src/app/py-detect/py-detect.component.ts

import { Component, OnDestroy, OnInit, signal, ViewChild, ElementRef, ChangeDetectorRef } from '@angular/core';
import { CommonModule } from '@angular/common';
import { Router, NavigationStart } from '@angular/router';
import { Subscription } from 'rxjs';
import { FormsModule } from '@angular/forms';
import { PyDetectService } from '../services/pydetect.service';

declare global {
  interface Window {
    webkitSpeechRecognition?: any;
    SpeechRecognition?: any;
  }
}

type QAResult = {
  question: string;
  transcript: string;
  language: string;
  avgPitchHz: number | null;
  avgVolume: number | null;   // 0..1 (rough RMS)
  audioUrl: string;
  startedAt: number;
  endedAt: number;
  skipped?: boolean;
};

@Component({
  standalone: true,
  selector: 'app-py-detect',
  imports: [CommonModule, FormsModule],
  templateUrl: './py-detect.component.html',
  styleUrls: ['./py-detect.component.css']
})
export class PyDetectComponent implements OnInit, OnDestroy {
  // Store body language explanation for UI
  public bodyLanguageExplanation: string | null = null;
  public bodyLanguageMeaning: string | null = null;

  // Fetch explanation for a body language cue from backend
  public fetchBodyLanguageExplanation(cue: string) {
    this.bodyLanguageExplanation = null;
    this.bodyLanguageMeaning = null;
    this.pyDetectService.bodyLanguageExplain(cue).subscribe({
      next: (resp) => {
        if (resp?.explanation) {
          this.bodyLanguageExplanation = resp.explanation;
        }
        if (resp?.meaning) {
          this.bodyLanguageMeaning = resp.meaning;
        }
        console.log('[PyDetect] Body Language:', {
          meaning: resp?.meaning,
          explanation: resp?.explanation
        });
      },
      error: () => {
        this.bodyLanguageExplanation = 'No explanation available.';
        this.bodyLanguageMeaning = null;
        console.warn('[PyDetect] No body language explanation available.');
      }
    });
  }
  // FER emotion result for UI display
  public ferEmotion: string | null = null;
  // Face detection score for UI display
  public faceDetectionScore: number | null = null;
  // --- Patch: Add missing properties for template and logic ---
  public currentQuestionIndex: number = -1;
  public totalQuestions: number = 0;
  public currentQuestionText: string = '';
  public evidenceSummary: string = '';
  // Store the truth score for the last submitted answer
  public truthScore: number | null = null;
  // Timing & frame streaming additions
  public questionWindowStartAt: number | null = null;
  public answerStartAt: number | null = null;
  public answerEndAt: number | null = null;
  public answerMode: 'voice' | 'text' | 'mixed' = 'text';
  private frameIntervalId: any;
  private frameStreamingActive: boolean = false;
  public involvementScore: number | null = null;
  public involvementCues: string[] = [];
  public dominantInvestigativeExpression: string | null = null;
  public behaviorTagDistribution: Record<string, number> | null = null;
  public guidanceCommand: string | null = null;

  // --- Patch: Add missing stub methods for template bindings ---
  public async speakQuestion(question: string) {
    // Use TTS to speak the question (stub)
    await this.speak(question);
  }

  public startRecognitionWithRecording(index: number) {
    // Stub for starting recognition with recording
    // You may want to start voice recording and speech recognition here
  }

  public async navigateToValidationPage() {
    // Stop video recording and release camera
    this.stopVideoRecording();
    if (this.videoStream) {
      this.videoStream.getTracks().forEach(t => t.stop());
      this.videoStream = undefined;
    }
    this.isRecording = false;
    // Wait for the video to finish processing if needed
    await this.sleep(500); // Give time for onstop to fire and recordedVideoUrl to be set
    // Automatically download the recorded video if available
    if (this.recordedVideoUrl) {
      const anchor = document.createElement('a');
      anchor.href = this.recordedVideoUrl;
      anchor.download = 'investigation-video.webm';
      anchor.style.display = 'none';
      document.body.appendChild(anchor);
      anchor.click();
      setTimeout(() => {
        document.body.removeChild(anchor);
        // Optionally revoke the object URL after download
        // URL.revokeObjectURL(this.recordedVideoUrl);
      }, 100);
    }
    // Then navigate to validation page
    this.router.navigate(['/validationpage']);
  }

  public uploadDocument() {
    // Stub for document upload logic
    // You may want to handle file upload here
  }

  public onEvidenceFileSelect(event: any, type: string) {
    // Stub for evidence file selection logic
    // You may want to process selected files here
  }
  // Manual answer submission for testing
  public submitTextAnswer() {
    if (!this.textAnswer || !this.sessionId || this.currentQuestionIndex < 0 || !this.questions[this.currentQuestionIndex]) {
      this.infoText = 'Please enter an answer and ensure a question is active.';
      return;
    }
    // Call backend to submit response
    this.pyDetectService.submitResponse(
      this.sessionId,
      this.textAnswer,
      this.questions[this.currentQuestionIndex]
    ).subscribe({
      next: async (res) => {
        // Extract truth score if present
        this.truthScore = (res && (res.truth_score || res.score)) ? Number(res.truth_score || res.score) : null;
        this.infoText = 'Answer submitted.' + (this.truthScore !== null ? ` Truth Score: ${this.truthScore}` : '');
        this.textAnswer = '';
        // Fetch body language explanation for the first involvement cue
        if (this.involvementCues.length) {
          this.fetchBodyLanguageExplanation(this.involvementCues[0]);
        }
        const response = await this.pyDetectService.askQuestion(
          this.sessionId,
          this.crimeType,
          this.briefDescription
        ).toPromise();
        if (response && response.question) {
          this.questions.push(response.question);
          this.currentQuestionIndex++;
          this.cdr.detectChanges();
          await this.speakQuestion(response.question);
        } else {
          this.infoText = 'No more questions.';
        }
      },
      error: (err) => {
        this.infoText = 'Error submitting answer.';
      }
    });
  }
  public showDetailsPanel: boolean = false;
  public metadata: any = null;

  // Backend-driven session and investigation state
  sessionId: string = '';
  caseData: any = null;
  briefDescription: string = '';
  isSessionStarted: boolean = false;
  isLoading: boolean = false;
  currentQuestion: string = '';
  textAnswer: string = '';
  lastAnalysisResult: any = null;
  questionCount: number = 0;
  currentInvestigationStage: string = 'Initial Investigation';
  questionNumber: number = 1;
  cameraActive: boolean = false;
  voiceRecordingActive: boolean = false;
  investigationActive: boolean = false;
  investigationStarted: boolean = false;
  caseSummary: any = null;
  processingResponse: boolean = false;
  videoStatus: string = 'Camera Ready';
  ttsEnabled: boolean = false;
  isListening: boolean = false;
  speechRecognition: any = null;
  // Combined answer submission: prefer text box, fallback to transcript
  public submitCombinedAnswer() {
    // Accept answer from text box or voice transcript
    let answerText = (this.textAnswer && this.textAnswer.trim()) ? this.textAnswer.trim() : (this.transcriptSoFar && this.transcriptSoFar.trim()) ? this.transcriptSoFar.trim() : '';
    if (!answerText || !this.sessionId || !this.questions[this.currentQuestionIndex]) {
      this.infoText = 'Please provide your answer before submitting.';
      return;
    }
    this.stopAudioRecording();
    this.infoText = 'Submitting answer...';
    this.textAnswer = '';
    this.transcriptSoFar = '';
    const endTs = Date.now();
    this.answerEndAt = endTs;
    if (!this.answerStartAt) this.answerStartAt = this.questionWindowStartAt || endTs;
    const durationMs = this.answerEndAt - this.answerStartAt;
    this.stopFrameStreaming();
    this.pyDetectService.submitResponse(
      this.sessionId,
      answerText,
      this.questions[this.currentQuestionIndex],
      {
        answer_start_at: this.answerStartAt,
        answer_end_at: this.answerEndAt,
        duration_ms: durationMs,
        mode: this.answerMode
      }
    ).subscribe({
      next: async (res) => {
        // Extract truth score if present
        this.truthScore = (res && (res.truth_score || res.score)) ? Number(res.truth_score || res.score) : null;
        this.infoText = 'Answer submitted.' + (this.truthScore !== null ? ` Truth Score: ${this.truthScore}` : '');
        // Pull involvement metrics
        this.fetchLatestInvolvement();
        // Fetch next question from backend
        const response = await this.pyDetectService.askQuestion(
          this.sessionId,
          this.crimeType,
          this.briefDescription
        ).toPromise();
        if (response && response.question) {
          this.questions.push(response.question);
          this.currentQuestionIndex++;
          this.questionNumber = this.currentQuestionIndex + 1;
          this.cdr.detectChanges();
        //  await this.startCamera();
          await this.startVideoRecording();
          await this.speakQuestion(response.question);
          // Restart window for next question
          this.startQuestionWindow();
          // Reset answer timing
          this.answerStartAt = null;
          this.answerEndAt = null;
          this.answerMode = 'text';
        } else {
          this.infoText = 'No more questions.';
          this.showSummary = true;
        }
      },
      error: () => {
        this.infoText = 'Error submitting answer.';
      }
    });
  }
  public stopAudioRecording() {
    if (this.mediaRecorder && this.mediaRecorder.state !== 'inactive') {
      this.mediaRecorder.stop();
      // Show the transcribed answer in the text box
      this.textAnswer = this.transcriptSoFar;
      this.infoText = 'Voice recording stopped.';
      // Stop speech recognition when recording stops
      if (this.recognition) {
        try { this.recognition.stop(); } catch { }
      }
    }
  }
  speechSynthesis: any = null;
  voiceSupported: boolean = false;
  microphoneSupported: boolean = false;
  microphonePermissionDenied: boolean = false;
  permissionStatus: string = 'unknown';

  // ---- TTS active flag ----
  private isActive = false;

  // ---- Q/A data ----
  // log: QAResult[] = [];
  log: QAResult[] = [];


  // ---- Constructor with Router Injection ----
  private routerSubscription?: Subscription;

  constructor(
    private router: Router,
    private cdr: ChangeDetectorRef,
    private pyDetectService: PyDetectService
  ) {
    // Cancel TTS on any navigation away
    this.routerSubscription = this.router.events.subscribe(event => {
      if (event instanceof NavigationStart) {
        if (window.speechSynthesis) {
          window.speechSynthesis.cancel();
        }
      }
    });
  }

  // ---- Recording/analysis handles ----
  private mediaStream?: MediaStream;
  private mediaRecorder?: MediaRecorder;
  private audioChunks: Blob[] = [];

  private audioCtx?: AudioContext;
  private analyser?: AnalyserNode;
  private sourceNode?: MediaStreamAudioSourceNode;

  private pitchSamples: number[] = [];
  private volumeSamples: number[] = [];
  private analyserBuffer: Float32Array = new Float32Array(2048);
  private analyserTimer?: any;

  // ---- Speech Recognition ----
  private recognition?: any;  // webkitSpeechRecognition
  private transcriptSoFar = '';
  private detectedLang = 'auto';

  // ---- Settings ----
  private maxAnswerMs = 10_000; // per answer recording window
  private silenceTimeout?: any;  // Declare silenceTimeout here

  private analyserWindowMs = 100;  // Declare analyserWindowMs property

  // Example question source (replace with API call when ready)
  // Remove legacy seedQuestions
  public questions: string[] = [];

  // Button state signals
  // Remove legacy button state signals

  // Add missing public methods and properties for template binding
  // videoStatus already declared above for backend workflow
  public videoStream?: MediaStream;
  @ViewChild('videoElement', { static: false }) videoElement?: ElementRef<HTMLVideoElement>;
  public videoChunks: Blob[] = [];
  public videoAnswers: Blob[] = [];
  public videoRecorder?: MediaRecorder;
  public recordedVideoUrl: string = '';

  // UI properties for template
  caseId: string = '';
  crimeType: string = '';
  dateTime: string = '';
  location: string = '';
  suspectName: string = '';
  statusText: string = '';
  investigationOfficer: string = '';
  progress: number = 0;
  progressStage: string = '';
  sessionTime: string = '';
  isRecording: boolean = false;
  isProcessing: boolean = false;
  transcriptLines: string[] = [];
  showSummary: boolean = false;
  summaryData: { question: string; answer: string; duration: number }[] = [];

  // Evidence panel state and placeholder data
  public showEvidencePanel: boolean = false;
  public showSummaryPanel: boolean = false;
  public uploadedDocuments: string[] = ['Report.pdf', 'Statement.docx'];
  public capturedPhotos: string[] = ['Photo1.jpg', 'Photo2.png'];
  public previousRecordings: string[] = ['Recording1.webm', 'Recording2.mp3'];

  // Info text for HUD below question
  public floatingInfoText: string | null = null;
  public infoText: string | null = null;

  // Elapsed and remaining time for recording status
  public elapsedTime: string = '00:00';
  public remainingTime: string = '00:00';
  private recordingTimerInterval: any;

  // Repeat current question using TTS
  public async repeatQuestion() {
    await this.speakQuestion(this.currentQuestionText);
    await this.sleep(1000);
    this.infoText = 'Recording in progress – Listening to answer.';
  }

  // Navigate back to the homepage

  navigateHome() {
    if (window.speechSynthesis) {
      window.speechSynthesis.cancel();
    }
    this.router.navigate(['/']);
  }

  goToInfoPage() {
    if (window.speechSynthesis) {
      window.speechSynthesis.cancel();
    }
    this.router.navigate(['/infopage']);
  }

  navigateBackToCaseDetails() {
    if (window.speechSynthesis) {
      window.speechSynthesis.cancel();
    }
    // Stop any <audio> elements
    const audioElems = document.querySelectorAll('audio');
    audioElems.forEach((audioElem) => {
      (audioElem as HTMLAudioElement).pause();
      (audioElem as HTMLAudioElement).currentTime = 0;
    });
    // Stop custom Audio object if present
    if ((window as any).pyDetectAudioObj && typeof (window as any).pyDetectAudioObj.pause === 'function') {
      (window as any).pyDetectAudioObj.pause();
      (window as any).pyDetectAudioObj.currentTime = 0;
    }
    // Stop any media streams
    if (this.mediaStream) {
      this.mediaStream.getTracks().forEach(t => t.stop());
      this.mediaStream = undefined;
    }
    this.router.navigate(['/case-details']);
  }


  // ======== Lifecycle ========
  ngOnInit(): void {
    this.isActive = true;
    // Do NOT set isRecording = true here; only set when question starts

    let metadata: any = null;
    const nav = this.router.getCurrentNavigation();
    if (nav?.extras?.state && nav.extras.state['metadata']) {
      metadata = nav.extras.state['metadata'];
      localStorage.setItem('pyDetectMetadata', JSON.stringify(metadata)); // Update localStorage on navigation
      console.log('Received metadata from navigation:', metadata);
    } else {
      // Fallback: read from localStorage
      const stored = localStorage.getItem('pyDetectMetadata');
      if (stored) {
        metadata = JSON.parse(stored);
        console.log('Loaded metadata from localStorage:', metadata);
      } else {
        console.warn('No metadata found in navigation state or localStorage');
      }
    }
    if (metadata) {
      this.caseId = metadata.caseId || '';
      this.crimeType = metadata.crimeType || '';
      this.dateTime = metadata.dateTime || '';
      this.location = metadata.location || '';
      this.suspectName = metadata.suspectName || '';
      this.statusText = metadata.status || '';
      this.investigationOfficer = metadata.investigationOfficer || '';
      this.progress = metadata.progress || 0;
      this.progressStage = metadata.progressStage || '';
      this.sessionTime = metadata.sessionTime || '';
      this.briefDescription = metadata.briefDescription || '';
    }
  }

  ngOnDestroy(): void {
    this.isActive = false;
    if (this.routerSubscription) {
      this.routerSubscription.unsubscribe();
    }
    this.cleanupAll();
    this.stopVideoRecording();
    this.videoStatus = '';
    if (this.videoStream) {
      this.videoStream.getTracks().forEach(t => t.stop());
      this.videoStream = undefined;
    }
    this.videoRecorder = undefined;
    if (window.speechSynthesis) {
      window.speechSynthesis.cancel(); // Stop any TTS audio
    }
  }

  // ======== Main flow ========
  // Legacy start method removed. Use backend-driven workflow only.

  // Legacy stopAll method removed. Use backend-driven workflow only.

  // Legacy resume method removed. Use backend-driven workflow only.

  // ======== Question source ========
  private async fetchNextQuestion(): Promise<string> {
    // Replace this with HTTP call to your backend if needed.
    // Example: const { question } = await this.http.get<{question:string}>('/api/next-question').toPromise();
    // Legacy fetchNextQuestion logic removed. Use backend-driven workflow only.
    return '';
  }

  // ======== TTS (question playback) ========
  private speak(text: string): Promise<void> {
    return new Promise<void>((resolve) => {
      if (!this.isActive) return resolve(); // Only play TTS if component is active
      const synth = window.speechSynthesis;
      if (!synth) return resolve(); // gracefully continue without TTS

      const utter = new SpeechSynthesisUtterance(text);
      // Optional voice selection: pick an Indian English voice if available
      const prefer = ['en-IN', 'en-GB', 'en-US'];
      const voices = synth.getVoices();
      const v = voices.find(v =>
        prefer.includes(v.lang) || v.lang.toLowerCase().startsWith('en'));
      if (v) utter.voice = v;

      utter.rate = 1.0;
      utter.pitch = 1.0;
      utter.onend = () => resolve();
      utter.onerror = () => resolve(); // do not block flow
      synth.cancel(); // ensure clean queue
      synth.speak(utter);
    });
  }

  // ======== Recording + Recognition + Analysis ========
  private async captureAnswerWithAnalysis(ms: number): Promise<{
    audioUrl: string; avgPitchHz: number | null; avgVolume: number | null; transcript: string; language: string;
  }> {
    // reset buffers
    this.audioChunks = [];
    this.pitchSamples = [];
    this.volumeSamples = [];
    this.transcriptSoFar = '';
    this.detectedLang = 'auto';

    // 1) mic stream
    this.mediaStream = await navigator.mediaDevices.getUserMedia({
      audio: { channelCount: 1, echoCancellation: true, noiseSuppression: true },
      video: false
    });
    // ...existing code...

    // 2) prepare MediaRecorder
    const mime = this.chooseMimeType();
    this.mediaRecorder = new MediaRecorder(this.mediaStream, { mimeType: mime });
    this.mediaRecorder.ondataavailable = (e) => {
      if (e.data && e.data.size > 0) this.audioChunks.push(e.data);
    };

    // 3) start recognition (if available)
    this.startRecognition('en-IN');

    // 4) start analysis
    await this.startAnalyser(this.mediaStream);

    // 5) record for fixed window
    const recordPromise = new Promise<void>((resolve) => {
      this.mediaRecorder!.onstop = () => resolve();
      this.mediaRecorder!.start(200); // gather chunks
      setTimeout(() => {
        if (this.mediaRecorder && this.mediaRecorder.state !== 'inactive') {
          this.mediaRecorder.stop();
        }
      }, ms);
    });

    await recordPromise;

    // 6) stop analysis + recognition + mic
    this.stopAnalyser();
    this.stopRecognition();
    this.cleanupMediaStream();
    // ...existing code...

    // 7) build audio URL
    const blob = new Blob(this.audioChunks, { type: mime });
    const audioUrl = URL.createObjectURL(blob);

    // 8) aggregate metrics
    const avgPitchHz = this.averageNonZero(this.pitchSamples) ?? null;
    const avgVolume = this.averageNonZero(this.volumeSamples) ?? null;

    const transcript = this.transcriptSoFar.trim();
    const language = this.detectedLang;

    return { audioUrl, avgPitchHz, avgVolume, transcript, language };
  }

  private waitForSilenceOrContinue() {
    if (this.silenceTimeout) clearTimeout(this.silenceTimeout);
    this.silenceTimeout = setTimeout(() => {
      // ...existing code...
    }, 5002); // Timeout after 5 seconds of silence
  }


  private chooseMimeType(): string {
    const candidates = [
      'audio/webm;codecs=opus',
      'audio/webm',
      'audio/mp4',
      'audio/mpeg'
    ];
    for (const c of candidates) {
      if (MediaRecorder.isTypeSupported(c)) return c;
    }
    return '';
  }

  // ======== Web Audio analysis (pitch + volume) ========
  private async startAnalyser(stream: MediaStream) {
    this.audioCtx = new (window.AudioContext || (window as any).webkitAudioContext)();
    this.sourceNode = this.audioCtx.createMediaStreamSource(stream);
    this.analyser = this.audioCtx.createAnalyser();
    this.analyser.fftSize = 2048;
    this.sourceNode.connect(this.analyser);

    // Use correct constructor for Float32Array
    this.analyserBuffer = new Float32Array(this.analyser.fftSize);

    const tick = () => {
      if (!this.analyser || !this.analyserBuffer) return;
      this.analyser.getFloatTimeDomainData(this.analyserBuffer);

      const pitch = this.estimatePitchFromAutocorrelation(
        this.analyserBuffer, this.audioCtx!.sampleRate
      );
      const vol = this.rootMeanSquare(this.analyserBuffer);

      if (pitch) this.pitchSamples.push(pitch);
      this.volumeSamples.push(vol);

      this.analyserTimer = setTimeout(tick, this.analyserWindowMs);
    };
    tick();
  }

  private stopAnalyser() {
    if (this.analyserTimer) clearTimeout(this.analyserTimer);
    this.analyserTimer = null;
    if (this.sourceNode) { try { this.sourceNode.disconnect(); } catch { } }
    if (this.analyser) { try { this.analyser.disconnect(); } catch { } }
    if (this.audioCtx) { try { this.audioCtx.close(); } catch { } }
    this.sourceNode = undefined;
    this.analyser = undefined;
    this.audioCtx = undefined;
  }

  // Simple autocorrelation-based pitch estimator
  private estimatePitchFromAutocorrelation(buf: Float32Array, sampleRate: number): number | null {
    // 1) normalize
    let size = buf.length;
    let rms = 0;
    for (let i = 0; i < size; i++) rms += buf[i] * buf[i];
    rms = Math.sqrt(rms / size);
    if (rms < 0.01) return null; // too quiet

    // 2) autocorrelation
    const MAX_SAMPLES = Math.floor(size / 2);
    let bestOffset = -1;
    let bestCorr = 0;
    let lastCorr = 1;

    for (let offset = 1; offset < MAX_SAMPLES; offset++) {
      let corr = 0;
      for (let i = 0; i < MAX_SAMPLES; i++) {
        corr += Math.abs(buf[i] - buf[i + offset]);
      }
      corr = 1 - (corr / MAX_SAMPLES);
      if (corr > 0.9 && corr > lastCorr) {
        bestCorr = corr;
        bestOffset = offset;
      }
      lastCorr = corr;
    }
    if (bestOffset > 0) {
      const freq = sampleRate / bestOffset;
      if (freq >= 50 && freq <= 400) return Math.round(freq); // human speech band (rough)
    }
    return null;
  }

  private rootMeanSquare(buf: Float32Array): number {
    let sum = 0;
    for (let i = 0; i < buf.length; i++) sum += buf[i] * buf[i];
    return Math.sqrt(sum / buf.length); // 0..~0.5 typical speech
  }

  private averageNonZero(arr: number[]): number | undefined {
    const f = arr.filter(x => x && isFinite(x));
    if (!f.length) return undefined;
    return Math.round((f.reduce((a, b) => a + b, 0) / f.length) * 100) / 100;
  }

  // ======== Speech Recognition ========
  private setupRecognition() {
    const Ctor = window.webkitSpeechRecognition || window.SpeechRecognition;
    if (!Ctor) return;

    this.recognition = new Ctor();
    this.recognition.continuous = true;
    this.recognition.interimResults = false;  // Disable interim results (only final results)

    this.recognition.onresult = (event: any) => {
      let finalText = '';

      // Loop over all result sets, but only process final results
      for (let i = event.resultIndex; i < event.results.length; i++) {
        const result = event.results[i];
        // Get the transcript of the final recognized word
        if (result.isFinal) {
          finalText += result[0].transcript.trim(); // Append final result and clean up
        }
      }

      // Clean up the result by removing filler words (optional)
      this.transcriptSoFar = this.removeFillerWords(finalText.trim());
    };

    this.recognition.onerror = (error: any) => {
      console.error('Speech recognition error', error);
    };

    this.recognition.onend = () => {
      console.log('Speech recognition has ended');
    };
  }

  private removeFillerWords(text: string): string {
    const fillerWords = ['um', 'ah', 'like', 'you know', 'so', 'actually', 'basically'];
    const regex = new RegExp(`\\b(${fillerWords.join('|')})\\b`, 'gi');
    return text.replace(regex, '').replace(/\s+/g, ' ').trim();  // Clean extra spaces after removal
  }

  private startRecognition(lang: string) {
    if (!this.recognition) return;
    try {
      this.recognition.lang = lang; // set your target language; change to 'ta-IN' for Tamil, etc.
      this.recognition.start();
    } catch { /* ignore double-start */ }
  }

  private stopRecognition() {
    if (!this.recognition) return;
    try { this.recognition.stop(); } catch { /* ignore */ }
  }

  // ======== Clean-up ========
  private cleanupMediaStream() {
    if (this.mediaStream) {
      this.mediaStream.getTracks().forEach(t => t.stop());
    }
    this.mediaStream = undefined;
  }

  private cleanupRecording() {
    try { if (this.mediaRecorder && this.mediaRecorder.state !== 'inactive') this.mediaRecorder.stop(); } catch { }
    this.mediaRecorder = undefined;
    this.audioChunks = [];
    this.stopAnalyser();
    this.cleanupMediaStream();
  }

  private cleanupAll() {
    this.stopRecognition();
    this.cleanupRecording();
  }

  // ======== Helpers ========
  private sleep(ms: number) { return new Promise(res => setTimeout(res, ms)); }

  public async startCamera() {
    if (!this.videoStream) {
      this.videoStream = await navigator.mediaDevices.getUserMedia({ video: true, audio: false });
      if (this.videoElement?.nativeElement) {
        this.videoElement.nativeElement.srcObject = this.videoStream;
      }
    }
  }

  // ===== Frame streaming for nonverbal analysis =====
  private startQuestionWindow() {
    this.questionWindowStartAt = Date.now();
    this.answerStartAt = null;
    this.answerEndAt = null;
    this.answerMode = 'text'; // default until voice starts
    this.startFrameStreaming();
  }

  private startFrameStreaming() {
    if (this.frameStreamingActive) return;
    if (!this.videoElement?.nativeElement) return;
    const videoEl = this.videoElement.nativeElement;
    const canvas = document.createElement('canvas');
    canvas.width = 320;
    canvas.height = 240;
    const ctx = canvas.getContext('2d');
    if (!ctx) return;
    this.frameStreamingActive = true;
    this.frameIntervalId = setInterval(() => {
      if (!this.frameStreamingActive) return;
      try {
        ctx.drawImage(videoEl, 0, 0, canvas.width, canvas.height);
        const dataUrl = canvas.toDataURL('image/jpeg', 0.6);
        if (this.sessionId) {
          this.pyDetectService.faceFrame(this.sessionId, dataUrl).subscribe({
            next: (resp) => {
              if (resp?.metrics?.emotion) this.ferEmotion = resp.metrics.emotion;
              if (resp?.command) this.guidanceCommand = resp.command;
            },
            error: () => { /* ignore */ }
          });
        }
      } catch { /* ignore */ }
    }, 150);
  }

  private stopFrameStreaming() {
    if (this.frameIntervalId) clearInterval(this.frameIntervalId);
    this.frameIntervalId = null;
    this.frameStreamingActive = false;
  }

  // Capture text start when user focuses the answer textarea
  public captureTextStart() {
    if (!this.answerStartAt) {
      this.answerStartAt = Date.now();
      if (this.answerMode === 'voice') {
        this.answerMode = 'mixed';
      } else {
        this.answerMode = 'text';
      }
    }
  }

  // Fetch latest involvement metrics (defined here to resolve reference)
  private fetchLatestInvolvement() {
    if (!this.sessionId) return;
    this.pyDetectService.getReport(this.sessionId).subscribe({
      next: (report) => {
        const responses = report?.responses || [];
        if (!responses.length) return;
        const last = responses[responses.length - 1];
        const assess = last?.investigative_assessment;
        const fb = last?.face_body?.metrics;
        if (assess) {
          this.involvementScore = typeof assess.involvement_score === 'number' ? assess.involvement_score : null;
          this.involvementCues = Array.isArray(assess.cues) ? assess.cues : [];
        }
        if (fb) {
          this.dominantInvestigativeExpression = fb.dominant_investigative_expression || null;
          this.behaviorTagDistribution = fb.behavior_tag_distribution || null;
        }
        this.cdr.detectChanges();
      },
      error: () => { /* silent fail */ }
    });
  }

  public async startVideoRecording() {
    if (!this.videoStream) return;
    // Prevent double-start
    if (this.videoRecorder && this.videoRecorder.state === 'recording') {
      console.warn('[PyDetect] Video recording already in progress.');
      return;
    }
    this.videoChunks = [];
    this.videoRecorder = new MediaRecorder(this.videoStream, { mimeType: 'video/webm' });
    this.videoRecorder.ondataavailable = (e: BlobEvent) => {
      if (e.data && e.data.size > 0) this.videoChunks.push(e.data);
    };
    this.videoRecorder.onstop = () => {
      const videoBlob = new Blob(this.videoChunks, { type: 'video/webm' });
      this.recordedVideoUrl = URL.createObjectURL(videoBlob);
      console.log('[PyDetect] Video recording complete. Blob URL:', this.recordedVideoUrl);
      if (this.videoStream) {
        this.videoStream.getTracks().forEach(t => t.stop());
        this.videoStream = undefined;
      }
      this.cdr.detectChanges();
    };
    this.videoRecorder.start();
    console.log('[PyDetect] Video recording started.');
  }

  public stopVideoRecording() {
    // Prevent double-stop
    if (this.videoRecorder && this.videoRecorder.state === 'recording') {
      this.videoRecorder.stop();
      // The onstop handler will release the camera and update the UI
    } else {
      console.warn('[PyDetect] Video recording already stopped or not started.');
    }
  }

  // Call startVideoRecording in onStartInvestigation
  public async onStartInvestigation() {
    this.isLoading = true;
    this.infoText = 'Starting investigation...';
   // await this.startCamera();
    await this.startVideoRecording();
    await this.startSession();
    // Ensure questions are loaded and index is set
    // Use fallback logic for brief description
    let briefDescriptionToSend = this.briefDescription?.trim() || '';
    if (!briefDescriptionToSend) {
      briefDescriptionToSend =
        sessionStorage.getItem('briefDescription')?.trim() ||
        this.caseData?.briefDescription?.trim() ||
        this.caseData?.police?.information?.trim() ||
        this.caseData?.crime?.trim() ||
        '';
    }
    const response = await this.pyDetectService.askQuestion(
      this.sessionId,
      this.crimeType,
      briefDescriptionToSend
    ).toPromise();
    if (response && response.question) {
      this.questions = [response.question]; // Wrap single question in array
      this.currentQuestionIndex = 0;
      this.cdr.detectChanges(); // Force UI update after async
      this.isRecording = true;
      this.infoText = 'Recording in progress – Asking question.';
      this.startRecognitionWithRecording(this.currentQuestionIndex);
      // Start the question window BEFORE speaking so question time included
      this.startQuestionWindow();
      // Speak the first question using TTS (inside window)
      await this.speakQuestion(this.questions[0]);
      this.infoText = 'Recording in progress – Listening to answer.';
    } else {
      this.questions = [];
      this.currentQuestionIndex = -1;
      this.cdr.detectChanges();
    }
    this.infoText = 'Investigation started. Please answer the question.';
    this.isLoading = false;
  }

  // Backend-driven session start and first question fetch
  public async startSession(): Promise<void> {
    try {
      this.isLoading = true;
      if (this.voiceSupported) {
        this.ttsEnabled = true;
        setTimeout(() => {
          this.speakQuestion('Investigation starting. I will ask you questions and you can respond using voice or text.');
        }, 1000);
      }
      let briefDescriptionToSend = this.briefDescription?.trim() || '';
      if (!briefDescriptionToSend) {
        briefDescriptionToSend =
          sessionStorage.getItem('briefDescription')?.trim() ||
          this.caseData?.briefDescription?.trim() ||
          this.caseData?.police?.information?.trim() ||
          this.caseData?.crime?.trim() ||
          '';
      }
      const sessionResponse = await this.pyDetectService.startSession(briefDescriptionToSend).toPromise();
      this.sessionId = sessionResponse.session_id;
      sessionStorage.setItem('sessionId', this.sessionId);
      localStorage.setItem('sessionId', this.sessionId);
      const caseData = this.caseData || {};
      const caseDataToSend = {
        ...caseData,
        brief_description: briefDescriptionToSend
      };
      await this.pyDetectService.submitCaseDetails(
        this.sessionId,
        caseDataToSend,
        briefDescriptionToSend
      ).toPromise();
      if (briefDescriptionToSend && briefDescriptionToSend.length > 0) {
        const questionsResponse = await this.pyDetectService.askQuestion(
          this.sessionId,
          this.crimeType,
          briefDescriptionToSend
        ).toPromise();
        if (questionsResponse && questionsResponse.questions && questionsResponse.questions.length > 0) {
          this.questions = questionsResponse.questions;
          this.currentQuestion = this.questions[0];
          this.currentQuestionIndex = 0;
          this.questionCount = this.questions.length;
          this.questionNumber = 1;
          // Optionally, update UI to show the first question
        } else {
          this.questions = [];
          this.currentQuestionIndex = -1;
        }
      }
      this.isSessionStarted = true;
      this.investigationStarted = true;
      this.investigationActive = true;
      this.isLoading = false;
    } catch (error) {
      alert('Failed to connect to backend. Please check if the Flask server is running on port 5002.');
      this.isLoading = false;
    }
  }
  public isVoiceRecording: boolean = false;

  // Start audio recording and speech recognition
  public async startAudioRecording() {
    // Debounce: Prevent rapid start
    if (this.isVoiceRecording) return;
    // Clear previous answer before starting new recording
    this.textAnswer = '';
    console.log('[PyDetect] Voice recording started.');
    try {
      // Request microphone access
      this.mediaStream = await navigator.mediaDevices.getUserMedia({ audio: true, video: false });
      // Setup MediaRecorder
      const mimeType = this.chooseMimeType();
      this.mediaRecorder = new MediaRecorder(this.mediaStream, { mimeType });
      this.audioChunks = [];
      this.mediaRecorder.ondataavailable = (e) => {
        if (e.data && e.data.size > 0) this.audioChunks.push(e.data);
      };
      this.mediaRecorder.onstop = () => {
        console.log('[PyDetect] Voice recording stopped.');
        // Stop speech recognition when recording stops
        if (this.recognition) {
          try { this.recognition.stop(); } catch { }
        }
        // UI feedback if no transcript
        if (!this.transcriptSoFar) {
          this.infoText = 'No voice detected. Please try again or type your answer.';
        } else {
          this.infoText = 'Voice recording stopped.';
        }
      };
      this.mediaRecorder.start();
      // Setup speech recognition
      const Ctor = window.webkitSpeechRecognition || window.SpeechRecognition;
      if (Ctor) {
        this.recognition = new Ctor();
        this.recognition.lang = 'en-IN';
        this.recognition.continuous = true;
        this.recognition.interimResults = false;
        this.transcriptSoFar = '';
        this.recognition.onstart = () => {
          this.infoText = 'Listening...';
        };
        this.recognition.onresult = (event: any) => {
          let finalText = '';
          for (let i = event.resultIndex; i < event.results.length; i++) {
            const result = event.results[i];
            if (result.isFinal) {
              finalText += result[0].transcript.trim();
            }
          }
          this.transcriptSoFar = finalText.trim();
          this.textAnswer = this.transcriptSoFar;
        };
        this.recognition.onerror = (error: any) => {
          this.infoText = 'Speech recognition error: ' + error.error;
        };
        this.recognition.onend = () => {
          if (!this.transcriptSoFar) {
            this.infoText = 'No voice detected. Please try again or type your answer.';
          } else {
            this.infoText = 'Voice recording stopped.';
          }
        };
        this.recognition.start();
      } else {
        this.infoText = 'Speech Recognition not supported.';
      }
      this.isVoiceRecording = true;
    } catch (err) {
      this.infoText = 'Could not start audio recording.';
    }
  }
  public async toggleVoiceRecording() {
    if (this.isVoiceRecording) {
      this.stopAudioRecording();
      this.isVoiceRecording = false;
      this.infoText = 'Voice recording stopped.';
    } else {
      await this.startAudioRecording();
      this.isVoiceRecording = true;
      this.infoText = 'Voice recording started. Speak your answer.';
    }
  }

  // Ensure the class is properly closed
}