import { spawn } from 'child_process';
import { v4 as uuidv4 } from 'uuid';
import { createUploadStream } from './s3/client.js';

const S3_BUCKET = process.env.S3_BUCKET || 'wild-dragon';

class CaptureManager {
  constructor() {
    this.state = {
      recording: false,
      sessionId: null,
      processes: {},
      currentSession: {},
    };
  }

  /**
   * Start a new capture session
   * @param {Object} params - { projectId, binId, clipName, device }
   * @returns {Object} Session info
   */
  async start({ projectId, binId, clipName, device }) {
    if (this.state.recording) {
      throw new Error('Capture already in progress');
    }

    const sessionId = uuidv4();
    const hiresKey = `projects/${projectId}/masters/${clipName}.mov`;
    const proxyKey = `projects/${projectId}/proxies/${clipName}.mp4`;
    const startedAt = new Date().toISOString();

    // Spawn FFmpeg processes
    const hiresProcess = spawn('ffmpeg', [
      '-f', 'decklink',
      '-i', device,
      '-c:v', 'prores_ks',
      '-profile:v', '3',
      '-c:a', 'pcm_s24le',
      '-f', 'mov',
      'pipe:1',
    ], {
      stdio: ['ignore', 'pipe', 'pipe'],
    });

    const proxyProcess = spawn('ffmpeg', [
      '-f', 'decklink',
      '-i', device,
      '-c:v', 'libx264',
      '-preset', 'fast',
      '-b:v', '10M',
      '-c:a', 'aac',
      '-b:a', '192k',
      '-movflags', '+frag_keyframe+empty_moov',
      '-f', 'mp4',
      'pipe:1',
    ], {
      stdio: ['ignore', 'pipe', 'pipe'],
    });

    // Start S3 uploads from FFmpeg stdout
    const hiresUpload = createUploadStream(S3_BUCKET, hiresKey, hiresProcess.stdout);
    const proxyUpload = createUploadStream(S3_BUCKET, proxyKey, proxyProcess.stdout);

    this.state.recording = true;
    this.state.sessionId = sessionId;
    this.state.processes = {
      hires: hiresProcess,
      proxy: proxyProcess,
    };
    this.state.currentSession = {
      sessionId,
      projectId,
      binId,
      clipName,
      device,
      hiresKey,
      proxyKey,
      startedAt,
      duration: 0,
      uploads: {
        hires: hiresUpload,
        proxy: proxyUpload,
      },
    };

    // Handle process errors
    hiresProcess.stderr.on('data', (data) => {
      console.error(`[HIRES] ${data}`);
    });
    proxyProcess.stderr.on('data', (data) => {
      console.error(`[PROXY] ${data}`);
    });

    return this._formatSessionResponse();
  }

  /**
   * Stop the current capture session
   * @param {string} sessionId - Session ID to stop
   * @returns {Object} Completed session info
   */
  async stop(sessionId) {
    if (!this.state.recording || this.state.sessionId !== sessionId) {
      throw new Error('No active capture session or session ID mismatch');
    }

    const { processes, currentSession } = this.state;

    // Send SIGINT to both processes
    if (processes.hires) {
      processes.hires.kill('SIGINT');
    }
    if (processes.proxy) {
      processes.proxy.kill('SIGINT');
    }

    try {
      // Wait for uploads to complete
      if (currentSession.uploads) {
        await Promise.all([
          currentSession.uploads.hires,
          currentSession.uploads.proxy,
        ]);
      }
    } catch (error) {
      console.error('Error during upload completion:', error);
    }

    const stoppedAt = new Date().toISOString();
    const startTime = new Date(currentSession.startedAt);
    const stopTime = new Date(stoppedAt);
    const duration = Math.round((stopTime - startTime) / 1000);

    // Reset state
    this.state.recording = false;
    this.state.sessionId = null;
    this.state.processes = {};

    return {
      sessionId,
      projectId: currentSession.projectId,
      binId: currentSession.binId,
      clipName: currentSession.clipName,
      hiresKey: currentSession.hiresKey,
      proxyKey: currentSession.proxyKey,
      startedAt: currentSession.startedAt,
      stoppedAt,
      duration,
    };
  }

  /**
   * Get current capture status
   * @returns {Object} Current state
   */
  getStatus() {
    if (!this.state.recording) {
      return {
        recording: false,
      };
    }

    const startTime = new Date(this.state.currentSession.startedAt);
    const now = new Date();
    const duration = Math.round((now - startTime) / 1000);

    return {
      recording: true,
      sessionId: this.state.sessionId,
      device: this.state.currentSession.device,
      clipName: this.state.currentSession.clipName,
      projectId: this.state.currentSession.projectId,
      binId: this.state.currentSession.binId,
      duration,
      startedAt: this.state.currentSession.startedAt,
    };
  }

  /**
   * Format session response
   * @private
   */
  _formatSessionResponse() {
    const { currentSession, sessionId } = this.state;
    return {
      sessionId,
      projectId: currentSession.projectId,
      binId: currentSession.binId,
      clipName: currentSession.clipName,
      device: currentSession.device,
      hiresKey: currentSession.hiresKey,
      proxyKey: currentSession.proxyKey,
      startedAt: currentSession.startedAt,
    };
  }
}

export default new CaptureManager();