waveterm/pkg/cmdrunner/cmdrunner.go

package cmdrunner

import (
	"bytes"
	"context"
	"fmt"
	"log"
	"os"
	"regexp"
	"sort"
	"strconv"
	"strings"
	"syscall"
	"time"

	"github.com/alessio/shellescape"
	"github.com/google/uuid"
	"github.com/scripthaus-dev/mshell/pkg/base"
	"github.com/scripthaus-dev/mshell/pkg/packet"
	"github.com/scripthaus-dev/mshell/pkg/shexec"
	"github.com/scripthaus-dev/sh2-server/pkg/comp"
	"github.com/scripthaus-dev/sh2-server/pkg/remote"
	"github.com/scripthaus-dev/sh2-server/pkg/scbase"
	"github.com/scripthaus-dev/sh2-server/pkg/scpacket"
	"github.com/scripthaus-dev/sh2-server/pkg/sstore"
	"github.com/scripthaus-dev/sh2-server/pkg/utilfn"
)

const (
	HistoryTypeWindow  = "window"
	HistoryTypeSession = "session"
	HistoryTypeGlobal  = "global"
)

func init() {
	comp.RegisterSimpleCompFn(comp.CGTypeMeta, simpleCompMeta)
	comp.RegisterSimpleCompFn(comp.CGTypeCommandMeta, simpleCompCommandMeta)
}

const DefaultUserId = "sawka"
const MaxNameLen = 50
const MaxRemoteAliasLen = 50
const PasswordUnchangedSentinel = "--unchanged--"
const DefaultPTERM = "MxM"
const MaxCommandLen = 4096
const MaxSignalLen = 12
const MaxSignalNum = 64

var ColorNames = []string{"black", "red", "green", "yellow", "blue", "magenta", "cyan", "white", "orange"}
var RemoteColorNames = []string{"red", "green", "yellow", "blue", "magenta", "cyan", "white", "orange"}
var RemoteSetArgs = []string{"alias", "connectmode", "key", "password", "autoinstall", "color"}

var WindowCmds = []string{"run", "comment", "cd", "cr", "clear", "sw", "reset", "signal"}
var NoHistCmds = []string{"_compgen", "line", "_history", "_killserver"}
var GlobalCmds = []string{"session", "screen", "remote", "set"}

var SetVarNameMap map[string]string = map[string]string{
	"tabcolor": "screen.tabcolor",
	"pterm":    "window.pterm",
	"anchor":   "sw.anchor",
	"focus":    "sw.focus",
	"line":     "sw.line",
}

var SetVarScopes = []SetVarScope{
	SetVarScope{ScopeName: "global", VarNames: []string{}},
	SetVarScope{ScopeName: "session", VarNames: []string{"name", "pos"}},
	SetVarScope{ScopeName: "screen", VarNames: []string{"name", "tabcolor", "pos"}},
	SetVarScope{ScopeName: "window", VarNames: []string{"pterm"}},
	SetVarScope{ScopeName: "sw", VarNames: []string{"anchor", "focus", "line"}},
	SetVarScope{ScopeName: "line", VarNames: []string{}},
	// connection = remote, remote = remoteinstance
	SetVarScope{ScopeName: "connection", VarNames: []string{"alias", "connectmode", "key", "password", "autoinstall", "color"}},
	SetVarScope{ScopeName: "remote", VarNames: []string{}},
}

var hostNameRe = regexp.MustCompile("^[a-z][a-z0-9.-]*$")
var userHostRe = regexp.MustCompile("^(sudo@)?([a-z][a-z0-9-]*)@([a-z][a-z0-9.-]*)(?::([0-9]+))?$")
var remoteAliasRe = regexp.MustCompile("^[a-zA-Z][a-zA-Z0-9_-]*$")
var genericNameRe = regexp.MustCompile("^[a-zA-Z][a-zA-Z0-9_ .()<>,/\"'\\[\\]{}=+$@!*-]*$")
var positionRe = regexp.MustCompile("^((S?\\+|E?-)?[0-9]+|(\\+|-|S|E))$")
var wsRe = regexp.MustCompile("\\s+")
var sigNameRe = regexp.MustCompile("^((SIG[A-Z0-9]+)|(\\d+))$")

type contextType string

var historyContextKey = contextType("history")

type SetVarScope struct {
	ScopeName string
	VarNames  []string
}

type historyContextType struct {
	LineId    string
	CmdId     string
	RemotePtr *sstore.RemotePtrType
}

type MetaCmdFnType = func(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error)
type MetaCmdEntryType struct {
	IsAlias bool
	Fn      MetaCmdFnType
}

var MetaCmdFnMap = make(map[string]MetaCmdEntryType)

func init() {
	registerCmdFn("run", RunCommand)
	registerCmdFn("eval", EvalCommand)
	registerCmdFn("comment", CommentCommand)
	registerCmdFn("cr", CrCommand)
	registerCmdFn("_compgen", CompGenCommand)
	registerCmdFn("clear", ClearCommand)
	registerCmdFn("reset", RemoteResetCommand)
	registerCmdFn("signal", SignalCommand)

	registerCmdFn("session", SessionCommand)
	registerCmdFn("session:open", SessionOpenCommand)
	registerCmdAlias("session:new", SessionOpenCommand)
	registerCmdFn("session:set", SessionSetCommand)
	registerCmdFn("session:delete", SessionDeleteCommand)
	registerCmdFn("session:archive", SessionArchiveCommand)
	registerCmdFn("session:showall", SessionShowAllCommand)
	registerCmdFn("session:show", SessionShowCommand)

	registerCmdFn("screen", ScreenCommand)
	registerCmdFn("screen:archive", ScreenArchiveCommand)
	registerCmdFn("screen:purge", ScreenPurgeCommand)
	registerCmdFn("screen:open", ScreenOpenCommand)
	registerCmdAlias("screen:new", ScreenOpenCommand)
	registerCmdFn("screen:set", ScreenSetCommand)
	registerCmdFn("screen:showall", ScreenShowAllCommand)

	registerCmdAlias("remote", RemoteCommand)
	registerCmdFn("remote:show", RemoteShowCommand)
	registerCmdFn("remote:showall", RemoteShowAllCommand)
	registerCmdFn("remote:new", RemoteNewCommand)
	registerCmdFn("remote:archive", RemoteArchiveCommand)
	registerCmdFn("remote:set", RemoteSetCommand)
	registerCmdFn("remote:disconnect", RemoteDisconnectCommand)
	registerCmdFn("remote:connect", RemoteConnectCommand)
	registerCmdFn("remote:install", RemoteInstallCommand)
	registerCmdFn("remote:installcancel", RemoteInstallCancelCommand)

	registerCmdFn("sw:set", SwSetCommand)
	registerCmdFn("sw:resize", SwResizeCommand)

	// sw:resize
	registerCmdFn("window:resize", SwResizeCommand)

	registerCmdFn("line", LineCommand)
	registerCmdFn("line:show", LineShowCommand)
	registerCmdFn("line:star", LineStarCommand)
	registerCmdFn("line:archive", LineArchiveCommand)
	registerCmdFn("line:purge", LinePurgeCommand)

	registerCmdFn("_history", HistoryCommand)

	registerCmdFn("_killserver", KillServerCommand)

	registerCmdFn("set", SetCommand)
}

func getValidCommands() []string {
	var rtn []string
	for key, val := range MetaCmdFnMap {
		if val.IsAlias {
			continue
		}
		rtn = append(rtn, "/"+key)
	}
	return rtn
}

func registerCmdFn(cmdName string, fn MetaCmdFnType) {
	MetaCmdFnMap[cmdName] = MetaCmdEntryType{Fn: fn}
}

func registerCmdAlias(cmdName string, fn MetaCmdFnType) {
	MetaCmdFnMap[cmdName] = MetaCmdEntryType{IsAlias: true, Fn: fn}
}

func HandleCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	metaCmd := SubMetaCmd(pk.MetaCmd)
	var cmdName string
	if pk.MetaSubCmd == "" {
		cmdName = metaCmd
	} else {
		cmdName = fmt.Sprintf("%s:%s", pk.MetaCmd, pk.MetaSubCmd)
	}
	entry := MetaCmdFnMap[cmdName]
	if entry.Fn == nil {
		if MetaCmdFnMap[metaCmd].Fn != nil {
			return nil, fmt.Errorf("invalid /%s subcommand '%s'", metaCmd, pk.MetaSubCmd)
		}
		return nil, fmt.Errorf("invalid command '/%s', no handler", cmdName)
	}
	return entry.Fn(ctx, pk)
}

func firstArg(pk *scpacket.FeCommandPacketType) string {
	if len(pk.Args) == 0 {
		return ""
	}
	return pk.Args[0]
}

func argN(pk *scpacket.FeCommandPacketType, n int) string {
	if len(pk.Args) <= n {
		return ""
	}
	return pk.Args[n]
}

func resolveBool(arg string, def bool) bool {
	if arg == "" {
		return def
	}
	if arg == "0" || arg == "false" {
		return false
	}
	return true
}

func defaultStr(arg string, def string) string {
	if arg == "" {
		return def
	}
	return arg
}

func resolveFile(arg string) (string, error) {
	if arg == "" {
		return "", nil
	}
	fileName := base.ExpandHomeDir(arg)
	if !strings.HasPrefix(fileName, "/") {
		return "", fmt.Errorf("must be absolute, cannot be a relative path")
	}
	fd, err := os.Open(fileName)
	if fd != nil {
		fd.Close()
	}
	if err != nil {
		return "", fmt.Errorf("cannot open file: %v", err)
	}
	return fileName, nil
}

func resolvePosInt(arg string, def int) (int, error) {
	if arg == "" {
		return def, nil
	}
	ival, err := strconv.Atoi(arg)
	if err != nil {
		return 0, err
	}
	if ival <= 0 {
		return 0, fmt.Errorf("must be greater than 0")
	}
	return ival, nil
}

func isAllDigits(arg string) bool {
	if len(arg) == 0 {
		return false
	}
	for i := 0; i < len(arg); i++ {
		if arg[i] >= '0' && arg[i] <= '9' {
			continue
		}
		return false
	}
	return true
}

func resolveNonNegInt(arg string, def int) (int, error) {
	if arg == "" {
		return def, nil
	}
	ival, err := strconv.Atoi(arg)
	if err != nil {
		return 0, err
	}
	if ival < 0 {
		return 0, fmt.Errorf("cannot be negative")
	}
	return ival, nil
}

func RunCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Screen|R_Window|R_RemoteConnected)
	if err != nil {
		return nil, fmt.Errorf("/run error: %w", err)
	}
	cmdStr := firstArg(pk)
	isRtnStateCmd := IsReturnStateCommand(cmdStr)
	// runPacket.State is set in remote.RunCommand()
	runPacket := packet.MakeRunPacket()
	runPacket.ReqId = uuid.New().String()
	runPacket.CK = base.MakeCommandKey(ids.SessionId, scbase.GenPromptUUID())
	runPacket.UsePty = true
	ptermVal := defaultStr(pk.Kwargs["pterm"], DefaultPTERM)
	runPacket.TermOpts, err = GetUITermOpts(pk.UIContext.WinSize, ptermVal)
	if err != nil {
		return nil, fmt.Errorf("/run error, invalid 'pterm' value %q: %v", ptermVal, err)
	}
	runPacket.Command = strings.TrimSpace(cmdStr)
	runPacket.ReturnState = resolveBool(pk.Kwargs["rtnstate"], isRtnStateCmd)
	cmd, callback, err := remote.RunCommand(ctx, ids.SessionId, ids.WindowId, ids.Remote.RemotePtr, runPacket)
	if callback != nil {
		defer callback()
	}
	if err != nil {
		return nil, err
	}
	update, err := addLineForCmd(ctx, "/run", true, ids, cmd)
	if err != nil {
		return nil, err
	}
	update.Interactive = pk.Interactive
	sstore.MainBus.SendUpdate(ids.SessionId, update)
	return nil, nil
}

func addToHistory(ctx context.Context, pk *scpacket.FeCommandPacketType, historyContext historyContextType, isMetaCmd bool, hadError bool) error {
	cmdStr := firstArg(pk)
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Screen|R_Window)
	if err != nil {
		return err
	}
	isIncognito, err := sstore.IsIncognitoScreen(ctx, ids.SessionId, ids.ScreenId)
	if err != nil {
		return fmt.Errorf("cannot add to history, error looking up incognito status of screen: %v", err)
	}
	hitem := &sstore.HistoryItemType{
		HistoryId: scbase.GenPromptUUID(),
		Ts:        time.Now().UnixMilli(),
		UserId:    DefaultUserId,
		SessionId: ids.SessionId,
		ScreenId:  ids.ScreenId,
		WindowId:  ids.WindowId,
		LineId:    historyContext.LineId,
		HadError:  hadError,
		CmdId:     historyContext.CmdId,
		CmdStr:    cmdStr,
		IsMetaCmd: isMetaCmd,
		Incognito: isIncognito,
	}
	if !isMetaCmd && historyContext.RemotePtr != nil {
		hitem.Remote = *historyContext.RemotePtr
	}
	err = sstore.InsertHistoryItem(ctx, hitem)
	if err != nil {
		return err
	}
	return nil
}

func EvalCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	if len(pk.Args) == 0 {
		return nil, fmt.Errorf("usage: /eval [command], no command passed to eval")
	}
	if len(pk.Args[0]) > MaxCommandLen {
		return nil, fmt.Errorf("command length too long len:%d, max:%d", len(pk.Args[0]), MaxCommandLen)
	}
	var historyContext historyContextType
	ctxWithHistory := context.WithValue(ctx, historyContextKey, &historyContext)
	var update sstore.UpdatePacket
	newPk, rtnErr := EvalMetaCommand(ctxWithHistory, pk)
	if rtnErr == nil {
		update, rtnErr = HandleCommand(ctxWithHistory, newPk)
	}
	if !resolveBool(pk.Kwargs["nohist"], false) {
		err := addToHistory(ctx, pk, historyContext, (newPk.MetaCmd != "run"), (rtnErr != nil))
		if err != nil {
			log.Printf("[error] adding to history: %v\n", err)
			// continue...
		}
	}
	return update, rtnErr
}

func ScreenArchiveCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session) // don't force R_Screen
	if err != nil {
		return nil, fmt.Errorf("/screen:archive cannot archive screen: %w", err)
	}
	screenId := ids.ScreenId
	if len(pk.Args) > 0 {
		ri, err := resolveSessionScreen(ctx, ids.SessionId, pk.Args[0], ids.ScreenId)
		if err != nil {
			return nil, fmt.Errorf("/screen:archive cannot resolve screen arg: %v", err)
		}
		screenId = ri.Id
	}
	if screenId == "" {
		return nil, fmt.Errorf("/screen:archive no active screen or screen arg passed")
	}
	archiveVal := true
	if len(pk.Args) > 1 {
		archiveVal = resolveBool(pk.Args[1], true)
	}
	var update sstore.UpdatePacket
	if archiveVal {
		update, err = sstore.ArchiveScreen(ctx, ids.SessionId, screenId)
		if err != nil {
			return nil, err
		}
		return update, nil
	} else {
		fmt.Printf("unarchive screen %s\n", screenId)
		err = sstore.UnArchiveScreen(ctx, ids.SessionId, screenId)
		if err != nil {
			return nil, fmt.Errorf("/screen:archive cannot re-open screen: %v", err)
		}
		screen, err := sstore.GetScreenById(ctx, ids.SessionId, screenId)
		if err != nil {
			return nil, fmt.Errorf("/screen:archive cannot get updated screen obj: %v", err)
		}
		bareSession, err := sstore.GetBareSessionById(ctx, ids.SessionId)
		if err != nil {
			return nil, fmt.Errorf("/screen:archive cannot retrieve updated session obj: %v", err)
		}
		bareSession.Screens = append(bareSession.Screens, screen)
		update := sstore.ModelUpdate{
			Sessions: []*sstore.SessionType{bareSession},
		}
		return update, nil
	}
}

func ScreenPurgeCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Screen)
	if err != nil {
		return nil, fmt.Errorf("/screen:purge cannot purge screen: %w", err)
	}
	update, err := sstore.DeleteScreen(ctx, ids.SessionId, ids.ScreenId)
	if err != nil {
		return nil, err
	}
	return update, nil
}

func ScreenOpenCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session)
	if err != nil {
		return nil, fmt.Errorf("/screen:open cannot open screen: %w", err)
	}
	activate := resolveBool(pk.Kwargs["activate"], true)
	newName := pk.Kwargs["name"]
	if newName != "" {
		err := validateName(newName, "screen")
		if err != nil {
			return nil, err
		}
	}
	update, err := sstore.InsertScreen(ctx, ids.SessionId, newName, activate)
	if err != nil {
		return nil, err
	}
	return update, nil
}

func ScreenSetCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Screen)
	if err != nil {
		return nil, err
	}
	var varsUpdated []string
	if pk.Kwargs["name"] != "" {
		newName := pk.Kwargs["name"]
		err = validateName(newName, "screen")
		if err != nil {
			return nil, err
		}
		err = sstore.SetScreenName(ctx, ids.SessionId, ids.ScreenId, newName)
		if err != nil {
			return nil, fmt.Errorf("setting screen name: %v", err)
		}
		varsUpdated = append(varsUpdated, "name")
	}
	if pk.Kwargs["tabcolor"] != "" {
		color := pk.Kwargs["tabcolor"]
		err = validateColor(color, "screen tabcolor")
		if err != nil {
			return nil, err
		}
		screenObj, err := sstore.GetScreenById(ctx, ids.SessionId, ids.ScreenId)
		if err != nil {
			return nil, err
		}
		opts := screenObj.ScreenOpts
		if opts == nil {
			opts = &sstore.ScreenOptsType{}
		}
		opts.TabColor = color
		err = sstore.SetScreenOpts(ctx, ids.SessionId, ids.ScreenId, opts)
		if err != nil {
			return nil, fmt.Errorf("setting screen opts: %v", err)
		}
		varsUpdated = append(varsUpdated, "tabcolor")
	}
	if len(varsUpdated) == 0 {
		return nil, fmt.Errorf("/screen:set no updates, can set %s", formatStrs([]string{"name", "pos", "tabcolor"}, "or", false))
	}
	screenObj, err := sstore.GetScreenById(ctx, ids.SessionId, ids.ScreenId)
	if err != nil {
		return nil, err
	}
	bareSession, err := sstore.GetBareSessionById(ctx, ids.SessionId)
	if err != nil {
		return nil, fmt.Errorf("/screen:set cannot retrieve session: %v", err)
	}
	bareSession.Screens = append(bareSession.Screens, screenObj)
	update := sstore.ModelUpdate{
		Sessions: []*sstore.SessionType{bareSession},
		Info: &sstore.InfoMsgType{
			InfoMsg:   fmt.Sprintf("screen updated %s", formatStrs(varsUpdated, "and", false)),
			TimeoutMs: 2000,
		},
	}
	return update, nil
}

func ScreenCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session)
	if err != nil {
		return nil, fmt.Errorf("/screen cannot switch to screen: %w", err)
	}
	firstArg := firstArg(pk)
	if firstArg == "" {
		return nil, fmt.Errorf("usage /screen [screen-name|screen-index|screen-id], no param specified")
	}
	ritem, err := resolveSessionScreen(ctx, ids.SessionId, firstArg, ids.ScreenId)
	if err != nil {
		return nil, err
	}
	update, err := sstore.SwitchScreenById(ctx, ids.SessionId, ritem.Id)
	if err != nil {
		return nil, err
	}
	return update, nil
}

var swAnchorRe = regexp.MustCompile("^(\\d+)(?::(-?\\d+))?$")

func SwSetCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Screen|R_Window)
	if err != nil {
		return nil, fmt.Errorf("/sw:set cannot resolve current screen-window: %w", err)
	}
	var setNonST bool // scrolltop does not receive an update
	updateMap := make(map[string]interface{})
	if pk.Kwargs["anchor"] != "" {
		m := swAnchorRe.FindStringSubmatch(pk.Kwargs["anchor"])
		if m == nil {
			return nil, fmt.Errorf("/sw:set invalid anchor argument (must be [line] or [line]:[offset])")
		}
		anchorLine, _ := strconv.Atoi(m[1])
		updateMap[sstore.SWField_AnchorLine] = anchorLine
		if m[2] != "" {
			anchorOffset, _ := strconv.Atoi(m[2])
			updateMap[sstore.SWField_AnchorOffset] = anchorOffset
		}
	}
	if pk.Kwargs["focus"] != "" {
		focusVal := pk.Kwargs["focus"]
		if focusVal != sstore.SWFocusInput && focusVal != sstore.SWFocusCmd && focusVal != sstore.SWFocusCmdFg {
			return nil, fmt.Errorf("/sw:set invalid focus argument %q, must be %s", focusVal, formatStrs([]string{sstore.SWFocusInput, sstore.SWFocusCmd, sstore.SWFocusCmdFg}, "or", false))
		}
		updateMap[sstore.SWField_Focus] = focusVal
		setNonST = true
	}
	if pk.Kwargs["line"] != "" {
		sw, err := sstore.GetScreenWindowByIds(ctx, ids.SessionId, ids.ScreenId, ids.WindowId)
		if err != nil {
			return nil, fmt.Errorf("/sw:set cannot get screen-window: %v", err)
		}
		var selectedLineStr string
		if sw.SelectedLine > 0 {
			selectedLineStr = strconv.Itoa(sw.SelectedLine)
		}
		ritem, err := resolveLine(ctx, ids.SessionId, ids.WindowId, pk.Kwargs["line"], selectedLineStr)
		if err != nil {
			return nil, fmt.Errorf("/sw:set error resolving line: %v", err)
		}
		if ritem == nil {
			return nil, fmt.Errorf("/sw:set could not resolve line %q", pk.Kwargs["line"])
		}
		setNonST = true
		updateMap[sstore.SWField_SelectedLine] = ritem.Num
	}
	if len(updateMap) == 0 {
		return nil, fmt.Errorf("/sw:set no updates, can set %s", formatStrs([]string{"line", "scrolltop", "focus"}, "or", false))
	}
	sw, err := sstore.UpdateScreenWindow(ctx, ids.SessionId, ids.ScreenId, ids.WindowId, updateMap)
	if err != nil {
		return nil, fmt.Errorf("/sw:set failed to update: %v", err)
	}
	if !setNonST {
		return nil, nil
	}
	return sstore.ModelUpdate{ScreenWindows: []*sstore.ScreenWindowType{sw}}, nil
}

func RemoteInstallCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Window|R_Remote)
	if err != nil {
		return nil, err
	}
	mshell := ids.Remote.MShell
	go mshell.RunInstall()
	return sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			PtyRemoteId: ids.Remote.RemotePtr.RemoteId,
		},
	}, nil
}

func RemoteInstallCancelCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Window|R_Remote)
	if err != nil {
		return nil, err
	}
	mshell := ids.Remote.MShell
	go mshell.CancelInstall()
	return sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			PtyRemoteId: ids.Remote.RemotePtr.RemoteId,
		},
	}, nil
}

func RemoteConnectCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Window|R_Remote)
	if err != nil {
		return nil, err
	}
	go ids.Remote.MShell.Launch()
	return sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			PtyRemoteId: ids.Remote.RemotePtr.RemoteId,
		},
	}, nil
}

func RemoteDisconnectCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Window|R_Remote)
	if err != nil {
		return nil, err
	}
	force := resolveBool(pk.Kwargs["force"], false)
	go ids.Remote.MShell.Disconnect(force)
	return sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			PtyRemoteId: ids.Remote.RemotePtr.RemoteId,
		},
	}, nil
}

func makeRemoteEditUpdate_new(err error) sstore.UpdatePacket {
	redit := &sstore.RemoteEditType{
		RemoteEdit: true,
	}
	if err != nil {
		redit.ErrorStr = err.Error()
	}
	update := sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			RemoteEdit: redit,
		},
	}
	return update
}

func makeRemoteEditErrorReturn_new(visual bool, err error) (sstore.UpdatePacket, error) {
	if visual {
		return makeRemoteEditUpdate_new(err), nil
	}
	return nil, err
}

func makeRemoteEditUpdate_edit(ids resolvedIds, err error) sstore.UpdatePacket {
	redit := &sstore.RemoteEditType{
		RemoteEdit: true,
	}
	redit.RemoteId = ids.Remote.RemotePtr.RemoteId
	if ids.Remote.RemoteCopy.SSHOpts != nil {
		redit.KeyStr = ids.Remote.RemoteCopy.SSHOpts.SSHIdentity
		redit.HasPassword = (ids.Remote.RemoteCopy.SSHOpts.SSHPassword != "")
	}
	if err != nil {
		redit.ErrorStr = err.Error()
	}
	update := sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			RemoteEdit: redit,
		},
	}
	return update
}

func makeRemoteEditErrorReturn_edit(ids resolvedIds, visual bool, err error) (sstore.UpdatePacket, error) {
	if visual {
		return makeRemoteEditUpdate_edit(ids, err), nil
	}
	return nil, err
}

type RemoteEditArgs struct {
	CanonicalName string
	SSHOpts       *sstore.SSHOpts
	Sudo          bool
	ConnectMode   string
	Alias         string
	AutoInstall   bool
	SSHPassword   string
	SSHKeyFile    string
	Color         string
	EditMap       map[string]interface{}
}

func parseRemoteEditArgs(isNew bool, pk *scpacket.FeCommandPacketType) (*RemoteEditArgs, error) {
	var canonicalName string
	var sshOpts *sstore.SSHOpts
	var isSudo bool

	if isNew {
		if len(pk.Args) == 0 {
			return nil, fmt.Errorf("/remote:new must specify user@host argument (set visual=1 to edit in UI)")
		}
		userHost := pk.Args[0]
		m := userHostRe.FindStringSubmatch(userHost)
		if m == nil {
			return nil, fmt.Errorf("invalid format of user@host argument")
		}
		sudoStr, remoteUser, remoteHost, remotePortStr := m[1], m[2], m[3], m[4]
		var uhPort int
		if remotePortStr != "" {
			var err error
			uhPort, err = strconv.Atoi(remotePortStr)
			if err != nil {
				return nil, fmt.Errorf("invalid port specified on user@host argument")
			}
		}
		if sudoStr != "" {
			isSudo = true
		}
		if pk.Kwargs["sudo"] != "" {
			sudoArg := resolveBool(pk.Kwargs["sudo"], false)
			if isSudo && !sudoArg {
				return nil, fmt.Errorf("invalid 'sudo' argument, with sudo kw arg set to false")
			}
			if !isSudo && sudoArg {
				isSudo = true
			}
		}
		sshOpts = &sstore.SSHOpts{
			Local:   false,
			SSHHost: remoteHost,
			SSHUser: remoteUser,
		}
		portVal, err := resolvePosInt(pk.Kwargs["port"], 0)
		if err != nil {
			return nil, fmt.Errorf("invalid port %q: %v", pk.Kwargs["port"], err)
		}
		if portVal != 0 && uhPort != 0 && portVal != uhPort {
			return nil, fmt.Errorf("invalid port argument, does not match port specified in 'user@host:port' argument")
		}
		if portVal == 0 && uhPort != 0 {
			portVal = uhPort
		}
		sshOpts.SSHPort = portVal
		canonicalName = remoteUser + "@" + remoteHost
		if isSudo {
			canonicalName = "sudo@" + canonicalName
		}
	} else {
		if pk.Kwargs["sudo"] != "" {
			return nil, fmt.Errorf("cannot update 'sudo' value")
		}
		if pk.Kwargs["port"] != "" {
			return nil, fmt.Errorf("cannot update 'port' value")
		}
	}
	alias := pk.Kwargs["alias"]
	if alias != "" {
		if len(alias) > MaxRemoteAliasLen {
			return nil, fmt.Errorf("alias too long, max length = %d", MaxRemoteAliasLen)
		}
		if !remoteAliasRe.MatchString(alias) {
			return nil, fmt.Errorf("invalid alias format")
		}
	}
	var connectMode string
	if isNew {
		connectMode = sstore.ConnectModeAuto
	}
	if pk.Kwargs["connectmode"] != "" {
		connectMode = pk.Kwargs["connectmode"]
	}
	if connectMode != "" && !sstore.IsValidConnectMode(connectMode) {
		err := fmt.Errorf("invalid connectmode %q: valid modes are %s", connectMode, formatStrs([]string{sstore.ConnectModeStartup, sstore.ConnectModeAuto, sstore.ConnectModeManual}, "or", false))
		return nil, err
	}
	autoInstall := resolveBool(pk.Kwargs["autoinstall"], true)
	keyFile, err := resolveFile(pk.Kwargs["key"])
	if err != nil {
		return nil, fmt.Errorf("invalid ssh keyfile %q: %v", pk.Kwargs["key"], err)
	}
	color := pk.Kwargs["color"]
	if color != "" {
		err := validateRemoteColor(color, "remote color")
		if err != nil {
			return nil, err
		}
	}
	sshPassword := pk.Kwargs["password"]
	if sshOpts != nil {
		sshOpts.SSHIdentity = keyFile
		sshOpts.SSHPassword = sshPassword
	}

	// set up editmap
	editMap := make(map[string]interface{})
	if _, found := pk.Kwargs[sstore.RemoteField_Alias]; found {
		editMap[sstore.RemoteField_Alias] = alias
	}
	if connectMode != "" {
		editMap[sstore.RemoteField_ConnectMode] = connectMode
	}
	if _, found := pk.Kwargs[sstore.RemoteField_AutoInstall]; found {
		editMap[sstore.RemoteField_AutoInstall] = autoInstall
	}
	if _, found := pk.Kwargs["key"]; found {
		editMap[sstore.RemoteField_SSHKey] = keyFile
	}
	if _, found := pk.Kwargs[sstore.RemoteField_Color]; found {
		editMap[sstore.RemoteField_Color] = color
	}
	if _, found := pk.Kwargs["password"]; found && pk.Kwargs["password"] != PasswordUnchangedSentinel {
		editMap[sstore.RemoteField_SSHPassword] = sshPassword
	}

	return &RemoteEditArgs{
		SSHOpts:       sshOpts,
		Sudo:          isSudo,
		ConnectMode:   connectMode,
		Alias:         alias,
		AutoInstall:   autoInstall,
		CanonicalName: canonicalName,
		SSHKeyFile:    keyFile,
		SSHPassword:   sshPassword,
		Color:         color,
		EditMap:       editMap,
	}, nil
}

func RemoteNewCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	visualEdit := resolveBool(pk.Kwargs["visual"], false)
	isSubmitted := resolveBool(pk.Kwargs["submit"], false)
	if visualEdit && !isSubmitted && len(pk.Args) == 0 {
		return makeRemoteEditUpdate_new(nil), nil
	}
	editArgs, err := parseRemoteEditArgs(true, pk)
	if err != nil {
		return makeRemoteEditErrorReturn_new(visualEdit, fmt.Errorf("/remote:new %v", err))
	}
	r := &sstore.RemoteType{
		RemoteId:            scbase.GenPromptUUID(),
		PhysicalId:          "",
		RemoteType:          sstore.RemoteTypeSsh,
		RemoteAlias:         editArgs.Alias,
		RemoteCanonicalName: editArgs.CanonicalName,
		RemoteSudo:          editArgs.Sudo,
		RemoteUser:          editArgs.SSHOpts.SSHUser,
		RemoteHost:          editArgs.SSHOpts.SSHHost,
		ConnectMode:         editArgs.ConnectMode,
		AutoInstall:         editArgs.AutoInstall,
		SSHOpts:             editArgs.SSHOpts,
	}
	if editArgs.Color != "" {
		r.RemoteOpts = &sstore.RemoteOptsType{Color: editArgs.Color}
	}
	err = remote.AddRemote(ctx, r)
	if err != nil {
		return makeRemoteEditErrorReturn_new(visualEdit, fmt.Errorf("cannot create remote %q: %v", r.RemoteCanonicalName, err))
	}
	// SUCCESS
	update := sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			InfoMsg:   fmt.Sprintf("remote %q created", r.RemoteCanonicalName),
			TimeoutMs: 2000,
		},
	}
	return update, nil
}

func RemoteSetCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Window|R_Remote)
	if err != nil {
		return nil, err
	}
	visualEdit := resolveBool(pk.Kwargs["visual"], false)
	isSubmitted := resolveBool(pk.Kwargs["submit"], false)
	editArgs, err := parseRemoteEditArgs(false, pk)
	if err != nil {
		return makeRemoteEditErrorReturn_edit(ids, visualEdit, fmt.Errorf("/remote:new %v", err))
	}
	if visualEdit && !isSubmitted && len(editArgs.EditMap) == 0 {
		return makeRemoteEditUpdate_edit(ids, nil), nil
	}
	if !visualEdit && len(editArgs.EditMap) == 0 {
		return nil, fmt.Errorf("/remote:set no updates, can set %s.  (set visual=1 to edit in UI)", formatStrs(RemoteSetArgs, "or", false))
	}
	err = ids.Remote.MShell.UpdateRemote(ctx, editArgs.EditMap)
	if err != nil {
		return makeRemoteEditErrorReturn_edit(ids, visualEdit, fmt.Errorf("/remote:new error updating remote: %v", err))
	}
	update := sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			InfoMsg:   fmt.Sprintf("remote %q updated", ids.Remote.DisplayName),
			TimeoutMs: 2000,
		},
	}
	return update, nil
}

func RemoteShowCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Window|R_Remote)
	if err != nil {
		return nil, err
	}
	state := ids.Remote.RState
	return sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			PtyRemoteId: state.RemoteId,
		},
	}, nil
}

func RemoteShowAllCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	stateArr := remote.GetAllRemoteRuntimeState()
	var buf bytes.Buffer
	for _, rstate := range stateArr {
		var name string
		if rstate.RemoteAlias == "" {
			name = rstate.RemoteCanonicalName
		} else {
			name = fmt.Sprintf("%s (%s)", rstate.RemoteCanonicalName, rstate.RemoteAlias)
		}
		buf.WriteString(fmt.Sprintf("%-12s %-5s %8s  %s\n", rstate.Status, rstate.RemoteType, rstate.RemoteId[0:8], name))
	}
	return sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			RemoteShowAll: true,
		},
	}, nil
}

func ScreenShowAllCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session)
	screenArr, err := sstore.GetBareSessionScreens(ctx, ids.SessionId)
	if err != nil {
		return nil, fmt.Errorf("/screen:showall error getting screen list: %v", err)
	}
	var buf bytes.Buffer
	for _, screen := range screenArr {
		var archivedStr string
		if screen.Archived {
			archivedStr = " (archived)"
		}
		screenIdxStr := "-"
		if screen.ScreenIdx != 0 {
			screenIdxStr = strconv.Itoa(int(screen.ScreenIdx))
		}
		outStr := fmt.Sprintf("%-30s %s  %s\n", screen.Name+archivedStr, screen.ScreenId, screenIdxStr)
		buf.WriteString(outStr)
	}
	return sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			InfoTitle: fmt.Sprintf("all screens for session"),
			InfoLines: splitLinesForInfo(buf.String()),
		},
	}, nil
}

func RemoteArchiveCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Window|R_Remote)
	if err != nil {
		return nil, err
	}
	err = remote.ArchiveRemote(ctx, ids.Remote.RemotePtr.RemoteId)
	if err != nil {
		return nil, fmt.Errorf("archiving remote: %v", err)
	}
	update := sstore.InfoMsgUpdate("remote [%s] archived", ids.Remote.DisplayName)
	localRemote := remote.GetLocalRemote()
	if localRemote != nil {
		update.Window = &sstore.WindowType{
			SessionId: ids.SessionId,
			WindowId:  ids.WindowId,
			CurRemote: sstore.RemotePtrType{RemoteId: localRemote.GetRemoteId()},
		}
	}
	return update, nil
}

func RemoteCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	return nil, fmt.Errorf("/remote requires a subcommand: %s", formatStrs([]string{"show"}, "or", false))
}

func CrCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Window)
	if err != nil {
		return nil, fmt.Errorf("/cr error: %w", err)
	}
	newRemote := firstArg(pk)
	if newRemote == "" {
		return nil, nil
	}
	remoteName, rptr, rstate, err := resolveRemote(ctx, newRemote, ids.SessionId, ids.WindowId)
	if err != nil {
		return nil, err
	}
	if rptr == nil {
		return nil, fmt.Errorf("/cr error: remote %q not found", newRemote)
	}
	if rstate.Archived {
		return nil, fmt.Errorf("/cr error: remote %q cannot switch to archived remote", newRemote)
	}
	err = sstore.UpdateCurRemote(ctx, ids.SessionId, ids.WindowId, *rptr)
	if err != nil {
		return nil, fmt.Errorf("/cr error: cannot update curremote: %w", err)
	}
	update := sstore.ModelUpdate{
		Window: &sstore.WindowType{
			SessionId: ids.SessionId,
			WindowId:  ids.WindowId,
			CurRemote: *rptr,
		},
		Info: &sstore.InfoMsgType{
			InfoMsg:   fmt.Sprintf("current remote = %q", remoteName),
			TimeoutMs: 2000,
		},
	}
	return update, nil
}

func makeStaticCmd(ctx context.Context, metaCmd string, ids resolvedIds, cmdStr string, cmdOutput []byte) (*sstore.CmdType, error) {
	cmd := &sstore.CmdType{
		SessionId: ids.SessionId,
		CmdId:     scbase.GenPromptUUID(),
		CmdStr:    cmdStr,
		Remote:    ids.Remote.RemotePtr,
		TermOpts:  sstore.TermOpts{Rows: shexec.DefaultTermRows, Cols: shexec.DefaultTermCols, FlexRows: true, MaxPtySize: remote.DefaultMaxPtySize},
		Status:    sstore.CmdStatusDone,
		StartPk:   nil,
		DoneInfo:  nil,
		RunOut:    nil,
	}
	if ids.Remote.StatePtr != nil {
		cmd.StatePtr = *ids.Remote.StatePtr
	}
	if ids.Remote.FeState != nil {
		cmd.FeState = *ids.Remote.FeState
	}
	err := sstore.CreateCmdPtyFile(ctx, cmd.SessionId, cmd.CmdId, cmd.TermOpts.MaxPtySize)
	if err != nil {
		// TODO tricky error since the command was a success, but we can't show the output
		return nil, fmt.Errorf("cannot create local ptyout file for %s command: %w", metaCmd, err)
	}
	// can ignore ptyupdate
	_, err = sstore.AppendToCmdPtyBlob(ctx, cmd.SessionId, cmd.CmdId, cmdOutput, 0)
	if err != nil {
		// TODO tricky error since the command was a success, but we can't show the output
		return nil, fmt.Errorf("cannot append to local ptyout file for %s command: %v", metaCmd, err)
	}
	return cmd, nil
}

func addLineForCmd(ctx context.Context, metaCmd string, shouldFocus bool, ids resolvedIds, cmd *sstore.CmdType) (*sstore.ModelUpdate, error) {
	rtnLine, err := sstore.AddCmdLine(ctx, ids.SessionId, ids.WindowId, DefaultUserId, cmd)
	if err != nil {
		return nil, err
	}
	sw, err := sstore.GetScreenWindowByIds(ctx, ids.SessionId, ids.ScreenId, ids.WindowId)
	if err != nil {
		// ignore error here, because the command has already run (nothing to do)
		log.Printf("%s error getting screen-window: %v\n", metaCmd, err)
	}
	if sw != nil {
		updateMap := make(map[string]interface{})
		updateMap[sstore.SWField_SelectedLine] = rtnLine.LineNum
		if shouldFocus {
			updateMap[sstore.SWField_Focus] = sstore.SWFocusCmdFg
		}
		sw, err = sstore.UpdateScreenWindow(ctx, ids.SessionId, ids.ScreenId, ids.WindowId, updateMap)
		if err != nil {
			// ignore error again (nothing to do)
			log.Printf("%s error updating screen-window selected line: %v\n", metaCmd, err)
		}
	}
	update := &sstore.ModelUpdate{
		Line:          rtnLine,
		Cmd:           cmd,
		ScreenWindows: []*sstore.ScreenWindowType{sw},
	}
	updateHistoryContext(ctx, rtnLine, cmd)
	return update, nil
}

func updateHistoryContext(ctx context.Context, line *sstore.LineType, cmd *sstore.CmdType) {
	ctxVal := ctx.Value(historyContextKey)
	if ctxVal == nil {
		return
	}
	hctx := ctxVal.(*historyContextType)
	if line != nil {
		hctx.LineId = line.LineId
	}
	if cmd != nil {
		hctx.CmdId = cmd.CmdId
		hctx.RemotePtr = &cmd.Remote
	}
}

func makeInfoFromComps(compType string, comps []string, hasMore bool) sstore.UpdatePacket {
	sort.Slice(comps, func(i int, j int) bool {
		c1 := comps[i]
		c2 := comps[j]
		c1mc := strings.HasPrefix(c1, "^")
		c2mc := strings.HasPrefix(c2, "^")
		if c1mc && !c2mc {
			return true
		}
		if !c1mc && c2mc {
			return false
		}
		return c1 < c2
	})
	if len(comps) == 0 {
		comps = []string{"(no completions)"}
	}
	update := sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			InfoTitle:     fmt.Sprintf("%s completions", compType),
			InfoComps:     comps,
			InfoCompsMore: hasMore,
		},
	}
	return update
}

func simpleCompCommandMeta(ctx context.Context, prefix string, compCtx comp.CompContext, args []interface{}) (*comp.CompReturn, error) {
	if strings.HasPrefix(prefix, "/") {
		compsCmd, _ := comp.DoSimpleComp(ctx, comp.CGTypeCommand, prefix, compCtx, nil)
		compsMeta, _ := simpleCompMeta(ctx, prefix, compCtx, nil)
		return comp.CombineCompReturn(comp.CGTypeCommandMeta, compsCmd, compsMeta), nil
	} else {
		return comp.DoSimpleComp(ctx, comp.CGTypeCommand, prefix, compCtx, nil)
	}
}

func simpleCompMeta(ctx context.Context, prefix string, compCtx comp.CompContext, args []interface{}) (*comp.CompReturn, error) {
	rtn := comp.CompReturn{}
	validCommands := getValidCommands()
	for _, cmd := range validCommands {
		if strings.HasPrefix(cmd, "/_") && !strings.HasPrefix(prefix, "/_") {
			continue
		}
		if strings.HasPrefix(cmd, prefix) {
			rtn.Entries = append(rtn.Entries, comp.CompEntry{Word: cmd, IsMetaCmd: true})
		}
	}
	return &rtn, nil
}

func doMetaCompGen(ctx context.Context, pk *scpacket.FeCommandPacketType, prefix string, forDisplay bool) ([]string, bool, error) {
	ids, err := resolveUiIds(ctx, pk, 0) // best effort
	var comps []string
	var hasMore bool
	if ids.Remote != nil && ids.Remote.RState.IsConnected() {
		comps, hasMore, err = doCompGen(ctx, pk, prefix, "file", forDisplay)
		if err != nil {
			return nil, false, err
		}
	}
	validCommands := getValidCommands()
	for _, cmd := range validCommands {
		if strings.HasPrefix(cmd, prefix) {
			if forDisplay {
				comps = append(comps, "^"+cmd)
			} else {
				comps = append(comps, cmd)
			}
		}
	}
	return comps, hasMore, nil
}

func doCompGen(ctx context.Context, pk *scpacket.FeCommandPacketType, prefix string, compType string, forDisplay bool) ([]string, bool, error) {
	if compType == "metacommand" {
		return doMetaCompGen(ctx, pk, prefix, forDisplay)
	}
	if !packet.IsValidCompGenType(compType) {
		return nil, false, fmt.Errorf("/_compgen invalid type '%s'", compType)
	}
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Window|R_RemoteConnected)
	if err != nil {
		return nil, false, fmt.Errorf("/_compgen error: %w", err)
	}
	cgPacket := packet.MakeCompGenPacket()
	cgPacket.ReqId = uuid.New().String()
	cgPacket.CompType = compType
	cgPacket.Prefix = prefix
	cgPacket.Cwd = ids.Remote.FeState.Cwd
	resp, err := ids.Remote.MShell.PacketRpc(ctx, cgPacket)
	if err != nil {
		return nil, false, err
	}
	if err = resp.Err(); err != nil {
		return nil, false, err
	}
	comps := utilfn.GetStrArr(resp.Data, "comps")
	hasMore := utilfn.GetBool(resp.Data, "hasmore")
	return comps, hasMore, nil
}

func CompGenCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, 0) // best-effort
	if err != nil {
		return nil, fmt.Errorf("/_compgen error: %w", err)
	}
	cmdLine := firstArg(pk)
	pos := len(cmdLine)
	if pk.Kwargs["comppos"] != "" {
		posArg, err := strconv.Atoi(pk.Kwargs["comppos"])
		if err != nil {
			return nil, fmt.Errorf("/_compgen invalid comppos '%s': %w", pk.Kwargs["comppos"], err)
		}
		pos = posArg
	}
	if pos < 0 {
		pos = 0
	}
	if pos > len(cmdLine) {
		pos = len(cmdLine)
	}
	showComps := resolveBool(pk.Kwargs["compshow"], false)
	cmdSP := utilfn.StrWithPos{Str: cmdLine, Pos: pos}
	compCtx := comp.CompContext{}
	if ids.Remote != nil {
		rptr := ids.Remote.RemotePtr
		compCtx.RemotePtr = &rptr
		if ids.Remote.FeState != nil {
			compCtx.Cwd = ids.Remote.FeState.Cwd
		}
	}
	compCtx.ForDisplay = showComps
	crtn, newSP, err := comp.DoCompGen(ctx, cmdSP, compCtx)
	if err != nil {
		return nil, err
	}
	if crtn == nil {
		return nil, nil
	}
	if showComps {
		compStrs := crtn.GetCompDisplayStrs()
		return makeInfoFromComps(crtn.CompType, compStrs, crtn.HasMore), nil
	}
	if newSP == nil || cmdSP == *newSP {
		return nil, nil
	}
	update := sstore.ModelUpdate{
		CmdLine: &sstore.CmdLineType{CmdLine: newSP.Str, CursorPos: newSP.Pos},
	}
	return update, nil
}

func CommentCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Window)
	if err != nil {
		return nil, fmt.Errorf("/comment error: %w", err)
	}
	text := firstArg(pk)
	if strings.TrimSpace(text) == "" {
		return nil, fmt.Errorf("cannot post empty comment")
	}
	rtnLine, err := sstore.AddCommentLine(ctx, ids.SessionId, ids.WindowId, DefaultUserId, text)
	if err != nil {
		return nil, err
	}
	updateMap := make(map[string]interface{})
	updateMap[sstore.SWField_SelectedLine] = rtnLine.LineNum
	updateMap[sstore.SWField_Focus] = sstore.SWFocusInput
	sw, err := sstore.UpdateScreenWindow(ctx, ids.SessionId, ids.ScreenId, ids.WindowId, updateMap)
	if err != nil {
		// ignore error again (nothing to do)
		log.Printf("/comment error updating screen-window selected line: %v\n", err)
	}
	update := sstore.ModelUpdate{Line: rtnLine, ScreenWindows: []*sstore.ScreenWindowType{sw}}
	return update, nil
}

func maybeQuote(s string, quote bool) string {
	if quote {
		return fmt.Sprintf("%q", s)
	}
	return s
}

func mapToStrs(m map[string]bool) []string {
	var rtn []string
	for key, val := range m {
		if val {
			rtn = append(rtn, key)
		}
	}
	return rtn
}

func formatStrs(strs []string, conj string, quote bool) string {
	if len(strs) == 0 {
		return "(none)"
	}
	if len(strs) == 1 {
		return maybeQuote(strs[0], quote)
	}
	if len(strs) == 2 {
		return fmt.Sprintf("%s %s %s", maybeQuote(strs[0], quote), conj, maybeQuote(strs[1], quote))
	}
	var buf bytes.Buffer
	for idx := 0; idx < len(strs)-1; idx++ {
		buf.WriteString(maybeQuote(strs[idx], quote))
		buf.WriteString(", ")
	}
	buf.WriteString(conj)
	buf.WriteString(" ")
	buf.WriteString(maybeQuote(strs[len(strs)-1], quote))
	return buf.String()
}

func validateName(name string, typeStr string) error {
	if len(name) > MaxNameLen {
		return fmt.Errorf("%s name too long, max length is %d", typeStr, MaxNameLen)
	}
	if !genericNameRe.MatchString(name) {
		return fmt.Errorf("invalid %s name", typeStr)
	}
	return nil
}

func validateColor(color string, typeStr string) error {
	for _, c := range ColorNames {
		if color == c {
			return nil
		}
	}
	return fmt.Errorf("invalid %s, valid colors are: %s", typeStr, formatStrs(ColorNames, "or", false))
}

func validateRemoteColor(color string, typeStr string) error {
	for _, c := range RemoteColorNames {
		if color == c {
			return nil
		}
	}
	return fmt.Errorf("invalid %s, valid colors are: %s", typeStr, formatStrs(RemoteColorNames, "or", false))
}

func SessionOpenCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	activate := resolveBool(pk.Kwargs["activate"], true)
	newName := pk.Kwargs["name"]
	if newName != "" {
		err := validateName(newName, "session")
		if err != nil {
			return nil, err
		}
	}
	update, err := sstore.InsertSessionWithName(ctx, newName, activate)
	if err != nil {
		return nil, err
	}
	return update, nil
}

func SessionDeleteCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session)
	if err != nil {
		return nil, err
	}
	update, err := sstore.DeleteSession(ctx, ids.SessionId)
	if err != nil {
		return nil, fmt.Errorf("cannot delete session: %v", err)
	}
	return update, nil
}

func SessionArchiveCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, 0) // don't force R_Session
	if err != nil {
		return nil, err
	}
	sessionId := ""
	if len(pk.Args) >= 1 {
		ritem, err := resolveSession(ctx, pk.Args[0], ids.SessionId)
		if err != nil {
			return nil, fmt.Errorf("/session:archive error resolving session %q: %w", pk.Args[0], err)
		}
		if ritem == nil {
			return nil, fmt.Errorf("/session:archive session %q not found", pk.Args[0])
		}
		sessionId = ritem.Id
	} else {
		sessionId = ids.SessionId
	}
	if sessionId == "" {
		return nil, fmt.Errorf("/session:archive no sessionid found")
	}
	archiveVal := true
	if len(pk.Args) >= 2 {
		archiveVal = resolveBool(pk.Args[1], true)
	}
	if archiveVal {
		update, err := sstore.ArchiveSession(ctx, sessionId)
		if err != nil {
			return nil, fmt.Errorf("cannot archive session: %v", err)
		}
		update.Info = &sstore.InfoMsgType{
			InfoMsg: "session archived",
		}
		return update, nil
	} else {
		activate := resolveBool(pk.Kwargs["activate"], false)
		update, err := sstore.UnArchiveSession(ctx, sessionId, activate)
		if err != nil {
			return nil, fmt.Errorf("cannot un-archive session: %v", err)
		}
		update.Info = &sstore.InfoMsgType{
			InfoMsg: "session un-archived",
		}
		return update, nil
	}
}

func SessionShowCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session)
	if err != nil {
		return nil, err
	}
	session, err := sstore.GetSessionById(ctx, ids.SessionId)
	if err != nil {
		return nil, fmt.Errorf("cannot get session: %w", err)
	}
	if session == nil {
		return nil, fmt.Errorf("session not found")
	}
	var buf bytes.Buffer
	buf.WriteString(fmt.Sprintf("  %-15s %s\n", "sessionid", session.SessionId))
	buf.WriteString(fmt.Sprintf("  %-15s %s\n", "name", session.Name))
	if session.SessionIdx != 0 {
		buf.WriteString(fmt.Sprintf("  %-15s %d\n", "index", session.SessionIdx))
	}
	if session.Archived {
		buf.WriteString(fmt.Sprintf("  %-15s %s\n", "archived", "true"))
		ts := time.UnixMilli(session.ArchivedTs)
		buf.WriteString(fmt.Sprintf("  %-15s %s\n", "archivedts", ts.Format("2006-01-02 15:04:05")))
	}
	stats, err := sstore.GetSessionStats(ctx, ids.SessionId)
	if err != nil {
		return nil, fmt.Errorf("error getting session stats: %w", err)
	}
	var screenArchiveStr string
	if stats.NumArchivedScreens > 0 {
		screenArchiveStr = fmt.Sprintf(" (%d archived)", stats.NumArchivedScreens)
	}
	buf.WriteString(fmt.Sprintf("  %-15s %d%s\n", "screens", stats.NumScreens, screenArchiveStr))
	buf.WriteString(fmt.Sprintf("  %-15s %d\n", "lines", stats.NumLines))
	buf.WriteString(fmt.Sprintf("  %-15s %d\n", "cmds", stats.NumCmds))
	buf.WriteString(fmt.Sprintf("  %-15s %0.2fM\n", "disksize", float64(stats.DiskStats.TotalSize)/1000000))
	buf.WriteString(fmt.Sprintf("  %-15s %s\n", "disk-location", stats.DiskStats.Location))
	return sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			InfoTitle: "session info",
			InfoLines: splitLinesForInfo(buf.String()),
		},
	}, nil
}

func SessionShowAllCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	sessions, err := sstore.GetBareSessions(ctx)
	if err != nil {
		return nil, fmt.Errorf("error retrieving sessions: %v", err)
	}
	var buf bytes.Buffer
	for _, session := range sessions {
		var archivedStr string
		if session.Archived {
			archivedStr = " (archived)"
		}
		sessionIdxStr := "-"
		if session.SessionIdx != 0 {
			sessionIdxStr = strconv.Itoa(int(session.SessionIdx))
		}
		outStr := fmt.Sprintf("%-30s %s  %s\n", session.Name+archivedStr, session.SessionId, sessionIdxStr)
		buf.WriteString(outStr)
	}
	return sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			InfoTitle: "all sessions",
			InfoLines: splitLinesForInfo(buf.String()),
		},
	}, nil
}

func SessionSetCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session)
	if err != nil {
		return nil, err
	}
	var varsUpdated []string
	if pk.Kwargs["name"] != "" {
		newName := pk.Kwargs["name"]
		err = validateName(newName, "session")
		if err != nil {
			return nil, err
		}
		err = sstore.SetSessionName(ctx, ids.SessionId, newName)
		if err != nil {
			return nil, fmt.Errorf("setting session name: %v", err)
		}
		varsUpdated = append(varsUpdated, "name")
	}
	if pk.Kwargs["pos"] != "" {

	}
	if len(varsUpdated) == 0 {
		return nil, fmt.Errorf("/session:set no updates, can set %s", formatStrs([]string{"name", "pos"}, "or", false))
	}
	bareSession, err := sstore.GetBareSessionById(ctx, ids.SessionId)
	update := sstore.ModelUpdate{
		Sessions: []*sstore.SessionType{bareSession},
		Info: &sstore.InfoMsgType{
			InfoMsg:   fmt.Sprintf("session updated %s", formatStrs(varsUpdated, "and", false)),
			TimeoutMs: 2000,
		},
	}
	return update, nil
}

func SessionCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, 0)
	if err != nil {
		return nil, err
	}
	firstArg := firstArg(pk)
	if firstArg == "" {
		return nil, fmt.Errorf("usage /session [name|id|pos], no param specified")
	}
	ritem, err := resolveSession(ctx, firstArg, ids.SessionId)
	if err != nil {
		return nil, err
	}
	err = sstore.SetActiveSessionId(ctx, ritem.Id)
	if err != nil {
		return nil, err
	}
	update := sstore.ModelUpdate{
		ActiveSessionId: ritem.Id,
		Info: &sstore.InfoMsgType{
			InfoMsg:   fmt.Sprintf("switched to session %q", ritem.Name),
			TimeoutMs: 2000,
		},
	}
	return update, nil
}

func RemoteResetCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Screen|R_Window)
	if err != nil {
		return nil, err
	}
	initPk, err := ids.Remote.MShell.ReInit(ctx)
	if err != nil {
		return nil, err
	}
	if initPk == nil || initPk.State == nil {
		return nil, fmt.Errorf("invalid initpk received from remote (no remote state)")
	}
	feState := sstore.FeStateFromShellState(initPk.State)
	remoteInst, err := sstore.UpdateRemoteState(ctx, ids.SessionId, ids.WindowId, ids.Remote.RemotePtr, *feState, initPk.State, nil)
	if err != nil {
		return nil, err
	}
	outputStr := "reset remote state"
	cmd, err := makeStaticCmd(ctx, "reset", ids, pk.GetRawStr(), []byte(outputStr))
	if err != nil {
		// TODO tricky error since the command was a success, but we can't show the output
		return nil, err
	}
	update, err := addLineForCmd(ctx, "/reset", false, ids, cmd)
	if err != nil {
		// TODO tricky error since the command was a success, but we can't show the output
		return nil, err
	}
	update.Interactive = pk.Interactive
	update.Sessions = sstore.MakeSessionsUpdateForRemote(ids.SessionId, remoteInst)
	return update, nil
}

func ClearCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Screen|R_Window)
	if err != nil {
		return nil, err
	}
	update, err := sstore.ClearWindow(ctx, ids.SessionId, ids.WindowId)
	if err != nil {
		return nil, fmt.Errorf("clearing window: %v", err)
	}
	update.Info = &sstore.InfoMsgType{
		InfoMsg:   fmt.Sprintf("window cleared"),
		TimeoutMs: 2000,
	}
	return update, nil
}

const DefaultMaxHistoryItems = 10000

func HistoryCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Screen|R_Window|R_Remote)
	if err != nil {
		return nil, err
	}
	maxItems, err := resolvePosInt(pk.Kwargs["maxitems"], DefaultMaxHistoryItems)
	if err != nil {
		return nil, fmt.Errorf("invalid maxitems value '%s' (must be a number): %v", pk.Kwargs["maxitems"], err)
	}
	if maxItems < 0 {
		return nil, fmt.Errorf("invalid maxitems value '%d' (cannot be negative)", maxItems)
	}
	if maxItems == 0 {
		maxItems = DefaultMaxHistoryItems
	}
	htype := HistoryTypeWindow
	hSessionId := ids.SessionId
	hWindowId := ids.WindowId
	if pk.Kwargs["type"] != "" {
		htype = pk.Kwargs["type"]
		if htype != HistoryTypeWindow && htype != HistoryTypeSession && htype != HistoryTypeGlobal {
			return nil, fmt.Errorf("invalid history type '%s', valid types: %s", htype, formatStrs([]string{HistoryTypeWindow, HistoryTypeSession, HistoryTypeGlobal}, "or", false))
		}
	}
	if htype == HistoryTypeGlobal {
		hSessionId = ""
		hWindowId = ""
	} else if htype == HistoryTypeSession {
		hWindowId = ""
	}
	hitems, err := sstore.GetHistoryItems(ctx, hSessionId, hWindowId, sstore.HistoryQueryOpts{MaxItems: maxItems})
	if err != nil {
		return nil, err
	}
	show := !resolveBool(pk.Kwargs["noshow"], false)
	update := sstore.ModelUpdate{}
	update.History = &sstore.HistoryInfoType{
		HistoryType: htype,
		SessionId:   ids.SessionId,
		WindowId:    ids.WindowId,
		Items:       hitems,
		Show:        show,
	}
	return update, nil
}

func splitLinesForInfo(str string) []string {
	rtn := strings.Split(str, "\n")
	if rtn[len(rtn)-1] == "" {
		return rtn[:len(rtn)-1]
	}
	return rtn
}

func resizeRunningCommand(ctx context.Context, cmd *sstore.CmdType, newCols int) error {
	siPk := packet.MakeSpecialInputPacket()
	siPk.CK = base.MakeCommandKey(cmd.SessionId, cmd.CmdId)
	siPk.WinSize = &packet.WinSize{Rows: int(cmd.TermOpts.Rows), Cols: newCols}
	msh := remote.GetRemoteById(cmd.Remote.RemoteId)
	if msh == nil {
		return fmt.Errorf("cannot resize, cmd remote not found")
	}
	err := msh.SendSpecialInput(siPk)
	if err != nil {
		return err
	}
	newTermOpts := cmd.TermOpts
	newTermOpts.Cols = int64(newCols)
	err = sstore.UpdateCmdTermOpts(ctx, cmd.SessionId, cmd.CmdId, newTermOpts)
	if err != nil {
		return err
	}
	return nil
}

func SwResizeCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Screen|R_Window)
	if err != nil {
		return nil, err
	}
	colsStr := pk.Kwargs["cols"]
	if colsStr == "" {
		return nil, fmt.Errorf("/sw:resize requires a numeric 'cols' argument")
	}
	cols, err := strconv.Atoi(colsStr)
	if err != nil {
		return nil, fmt.Errorf("/sw:resize requires a numeric 'cols' argument: %v", err)
	}
	if cols <= 0 {
		return nil, fmt.Errorf("/sw:resize invalid zero/negative 'cols' argument")
	}
	cols = base.BoundInt(cols, shexec.MinTermCols, shexec.MaxTermCols)
	runningCmds, err := sstore.GetRunningWindowCmds(ctx, ids.SessionId, ids.WindowId)
	if err != nil {
		return nil, fmt.Errorf("/sw:resize cannot get running commands: %v", err)
	}
	if len(runningCmds) == 0 {
		return nil, nil
	}
	for _, cmd := range runningCmds {
		if int(cmd.TermOpts.Cols) != cols {
			resizeRunningCommand(ctx, cmd, cols)
		}
	}
	return nil, nil
}

func LineCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	return nil, fmt.Errorf("/line requires a subcommand: %s", formatStrs([]string{"show", "star", "hide", "purge"}, "or", false))
}

func LineStarCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Screen|R_Window)
	if err != nil {
		return nil, err
	}
	if len(pk.Args) == 0 {
		return nil, fmt.Errorf("/line:star requires an argument (line number or id)")
	}
	if len(pk.Args) > 2 {
		return nil, fmt.Errorf("/line:star only takes up to 2 arguments (line-number and star-value)")
	}
	lineArg := pk.Args[0]
	lineId, err := sstore.FindLineIdByArg(ctx, ids.SessionId, ids.WindowId, lineArg)
	if err != nil {
		return nil, fmt.Errorf("error looking up lineid: %v", err)
	}
	if lineId == "" {
		return nil, fmt.Errorf("line %q not found", lineArg)
	}
	starVal, err := resolveNonNegInt(pk.Args[1], 1)
	if err != nil {
		return nil, fmt.Errorf("/line:star invalid star-value (not integer): %v", err)
	}
	if starVal > 5 {
		return nil, fmt.Errorf("/line:star invalid star-value must be in the range of 0-5")
	}
	err = sstore.UpdateLineStar(ctx, lineId, starVal)
	if err != nil {
		return nil, fmt.Errorf("/line:star error updating star value: %v", err)
	}
	lineObj, err := sstore.GetLineById(ctx, lineId)
	if err != nil {
		return nil, fmt.Errorf("/line:star error getting line: %v", err)
	}
	if lineObj == nil {
		// no line (which is strange given we checked for it above).  just return a nop.
		return nil, nil
	}
	return sstore.ModelUpdate{Line: lineObj}, nil
}

func LineArchiveCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Screen|R_Window)
	if err != nil {
		return nil, err
	}
	if len(pk.Args) == 0 {
		return nil, fmt.Errorf("/line:archive requires an argument (line number or id)")
	}
	lineArg := pk.Args[0]
	lineId, err := sstore.FindLineIdByArg(ctx, ids.SessionId, ids.WindowId, lineArg)
	if err != nil {
		return nil, fmt.Errorf("error looking up lineid: %v", err)
	}
	if lineId == "" {
		return nil, fmt.Errorf("line %q not found", lineArg)
	}
	shouldArchive := true
	if len(pk.Args) >= 2 {
		shouldArchive = resolveBool(pk.Args[1], true)
	}
	err = sstore.SetLineArchivedById(ctx, lineId, shouldArchive)
	if err != nil {
		return nil, fmt.Errorf("/line:archive error updating hidden status: %v", err)
	}
	lineObj, err := sstore.GetLineById(ctx, lineId)
	if err != nil {
		return nil, fmt.Errorf("/line:archive error getting line: %v", err)
	}
	if lineObj == nil {
		// no line (which is strange given we checked for it above).  just return a nop.
		return nil, nil
	}
	return sstore.ModelUpdate{Line: lineObj}, nil
}

func LinePurgeCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Screen|R_Window)
	if err != nil {
		return nil, err
	}
	if len(pk.Args) == 0 {
		return nil, fmt.Errorf("/line:purge requires an argument (line number or id)")
	}
	lineArg := pk.Args[0]
	lineId, err := sstore.FindLineIdByArg(ctx, ids.SessionId, ids.WindowId, lineArg)
	if err != nil {
		return nil, fmt.Errorf("error looking up lineid: %v", err)
	}
	if lineId == "" {
		return nil, fmt.Errorf("line %q not found", lineArg)
	}
	err = sstore.PurgeLineById(ctx, ids.SessionId, lineId)
	if err != nil {
		return nil, fmt.Errorf("/line:purge error purging line: %v", err)
	}
	lineObj := &sstore.LineType{
		SessionId: ids.SessionId,
		WindowId:  ids.WindowId,
		LineId:    lineId,
		Remove:    true,
	}
	return sstore.ModelUpdate{Line: lineObj}, nil
}

func LineShowCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Screen|R_Window)
	if err != nil {
		return nil, err
	}
	if len(pk.Args) == 0 {
		return nil, fmt.Errorf("/line:show requires an argument (line number or id)")
	}
	lineArg := pk.Args[0]
	lineId, err := sstore.FindLineIdByArg(ctx, ids.SessionId, ids.WindowId, lineArg)
	if err != nil {
		return nil, fmt.Errorf("error looking up lineid: %v", err)
	}
	if lineId == "" {
		return nil, fmt.Errorf("line %q not found", lineArg)
	}
	line, cmd, err := sstore.GetLineCmdByLineId(ctx, ids.SessionId, ids.WindowId, lineId)
	if err != nil {
		return nil, fmt.Errorf("error getting line: %v", err)
	}
	if line == nil {
		return nil, fmt.Errorf("line %q not found", lineArg)
	}
	var buf bytes.Buffer
	buf.WriteString(fmt.Sprintf("  %-15s %s\n", "lineid", line.LineId))
	buf.WriteString(fmt.Sprintf("  %-15s %s\n", "type", line.LineType))
	lineNumStr := strconv.FormatInt(line.LineNum, 10)
	if line.LineNumTemp {
		lineNumStr = "~" + lineNumStr
	}
	buf.WriteString(fmt.Sprintf("  %-15s %s\n", "linenum", lineNumStr))
	ts := time.UnixMilli(line.Ts)
	buf.WriteString(fmt.Sprintf("  %-15s %s\n", "ts", ts.Format("2006-01-02 15:04:05")))
	if line.Ephemeral {
		buf.WriteString(fmt.Sprintf("  %-15s %v\n", "ephemeral", true))
	}
	if cmd != nil {
		buf.WriteString(fmt.Sprintf("  %-15s %s\n", "cmdid", cmd.CmdId))
		buf.WriteString(fmt.Sprintf("  %-15s %s\n", "remote", cmd.Remote.MakeFullRemoteRef()))
		buf.WriteString(fmt.Sprintf("  %-15s %s\n", "status", cmd.Status))
		if cmd.FeState.Cwd != "" {
			buf.WriteString(fmt.Sprintf("  %-15s %s\n", "cwd", cmd.FeState.Cwd))
		}
		buf.WriteString(fmt.Sprintf("  %-15s %s\n", "termopts", formatTermOpts(cmd.TermOpts)))
		if cmd.TermOpts != cmd.OrigTermOpts {
			buf.WriteString(fmt.Sprintf("  %-15s %s\n", "orig-termopts", formatTermOpts(cmd.OrigTermOpts)))
		}
		if cmd.RtnState {
			buf.WriteString(fmt.Sprintf("  %-15s %s\n", "rtnstate", "true"))
		}
	}
	update := sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			InfoTitle: fmt.Sprintf("line %d info", line.LineNum),
			InfoLines: splitLinesForInfo(buf.String()),
		},
	}
	return update, nil
}

func SetCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	var setMap map[string]map[string]string
	setMap = make(map[string]map[string]string)
	_, err := resolveUiIds(ctx, pk, 0) // best effort
	if err != nil {
		return nil, err
	}
	for argIdx, rawArgVal := range pk.Args {
		eqIdx := strings.Index(rawArgVal, "=")
		if eqIdx == -1 {
			return nil, fmt.Errorf("/set invalid argument %d, does not contain an '='", argIdx)
		}
		argName := rawArgVal[:eqIdx]
		argVal := rawArgVal[eqIdx+1:]
		ok, scopeName, varName := resolveSetArg(argName)
		if !ok {
			return nil, fmt.Errorf("/set invalid setvar %q", argName)
		}
		if _, ok := setMap[scopeName]; !ok {
			setMap[scopeName] = make(map[string]string)
		}
		setMap[scopeName][varName] = argVal
	}
	fmt.Printf("setmap: %#v\n", setMap)
	return nil, nil
}

func SignalCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	ids, err := resolveUiIds(ctx, pk, R_Session|R_Screen|R_Window)
	if err != nil {
		return nil, err
	}
	if len(pk.Args) == 0 {
		return nil, fmt.Errorf("/signal requires a first argument (line number or id)")
	}
	if len(pk.Args) == 1 {
		return nil, fmt.Errorf("/signal requires a second argument (signal name)")
	}
	lineArg := pk.Args[0]
	lineId, err := sstore.FindLineIdByArg(ctx, ids.SessionId, ids.WindowId, lineArg)
	if err != nil {
		return nil, fmt.Errorf("error looking up lineid: %v", err)
	}
	line, cmd, err := sstore.GetLineCmdByLineId(ctx, ids.SessionId, ids.WindowId, lineId)
	if err != nil {
		return nil, fmt.Errorf("error getting line: %v", err)
	}
	if line == nil {
		return nil, fmt.Errorf("line %q not found", lineArg)
	}
	if cmd == nil {
		return nil, fmt.Errorf("line %q does not have a command", lineArg)
	}
	if cmd.Status != sstore.CmdStatusRunning {
		return nil, fmt.Errorf("line %q command is not running, cannot send signal", lineArg)
	}
	sigArg := pk.Args[1]
	if isAllDigits(sigArg) {
		val, _ := strconv.Atoi(sigArg)
		if val <= 0 || val > MaxSignalNum {
			return nil, fmt.Errorf("signal number is out of bounds: %q", sigArg)
		}
	} else if !strings.HasPrefix(sigArg, "SIG") {
		sigArg = "SIG" + sigArg
	}
	sigArg = strings.ToUpper(sigArg)
	if len(sigArg) > 12 {
		return nil, fmt.Errorf("invalid signal (too long): %q", sigArg)
	}
	if !sigNameRe.MatchString(sigArg) {
		return nil, fmt.Errorf("invalid signal name/number: %q", sigArg)
	}
	msh := remote.GetRemoteById(cmd.Remote.RemoteId)
	if msh == nil {
		return nil, fmt.Errorf("cannot send signal, no remote found for command")
	}
	if !msh.IsConnected() {
		return nil, fmt.Errorf("cannot send signal, remote is not connected")
	}
	siPk := packet.MakeSpecialInputPacket()
	siPk.CK = base.MakeCommandKey(cmd.SessionId, cmd.CmdId)
	siPk.SigName = sigArg
	err = msh.SendSpecialInput(siPk)
	if err != nil {
		return nil, fmt.Errorf("cannot send signal: %v", err)
	}
	update := sstore.ModelUpdate{
		Info: &sstore.InfoMsgType{
			InfoMsg: fmt.Sprintf("sent line %s signal %s", lineArg, sigArg),
		},
	}
	return update, nil
}

func KillServerCommand(ctx context.Context, pk *scpacket.FeCommandPacketType) (sstore.UpdatePacket, error) {
	go func() {
		log.Printf("received /killserver, shutting down\n")
		time.Sleep(1 * time.Second)
		syscall.Kill(syscall.Getpid(), syscall.SIGINT)
	}()
	return nil, nil
}

func formatTermOpts(termOpts sstore.TermOpts) string {
	if termOpts.Cols == 0 {
		return "???"
	}
	rtnStr := fmt.Sprintf("%dx%d", termOpts.Rows, termOpts.Cols)
	if termOpts.FlexRows {
		rtnStr += " flexrows"
	}
	if termOpts.MaxPtySize > 0 {
		rtnStr += " maxbuf=" + scbase.NumFormatB2(termOpts.MaxPtySize)
	}
	return rtnStr
}

type ColMeta struct {
	Title   string
	MinCols int
	MaxCols int
}

func toInterfaceArr(sarr []string) []interface{} {
	rtn := make([]interface{}, len(sarr))
	for idx, s := range sarr {
		rtn[idx] = s
	}
	return rtn
}

func formatTextTable(totalCols int, data [][]string, colMeta []ColMeta) []string {
	numCols := len(colMeta)
	maxColLen := make([]int, len(colMeta))
	for i, cm := range colMeta {
		maxColLen[i] = cm.MinCols
	}
	for _, row := range data {
		for i := 0; i < numCols && i < len(row); i++ {
			dlen := len(row[i])
			if dlen > maxColLen[i] {
				maxColLen[i] = dlen
			}
		}
	}
	fmtStr := ""
	for idx, clen := range maxColLen {
		if idx != 0 {
			fmtStr += " "
		}
		fmtStr += fmt.Sprintf("%%%ds", clen)
	}
	var rtn []string
	for _, row := range data {
		sval := fmt.Sprintf(fmtStr, toInterfaceArr(row)...)
		rtn = append(rtn, sval)
	}
	return rtn
}

const MaxDiffKeyLen = 40
const MaxDiffValLen = 50

func displayStateUpdateDiff(buf *bytes.Buffer, oldState packet.ShellState, newState packet.ShellState) {
	if newState.Cwd != oldState.Cwd {
		buf.WriteString(fmt.Sprintf("cwd %s\n", newState.Cwd))
	}
	if !bytes.Equal(newState.ShellVars, oldState.ShellVars) {
		newEnvMap := shexec.DeclMapFromState(&newState)
		oldEnvMap := shexec.DeclMapFromState(&oldState)
		for key, newVal := range newEnvMap {
			oldVal, found := oldEnvMap[key]
			if !found || !shexec.DeclsEqual(false, oldVal, newVal) {
				var exportStr string
				if newVal.IsExport() {
					exportStr = "export "
				}
				buf.WriteString(fmt.Sprintf("%s%s=%s\n", exportStr, utilfn.EllipsisStr(key, MaxDiffKeyLen), utilfn.EllipsisStr(newVal.Value, MaxDiffValLen)))
			}
		}
		for key, _ := range oldEnvMap {
			_, found := newEnvMap[key]
			if !found {
				buf.WriteString(fmt.Sprintf("unset %s\n", utilfn.EllipsisStr(key, MaxDiffKeyLen)))
			}
		}
	}
	if newState.Aliases != oldState.Aliases {
		newAliasMap, _ := ParseAliases(newState.Aliases)
		oldAliasMap, _ := ParseAliases(oldState.Aliases)
		for aliasName, newAliasVal := range newAliasMap {
			oldAliasVal, found := oldAliasMap[aliasName]
			if !found || newAliasVal != oldAliasVal {
				buf.WriteString(fmt.Sprintf("alias %s\n", utilfn.EllipsisStr(shellescape.Quote(aliasName), MaxDiffKeyLen)))
			}
		}
		for aliasName, _ := range oldAliasMap {
			_, found := newAliasMap[aliasName]
			if !found {
				buf.WriteString(fmt.Sprintf("unalias %s\n", utilfn.EllipsisStr(shellescape.Quote(aliasName), MaxDiffKeyLen)))
			}
		}
	}
	if newState.Funcs != oldState.Funcs {
		newFuncMap, _ := ParseFuncs(newState.Funcs)
		oldFuncMap, _ := ParseFuncs(oldState.Funcs)
		for funcName, newFuncVal := range newFuncMap {
			oldFuncVal, found := oldFuncMap[funcName]
			if !found || newFuncVal != oldFuncVal {
				buf.WriteString(fmt.Sprintf("function %s\n", utilfn.EllipsisStr(shellescape.Quote(funcName), MaxDiffKeyLen)))
			}
		}
		for funcName, _ := range oldFuncMap {
			_, found := newFuncMap[funcName]
			if !found {
				buf.WriteString(fmt.Sprintf("unset -f %s\n", utilfn.EllipsisStr(shellescape.Quote(funcName), MaxDiffKeyLen)))
			}
		}
	}
}

func GetRtnStateDiff(ctx context.Context, sessionId string, cmdId string) ([]byte, error) {
	cmd, err := sstore.GetCmdById(ctx, sessionId, cmdId)
	if err != nil {
		return nil, err
	}
	if cmd == nil {
		return nil, nil
	}
	if !cmd.RtnState {
		return nil, nil
	}
	if cmd.RtnStatePtr.IsEmpty() {
		return nil, nil
	}
	var outputBytes bytes.Buffer
	initialState, err := sstore.GetFullState(ctx, cmd.StatePtr)
	if err != nil {
		return nil, fmt.Errorf("getting initial full state: %v", err)
	}
	rtnState, err := sstore.GetFullState(ctx, cmd.RtnStatePtr)
	if err != nil {
		return nil, fmt.Errorf("getting rtn full state: %v", err)
	}
	displayStateUpdateDiff(&outputBytes, *initialState, *rtnState)
	return outputBytes.Bytes(), nil
}

func isValidInScope(scopeName string, varName string) bool {
	for _, varScope := range SetVarScopes {
		if varScope.ScopeName == scopeName {
			return utilfn.ContainsStr(varScope.VarNames, varName)
		}
	}
	return false
}

// returns (is-valid, scope, name)
// TODO write a full resolver to allow for indexed arguments.  e.g. session[1].screen[1].window.pterm="25x80"
func resolveSetArg(argName string) (bool, string, string) {
	dotIdx := strings.Index(argName, ".")
	if dotIdx == -1 {
		argName = SetVarNameMap[argName]
		dotIdx = strings.Index(argName, ".")
	}
	if argName == "" {
		return false, "", ""
	}
	scopeName := argName[0:dotIdx]
	varName := argName[dotIdx+1:]
	if !isValidInScope(scopeName, varName) {
		return false, "", ""
	}
	return true, scopeName, varName
}