package main

import (
	"strings"
	"sync/atomic"
	"testing"
	"time"

	"voicesnap/internal/engine"
)

func TestLiveCaptionDisplayTextFitsOverlayBuffer(t *testing.T) {
	input := strings.Repeat("这是一句实时字幕", 12)
	got := liveCaptionDisplayText(input)
	if got == "" {
		t.Fatal("caption should not be empty")
	}
	if len([]byte(got)) > liveCaptionMaxBytes {
		t.Fatalf("caption bytes = %d, want <= %d", len([]byte(got)), liveCaptionMaxBytes)
	}
	if !strings.HasPrefix(got, "...") {
		t.Fatalf("caption = %q, want leading truncation marker", got)
	}
}

func TestReleaseTailCaptureDelayUsesEngineCapability(t *testing.T) {
	a := &App{}
	a.replaceEngine(tailCaptureTestEngine{delay: 300 * time.Millisecond})

	if got := a.releaseTailCaptureDelay(); got != 300*time.Millisecond {
		t.Fatalf("releaseTailCaptureDelay() = %v, want 300ms", got)
	}
}

func TestReleaseTailCaptureDelayCanBeDisabledByEngineCapability(t *testing.T) {
	a := &App{}
	a.replaceEngine(tailCaptureTestEngine{delay: 0})

	if got := a.releaseTailCaptureDelay(); got != 0 {
		t.Fatalf("releaseTailCaptureDelay() = %v, want 0", got)
	}
}

func TestReleaseTailCaptureDelayDefaultsToNoProtectionWindow(t *testing.T) {
	a := &App{}
	a.replaceEngine(plainTestEngine{})

	if got := a.releaseTailCaptureDelay(); got != 0 {
		t.Fatalf("releaseTailCaptureDelay() = %v, want 0", got)
	}
}

func TestReleaseTailCaptureDelayDisabledWithoutEngine(t *testing.T) {
	a := &App{}
	a.replaceEngine(nil)

	if got := a.releaseTailCaptureDelay(); got != 0 {
		t.Fatalf("releaseTailCaptureDelay() = %v, want 0 without engine", got)
	}
}

func TestSlowRecognitionReason(t *testing.T) {
	tests := []struct {
		name        string
		recognizeMS int64
		totalMS     int64
		want        string
	}{
		{name: "fast", recognizeMS: 2000, totalMS: 2500, want: ""},
		{name: "recognize", recognizeMS: 2001, totalMS: 2400, want: "recognize"},
		{name: "total", recognizeMS: 1000, totalMS: 2501, want: "total"},
		{name: "both", recognizeMS: 2001, totalMS: 2501, want: "recognize,total"},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := slowRecognitionReason(tt.recognizeMS, tt.totalMS); got != tt.want {
				t.Fatalf("slowRecognitionReason(%d, %d) = %q, want %q", tt.recognizeMS, tt.totalMS, got, tt.want)
			}
		})
	}
}

func TestHoldPreCaptureUsesEngineCapability(t *testing.T) {
	a := &App{}
	a.replaceEngine(holdPreCaptureTestEngine{enabled: true})

	if !a.holdPreCaptureEnabled.Load() {
		t.Fatal("hold pre-capture should be enabled by engine capability")
	}
}

func TestHoldPreCaptureCanBeDisabledByEngineCapability(t *testing.T) {
	a := &App{}
	a.replaceEngine(holdPreCaptureTestEngine{enabled: false})

	if a.holdPreCaptureEnabled.Load() {
		t.Fatal("hold pre-capture should respect engine capability false")
	}
}

func TestHoldPreCaptureDefaultsToTrueForReadyEngine(t *testing.T) {
	a := &App{}
	a.replaceEngine(plainTestEngine{})

	if !a.holdPreCaptureEnabled.Load() {
		t.Fatal("hold pre-capture should default to true for ready engines")
	}
}

func TestHoldPreCaptureDisabledWithoutEngine(t *testing.T) {
	a := &App{}
	a.replaceEngine(nil)

	if a.holdPreCaptureEnabled.Load() {
		t.Fatal("hold pre-capture should be disabled without an engine")
	}
}

func TestHasEngineReflectsCurrentEngine(t *testing.T) {
	a := &App{}
	if a.hasEngine() {
		t.Fatal("new app should not report an engine")
	}

	a.replaceEngine(plainTestEngine{})
	if !a.hasEngine() {
		t.Fatal("app should report an engine after replaceEngine")
	}

	a.replaceEngine(nil)
	if a.hasEngine() {
		t.Fatal("app should not report an engine after clearing")
	}
}

func TestInitEngineSerializesAndDiscardsStaleEngine(t *testing.T) {
	first := &closeTrackingTestEngine{name: "first"}
	second := &closeTrackingTestEngine{name: "second"}
	firstStarted := make(chan struct{})
	allowFirst := make(chan struct{})
	calls := atomic.Int32{}

	a := &App{
		engineFactory: func(initID uint64) (engine.Engine, engineMetadata, bool, error) {
			call := calls.Add(1)
			switch call {
			case 1:
				close(firstStarted)
				<-allowFirst
				return first, engineMetadata{InitID: initID, ResolvedModelID: "first", HardwareInfo: "first"}, true, nil
			case 2:
				return second, engineMetadata{InitID: initID, ResolvedModelID: "second", HardwareInfo: "second"}, true, nil
			default:
				t.Fatalf("unexpected engine factory call %d", call)
				return nil, engineMetadata{}, false, nil
			}
		},
	}

	doneFirst := make(chan struct{})
	go func() {
		a.initEngine()
		close(doneFirst)
	}()

	select {
	case <-firstStarted:
	case <-time.After(time.Second):
		t.Fatal("first engine init did not start")
	}

	doneSecond := make(chan struct{})
	go func() {
		a.initEngine()
		close(doneSecond)
	}()

	waitForCondition(t, time.Second, func() bool {
		return a.engineInitSeq.Load() == 2
	})
	close(allowFirst)

	select {
	case <-doneFirst:
	case <-time.After(time.Second):
		t.Fatal("first engine init did not finish")
	}
	select {
	case <-doneSecond:
	case <-time.After(time.Second):
		t.Fatal("second engine init did not finish")
	}

	a.engineMu.Lock()
	gotEngine := a.eng
	gotMeta := a.engineMeta
	a.engineMu.Unlock()

	if gotEngine != second {
		t.Fatalf("final engine = %#v, want second", gotEngine)
	}
	if !first.closed.Load() {
		t.Fatal("stale first engine should be closed")
	}
	if second.closed.Load() {
		t.Fatal("current second engine should remain open")
	}
	if gotMeta.ResolvedModelID != "second" || gotMeta.InitID != 2 {
		t.Fatalf("engine metadata = %+v, want second init metadata", gotMeta)
	}
}

func waitForCondition(t *testing.T, timeout time.Duration, fn func() bool) {
	t.Helper()
	deadline := time.Now().Add(timeout)
	for time.Now().Before(deadline) {
		if fn() {
			return
		}
		time.Sleep(10 * time.Millisecond)
	}
	t.Fatal("condition was not met before timeout")
}

func TestShouldStartHoldPreCaptureLocked(t *testing.T) {
	a := &App{}
	a.holdPreCaptureEnabled.Store(true)

	if !a.shouldStartHoldPreCaptureLocked() {
		t.Fatal("expected hold pre-capture to start when enabled and idle")
	}

	a.isRecording = true
	if a.shouldStartHoldPreCaptureLocked() {
		t.Fatal("should not pre-capture while already recording")
	}
	a.isRecording = false

	a.isStoppingRecording = true
	if a.shouldStartHoldPreCaptureLocked() {
		t.Fatal("should not pre-capture while stopping")
	}
	a.isStoppingRecording = false

	a.isFreetalking = true
	if a.shouldStartHoldPreCaptureLocked() {
		t.Fatal("should not pre-capture while tap recording is active")
	}
	a.isFreetalking = false

	a.lastStopTime = time.Now()
	if a.shouldStartHoldPreCaptureLocked() {
		t.Fatal("should not pre-capture during post-stop debounce")
	}
}

func TestStartRecordingIgnoredWhileStoppingRecording(t *testing.T) {
	a := &App{isStoppingRecording: true}

	a.startRecordingLocked()

	if a.isRecording {
		t.Fatal("startRecordingLocked should not start while stop tail capture is pending")
	}
}

func TestStartTapRecordingIgnoredWhileStoppingRecording(t *testing.T) {
	a := &App{isStoppingRecording: true}

	a.startTapRecordingLocked()

	if a.isRecording || a.isFreetalking {
		t.Fatal("startTapRecordingLocked should not start while stop tail capture is pending")
	}
}

type plainTestEngine struct{}

func (plainTestEngine) Recognize([]float32) (string, error) { return "", nil }
func (plainTestEngine) HardwareInfo() string                { return "test" }
func (plainTestEngine) Close()                              {}

type closeTrackingTestEngine struct {
	plainTestEngine
	name   string
	closed atomic.Bool
}

func (e *closeTrackingTestEngine) HardwareInfo() string { return e.name }
func (e *closeTrackingTestEngine) Close()               { e.closed.Store(true) }

type tailCaptureTestEngine struct {
	plainTestEngine
	delay time.Duration
}

func (e tailCaptureTestEngine) ReleaseTailCaptureDelay() time.Duration {
	return e.delay
}

type holdPreCaptureTestEngine struct {
	plainTestEngine
	enabled bool
}

func (e holdPreCaptureTestEngine) HoldPreCaptureEnabled() bool {
	return e.enabled
}