// Copyright (c) 2026 Storm Dragon
// Authors: Storm Dragon, Angus Kola
// SPDX-License-Identifier: GPL-3.0-or-later

package app

import (
	"context"
	"errors"
	"log/slog"
	"testing"
	"time"

	"git.stormux.org/storm/cthulhu/internal/atspi"
	"git.stormux.org/storm/cthulhu/internal/input"
	"git.stormux.org/storm/cthulhu/internal/presentation"
	"git.stormux.org/storm/cthulhu/internal/review"
	"git.stormux.org/storm/cthulhu/internal/sound"
)

type modeKeys struct {
	enabled           bool
	nativeButtonFocus bool
}

func (keys *modeKeys) SetBrowseNavigation(enabled bool) { keys.enabled = enabled }
func (keys *modeKeys) SetNativeButtonFocus(focused bool) {
	keys.nativeButtonFocus = focused
}

func TestBrowserModeClearsNativeButtonFocus(t *testing.T) {
	keys := &modeKeys{}
	browser := newBrowserModeController(nil, keys, nil)
	browser.nativeButtonFocus(true)
	if !keys.nativeButtonFocus {
		t.Fatal("focused button did not request native Return")
	}
	browser.clear()
	if keys.nativeButtonFocus {
		t.Fatal("departed button retained native Return policy")
	}
}

type modeSoundQueue struct {
	speech *fakeSpeechQueue
	sounds chan sound.Cue
}

func (queue *modeSoundQueue) Enqueue(request speechRequest) {
	queue.speech.Enqueue(request)
	for _, cue := range request.Sound {
		queue.sounds <- cue
	}
}

func (queue *modeSoundQueue) Interrupt() {
	queue.speech.Interrupt()
}

func modeContext(t *testing.T, role string, editableAncestor bool) atspi.DocumentContext {
	t.Helper()
	return modeContextInDocument(t, role, editableAncestor, "/document")
}
func modeContextInDocument(t *testing.T, role string, editableAncestor bool, documentPath string) atspi.DocumentContext {
	t.Helper()
	snapshot := atspi.Snapshot{BusName: ":1.42", Path: "/target", Role: role, StatesKnown: true}
	doc := atspi.Snapshot{BusName: ":1.42", Path: documentPath, Role: "document web", StatesKnown: true, Editable: editableAncestor}
	tree, err := atspi.NewAccessibleTree(doc.ID(), []atspi.TreeNode{{Snapshot: doc, Children: []atspi.ObjectID{snapshot.ID()}}, {Snapshot: snapshot}})
	if err != nil {
		t.Fatal(err)
	}
	ref, _ := tree.Reference(snapshot.ID())
	owner, err := tree.DocumentContext(ref)
	if err != nil {
		t.Fatal(err)
	}
	return owner
}
func TestBrowserModeRejectsDepartedFocusAndPreservesTyping(t *testing.T) {
	keys := &modeKeys{}
	browser := newBrowserModeController(nil, keys, nil)
	queue := &fakeSpeechQueue{spoken: make(chan string, 16)}
	heading := modeContext(t, "heading", false)
	focus := heading.Ancestors[0].ID()
	browser.follow(focus)
	browser.accept(browserModeResult{focus: focus, generation: 1, owner: heading}, queue)
	if !keys.enabled {
		t.Fatal("heading did not enable browse keys")
	}
	browser.toggle(queue)
	if keys.enabled {
		t.Fatal("manual focus mode retained letters")
	}
	browser.toggle(queue)
	if !keys.enabled {
		t.Fatal("manual browse mode did not restore letters")
	}
	chrome := atspi.NewObjectID(":1.42", "/chrome")
	browser.follow(chrome)
	if keys.enabled {
		t.Fatal("leaving content did not immediately release letters")
	}
	browser.accept(browserModeResult{focus: focus, generation: 1, owner: heading}, queue)
	if keys.enabled {
		t.Fatal("late result re-enabled letters in chrome")
	}
	browser.accept(browserModeResult{focus: chrome, generation: 2, err: atspi.ErrNotInDocument}, queue)
	browser.toggle(queue)
	if keys.enabled {
		t.Fatal("toggle in chrome enabled letters")
	}
	entry := modeContext(t, "entry", false)
	entryFocus := atspi.NewObjectID(":1.42", "/entry")
	browser.follow(entryFocus)
	browser.accept(browserModeResult{focus: entryFocus, generation: 3, owner: entry}, queue)
	if keys.enabled || browser.mode != review.FocusMode {
		t.Fatal("entry did not preserve typing")
	}
	browser.follow(focus)
	browser.accept(browserModeResult{focus: focus, generation: 4, owner: heading}, queue)
	if !keys.enabled {
		t.Fatal("return to content did not restore navigation")
	}
}

func TestBrowserModeDuplicateFocusKeepsBrowseRouting(t *testing.T) {
	keys := &modeKeys{}
	browser := newBrowserModeController(nil, keys, nil)
	heading := modeContext(t, "heading", false)
	focus := heading.Ancestors[0].ID()
	browser.follow(focus)
	browser.accept(browserModeResult{focus: focus, generation: 1, owner: heading}, &fakeSpeechQueue{spoken: make(chan string, 1)})
	if !browser.ready || !keys.enabled {
		t.Fatal("initial browse routing was not ready")
	}
	browser.follow(focus)
	if !browser.ready || !keys.enabled || browser.generation != 1 {
		t.Fatal("duplicate focus restarted browser capture or released browse routing")
	}
}

func TestBrowserCaretLeavesFocusModeForDocumentText(t *testing.T) {
	keys := &modeKeys{}
	browser := newBrowserModeController(nil, keys, nil)
	queue := &fakeSpeechQueue{spoken: make(chan string, 4)}
	entry := modeContext(t, "entry", false)
	entryFocus := atspi.NewObjectID(":1.42", "/entry")
	browser.follow(entryFocus)
	browser.accept(browserModeResult{focus: entryFocus, generation: 1, owner: entry}, queue)
	if browser.mode != review.FocusMode || keys.enabled {
		t.Fatal("entry did not enter focus mode")
	}

	paragraph := modeContext(t, "paragraph", false)
	caret := paragraph.Ancestors[0].ID()
	browser.followCaret(caret)
	if browser.focus != caret || browser.origin != review.CaretNavigation {
		t.Fatal("document caret was not tracked")
	}
	browser.accept(browserModeResult{focus: caret, generation: 2, owner: paragraph, origin: review.CaretNavigation}, queue)
	if browser.mode != review.BrowseMode || !keys.enabled {
		t.Fatal("caret navigation did not restore browse keys")
	}
	browser.followCaret(caret)
	if browser.generation != 2 || !keys.enabled {
		t.Fatal("repeated caret movement restarted browse routing")
	}
}

func TestBrowserModePlaysModeChangeSounds(t *testing.T) {
	keys := &modeKeys{}
	browser := newBrowserModeController(nil, keys, nil)
	speech := &fakeSpeechQueue{spoken: make(chan string, 16)}
	queue := &modeSoundQueue{speech: speech, sounds: make(chan sound.Cue, 16)}
	heading := modeContext(t, "heading", false)
	entry := modeContext(t, "entry", false)
	focus := heading.Ancestors[0].ID()

	browser.follow(focus)
	browser.accept(browserModeResult{focus: focus, generation: 1, owner: heading}, queue)
	if len(queue.sounds) != 0 || len(speech.spoken) != 0 {
		t.Fatal("initial browse mode was announced")
	}

	browser.toggle(queue)
	assertModeSound(t, queue, speech, "focus_mode", "Focus mode")

	browser.follow(focus)
	browser.accept(browserModeResult{focus: focus, generation: 2, owner: entry}, queue)
	if len(queue.sounds) != 0 {
		t.Fatalf("unchanged mode queued cue %#v", <-queue.sounds)
	}

	browser.toggle(queue)
	assertModeSound(t, queue, speech, "browse_mode", "Browse mode")
}

func assertModeSound(t *testing.T, queue *modeSoundQueue, speech *fakeSpeechQueue, wantCue, wantText string) {
	t.Helper()
	select {
	case cue := <-queue.sounds:
		if cue.Name != wantCue || cue.Pan != 0 {
			t.Fatalf("got mode cue %#v want centered %q", cue, wantCue)
		}
	case <-time.After(time.Second):
		t.Fatalf("mode cue %q was not queued", wantCue)
	}
	select {
	case text := <-speech.spoken:
		if text != wantText {
			t.Fatalf("got mode text %q want %q", text, wantText)
		}
	case <-time.After(time.Second):
		t.Fatalf("mode text %q was not spoken", wantText)
	}
}

func TestBrowserModeAcceptsSameDocumentNavigationDuringRecapture(t *testing.T) {
	browser := newBrowserModeController(nil, &modeKeys{}, nil)
	heading := modeContext(t, "heading", false)
	focus := heading.Ancestors[0].ID()
	browser.follow(focus)
	queue := &fakeSpeechQueue{spoken: make(chan string, 1)}
	browser.accept(browserModeResult{focus: focus, generation: 1, owner: heading}, queue)
	position := review.DocumentPosition{
		Document: heading.TopLevel,
		Snapshot: heading.Ancestors[0],
	}
	if !browser.acceptsDocumentResult(review.Result{DocumentPosition: position}) {
		t.Fatal("same-document navigation result rejected")
	}
	browser.follow(atspi.NewObjectID(":1.42", "/second"))
	if browser.ready {
		t.Fatal("new focus did not start recapture")
	}
	if browser.acceptsDocumentResult(review.Result{DocumentPosition: position}) {
		t.Fatal("old result accepted while the new focus document is unknown")
	}
	browser.follow(position.Snapshot.ID())
	if !browser.acceptsDocumentResult(review.Result{DocumentPosition: position}) {
		t.Fatal("native focus echo on the structural target rejected")
	}
	other := modeContextInDocument(t, "heading", false, "/other_document").TopLevel
	if browser.acceptsDocumentResult(review.Result{DocumentPosition: review.DocumentPosition{Document: other}}) {
		t.Fatal("other-document result accepted")
	}
	if browser.acceptsDocumentResult(review.Result{Err: errors.New("capture failed"), DocumentPosition: position}) {
		t.Fatal("failed result accepted")
	}
	if !browser.acceptsDocumentResult(review.Result{Err: errors.New("capture failed"), DocumentFocus: position.Snapshot.ID()}) {
		t.Fatal("current navigation failure would be silently discarded")
	}
}
func TestBrowserRuntimeModeProtectsAmbiguousAndEditableContent(t *testing.T) {
	for _, tc := range []struct {
		role     string
		editable bool
		want     review.DocumentMode
	}{
		{"heading", false, review.BrowseMode}, {"entry", false, review.FocusMode},
		{"paragraph", true, review.FocusMode}, {"table cell", false, review.FocusMode},
		{"embedded", false, review.FocusMode}, {"menu item", false, review.FocusMode},
	} {
		t.Run(tc.role, func(t *testing.T) {
			var state review.DocumentModeState
			got := state.Update(runtimeModeInput(modeContext(t, tc.role, tc.editable)), review.DefaultModeSettings())
			if got != tc.want {
				t.Fatalf("got %v want %v", got, tc.want)
			}
		})
	}
}

type canceledModeCapture struct{ started chan struct{} }

func (capture canceledModeCapture) CaptureDocumentContext(ctx context.Context, _ atspi.ObjectID) (atspi.DocumentContext, error) {
	close(capture.started)
	<-ctx.Done()
	return atspi.DocumentContext{}, ctx.Err()
}
func TestBrowserModeShutdownCancelsNativeWait(t *testing.T) {
	capture := canceledModeCapture{make(chan struct{})}
	browser := newBrowserModeController(nil, &modeKeys{}, capture)
	if err := browser.Start(context.Background()); err != nil {
		t.Fatal(err)
	}
	browser.follow(atspi.NewObjectID(":1.42", "/target"))
	select {
	case <-capture.started:
	case <-time.After(time.Second):
		t.Fatal("capture did not start")
	}
	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	if err := browser.Stop(ctx); err != nil && !errors.Is(err, context.Canceled) {
		t.Fatal(err)
	}
}

type timeoutThenModeCapture struct {
	calls chan struct{}
	owner atspi.DocumentContext
}

func (capture *timeoutThenModeCapture) CaptureDocumentContext(ctx context.Context, _ atspi.ObjectID) (atspi.DocumentContext, error) {
	capture.calls <- struct{}{}
	if len(capture.calls) == 1 {
		<-ctx.Done()
		return atspi.DocumentContext{}, ctx.Err()
	}
	return capture.owner, nil
}

func TestBrowserModeRetriesTimedOutCurrentFocus(t *testing.T) {
	owner := modeContext(t, "heading", false)
	focus := owner.Ancestors[0].ID()
	capture := &timeoutThenModeCapture{calls: make(chan struct{}, 2), owner: owner}
	keys := &modeKeys{}
	browser := newBrowserModeController(nil, keys, capture)
	browser.captureTimeout = 20 * time.Millisecond
	if err := browser.Start(context.Background()); err != nil {
		t.Fatal(err)
	}
	defer browser.Stop(context.Background())
	browser.follow(focus)
	select {
	case result := <-browser.results:
		browser.accept(result, &fakeSpeechQueue{spoken: make(chan string, 1)})
		if result.err != nil || result.focus != focus || !keys.enabled || len(capture.calls) != 2 {
			t.Fatalf("timed-out capture did not recover: %+v, calls %d", result, len(capture.calls))
		}
	case <-time.After(time.Second):
		t.Fatal("timed-out capture was not retried")
	}
}

type cancelableModeCapture struct {
	started  chan atspi.ObjectID
	canceled chan atspi.ObjectID
}

func (capture *cancelableModeCapture) CaptureDocumentContext(ctx context.Context, focus atspi.ObjectID) (atspi.DocumentContext, error) {
	started := false
	for !started {
		select {
		case capture.started <- focus:
			started = true
		case <-ctx.Done():
			return atspi.DocumentContext{}, ctx.Err()
		}
	}
	<-ctx.Done()
	select {
	case capture.canceled <- focus:
	case <-context.Background().Done():
	}
	return atspi.DocumentContext{}, ctx.Err()
}

func TestBrowserModeCancelsCaptureOnLoadLifecycle(t *testing.T) {
	first := atspi.NewObjectID(":1.42", "/first")
	second := atspi.NewObjectID(":1.42", "/second")
	capture := &cancelableModeCapture{
		started:  make(chan atspi.ObjectID, 1),
		canceled: make(chan atspi.ObjectID, 1),
	}
	browser := newBrowserModeController(nil, &modeKeys{}, capture)
	if err := browser.Start(context.Background()); err != nil {
		t.Fatal(err)
	}
	defer browser.Stop(context.Background())

	browser.follow(first)
	select {
	case got := <-capture.started:
		if got != first {
			t.Fatalf("first capture focus = %v", got)
		}
	case <-time.After(time.Second):
		t.Fatal("first capture did not start")
	}

	browser.loading()
	select {
	case got := <-capture.canceled:
		if got != first {
			t.Fatalf("canceled capture focus = %v", got)
		}
	case <-time.After(time.Second):
		t.Fatal("page loading did not cancel the old capture")
	}
	if len(capture.started) != 0 {
		t.Fatal("page loading started a new capture before load completion")
	}
	browser.loaded(second)
	select {
	case got := <-capture.started:
		if got != second {
			t.Fatalf("second capture focus = %v", got)
		}
	case <-time.After(time.Second):
		t.Fatal("load completion did not start the latest capture")
	}
}

func TestBrowserLoadingRejectsOldCaptureAndRecoversOnStop(t *testing.T) {
	owner := modeContext(t, "heading", false)
	focus := owner.Ancestors[0].ID()
	keys := &modeKeys{}
	browser := newBrowserModeController(nil, keys, nil)
	speech := &fakeSpeechQueue{spoken: make(chan string, 1)}
	browser.follow(focus)
	browser.accept(browserModeResult{focus: focus, generation: 1, owner: owner}, speech)
	if !keys.enabled {
		t.Fatal("initial page did not enable browse mode")
	}
	browser.loading()
	if browser.ready || keys.enabled {
		t.Fatal("reloading page retained old browse keys")
	}
	browser.accept(browserModeResult{focus: focus, generation: 1, owner: owner}, speech)
	if browser.ready || keys.enabled {
		t.Fatal("late pre-reload capture restored the old page")
	}
	browser.loaded(focus)
	browser.accept(browserModeResult{focus: focus, generation: browser.generation, owner: owner}, speech)
	if !browser.ready || !keys.enabled {
		t.Fatal("stopped page load did not restore browse mode")
	}
}

func TestBrowserModeSuppressesStructuralNavigationEcho(t *testing.T) {
	keys := &modeKeys{}
	browser := newBrowserModeController(nil, keys, nil)
	target := atspi.NewSnapshot("/target", "Target", "heading", "", "")
	target.BusName = ":1.42"
	owner := modeContext(t, "heading", false)
	browser.navigated(review.DocumentPosition{
		Document: owner.TopLevel,
		Snapshot: target,
	}, target.ID())

	for _, eventType := range []string{atspi.CaretEvent, atspi.FocusEvent, atspi.FocusedStateEvent} {
		if !browser.suppressNavigationEcho(atspi.NewEvent(eventType, target)) {
			t.Fatalf("%s echo was not suppressed", eventType)
		}
	}
	child := atspi.NewSnapshot("/new-child", "Child", "static", "", "")
	child.BusName = ":1.42"
	for _, eventType := range []string{atspi.CaretEvent, atspi.FocusEvent, atspi.FocusedStateEvent} {
		if !browser.suppressNavigationEcho(atspi.NewEvent(eventType, child)) {
			t.Fatalf("%s descendant echo was not suppressed", eventType)
		}
	}

	other := atspi.NewSnapshot("/other", "Other", "heading", "", "")
	other.BusName = ":1.99"
	if browser.suppressNavigationEcho(atspi.NewEvent(atspi.FocusEvent, other)) {
		t.Fatal("unrelated focus echo was suppressed")
	}

	browser.observeCommand(input.ToggleDocumentMode)
	if browser.suppressNavigationEcho(atspi.NewEvent(atspi.FocusEvent, target)) {
		t.Fatal("non-structural command retained navigation suppression")
	}
}

func TestBrowserNavigationEchoEndsOnNativeKey(t *testing.T) {
	tracker := &input.IntentTracker{}
	tracker.Observe(input.NewKeyEvent(0, true, "h"))
	browser := newBrowserModeController(tracker, &modeKeys{}, nil)
	target := atspi.Snapshot{BusName: ":1.42", Path: "/heading", Role: "heading"}
	browser.navigated(review.DocumentPosition{Snapshot: target}, target.ID())
	if !browser.suppressNavigationEcho(atspi.NewEvent(atspi.CaretEvent, target)) {
		t.Fatal("structural echo was not suppressed")
	}
	tracker.Observe(input.NewKeyEvent(0, true, "Up"))
	if browser.suppressNavigationEcho(atspi.NewEvent(atspi.CaretEvent, target)) {
		t.Fatal("native movement back into heading was suppressed")
	}
}

func TestBrowserTracksRecentlyConsumedCommand(t *testing.T) {
	browser := newBrowserModeController(nil, &modeKeys{}, nil)
	if browser.recentConsumedCommand() {
		t.Fatal("new browser controller reported a consumed command")
	}
	browser.observeCommand(input.ReviewNextLine)
	if !browser.recentConsumedCommand() {
		t.Fatal("fresh command was not reported as consumed")
	}
	browser.mutex.Lock()
	browser.commandAt = time.Now().Add(-time.Second)
	browser.mutex.Unlock()
	if browser.recentConsumedCommand() {
		t.Fatal("stale command was reported as recently consumed")
	}
}

type activeCommandKeys struct {
	modeKeys
	active bool
}

func (keys *activeCommandKeys) CommandGrabActive() bool { return keys.active }

func TestBrowserRecognizesCommandGrabBeforeDispatch(t *testing.T) {
	keys := &activeCommandKeys{active: true}
	browser := newBrowserModeController(nil, keys, nil)
	if !browser.recentConsumedCommand() {
		t.Fatal("active command grab was not recognized before dispatch")
	}
	keys.active = false
	if browser.recentConsumedCommand() {
		t.Fatal("inactive command grab was reported without a dispatched command")
	}
}

func TestBrowserNavigationEchoSurvivesFastStructuralRepeat(t *testing.T) {
	tracker := &input.IntentTracker{}
	tracker.Observe(input.NewKeyEvent(0, true, "h"))
	browser := newBrowserModeController(tracker, &modeKeys{}, nil)
	owner := modeContext(t, "heading", false)
	target := atspi.Snapshot{BusName: ":1.42", Path: "/heading", Role: "heading"}
	browser.navigated(review.DocumentPosition{Document: owner.TopLevel, Snapshot: target}, target.ID())

	tracker.Observe(input.NewKeyEvent(0, true, "h"))
	browser.observeCommand(input.DocumentNextHeading)
	child := atspi.Snapshot{BusName: ":1.42", Path: "/replacement", Role: "static"}
	if !browser.suppressNavigationEcho(atspi.NewEvent(atspi.CaretEvent, child)) {
		t.Fatal("fast repeated structural command exposed prior caret echo")
	}
}

func TestBrowserNavigationOwnershipSurvivesQueuedReaderCommands(t *testing.T) {
	for _, test := range []struct {
		name, key string
		command   input.Command
	}{
		{"heading", "h", input.DocumentNextHeading},
		{"reverse heading", "h", input.DocumentPreviousHeading},
		{"line", "Down", input.DocumentCaretNextLine},
		{"character", "Right", input.DocumentCaretNextCharacter},
	} {
		t.Run(test.name, func(t *testing.T) {
			tracker := &input.IntentTracker{}
			tracker.Observe(input.NewKeyEvent(0, true, "h"))
			browser := newBrowserModeController(tracker, &modeKeys{}, nil)
			owner := modeContext(t, "heading", false)
			target := owner.Ancestors[0]
			browser.navigated(review.DocumentPosition{Document: owner.TopLevel, Snapshot: target}, owner.TopLevel.ID())
			tracker.Observe(input.NewKeyEvent(0, true, test.key))
			browser.observeCommand(test.command)
			child := atspi.Snapshot{BusName: target.BusName, Path: "/old-heading-child", Role: "static"}
			if !browser.suppressNavigationEcho(atspi.NewEvent(atspi.CaretEvent, child)) {
				t.Fatal("delayed caret reset the cursor while a reader command was pending")
			}
			tracker.Observe(input.NewKeyEvent(0, true, "Tab"))
			if browser.suppressNavigationEcho(atspi.NewEvent(atspi.FocusEvent, child)) {
				t.Fatal("native Tab did not release navigation ownership")
			}
		})
	}
}

func TestBrowserNavigationOwnershipSurvivesIdleAndEndsOnPointer(t *testing.T) {
	source := &fixedInputActivity{activity: input.Activity{InputSequence: 1, Sequence: 1, Intent: input.TypingIntent}}
	browser := newBrowserModeController(source, &modeKeys{}, nil)
	owner := modeContext(t, "heading", false)
	target := owner.Ancestors[0]
	browser.navigated(review.DocumentPosition{Document: owner.TopLevel, Snapshot: target}, owner.TopLevel.ID())
	source.activity = input.Activity{InputSequence: 1}
	if !browser.suppressNavigationEcho(atspi.NewEvent(atspi.CaretEvent, target)) {
		t.Fatal("expired speech intent released the virtual caret")
	}
	for _, snapshot := range []atspi.Snapshot{
		{BusName: target.BusName, Path: "/entry", Role: "entry", Editable: true},
		{BusName: target.BusName, Path: "/menu", Role: "menu"},
		{BusName: target.BusName, Path: "/other-document", Role: "document web"},
	} {
		if browser.suppressNavigationEcho(atspi.NewEvent(atspi.FocusEvent, snapshot)) {
			t.Fatalf("suppressed focus on %s", snapshot.Role)
		}
	}
	chrome := atspi.NewEvent(atspi.FocusEvent, target)
	chrome.FocusOutsideDocument = atspi.NewObjectID(target.BusName, "/chrome")
	if browser.suppressNavigationEcho(chrome) {
		t.Fatal("suppressed chrome focus")
	}
	handler := &accessibilityEventHandler{state: &eventLoopState{}, browser: browser, logger: slog.New(slog.DiscardHandler)}
	handler.handle(atspi.Event{Type: atspi.MouseButtonEvent})
	if browser.suppressNavigationEcho(atspi.NewEvent(atspi.CaretEvent, target)) {
		t.Fatal("pointer click did not release the virtual caret")
	}
}

func TestQueuedHeadingOwnsCaretAfterActivation(t *testing.T) {
	tracker := &input.IntentTracker{}
	browser := newBrowserModeController(tracker, &modeKeys{}, nil)
	owner := modeContext(t, "link", false)
	target := owner.Ancestors[0]
	browser.navigated(review.DocumentPosition{Document: owner.TopLevel, Snapshot: target}, owner.TopLevel.ID())
	tracker.Observe(input.NewKeyEvent(0, true, "Return"))
	browser.observeCommand(input.DocumentActivate)
	tracker.Observe(input.NewKeyEvent(0, true, "h"))
	browser.observeCommand(input.DocumentNextHeading)
	// A fragment activation can emit multiple paragraph caret events. The
	// second can arrive after the heading request but before its result.
	paragraph := atspi.Snapshot{BusName: target.BusName, Path: "/fragment", Role: "paragraph"}
	if !browser.suppressNavigationEcho(atspi.NewEvent(atspi.CaretEvent, paragraph)) {
		t.Fatal("activation caret was allowed to queue behind the heading move")
	}
}

func TestBrowserVirtualPositionSurvivesNativePlacementFailure(t *testing.T) {
	worker, err := review.NewWorker(&documentLineCapturer{}, time.Second)
	if err != nil {
		t.Fatal(err)
	}
	owner := modeContext(t, "heading", false)
	anchor := owner.TopLevel.ID()
	worker.SyncFocus(anchor)
	browser := newBrowserModeController(nil, &modeKeys{}, nil)
	initial := review.DocumentPosition{Document: owner.TopLevel, Snapshot: owner.Ancestors[0]}
	browser.navigated(initial, anchor)
	state := &eventLoopState{}
	state.current, state.presentationOptions = initial.Snapshot, presentation.DefaultOptions()
	queue := &fakeSpeechQueue{spoken: make(chan string, 8)}
	handler := &eventReviewHandler{state: state, browser: browser, objectReview: worker, speech: queue,
		logger: slog.New(slog.DiscardHandler), syncForeground: func() {}}
	target := atspi.Snapshot{BusName: anchor.BusName, Path: "/replacement-text", Role: "static", Name: "Current total"}
	result := review.Result{DocumentEpoch: worker.DocumentEpoch(), DocumentFocus: anchor,
		DocumentCaretCommand: review.CaretNextLine, DocumentCaretText: target.Name, Moved: true,
		DocumentPosition: review.DocumentPosition{Document: owner.TopLevel, Snapshot: target, Offset: 4},
		CaretErr:         atspi.ErrStaleSnapshot}
	handler.handle(result)
	if state.current.ID() != target.ID() || browser.navigation != target.ID() || worker.Focus() != anchor {
		t.Fatal("native placement failure displaced the virtual position or its native anchor")
	}
	// A late result still cannot overwrite a newly focused browser control.
	browser.follow(atspi.NewObjectID(anchor.BusName, "/address"))
	state.current = atspi.Snapshot{BusName: anchor.BusName, Path: "/address", Role: "entry", Editable: true}
	handler.handle(result)
	if state.current.Path != "/address" {
		t.Fatal("late virtual move displaced browser chrome")
	}
}

func TestBrowserLoadRetiresPositionEvenWhenPathIsReused(t *testing.T) {
	browser := newBrowserModeController(nil, &modeKeys{}, nil)
	owner := modeContext(t, "heading", false)
	position := review.DocumentPosition{Document: owner.TopLevel, Snapshot: owner.Ancestors[0]}
	browser.navigated(position, position.Snapshot.ID())
	browser.loaded(position.Snapshot.ID())
	if browser.ready || browser.mode != review.InactiveMode || browser.acceptsDocumentResult(review.Result{DocumentPosition: position}) {
		t.Fatal("load retained the old document position")
	}
	if browser.suppressNavigationEcho(atspi.NewEvent(atspi.FocusEvent, position.Snapshot)) {
		t.Fatal("load retained old navigation echo suppression")
	}
	select {
	case <-browser.wake:
	default:
		t.Fatal("same-path load did not schedule fresh context capture")
	}
}

func TestBrowserLoadAcceptsCurrentFragmentTarget(t *testing.T) {
	browser := newBrowserModeController(nil, &modeKeys{}, nil)
	document := atspi.NewObjectID(":1.42", "/document")
	browser.loaded(document)
	result := review.Result{DocumentFragment: true, DocumentFocus: document, Moved: true}
	if !browser.acceptsDocumentResult(result) {
		t.Fatal("current document fragment was rejected before context resolution")
	}
	result.DocumentFocus = atspi.NewObjectID(":1.42", "/old_document")
	if browser.acceptsDocumentResult(result) {
		t.Fatal("old document fragment crossed a page load")
	}
}

func TestBrowserModeRetriesSameFocusAfterCaptureFailure(t *testing.T) {
	browser := newBrowserModeController(nil, &modeKeys{}, nil)
	owner := modeContext(t, "heading", false)
	focus := owner.Ancestors[0].ID()
	browser.follow(focus)
	browser.accept(browserModeResult{focus: focus, generation: 1, err: atspi.ErrStaleObject}, &fakeSpeechQueue{})
	browser.follow(focus)
	if browser.generation != 2 {
		t.Fatal("transient context failure permanently disabled same-object navigation")
	}
	browser.accept(browserModeResult{focus: focus, generation: 2, owner: owner}, &fakeSpeechQueue{})
	if !browser.ready || browser.mode != review.BrowseMode {
		t.Fatal("same-object retry did not restore browse mode")
	}
}

func TestBrowserReportsNavigationFailureAfterCaretMovesFromNativeFocus(t *testing.T) {
	browser := newBrowserModeController(nil, &modeKeys{}, nil)
	owner := modeContext(t, "heading", false)
	anchor := owner.TopLevel.ID()
	position := review.DocumentPosition{Document: owner.TopLevel, Snapshot: owner.Ancestors[0], Origin: review.CaretNavigation}
	browser.navigated(position, anchor)
	for _, result := range []review.Result{
		{DocumentCaretCommand: review.CaretNextLine, DocumentFocus: anchor, Err: context.DeadlineExceeded},
		{DocumentTarget: review.DocumentHeading, DocumentFocus: anchor, Err: context.DeadlineExceeded},
		{DocumentActivate: true, DocumentFocus: anchor, Err: context.DeadlineExceeded},
	} {
		if !browser.acceptsDocumentResult(result) {
			t.Fatalf("current navigation error was silently discarded: %+v", result)
		}
		result.DocumentFocus = atspi.NewObjectID(anchor.BusName, "/another-document")
		if browser.acceptsDocumentResult(result) {
			t.Fatal("accepted an unrelated navigation error")
		}
	}
	browser.follow(atspi.NewObjectID(anchor.BusName, "/address-bar"))
	if browser.acceptsDocumentResult(review.Result{DocumentCaretCommand: review.CaretNextLine, DocumentFocus: anchor, Err: context.DeadlineExceeded}) {
		t.Fatal("old document error interrupted chrome focus")
	}
}

func TestStickyBrowserModeSurvivesNavigationChromeAndWindowSuspension(t *testing.T) {
	for _, mode := range []review.DocumentMode{review.BrowseMode, review.FocusMode} {
		keys := &modeKeys{}
		browser := newBrowserModeController(nil, keys, nil)
		queue := &fakeSpeechQueue{spoken: make(chan string, 20)}
		owner := modeContext(t, "paragraph", false)
		focus := owner.Ancestors[0].ID()
		accept := func(owner atspi.DocumentContext) {
			browser.follow(focus)
			browser.accept(browserModeResult{focus: focus, generation: browser.generation, owner: owner}, queue)
		}
		accept(owner)
		browser.sticky(mode, queue)
		browser.navigated(review.DocumentPosition{Document: owner.TopLevel, Snapshot: owner.Ancestors[0]}, focus)
		if browser.mode != mode {
			t.Fatal("navigation discarded sticky mode")
		}
		browser.clear()
		accept(modeContext(t, "entry", false))
		if browser.mode != mode || keys.enabled != (mode == review.BrowseMode) {
			t.Fatal("window return lost sticky mode")
		}
		browser.loaded(focus)
		accept(modeContextInDocument(t, "entry", false, "/new_document"))
		if browser.mode != mode {
			t.Fatal("new document lost sticky mode")
		}
		browser.toggle(queue)
		if browser.state.Sticky() != review.InactiveMode || len(browser.stickyModes) != 0 {
			t.Fatal("single press failed to clear sticky mode")
		}
	}
}

func TestStructuralNavigationAutomaticFocus(t *testing.T) {
	for _, tc := range []struct {
		name, role   string
		enabled      bool
		origin       review.NavigationOrigin
		sticky, want review.DocumentMode
	}{
		{name: "default entry", role: "entry", want: review.BrowseMode},
		{name: "entry opt in", role: "entry", enabled: true, want: review.FocusMode},
		{name: "combo opt in", role: "combo box", enabled: true, want: review.FocusMode},
		{name: "heading stays browse", role: "heading", enabled: true, want: review.BrowseMode},
		{name: "link stays browse", role: "link", enabled: true, want: review.BrowseMode},
		{name: "sticky browse", role: "entry", enabled: true, sticky: review.BrowseMode, want: review.BrowseMode},
		{name: "sticky focus", role: "heading", enabled: true, sticky: review.FocusMode, want: review.FocusMode},
		{name: "caret unchanged", role: "entry", enabled: true, origin: review.CaretNavigation, want: review.BrowseMode},
	} {
		t.Run(tc.name, func(t *testing.T) {
			keys := &modeKeys{}
			browser := newBrowserModeController(nil, keys, nil)
			browser.settings = func() review.ModeSettings {
				settings := review.DefaultModeSettings()
				settings.StructuralTriggersFocus = tc.enabled
				return settings
			}
			owner := modeContext(t, tc.role, false)
			browser.stickyModes[owner.TopLevel.ID().BusName] = tc.sticky
			origin := tc.origin
			if origin == review.NativeNavigation {
				origin = review.StructuralNavigation
			}
			result := review.Result{DocumentPosition: review.DocumentPosition{Document: owner.TopLevel, Snapshot: owner.Ancestors[0], Origin: origin}, DocumentCaretContext: owner.Ancestors}
			queue := &fakeSpeechQueue{spoken: make(chan string, 4)}
			browser.navigated(result.DocumentPosition, owner.TopLevel.ID())
			browser.navigationMode(result, queue)
			if browser.mode != tc.want || keys.enabled != (tc.want == review.BrowseMode) {
				t.Fatalf("mode=%v browse keys=%t, want %v", browser.mode, keys.enabled, tc.want)
			}
			if tc.want == review.FocusMode && tc.sticky == review.InactiveMode {
				select {
				case message := <-queue.spoken:
					if message != "Focus mode" {
						t.Fatalf("announcement=%q", message)
					}
				default:
					t.Fatal("missing focus mode announcement")
				}
			} else if len(queue.spoken) != 0 {
				t.Fatal("unnecessary mode announcement")
			}
		})
	}
}