

func checkAndInstallWSL(opts machine.InitOptions) (bool, error) {
	if isWSLInstalled() {
		return true, nil
	}

	admin := hasAdminRights()

	if !isWSLFeatureEnabled() {
		return false, attemptFeatureInstall(opts, admin)
	}

	skip := false
	if !opts.ReExec && !admin {
		fmt.Println("Launching WSL Kernel Install...")
		if err := launchElevate(wslInstallKernel); err != nil {
			return false, err
		}

		skip = true
	}

	if !skip {
		if err := installWslKernel(); err != nil {
			fmt.Fprintf(os.Stderr, wslKernelError, wslInstallKernel)
			return false, err
		}

		if opts.ReExec {
			return false, nil
		}
	}

	return true, nil
}

func attemptFeatureInstall(opts machine.InitOptions, admin bool) error {
	if !winVersionAtLeast(10, 0, 18362) {
		return errors.Errorf("Your version of Windows does not support WSL. Update to Windows 10 Build 19041 or later")
	} else if !winVersionAtLeast(10, 0, 19041) {
		fmt.Fprint(os.Stderr, wslOldVersion)
		return errors.Errorf("WSL can not be automatically installed")
	}

	message := "WSL is not installed on this system, installing it.\n\n"

	if !admin {
		message += "Since you are not running as admin, a new window will open and " +
			"require you to approve administrator privileges.\n\n"
	}

	message += "NOTE: A system reboot will be required as part of this process. " +
		"If you prefer, you may abort now, and perform a manual installation using the \"wsl --install\" command."

	if !opts.ReExec && MessageBox(message, "Podman Machine", false) != 1 {
		return errors.Errorf("WSL installation aborted")
	}

	if !opts.ReExec && !admin {
		return launchElevate("install the Windows WSL Features")
	}

	return installWsl()
}

func launchElevate(operation string) error {
	truncateElevatedOutputFile()
	err := relaunchElevatedWait()
	if err != nil {
		if eerr, ok := err.(*ExitCodeError); ok {
			if eerr.code == ErrorSuccessRebootRequired {
				fmt.Println("Reboot is required to continue installation, please reboot at your convenience")
				return nil
			}
		}

		fmt.Fprintf(os.Stderr, "Elevated process failed with error: %v\n\n", err)
		dumpOutputFile()
		fmt.Fprintf(os.Stderr, wslInstallError, operation)
	}
	return err
}

func installWsl() error {
	log, err := getElevatedOutputFileWrite()
	if err != nil {
		return err
	}
	defer log.Close()
	if err := runCmdPassThroughTee(log, "dism", "/online", "/enable-feature",
		"/featurename:Microsoft-Windows-Subsystem-Linux", "/all", "/norestart"); isMsiError(err) {
		return errors.Wrap(err, "could not enable WSL Feature")
	}

	if err = runCmdPassThroughTee(log, "dism", "/online", "/enable-feature",
		"/featurename:VirtualMachinePlatform", "/all", "/norestart"); isMsiError(err) {
		return errors.Wrap(err, "could not enable Virtual Machine Feature")
	}
	log.Close()

	return reboot()
}

func installWslKernel() error {
	log, err := getElevatedOutputFileWrite()
	if err != nil {
		return err
	}
	defer log.Close()

	message := "Installing WSL Kernel Update"
	fmt.Println(message)
	fmt.Fprintln(log, message)

	backoff := 500 * time.Millisecond
	for i := 0; i < 5; i++ {
		err = runCmdPassThroughTee(log, "wsl", "--update")
		if err == nil {
			break
		}
		// In case of unusual circumstances (e.g. race with installer actions)
		// retry a few times
		message = "An error occurred attempting the WSL Kernel update, retrying..."
		fmt.Println(message)
		fmt.Fprintln(log, message)
		time.Sleep(backoff)
		backoff *= 2
	}

	if err != nil {
		return errors.Wrap(err, "could not install WSL Kernel")
	}

	return nil
}

func getElevatedOutputFileName() (string, error) {
	dir, err := homedir.GetDataHome()
	if err != nil {
		return "", err
	}
	return filepath.Join(dir, "podman-elevated-output.log"), nil
}

func dumpOutputFile() {
	file, err := getElevatedOutputFileRead()
	if err != nil {
		logrus.Debug("could not find elevated child output file")
		return
	}
	defer file.Close()
	_, _ = io.Copy(os.Stdout, file)
}

func getElevatedOutputFileRead() (*os.File, error) {
	return getElevatedOutputFile(os.O_RDONLY)
}

func getElevatedOutputFileWrite() (*os.File, error) {
	return getElevatedOutputFile(os.O_WRONLY | os.O_CREATE | os.O_APPEND)
}

func appendOutputIfError(write bool, err error) {
	if write && err == nil {
		return
	}

	if file, check := getElevatedOutputFileWrite(); check == nil {
		defer file.Close()
		fmt.Fprintf(file, "Error: %v\n", err)
	}
}

func truncateElevatedOutputFile() error {
	name, err := getElevatedOutputFileName()
	if err != nil {
		return err
	}

	return os.Truncate(name, 0)
}

func getElevatedOutputFile(mode int) (*os.File, error) {
	name, err := getElevatedOutputFileName()
	if err != nil {
		return nil, err
	}

	dir, err := homedir.GetDataHome()
	if err != nil {
		return nil, err
	}

	if err = os.MkdirAll(dir, 0755); err != nil {
		return nil, err
	}

	return os.OpenFile(name, mode, 0644)
}

func isMsiError(err error) bool {
	if err == nil {
		return false
	}

	if eerr, ok := err.(*exec.ExitError); ok {
		switch eerr.ExitCode() {
		case 0:
			fallthrough
		case ErrorSuccessRebootInitiated:
			fallthrough
		case ErrorSuccessRebootRequired:
			return false
		}
	}

	return true
}
func toDist(name string) string {
	if !strings.HasPrefix(name, "podman") {
		name = "podman-" + name
	}
	return name
}

func withUser(s string, user string) string {
	return strings.ReplaceAll(s, "[USER]", user)
}

func runCmdPassThrough(name string, arg ...string) error {
	logrus.Debugf("Running command: %s %v", name, arg)
	cmd := exec.Command(name, arg...)
	cmd.Stdin = os.Stdin
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	return cmd.Run()
}

func runCmdPassThroughTee(out io.Writer, name string, arg ...string) error {
	logrus.Debugf("Running command: %s %v", name, arg)

	// TODO - Perhaps improve this with a conpty pseudo console so that
	//        dism installer text bars mirror console behavior (redraw)
	cmd := exec.Command(name, arg...)
	cmd.Stdin = os.Stdin
	cmd.Stdout = io.MultiWriter(os.Stdout, out)
	cmd.Stderr = io.MultiWriter(os.Stderr, out)
	return cmd.Run()
}

func pipeCmdPassThrough(name string, input string, arg ...string) error {
	logrus.Debugf("Running command: %s %v", name, arg)
	cmd := exec.Command(name, arg...)
	cmd.Stdin = strings.NewReader(input)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	return cmd.Run()
}

func (v *MachineVM) Set(_ string, opts machine.SetOptions) ([]error, error) {
	// If one setting fails to be applied, the others settings will not fail and still be applied.
	// The setting(s) that failed to be applied will have its errors returned in setErrors
	var setErrors []error

	if opts.Rootful != nil && v.Rootful != *opts.Rootful {
		err := v.setRootful(*opts.Rootful)
		if err != nil {
			setErrors = append(setErrors, errors.Wrapf(err, "error setting rootful option"))
		} else {
			v.Rootful = *opts.Rootful
		}
	}

	if opts.CPUs != nil {
		setErrors = append(setErrors, errors.Errorf("changing CPUs not supported for WSL machines"))
	}

	if opts.Memory != nil {
		setErrors = append(setErrors, errors.Errorf("changing memory not supported for WSL machines"))

	}

	if opts.DiskSize != nil {
		setErrors = append(setErrors, errors.Errorf("changing Disk Size not supported for WSL machines"))
	}

	return setErrors, v.writeConfig()
}

func (v *MachineVM) Start(name string, _ machine.StartOptions) error {
	if v.isRunning() {
		return errors.Errorf("%q is already running", name)
	}

	dist := toDist(name)

	err := runCmdPassThrough("wsl", "-d", dist, "/root/bootstrap")
	if err != nil {
		return errors.Wrap(err, "WSL bootstrap script failed")
	}

	if !v.Rootful {
		fmt.Printf("\nThis machine is currently configured in rootless mode. If your containers\n")
		fmt.Printf("require root permissions (e.g. ports < 1024), or if you run into compatibility\n")
		fmt.Printf("issues with non-podman clients, you can switch using the following command: \n")

		suffix := ""
		if name != machine.DefaultMachineName {
			suffix = " " + name
		}
		fmt.Printf("\n\tpodman machine set --rootful%s\n\n", suffix)
	}

	globalName, pipeName, err := launchWinProxy(v)
	if err != nil {
		fmt.Fprintln(os.Stderr, "API forwarding for Docker API clients is not available due to the following startup failures.")
		fmt.Fprintf(os.Stderr, "\t%s\n", err.Error())
		fmt.Fprintln(os.Stderr, "\nPodman clients are still able to connect.")
	} else {
		fmt.Printf("API forwarding listening on: %s\n", pipeName)
		if globalName {
			fmt.Printf("\nDocker API clients default to this address. You do not need to set DOCKER_HOST.\n")
		} else {
			fmt.Printf("\nAnother process was listening on the default Docker API pipe address.\n")
			fmt.Printf("You can still connect Docker API clients by setting DOCKER HOST using the\n")
			fmt.Printf("following powershell command in your terminal session:\n")
			fmt.Printf("\n\t$Env:DOCKER_HOST = '%s'\n", pipeName)
			fmt.Printf("\nOr in a classic CMD prompt:\n")
			fmt.Printf("\n\tset DOCKER_HOST = '%s'\n", pipeName)
			fmt.Printf("\nAlternatively terminate the other process and restart podman machine.\n")
		}
	}

	_, _, err = v.updateTimeStamps(true)
	return err
}

func launchWinProxy(v *MachineVM) (bool, string, error) {
	machinePipe := toDist(v.Name)
	if !pipeAvailable(machinePipe) {
		return false, "", errors.Errorf("could not start api proxy since expected pipe is not available: %s", machinePipe)
	}

	globalName := false
	if pipeAvailable(globalPipe) {
		globalName = true
	}

	exe, err := os.Executable()
	if err != nil {
		return globalName, "", err
	}

	exe, err = filepath.EvalSymlinks(exe)
	if err != nil {
		return globalName, "", err
	}

	command := filepath.Join(filepath.Dir(exe), winSShProxy)
	stateDir, err := getWinProxyStateDir(v)
	if err != nil {
		return globalName, "", err
	}

	destSock := "/run/user/1000/podman/podman.sock"
	forwardUser := v.RemoteUsername

	if v.Rootful {
		destSock = "/run/podman/podman.sock"
		forwardUser = "root"
	}

	dest := fmt.Sprintf("ssh://%s@localhost:%d%s", forwardUser, v.Port, destSock)
	args := []string{v.Name, stateDir, pipePrefix + machinePipe, dest, v.IdentityPath}
	waitPipe := machinePipe
	if globalName {
		args = append(args, pipePrefix+globalPipe, dest, v.IdentityPath)
		waitPipe = globalPipe
	}

	cmd := exec.Command(command, args...)
	if err := cmd.Start(); err != nil {
		return globalName, "", err
	}

	return globalName, pipePrefix + waitPipe, waitPipeExists(waitPipe, 30, func() error {
		active, exitCode := getProcessState(cmd.Process.Pid)
		if !active {
			return errors.Errorf("win-sshproxy.exe failed to start, exit code: %d (see windows event logs)", exitCode)
		}

		return nil
	})
}

func getWinProxyStateDir(v *MachineVM) (string, error) {
	dir, err := machine.GetDataDir(vmtype)
	if err != nil {
		return "", err
	}
	stateDir := filepath.Join(dir, v.Name)
	if err = os.MkdirAll(stateDir, 0755); err != nil {
		return "", err
	}

	return stateDir, nil
}

func pipeAvailable(pipeName string) bool {
	_, err := os.Stat(`\\.\pipe\` + pipeName)
	return os.IsNotExist(err)
}

func waitPipeExists(pipeName string, retries int, checkFailure func() error) error {
	var err error
	for i := 0; i < retries; i++ {
		_, err = os.Stat(`\\.\pipe\` + pipeName)
		if err == nil {
			break
		}
		if fail := checkFailure(); fail != nil {
			return fail
		}
		time.Sleep(100 * time.Millisecond)
	}

	return err
}

func isWSLInstalled() bool {
	cmd := exec.Command("wsl", "--status")
	out, err := cmd.StdoutPipe()
	if err != nil {
		return false
	}
	if err = cmd.Start(); err != nil {
		return false
	}
	scanner := bufio.NewScanner(transform.NewReader(out, unicode.UTF16(unicode.LittleEndian, unicode.UseBOM).NewDecoder()))
	result := true
	for scanner.Scan() {
		line := scanner.Text()
		// Windows 11 does not set an error exit code when a kernel is not avail
		if strings.Contains(line, "kernel file is not found") {
			result = false
			break
		}
	}
	if err := cmd.Wait(); !result || err != nil {
		return false
	}

	return true
}

func isWSLFeatureEnabled() bool {
	cmd := exec.Command("wsl", "--set-default-version", "2")
	return cmd.Run() == nil
}

func isWSLRunning(dist string) (bool, error) {
	cmd := exec.Command("wsl", "-l", "--running")
	out, err := cmd.StdoutPipe()
	if err != nil {
		return false, err
	}
	if err = cmd.Start(); err != nil {
		return false, err
	}
	scanner := bufio.NewScanner(transform.NewReader(out, unicode.UTF16(unicode.LittleEndian, unicode.UseBOM).NewDecoder()))
	result := false
	for scanner.Scan() {
		fields := strings.Fields(scanner.Text())
		if len(fields) > 0 && dist == fields[0] {
			result = true
			break
		}
	}

	_ = cmd.Wait()

	return result, nil
}

func isSystemdRunning(dist string) (bool, error) {
	cmd := exec.Command("wsl", "-d", dist, "sh")
	cmd.Stdin = strings.NewReader(sysdpid + "\necho $SYSDPID\n")
	out, err := cmd.StdoutPipe()
	if err != nil {
		return false, err
	}
	if err = cmd.Start(); err != nil {
		return false, err
	}
	scanner := bufio.NewScanner(out)
	result := false
	if scanner.Scan() {
		text := scanner.Text()
		i, err := strconv.Atoi(text)
		if err == nil && i > 0 {
			result = true
		}
	}

	_ = cmd.Wait()

	return result, nil
}

func (v *MachineVM) Stop(name string, _ machine.StopOptions) error {
	dist := toDist(v.Name)

	wsl, err := isWSLRunning(dist)
	if err != nil {
		return err
	}

	sysd := false
	if wsl {
		sysd, err = isSystemdRunning(dist)
		if err != nil {
			return err
		}
	}

	if !wsl || !sysd {
		return errors.Errorf("%q is not running", v.Name)
	}

	_, _, _ = v.updateTimeStamps(true)

	if err := stopWinProxy(v); err != nil {
		fmt.Fprintf(os.Stderr, "Could not stop API forwarding service (win-sshproxy.exe): %s\n", err.Error())
	}

	cmd := exec.Command("wsl", "-d", dist, "sh")
	cmd.Stdin = strings.NewReader(waitTerm)
	if err = cmd.Start(); err != nil {
		return errors.Wrap(err, "Error executing wait command")
	}

	exitCmd := exec.Command("wsl", "-d", dist, "/usr/local/bin/enterns", "systemctl", "exit", "0")
	if err = exitCmd.Run(); err != nil {
		return errors.Wrap(err, "Error stopping sysd")
	}

	if err = cmd.Wait(); err != nil {
		return err
	}

	cmd = exec.Command("wsl", "--terminate", dist)
	if err = cmd.Run(); err != nil {
		return err
	}

	return nil
}

func (v *MachineVM) State(bypass bool) (machine.Status, error) {
	if v.isRunning() {
		return machine.Running, nil
	}

	return machine.Stopped, nil
}

func stopWinProxy(v *MachineVM) error {
	pid, tid, tidFile, err := readWinProxyTid(v)
	if err != nil {
		return err
	}

	proc, err := os.FindProcess(int(pid))
	if err != nil {
		return nil
	}
	sendQuit(tid)
	_ = waitTimeout(proc, 20*time.Second)
	_ = os.Remove(tidFile)

	return nil
}

func waitTimeout(proc *os.Process, timeout time.Duration) bool {
	done := make(chan bool)
	go func() {
		proc.Wait()
		done <- true
	}()
	ret := false
	select {
	case <-time.After(timeout):
		proc.Kill()
		<-done
	case <-done:
		ret = true
		break
	}

	return ret
}

func readWinProxyTid(v *MachineVM) (uint32, uint32, string, error) {
	stateDir, err := getWinProxyStateDir(v)
	if err != nil {
		return 0, 0, "", err
	}

	tidFile := filepath.Join(stateDir, winSshProxyTid)
	contents, err := ioutil.ReadFile(tidFile)
	if err != nil {
		return 0, 0, "", err
	}

	var pid, tid uint32
	fmt.Sscanf(string(contents), "%d:%d", &pid, &tid)
	return pid, tid, tidFile, nil
}

//nolint:cyclop
func (v *MachineVM) Remove(name string, opts machine.RemoveOptions) (string, func() error, error) {
	var files []string

	if v.isRunning() {
		return "", nil, errors.Errorf("running vm %q cannot be destroyed", v.Name)
	}

	// Collect all the files that need to be destroyed
	if !opts.SaveKeys {
		files = append(files, v.IdentityPath, v.IdentityPath+".pub")
	}
	if !opts.SaveImage {
		files = append(files, v.ImagePath)
	}

	vmConfigDir, err := machine.GetConfDir(vmtype)
	if err != nil {
		return "", nil, err
	}
	files = append(files, filepath.Join(vmConfigDir, v.Name+".json"))

	vmDataDir, err := machine.GetDataDir(vmtype)
	if err != nil {
		return "", nil, err
	}
	files = append(files, filepath.Join(vmDataDir, "wsldist", v.Name))

	confirmationMessage := "\nThe following files will be deleted:\n\n"
	for _, msg := range files {
		confirmationMessage += msg + "\n"
	}

	confirmationMessage += "\n"
	return confirmationMessage, func() error {
		if err := machine.RemoveConnection(v.Name); err != nil {
			logrus.Error(err)
		}
		if err := machine.RemoveConnection(v.Name + "-root"); err != nil {
			logrus.Error(err)
		}
		if err := runCmdPassThrough("wsl", "--unregister", toDist(v.Name)); err != nil {
			logrus.Error(err)
		}
		for _, f := range files {
			if err := os.RemoveAll(f); err != nil {
				logrus.Error(err)
			}
		}
		return nil
	}, nil
}

func (v *MachineVM) isRunning() bool {
	dist := toDist(v.Name)

	wsl, err := isWSLRunning(dist)
	if err != nil {
		return false
	}

	sysd := false
	if wsl {
		sysd, err = isSystemdRunning(dist)

		if err != nil {
			return false
		}
	}

	return sysd
}

// SSH opens an interactive SSH session to the vm specified.
// Added ssh function to VM interface: pkg/machine/config/go : line 58
func (v *MachineVM) SSH(name string, opts machine.SSHOptions) error {
	if !v.isRunning() {
		return errors.Errorf("vm %q is not running.", v.Name)
	}

	username := opts.Username
	if username == "" {
		username = v.RemoteUsername
	}

	sshDestination := username + "@localhost"
	port := strconv.Itoa(v.Port)

	args := []string{"-i", v.IdentityPath, "-p", port, sshDestination, "-o", "UserKnownHostsFile /dev/null", "-o", "StrictHostKeyChecking no"}
	if len(opts.Args) > 0 {
		args = append(args, opts.Args...)
	} else {
		fmt.Printf("Connecting to vm %s. To close connection, use `~.` or `exit`\n", v.Name)
	}

	cmd := exec.Command("ssh", args...)
	logrus.Debugf("Executing: ssh %v\n", args)

	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	cmd.Stdin = os.Stdin

	return cmd.Run()
}

// List lists all vm's that use qemu virtualization
func (p *Provider) List(_ machine.ListOptions) ([]*machine.ListResponse, error) {
	return GetVMInfos()
}

func GetVMInfos() ([]*machine.ListResponse, error) {
	vmConfigDir, err := machine.GetConfDir(vmtype)
	if err != nil {
		return nil, err
	}

	var listed []*machine.ListResponse

	if err = filepath.WalkDir(vmConfigDir, func(path string, d fs.DirEntry, err error) error {
		if strings.HasSuffix(d.Name(), ".json") {
			path := filepath.Join(vmConfigDir, d.Name())
			vm, err := readAndMigrate(path, strings.TrimSuffix(d.Name(), ".json"))
			if err != nil {
				return err
			}
			listEntry := new(machine.ListResponse)

			listEntry.Name = vm.Name
			listEntry.Stream = vm.ImageStream
			listEntry.VMType = "wsl"
			listEntry.CPUs, _ = getCPUs(vm)
			listEntry.Memory, _ = getMem(vm)
			listEntry.DiskSize = getDiskSize(vm)
			listEntry.RemoteUsername = vm.RemoteUsername
			listEntry.Port = vm.Port
			listEntry.IdentityPath = vm.IdentityPath
			listEntry.Starting = false

			running := vm.isRunning()
			listEntry.CreatedAt, listEntry.LastUp, _ = vm.updateTimeStamps(running)
			listEntry.Running = running

			listed = append(listed, listEntry)
		}
		return nil
	}); err != nil {
		return nil, err
	}
	return listed, err
}

func (vm *MachineVM) updateTimeStamps(updateLast bool) (time.Time, time.Time, error) {
	var err error
	if updateLast {
		vm.LastUp = time.Now()
		err = vm.writeConfig()
	}

	return vm.Created, vm.LastUp, err
}

func getDiskSize(vm *MachineVM) uint64 {
	vmDataDir, err := machine.GetDataDir(vmtype)
	if err != nil {
		return 0
	}
	distDir := filepath.Join(vmDataDir, "wsldist")
	disk := filepath.Join(distDir, vm.Name, "ext4.vhdx")
	info, err := os.Stat(disk)
	if err != nil {
		return 0
	}
	return uint64(info.Size())
}

func getCPUs(vm *MachineVM) (uint64, error) {
	dist := toDist(vm.Name)
	if run, _ := isWSLRunning(dist); !run {
		return 0, nil
	}
	cmd := exec.Command("wsl", "-d", dist, "nproc")
	out, err := cmd.StdoutPipe()
	if err != nil {
		return 0, err
	}
	if err = cmd.Start(); err != nil {
		return 0, err
	}
	scanner := bufio.NewScanner(out)
	var result string
	for scanner.Scan() {
		result = scanner.Text()
	}
	_ = cmd.Wait()

	ret, err := strconv.Atoi(result)
	return uint64(ret), err
}

func getMem(vm *MachineVM) (uint64, error) {
	dist := toDist(vm.Name)
	if run, _ := isWSLRunning(dist); !run {
		return 0, nil
	}
	cmd := exec.Command("wsl", "-d", dist, "cat", "/proc/meminfo")
	out, err := cmd.StdoutPipe()
	if err != nil {
		return 0, err
	}
	if err = cmd.Start(); err != nil {
		return 0, err
	}
	scanner := bufio.NewScanner(out)
	var (
		total, available uint64
		t, a             int
	)
	for scanner.Scan() {
		fields := strings.Fields(scanner.Text())
		if strings.HasPrefix(fields[0], "MemTotal") && len(fields) >= 2 {
			t, err = strconv.Atoi(fields[1])
			total = uint64(t) * 1024
		} else if strings.HasPrefix(fields[0], "MemAvailable") && len(fields) >= 2 {
			a, err = strconv.Atoi(fields[1])
			available = uint64(a) * 1024
		}
		if err != nil {
			break
		}
	}
	_ = cmd.Wait()

	return total - available, err
}

func (p *Provider) IsValidVMName(name string) (bool, error) {
	infos, err := GetVMInfos()
	if err != nil {
		return false, err
	}
	for _, vm := range infos {
		if vm.Name == name {
			return true, nil
		}
	}
	return false, nil
}

func (p *Provider) CheckExclusiveActiveVM() (bool, string, error) {
	return false, "", nil
}

func (v *MachineVM) setRootful(rootful bool) error {
	changeCon, err := machine.AnyConnectionDefault(v.Name, v.Name+"-root")
	if err != nil {
		return err
	}

	if changeCon {
		newDefault := v.Name
		if rootful {
			newDefault += "-root"
		}
		err := machine.ChangeDefault(newDefault)
		if err != nil {
			return err
		}
	}
	return nil
}

// Inspect returns verbose detail about the machine
func (v *MachineVM) Inspect() (*machine.InspectInfo, error) {
	state, err := v.State(false)
	if err != nil {
		return nil, err
	}

	created, lastUp, _ := v.updateTimeStamps(state == machine.Running)

	return &machine.InspectInfo{
		ConfigPath: machine.VMFile{Path: v.ConfigPath},
		Created:    created,
		Image: machine.ImageConfig{
			ImagePath:   machine.VMFile{Path: v.ImagePath},
			ImageStream: v.ImageStream,
		},
		LastUp:    lastUp,
		Name:      v.Name,
		Resources: v.getResources(),
		SSHConfig: v.SSHConfig,
		State:     state,
	}, nil
}

func (v *MachineVM) getResources() (resources machine.ResourceConfig) {
	resources.CPUs, _ = getCPUs(v)
	resources.Memory, _ = getMem(v)
	resources.DiskSize = getDiskSize(v)
	return
}

// RemoveAndCleanMachines removes all machine and cleans up any other files associated with podman machine
func (p *Provider) RemoveAndCleanMachines() error {
	var (
		vm             machine.VM
		listResponse   []*machine.ListResponse
		opts           machine.ListOptions
		destroyOptions machine.RemoveOptions
	)
	destroyOptions.Force = true
	var prevErr error

	listResponse, err := p.List(opts)
	if err != nil {
		return err
	}

	for _, mach := range listResponse {
		vm, err = p.LoadVMByName(mach.Name)
		if err != nil {
			if prevErr != nil {
				logrus.Error(prevErr)
			}
			prevErr = err
		}
		_, remove, err := vm.Remove(mach.Name, destroyOptions)
		if err != nil {
			if prevErr != nil {
				logrus.Error(prevErr)
			}
			prevErr = err
		} else {
			if err := remove(); err != nil {
				if prevErr != nil {
					logrus.Error(prevErr)
				}
				prevErr = err
			}
		}
	}

	// Clean leftover files in data dir
	dataDir, err := machine.DataDirPrefix()
	if err != nil {
		if prevErr != nil {
			logrus.Error(prevErr)
		}
		prevErr = err
	} else {
		err := os.RemoveAll(dataDir)
		if err != nil {
			if prevErr != nil {
				logrus.Error(prevErr)
			}
			prevErr = err
		}
	}

	// Clean leftover files in conf dir
	confDir, err := machine.ConfDirPrefix()
	if err != nil {
		if prevErr != nil {
			logrus.Error(prevErr)
		}
		prevErr = err
	} else {
		err := os.RemoveAll(confDir)
		if err != nil {
			if prevErr != nil {
				logrus.Error(prevErr)
			}
			prevErr = err
		}
	}
	return prevErr
}