backend.go

  1// Package backend provides transport-agnostic operations for managing
  2// workspaces, sessions, agents, permissions, and events. It is consumed
  3// by protocol-specific layers such as HTTP (server) and ACP.
  4package backend
  5
  6import (
  7	"context"
  8	"errors"
  9	"fmt"
 10	"log/slog"
 11	"path/filepath"
 12	"runtime"
 13	"sync"
 14	"time"
 15
 16	"github.com/charmbracelet/crush/internal/app"
 17	"github.com/charmbracelet/crush/internal/config"
 18	"github.com/charmbracelet/crush/internal/csync"
 19	"github.com/charmbracelet/crush/internal/db"
 20	"github.com/charmbracelet/crush/internal/proto"
 21	"github.com/charmbracelet/crush/internal/skills"
 22	"github.com/charmbracelet/crush/internal/ui/util"
 23	"github.com/charmbracelet/crush/internal/version"
 24	"github.com/google/uuid"
 25)
 26
 27// Common errors returned by backend operations.
 28var (
 29	ErrWorkspaceNotFound       = errors.New("workspace not found")
 30	ErrLSPClientNotFound       = errors.New("LSP client not found")
 31	ErrAgentNotInitialized     = errors.New("agent coordinator not initialized")
 32	ErrPathRequired            = errors.New("path is required")
 33	ErrInvalidPermissionAction = errors.New("invalid permission action")
 34	ErrUnknownCommand          = errors.New("unknown command")
 35	ErrInvalidClientID         = errors.New("invalid client_id")
 36	ErrClientNotAttached       = errors.New("client not attached")
 37)
 38
 39// DefaultCreateGrace is the window in which a client must open an SSE
 40// stream after creating a workspace before its creation hold is
 41// released. Exposed as a package variable so tests can shorten it.
 42var DefaultCreateGrace = 30 * time.Second
 43
 44// ShutdownFunc is called when the backend needs to trigger a server
 45// shutdown (e.g. when the last workspace is removed).
 46type ShutdownFunc func()
 47
 48// Backend provides transport-agnostic business logic for the Crush
 49// server. It manages workspaces and delegates to [app.App] services.
 50//
 51// Locking order: when both [Backend.mu] and [Workspace.clientsMu] are
 52// held at once, [Backend.mu] is acquired first. Detach paths
 53// ([detachStream], [releaseHoldLocked], [expireHold]) only hold
 54// [Workspace.clientsMu] briefly, drop it, then call [teardown] which
 55// takes [Backend.mu] (and then re-takes [Workspace.clientsMu] to
 56// re-check that the workspace has not been re-claimed). This avoids
 57// the AB/BA hazard with [CreateWorkspace], which holds [Backend.mu]
 58// while calling [registerClient] so that a workspace cannot be torn
 59// down beneath it.
 60type Backend struct {
 61	workspaces *csync.Map[string, *Workspace]
 62	// pathIndex maps a resolved absolute workspace path to its
 63	// workspace ID. Reads and writes are serialised via mu so
 64	// concurrent CreateWorkspace calls at the same path deduplicate
 65	// deterministically.
 66	pathIndex map[string]string
 67	mu        sync.Mutex
 68
 69	cfg         *config.ConfigStore
 70	ctx         context.Context
 71	shutdownFn  ShutdownFunc
 72	createGrace time.Duration
 73}
 74
 75// clientState tracks one client's claim on a workspace.
 76//
 77//   - streams counts the number of live SSE event streams the client
 78//     currently has open against the workspace.
 79//   - holdTimer is non-nil iff the client created the workspace but has
 80//     not yet attached an SSE stream; it fires after createGrace and
 81//     releases the hold.
 82//   - currentSessionID records which session this client is currently
 83//     viewing. Empty string means the client has no session selected
 84//     (e.g. the landing screen). Cleared automatically when the
 85//     clientState entry is removed.
 86//
 87// streams and holdTimer are mutually exclusive in practice (the hold
 88// timer is stopped the moment an SSE stream attaches), but both being
 89// zero/nil means the entry has been released and should be removed.
 90type clientState struct {
 91	streams          int
 92	holdTimer        *time.Timer
 93	currentSessionID string
 94}
 95
 96// Workspace represents a running [app.App] workspace with its
 97// associated resources and state.
 98type Workspace struct {
 99	*app.App
100	ID     string
101	Path   string
102	Cfg    *config.ConfigStore
103	Env    []string
104	Skills *skills.Manager
105
106	// resolvedPath is the path used as the dedup key in
107	// Backend.pathIndex. It is filepath.EvalSymlinks(filepath.Abs(Path))
108	// with fallback to the cleaned absolute path.
109	resolvedPath string
110
111	// clientsMu guards clients. It is held only briefly (no IO).
112	clientsMu sync.Mutex
113	// clients tracks each client's claim on this workspace. Refcount
114	// is a derived value: len(clients).
115	clients map[string]*clientState
116
117	// shutdownFn is the function invoked by [Backend.teardown] to
118	// release the workspace's underlying resources. It defaults to the
119	// embedded [app.App.Shutdown]; tests may override it to avoid
120	// driving a full [app.App] through shutdown.
121	shutdownFn func()
122}
123
124// invokeShutdown calls the workspace shutdown hook if set, falling
125// back to the embedded [app.App.Shutdown] when not.
126func (w *Workspace) invokeShutdown() {
127	if w.shutdownFn != nil {
128		w.shutdownFn()
129		return
130	}
131	if w.App != nil {
132		w.Shutdown()
133	}
134}
135
136// New creates a new [Backend].
137func New(ctx context.Context, cfg *config.ConfigStore, shutdownFn ShutdownFunc) *Backend {
138	return &Backend{
139		workspaces:  csync.NewMap[string, *Workspace](),
140		pathIndex:   make(map[string]string),
141		cfg:         cfg,
142		ctx:         ctx,
143		shutdownFn:  shutdownFn,
144		createGrace: DefaultCreateGrace,
145	}
146}
147
148// SetCreateGrace overrides the create-grace window. Intended for tests
149// that need short timeouts.
150func (b *Backend) SetCreateGrace(d time.Duration) {
151	b.mu.Lock()
152	defer b.mu.Unlock()
153	b.createGrace = d
154}
155
156// GetWorkspace retrieves a workspace by ID.
157func (b *Backend) GetWorkspace(id string) (*Workspace, error) {
158	ws, ok := b.workspaces.Get(id)
159	if !ok {
160		return nil, ErrWorkspaceNotFound
161	}
162	return ws, nil
163}
164
165// ListWorkspaces returns all running workspaces.
166func (b *Backend) ListWorkspaces() []proto.Workspace {
167	workspaces := []proto.Workspace{}
168	for _, ws := range b.workspaces.Seq2() {
169		workspaces = append(workspaces, workspaceToProto(ws))
170	}
171	return workspaces
172}
173
174// CreateWorkspace initializes a new workspace from the given
175// parameters, or returns an existing workspace if one already exists at
176// the same resolved path (first-wins semantics).
177//
178// args.ClientID must be a valid UUID identifying the calling client;
179// the resulting workspace registers a creation hold on behalf of that
180// client which is released either by the first SSE attach (which
181// converts it into a stream claim) or by the grace window expiring.
182func (b *Backend) CreateWorkspace(args proto.Workspace) (*Workspace, proto.Workspace, error) {
183	if args.Path == "" {
184		return nil, proto.Workspace{}, ErrPathRequired
185	}
186	clientID, err := validateClientID(args.ClientID)
187	if err != nil {
188		return nil, proto.Workspace{}, err
189	}
190
191	key, err := resolveWorkspaceKey(args.Path)
192	if err != nil {
193		return nil, proto.Workspace{}, fmt.Errorf("failed to resolve workspace path: %w", err)
194	}
195
196	b.mu.Lock()
197	if existingID, ok := b.pathIndex[key]; ok {
198		if ws, found := b.workspaces.Get(existingID); found {
199			// Hold b.mu while registering: teardown also
200			// acquires b.mu before tearing the workspace
201			// down, so this guarantees the workspace we
202			// return cannot be torn out from under us
203			// between lookup and registerClient. Lock order
204			// here is b.mu -> ws.clientsMu.
205			logFirstWinsMismatch(ws, args)
206			b.registerClient(ws, clientID)
207			b.mu.Unlock()
208			return ws, workspaceToProto(ws), nil
209		}
210		// pathIndex referenced a workspace that has since been
211		// removed; clean the stale entry and fall through.
212		delete(b.pathIndex, key)
213	}
214	b.mu.Unlock()
215
216	id := uuid.New().String()
217	cfg, err := config.Init(args.Path, args.DataDir, args.Debug)
218	if err != nil {
219		return nil, proto.Workspace{}, fmt.Errorf("failed to initialize config: %w", err)
220	}
221
222	cfg.Overrides().SkipPermissionRequests = args.YOLO
223
224	if err := createDotCrushDir(cfg.Config().Options.DataDirectory); err != nil {
225		return nil, proto.Workspace{}, fmt.Errorf("failed to create data directory: %w", err)
226	}
227
228	conn, err := db.Connect(b.ctx, cfg.Config().Options.DataDirectory, db.WithDataDirLock(true))
229	if err != nil {
230		return nil, proto.Workspace{}, fmt.Errorf("failed to connect to database: %w", err)
231	}
232
233	// Discover skills once per workspace, before app.New. The backend
234	// hosts multiple workspaces concurrently, so the manager is
235	// constructed WITHOUT WithGlobalMirror to prevent last-writer-wins
236	// cross-talk between workspaces.
237	allSkills, activeSkills, skillStates := skills.DiscoverFromConfig(skillsDiscoveryConfig(cfg))
238	skillsMgr := skills.NewManager(allSkills, activeSkills, skillStates)
239
240	appWorkspace, err := app.New(b.ctx, conn, cfg, skillsMgr)
241	if err != nil {
242		return nil, proto.Workspace{}, fmt.Errorf("failed to create app workspace: %w", err)
243	}
244
245	ws := &Workspace{
246		App:          appWorkspace,
247		ID:           id,
248		Path:         args.Path,
249		Cfg:          cfg,
250		Env:          args.Env,
251		Skills:       skillsMgr,
252		resolvedPath: key,
253		clients:      make(map[string]*clientState),
254	}
255
256	b.mu.Lock()
257	// Re-check the index under the lock: a concurrent caller may have
258	// won the race between the initial unlock and here.
259	if existingID, ok := b.pathIndex[key]; ok {
260		if existing, found := b.workspaces.Get(existingID); found {
261			// Register under b.mu so teardown cannot run
262			// between lookup and registerClient. Lock order
263			// is b.mu -> ws.clientsMu.
264			logFirstWinsMismatch(existing, args)
265			b.registerClient(existing, clientID)
266			b.mu.Unlock()
267			ws.invokeShutdown()
268			return existing, workspaceToProto(existing), nil
269		}
270		delete(b.pathIndex, key)
271	}
272	b.workspaces.Set(id, ws)
273	b.pathIndex[key] = id
274	// Register the originating client's hold while still holding
275	// b.mu so the workspace is observable with its claim from the
276	// moment it appears in the index.
277	b.registerClient(ws, clientID)
278	b.mu.Unlock()
279
280	if args.Version != "" && args.Version != version.Version {
281		slog.Warn(
282			"Client/server version mismatch",
283			"client", args.Version,
284			"server", version.Version,
285		)
286		appWorkspace.SendEvent(util.NewWarnMsg(fmt.Sprintf(
287			"Server version %q differs from client version %q. Consider restarting the server.",
288			version.Version, args.Version,
289		)))
290	}
291
292	return ws, workspaceToProto(ws), nil
293}
294
295// skillsDiscoveryConfig adapts a *config.ConfigStore to the
296// skills.DiscoveryConfig that DiscoverFromConfig consumes.
297func skillsDiscoveryConfig(cfg *config.ConfigStore) skills.DiscoveryConfig {
298	opts := cfg.Config().Options
299	var paths, disabled []string
300	if opts != nil {
301		paths = opts.SkillsPaths
302		disabled = opts.DisabledSkills
303	}
304	var resolver func(string) (string, error)
305	if r := cfg.Resolver(); r != nil {
306		resolver = r.ResolveValue
307	}
308	return skills.DiscoveryConfig{
309		SkillsPaths:    paths,
310		DisabledSkills: disabled,
311		Resolver:       resolver,
312	}
313}
314
315// skillStatesToProto converts internal skill discovery states into the
316// wire format.
317func skillStatesToProto(states []*skills.SkillState) []proto.SkillState {
318	if len(states) == 0 {
319		return nil
320	}
321	out := make([]proto.SkillState, len(states))
322	for i, s := range states {
323		entry := proto.SkillState{
324			Name:  s.Name,
325			Path:  s.Path,
326			State: proto.SkillDiscoveryState(s.State),
327		}
328		if s.Err != nil {
329			entry.Error = s.Err.Error()
330		}
331		out[i] = entry
332	}
333	return out
334}
335
336// AttachClient registers a new SSE stream for the given client on the
337// workspace. The stream's deferred cleanup must call DetachClient with
338// the same arguments to release the claim.
339//
340// The lookup and the clients-map mutation are performed under
341// [Backend.mu] so that AttachClient cannot race with [Backend.teardown]:
342// teardown also holds [Backend.mu] while removing the workspace from
343// b.workspaces, so once AttachClient observes the workspace and takes
344// ws.clientsMu (under b.mu), no concurrent teardown can succeed without
345// re-checking the (now non-empty) clients map. Lock order is the
346// canonical b.mu -> ws.clientsMu.
347func (b *Backend) AttachClient(workspaceID, clientID string) error {
348	if _, err := validateClientID(clientID); err != nil {
349		return err
350	}
351
352	b.mu.Lock()
353	defer b.mu.Unlock()
354	ws, ok := b.workspaces.Get(workspaceID)
355	if !ok {
356		return ErrWorkspaceNotFound
357	}
358
359	ws.clientsMu.Lock()
360	defer ws.clientsMu.Unlock()
361	cs, ok := ws.clients[clientID]
362	if !ok {
363		// Defensive: SSE attach without a prior CreateWorkspace by
364		// this client still installs a stream claim so the stream
365		// stays alive for its duration.
366		ws.clients[clientID] = &clientState{streams: 1}
367		return nil
368	}
369	if cs.holdTimer != nil {
370		cs.holdTimer.Stop()
371		cs.holdTimer = nil
372	}
373	cs.streams++
374	return nil
375}
376
377// DetachClient releases one SSE stream's hold on the workspace. If the
378// client has no other streams and no pending creation hold, its claim
379// is removed and the workspace is torn down once refcount hits zero.
380func (b *Backend) DetachClient(workspaceID, clientID string) {
381	ws, ok := b.workspaces.Get(workspaceID)
382	if !ok {
383		return
384	}
385	b.detachStream(ws, clientID)
386}
387
388// releaseHold releases the creation hold for a client, if any. Active
389// stream claims are unaffected. Idempotent: returns nil if the
390// workspace or the client's hold no longer exist.
391func (b *Backend) releaseHold(workspaceID, clientID string) error {
392	if _, err := validateClientID(clientID); err != nil {
393		return err
394	}
395	ws, ok := b.workspaces.Get(workspaceID)
396	if !ok {
397		return nil
398	}
399	b.releaseHoldLocked(ws, clientID)
400	return nil
401}
402
403// registerClient installs (idempotently) the given client's claim on
404// the workspace and starts a grace timer if the entry is fresh.
405func (b *Backend) registerClient(ws *Workspace, clientID string) {
406	ws.clientsMu.Lock()
407	defer ws.clientsMu.Unlock()
408	if _, ok := ws.clients[clientID]; ok {
409		// Idempotent: a duplicate CreateWorkspace from the same
410		// client does not add a second claim.
411		return
412	}
413	cs := &clientState{}
414	cs.holdTimer = time.AfterFunc(b.createGrace, func() {
415		b.expireHold(ws, clientID, cs)
416	})
417	ws.clients[clientID] = cs
418}
419
420// expireHold is the body of the grace timer. It runs in its own
421// goroutine and races against AttachClient/releaseHold; the timer
422// stays valid only while the entry's holdTimer still points at it.
423func (b *Backend) expireHold(ws *Workspace, clientID string, timer *clientState) {
424	ws.clientsMu.Lock()
425	cs, ok := ws.clients[clientID]
426	if !ok || cs != timer || cs.holdTimer == nil || cs.streams > 0 {
427		ws.clientsMu.Unlock()
428		return
429	}
430	cs.holdTimer = nil
431	delete(ws.clients, clientID)
432	teardown := len(ws.clients) == 0
433	ws.clientsMu.Unlock()
434	if teardown {
435		b.teardown(ws)
436	}
437}
438
439func (b *Backend) releaseHoldLocked(ws *Workspace, clientID string) {
440	ws.clientsMu.Lock()
441	cs, ok := ws.clients[clientID]
442	if !ok {
443		ws.clientsMu.Unlock()
444		return
445	}
446	if cs.holdTimer != nil {
447		cs.holdTimer.Stop()
448		cs.holdTimer = nil
449	}
450	teardown := false
451	if cs.streams == 0 {
452		delete(ws.clients, clientID)
453		teardown = len(ws.clients) == 0
454	}
455	ws.clientsMu.Unlock()
456	if teardown {
457		b.teardown(ws)
458	}
459}
460
461func (b *Backend) detachStream(ws *Workspace, clientID string) {
462	ws.clientsMu.Lock()
463	cs, ok := ws.clients[clientID]
464	if !ok {
465		ws.clientsMu.Unlock()
466		return
467	}
468	if cs.streams > 0 {
469		cs.streams--
470	}
471	teardown := false
472	if cs.streams == 0 && cs.holdTimer == nil {
473		delete(ws.clients, clientID)
474		teardown = len(ws.clients) == 0
475	}
476	ws.clientsMu.Unlock()
477	if teardown {
478		b.teardown(ws)
479	}
480}
481
482// teardown removes the workspace from the index, shuts down its
483// underlying [app.App], and triggers a server shutdown if it was the
484// last workspace alive.
485//
486// Callers reach teardown after observing len(ws.clients) == 0 while
487// holding ws.clientsMu and then releasing it. Between that release
488// and the b.mu.Lock below, a concurrent CreateWorkspace may have
489// re-registered a client (CreateWorkspace holds b.mu while doing so,
490// so it is mutually exclusive with this critical section). teardown
491// re-checks under both locks (in the canonical b.mu -> ws.clientsMu
492// order) and aborts if the workspace has been re-claimed.
493func (b *Backend) teardown(ws *Workspace) {
494	b.mu.Lock()
495	ws.clientsMu.Lock()
496	if len(ws.clients) > 0 {
497		// Race: a CreateWorkspace re-registered a client
498		// between the detach path dropping ws.clientsMu and us
499		// taking b.mu. Abort: the workspace is still alive.
500		ws.clientsMu.Unlock()
501		b.mu.Unlock()
502		return
503	}
504	ws.clientsMu.Unlock()
505	if existing, ok := b.pathIndex[ws.resolvedPath]; ok && existing == ws.ID {
506		delete(b.pathIndex, ws.resolvedPath)
507	}
508	b.workspaces.Del(ws.ID)
509	remaining := b.workspaces.Len()
510	b.mu.Unlock()
511
512	ws.invokeShutdown()
513
514	if remaining == 0 && b.shutdownFn != nil {
515		slog.Info("Last workspace removed, shutting down server...")
516		b.shutdownFn()
517	}
518}
519
520// DeleteWorkspace is the public entry point used by the HTTP DELETE
521// handler. It releases the named client's creation hold; live streams
522// from the same client remain attached and continue holding the
523// workspace open until their own deferred DetachClient runs.
524func (b *Backend) DeleteWorkspace(id, clientID string) error {
525	return b.releaseHold(id, clientID)
526}
527
528// SetCurrentSession records which session the given client is
529// currently viewing within the workspace. Passing an empty sessionID
530// clears the client's current-session entry (e.g. the client has
531// returned to the landing screen).
532//
533// The client must be actually attached — i.e. its [clientState] entry
534// must exist and have at least one live stream. A bare creation hold
535// (streams == 0) is rejected with [ErrClientNotAttached]. This
536// guards against zombie writes from a client that has detached and
537// against ghost presence from a hold-only client that never opened an
538// SSE stream.
539func (b *Backend) SetCurrentSession(workspaceID, clientID, sessionID string) error {
540	if _, err := validateClientID(clientID); err != nil {
541		return err
542	}
543	ws, ok := b.workspaces.Get(workspaceID)
544	if !ok {
545		return ErrWorkspaceNotFound
546	}
547	ws.clientsMu.Lock()
548	defer ws.clientsMu.Unlock()
549	cs, ok := ws.clients[clientID]
550	if !ok || cs.streams == 0 {
551		// No entry, or hold-only (no live stream): refuse the
552		// write. The presence record this is meant to feed
553		// should only reflect clients that can actually observe
554		// session events.
555		return ErrClientNotAttached
556	}
557	cs.currentSessionID = sessionID
558	return nil
559}
560
561// AttachedClients returns the number of clients currently viewing
562// sessionID in the given workspace. Only clients with at least one live
563// SSE stream (streams > 0) AND a matching currentSessionID are counted;
564// pure creation holds do not contribute. Returns [ErrWorkspaceNotFound]
565// if the workspace is unknown.
566func (b *Backend) AttachedClients(workspaceID, sessionID string) (int, error) {
567	ws, ok := b.workspaces.Get(workspaceID)
568	if !ok {
569		return 0, ErrWorkspaceNotFound
570	}
571	return ws.AttachedClientsForSession(sessionID), nil
572}
573
574// AttachedClientsForSession returns the number of clients in this
575// workspace whose currentSessionID equals sessionID and which have at
576// least one live SSE stream. Hold-only clients (streams == 0) do not
577// contribute. Acquires the workspace's [clientsMu] briefly; the
578// returned count is a point-in-time snapshot.
579func (w *Workspace) AttachedClientsForSession(sessionID string) int {
580	w.clientsMu.Lock()
581	defer w.clientsMu.Unlock()
582	n := 0
583	for _, cs := range w.clients {
584		if cs.streams > 0 && cs.currentSessionID == sessionID {
585			n++
586		}
587	}
588	return n
589}
590
591// GetWorkspaceProto returns the proto representation of a workspace.
592func (b *Backend) GetWorkspaceProto(id string) (proto.Workspace, error) {
593	ws, err := b.GetWorkspace(id)
594	if err != nil {
595		return proto.Workspace{}, err
596	}
597	return workspaceToProto(ws), nil
598}
599
600// VersionInfo returns server version information.
601func (b *Backend) VersionInfo() proto.VersionInfo {
602	return proto.VersionInfo{
603		Version:   version.Version,
604		Commit:    version.Commit,
605		BuildID:   version.BuildID,
606		GoVersion: runtime.Version(),
607		Platform:  fmt.Sprintf("%s/%s", runtime.GOOS, runtime.GOARCH),
608	}
609}
610
611// Config returns the server-level configuration.
612func (b *Backend) Config() *config.ConfigStore {
613	return b.cfg
614}
615
616// Shutdown initiates a graceful server shutdown.
617func (b *Backend) Shutdown() {
618	if b.shutdownFn != nil {
619		b.shutdownFn()
620	}
621}
622
623// resolveWorkspaceKey returns a stable canonical form of path suitable
624// for use as a dedup key. It applies filepath.Abs, then attempts
625// filepath.EvalSymlinks; because EvalSymlinks errors on non-existent
626// paths, it falls back to the cleaned absolute path in that case.
627func resolveWorkspaceKey(path string) (string, error) {
628	abs, err := filepath.Abs(path)
629	if err != nil {
630		return "", err
631	}
632	if resolved, err := filepath.EvalSymlinks(abs); err == nil {
633		return resolved, nil
634	}
635	return abs, nil
636}
637
638// validateClientID returns the trimmed UUID string or an error if the
639// input is empty or not a valid UUID.
640func validateClientID(id string) (string, error) {
641	if id == "" {
642		return "", ErrInvalidClientID
643	}
644	if _, err := uuid.Parse(id); err != nil {
645		return "", fmt.Errorf("%w: %v", ErrInvalidClientID, err)
646	}
647	return id, nil
648}
649
650func workspaceToProto(ws *Workspace) proto.Workspace {
651	cfg := ws.Cfg.Config()
652	out := proto.Workspace{
653		ID:      ws.ID,
654		Path:    ws.Path,
655		YOLO:    ws.Cfg.Overrides().SkipPermissionRequests,
656		DataDir: cfg.Options.DataDirectory,
657		Debug:   cfg.Options.Debug,
658		Config:  cfg,
659		Env:     ws.Env,
660		Version: version.Version,
661	}
662	if ws.Skills != nil {
663		out.Skills = skillStatesToProto(ws.Skills.States())
664	}
665	return out
666}
667
668// logFirstWinsMismatch emits a debug line whenever a second
669// CreateWorkspace at the same resolved path arrives with flags that
670// differ from the originating workspace. The existing workspace wins;
671// the incoming flags are silently ignored.
672//
673// The comparison is done against the incoming args as the caller sent
674// them — including empty/zero values — rather than after defaulting.
675// This means that, for example, a second caller who omits DataDir
676// while the first set one will still log the mismatch.
677func logFirstWinsMismatch(existing *Workspace, args proto.Workspace) {
678	existingCfg := existing.Cfg.Config()
679	existingYOLO := existing.Cfg.Overrides().SkipPermissionRequests
680	if existingYOLO == args.YOLO &&
681		existingCfg.Options.Debug == args.Debug &&
682		existingCfg.Options.DataDirectory == args.DataDir &&
683		stringSlicesEqual(existing.Env, args.Env) {
684		return
685	}
686	slog.Debug(
687		"Workspace flag mismatch on duplicate create; first wins",
688		"workspace_id", existing.ID,
689		"path", existing.Path,
690		"existing_yolo", existingYOLO,
691		"requested_yolo", args.YOLO,
692		"existing_debug", existingCfg.Options.Debug,
693		"requested_debug", args.Debug,
694		"existing_data_dir", existingCfg.Options.DataDirectory,
695		"requested_data_dir", args.DataDir,
696		"existing_env", existing.Env,
697		"requested_env", args.Env,
698	)
699}
700
701// stringSlicesEqual reports whether a and b contain the same strings
702// in the same order. nil and empty are treated as equal.
703func stringSlicesEqual(a, b []string) bool {
704	if len(a) != len(b) {
705		return false
706	}
707	for i := range a {
708		if a[i] != b[i] {
709			return false
710		}
711	}
712	return true
713}