interface WorkerMessage {
  id: string;
  type: 'compile' | 'render';
  code?: string;
  width?: number;
  height?: number;
  time?: number;
  renderMode?: string;
  valueMode?: string;
  hueShift?: number;
  startY?: number; // Y offset for tile rendering
  mouseX?: number;
  mouseY?: number;
  mousePressed?: boolean;
  mouseVX?: number;
  mouseVY?: number;
  mouseClickTime?: number;
  touchCount?: number;
  touch0X?: number;
  touch0Y?: number;
  touch1X?: number;
  touch1Y?: number;
  pinchScale?: number;
  pinchRotation?: number;
  accelX?: number;
  accelY?: number;
  accelZ?: number;
  gyroX?: number;
  gyroY?: number;
  gyroZ?: number;
  audioLevel?: number;
  bassLevel?: number;
  midLevel?: number;
  trebleLevel?: number;
  bpm?: number;
}

interface WorkerResponse {
  id: string;
  type: 'compiled' | 'rendered' | 'error';
  success: boolean;
  imageData?: ImageData;
  error?: string;
}

export class FakeShader {
  private canvas: HTMLCanvasElement;
  private ctx: CanvasRenderingContext2D;
  private code: string;
  private worker: Worker; // Single worker for backwards compatibility
  private workers: Worker[] = [];
  private workerCount: number;
  private animationId: number | null = null;
  private startTime: number = Date.now();
  private isCompiled: boolean = false;
  private isRendering: boolean = false;
  private pendingRenders: string[] = [];
  private renderMode: string = 'classic';
  private valueMode: string = 'integer';
  private hueShift: number = 0;
  private timeSpeed: number = 1.0;
  private currentBPM: number = 120;

  // Multi-worker state
  private tileResults: Map<number, ImageData> = new Map();
  private tilesCompleted: number = 0;
  private totalTiles: number = 0;

  private mouseX: number = 0;
  private mouseY: number = 0;
  private mousePressed: boolean = false;
  private mouseVX: number = 0;
  private mouseVY: number = 0;
  private mouseClickTime: number = 0;
  private touchCount: number = 0;
  private touch0X: number = 0;
  private touch0Y: number = 0;
  private touch1X: number = 0;
  private touch1Y: number = 0;
  private pinchScale: number = 1;
  private pinchRotation: number = 0;
  private accelX: number = 0;
  private accelY: number = 0;
  private accelZ: number = 0;
  private gyroX: number = 0;
  private gyroY: number = 0;
  private gyroZ: number = 0;
  private audioLevel: number = 0;
  private bassLevel: number = 0;
  private midLevel: number = 0;
  private trebleLevel: number = 0;

  // Frame rate limiting
  private targetFPS: number = 30;
  private frameInterval: number = 1000 / this.targetFPS;
  private lastFrameTime: number = 0;

  constructor(canvas: HTMLCanvasElement, code: string = 'x^y') {
    this.canvas = canvas;
    this.ctx = canvas.getContext('2d')!;
    this.code = code;

    // Initialize offscreen canvas if supported
    this.initializeOffscreenCanvas();

    // Always use maximum available cores
    this.workerCount = navigator.hardwareConcurrency || 4;
    // Some browsers report logical processors (hyperthreading), which is good
    // But cap at a reasonable maximum to avoid overhead
    this.workerCount = Math.min(this.workerCount, 32);
    console.log(
      `Auto-detected ${this.workerCount} CPU cores, using all for maximum performance`
    );

    // Initialize workers
    this.initializeWorkers();

    // Keep single worker reference for backwards compatibility
    this.worker = this.workers[0];

    this.compile();
  }

  private initializeOffscreenCanvas(): void {
    if (typeof OffscreenCanvas !== 'undefined') {
      try {
        // this.offscreenCanvas = new OffscreenCanvas(this.canvas.width, this.canvas.height); // Removed unused
        // this._offscreenCtx = this.offscreenCanvas.getContext('2d'); // Removed unused
        // this._useOffscreen = this._offscreenCtx !== null; // Removed unused property
      } catch (error) {
        console.warn('OffscreenCanvas not supported:', error);
        // this._useOffscreen = false; // Removed unused property
      }
    }
  }

  private initializeWorkers(): void {
    // Create worker pool
    for (let i = 0; i < this.workerCount; i++) {
      const worker = new Worker(new URL('./ShaderWorker.ts', import.meta.url), {
        type: 'module',
      });
      worker.onmessage = (e: MessageEvent<WorkerResponse>) =>
        this.handleWorkerMessage(e.data, i);
      worker.onerror = (error) => console.error(`Worker ${i} error:`, error);
      this.workers.push(worker);
    }
  }

  private handleWorkerMessage(
    response: WorkerResponse,
    workerIndex: number = 0
  ): void {
    switch (response.type) {
      case 'compiled':
        this.isCompiled = response.success;
        if (!response.success) {
          console.error('Compilation failed:', response.error);
          this.fillBlack();
        }
        break;

      case 'rendered':
        if (this.workerCount > 1) {
          this.handleTileResult(response, workerIndex);
        } else {
          // Single worker mode
          this.isRendering = false;
          if (response.success && response.imageData) {
            // Put ImageData directly on main canvas
            this.ctx.putImageData(response.imageData, 0, 0);
          } else {
            console.error('Render failed:', response.error);
            this.fillBlack();
          }
        }

        // Process pending renders
        if (this.pendingRenders.length > 0) {
          this.pendingRenders.shift(); // Remove completed render
          if (this.pendingRenders.length > 0) {
            // Skip to latest render request
            const latestId =
              this.pendingRenders[this.pendingRenders.length - 1];
            this.pendingRenders = [latestId];
            this.executeRender(latestId);
          }
        }
        break;

      case 'error':
        this.isRendering = false;
        console.error('Worker error:', response.error);
        this.fillBlack();
        break;
    }
  }

  private fillBlack(): void {
    this.ctx.fillStyle = '#000';
    this.ctx.fillRect(0, 0, this.canvas.width, this.canvas.height);
  }

  private compile(): void {
    this.isCompiled = false;
    const id = `compile_${Date.now()}`;

    // Send compile message to all workers
    this.workers.forEach((worker) => {
      worker.postMessage({
        id,
        type: 'compile',
        code: this.code,
      } as WorkerMessage);
    });
  }

  private executeRender(id: string): void {
    if (!this.isCompiled || this.isRendering) {
      return;
    }

    this.isRendering = true;
    // this._currentRenderID = id; // Removed unused property
    const currentTime = (Date.now() - this.startTime) / 1000 * this.timeSpeed;

    // Always use multiple workers if available
    if (this.workerCount > 1) {
      this.renderWithMultipleWorkers(id, currentTime);
    } else {
      this.renderWithSingleWorker(id, currentTime);
    }
  }

  private renderWithSingleWorker(id: string, currentTime: number): void {
    this.worker.postMessage({
      id,
      type: 'render',
      width: this.canvas.width,
      height: this.canvas.height,
      fullWidth: this.canvas.width,
      fullHeight: this.canvas.height,
      time: currentTime,
      renderMode: this.renderMode,
      valueMode: this.valueMode,
      hueShift: this.hueShift,
      mouseX: this.mouseX,
      mouseY: this.mouseY,
      mousePressed: this.mousePressed,
      mouseVX: this.mouseVX,
      mouseVY: this.mouseVY,
      mouseClickTime: this.mouseClickTime,
      touchCount: this.touchCount,
      touch0X: this.touch0X,
      touch0Y: this.touch0Y,
      touch1X: this.touch1X,
      touch1Y: this.touch1Y,
      pinchScale: this.pinchScale,
      pinchRotation: this.pinchRotation,
      accelX: this.accelX,
      accelY: this.accelY,
      accelZ: this.accelZ,
      gyroX: this.gyroX,
      gyroY: this.gyroY,
      gyroZ: this.gyroZ,
      audioLevel: this.audioLevel,
      bassLevel: this.bassLevel,
      midLevel: this.midLevel,
      trebleLevel: this.trebleLevel,
      bpm: this.currentBPM,
    } as WorkerMessage);
  }

  private renderWithMultipleWorkers(id: string, currentTime: number): void {
    // Reset tile tracking
    this.tileResults.clear();
    this.tilesCompleted = 0;
    this.totalTiles = this.workerCount;

    const width = this.canvas.width;
    const height = this.canvas.height;
    const tileHeight = Math.ceil(height / this.workerCount);

    // Distribute tiles to workers
    this.workers.forEach((worker, index) => {
      const startY = index * tileHeight;
      const endY = Math.min((index + 1) * tileHeight, height);

      if (startY >= height) return; // Skip if tile is outside canvas

      worker.postMessage({
        id: `${id}_tile_${index}`,
        type: 'render',
        width: width,
        height: endY - startY,
        // Pass the Y offset for correct coordinate calculation
        startY: startY,
        // Pass full canvas dimensions for center calculations
        fullWidth: width,
        fullHeight: height,
        time: currentTime,
        renderMode: this.renderMode,
        valueMode: this.valueMode,
        hueShift: this.hueShift,
        mouseX: this.mouseX,
        mouseY: this.mouseY,
        mousePressed: this.mousePressed,
        mouseVX: this.mouseVX,
        mouseVY: this.mouseVY,
        mouseClickTime: this.mouseClickTime,
        touchCount: this.touchCount,
        touch0X: this.touch0X,
        touch0Y: this.touch0Y,
        touch1X: this.touch1X,
        touch1Y: this.touch1Y,
        pinchScale: this.pinchScale,
        pinchRotation: this.pinchRotation,
        accelX: this.accelX,
        accelY: this.accelY,
        accelZ: this.accelZ,
        gyroX: this.gyroX,
        gyroY: this.gyroY,
        gyroZ: this.gyroZ,
        audioLevel: this.audioLevel,
        bassLevel: this.bassLevel,
        midLevel: this.midLevel,
        trebleLevel: this.trebleLevel,
        bpm: this.currentBPM,
      } as WorkerMessage);
    });
  }

  setCode(code: string): void {
    this.code = code;
    this.compile();
  }

  render(animate: boolean = false): void {
    const currentTime = performance.now();

    // Frame rate limiting
    if (animate && currentTime - this.lastFrameTime < this.frameInterval) {
      if (animate) {
        this.animationId = requestAnimationFrame(() => this.render(true));
      }
      return;
    }

    this.lastFrameTime = currentTime;

    if (!this.isCompiled) {
      this.fillBlack();
      if (animate) {
        this.animationId = requestAnimationFrame(() => this.render(true));
      }
      return;
    }

    const renderId = `render_${Date.now()}_${Math.random()}`;

    // Add to pending renders queue
    this.pendingRenders.push(renderId);

    // If not currently rendering, start immediately
    if (!this.isRendering) {
      this.executeRender(renderId);
    }

    // Continue animation
    if (animate) {
      this.animationId = requestAnimationFrame(() => this.render(true));
    }
  }

  startAnimation(): void {
    this.stopAnimation();
    this.startTime = Date.now();
    this.lastFrameTime = 0; // Reset frame timing
    this.render(true);
  }

  stopAnimation(): void {
    if (this.animationId !== null) {
      cancelAnimationFrame(this.animationId);
      this.animationId = null;
    }

    // Clear pending renders
    this.pendingRenders = [];
  }

  setTargetFPS(fps: number): void {
    this.targetFPS = Math.max(1, Math.min(120, fps)); // Clamp between 1-120 FPS
    this.frameInterval = 1000 / this.targetFPS;
  }

  setRenderMode(mode: string): void {
    this.renderMode = mode;
  }

  setValueMode(mode: string): void {
    this.valueMode = mode;
  }

  setHueShift(shift: number): void {
    this.hueShift = shift;
  }

  setTimeSpeed(speed: number): void {
    this.timeSpeed = speed;
  }

  setBPM(bpm: number): void {
    this.currentBPM = bpm;
  }

  setMousePosition(
    x: number,
    y: number,
    pressed: boolean = false,
    vx: number = 0,
    vy: number = 0,
    clickTime: number = 0
  ): void {
    this.mouseX = x;
    this.mouseY = y;
    this.mousePressed = pressed;
    this.mouseVX = vx;
    this.mouseVY = vy;
    this.mouseClickTime = clickTime;
  }

  setTouchPosition(
    count: number,
    x0: number = 0,
    y0: number = 0,
    x1: number = 0,
    y1: number = 0,
    scale: number = 1,
    rotation: number = 0
  ): void {
    this.touchCount = count;
    this.touch0X = x0;
    this.touch0Y = y0;
    this.touch1X = x1;
    this.touch1Y = y1;
    this.pinchScale = scale;
    this.pinchRotation = rotation;
  }

  setDeviceMotion(
    ax: number,
    ay: number,
    az: number,
    gx: number,
    gy: number,
    gz: number
  ): void {
    this.accelX = ax;
    this.accelY = ay;
    this.accelZ = az;
    this.gyroX = gx;
    this.gyroY = gy;
    this.gyroZ = gz;
  }

  setAudioData(level: number, bass: number, mid: number, treble: number): void {
    this.audioLevel = level;
    this.bassLevel = bass;
    this.midLevel = mid;
    this.trebleLevel = treble;
  }

  destroy(): void {
    this.stopAnimation();
    this.workers.forEach((worker) => worker.terminate());
  }

  private handleTileResult(
    response: WorkerResponse,
    workerIndex: number
  ): void {
    if (!response.success || !response.imageData) {
      console.error(
        `Tile render failed for worker ${workerIndex}:`,
        response.error
      );
      return;
    }

    // Store tile result
    this.tileResults.set(workerIndex, response.imageData);
    this.tilesCompleted++;

    // Check if all tiles are complete
    if (this.tilesCompleted === this.totalTiles) {
      this.compositeTiles();
    }
  }

  private async compositeTiles(): Promise<void> {
    const height = this.canvas.height;
    const tileHeight = Math.ceil(height / this.workerCount);

    // Use ImageBitmap for faster compositing if available
    if (typeof createImageBitmap !== 'undefined') {
      try {
        const bitmapPromises: Promise<ImageBitmap>[] = [];
        const positions: number[] = [];
        
        for (let i = 0; i < this.workerCount; i++) {
          const tileData = this.tileResults.get(i);
          if (tileData) {
            bitmapPromises.push(createImageBitmap(tileData));
            positions.push(i * tileHeight);
          }
        }
        
        const bitmaps = await Promise.all(bitmapPromises);
        
        for (let i = 0; i < bitmaps.length; i++) {
          this.ctx.drawImage(bitmaps[i], 0, positions[i]);
          bitmaps[i].close(); // Free memory
        }
      } catch (error) {
        // Fallback to putImageData if ImageBitmap fails
        this.fallbackCompositeTiles();
      }
    } else {
      this.fallbackCompositeTiles();
    }

    // Clear tile results
    this.tileResults.clear();

    // Mark rendering as complete
    this.isRendering = false;

    // Process pending renders
    if (this.pendingRenders.length > 0) {
      this.pendingRenders.shift();
      if (this.pendingRenders.length > 0) {
        const latestId = this.pendingRenders[this.pendingRenders.length - 1];
        this.pendingRenders = [latestId];
        this.executeRender(latestId);
      }
    }
  }

  private fallbackCompositeTiles(): void {
    const tileHeight = Math.ceil(this.canvas.height / this.workerCount);
    
    for (let i = 0; i < this.workerCount; i++) {
      const tileData = this.tileResults.get(i);
      if (tileData) {
        const startY = i * tileHeight;
        this.ctx.putImageData(tileData, 0, startY);
      }
    }
  }

  // Simplified method - kept for backward compatibility but always uses all cores
  setMultiWorkerMode(_enabled: boolean, _workerCount?: number): void {
    // Always use all available cores, ignore the enabled parameter
    console.log(
      `Multi-worker mode is always enabled, using ${this.workerCount} cores for maximum performance`
    );
  }

  getWorkerCount(): number {
    return this.workerCount;
  }

  static generateRandomCode(): string {
    const presets = [
      'x^y',
      'x&y',
      'x|y',
      '(x*y)%256',
      '(x+y+t*10)%256',
      '((x>>4)^(y>>4))<<4',
      '(x^y^(x*y))%256',
      '((x&y)|(x^y))%256',
      '(x+y)&255',
      'x%y',
      '(x^(y<<2))%256',
      '((x*t)^y)%256',
      '(x&(y|t*8))%256',
      '((x>>2)|(y<<2))%256',
      '(x*y*t)%256',
      '(x+y*t)%256',
      '(x^y^(t*16))%256',
      '((x*t)&(y*t))%256',
      '(x+(y<<(t%4)))%256',
      '((x*t%128)^y)%256',
      '(x^(y*t*2))%256',
      '((x+t)*(y+t))%256',
      '(x&y&(t*8))%256',
      '((x|t)^(y|t))%256',
    ];

    const vars = ['x', 'y', 't', 'i'];
    const ops = ['^', '&', '|', '+', '-', '*', '%'];
    const shifts = ['<<', '>>'];
    const numbers = ['2', '4', '8', '16', '32', '64', '128', '256'];

    const randomChoice = <T>(arr: T[]): T =>
      arr[Math.floor(Math.random() * arr.length)];

    const dynamicExpressions = [
      () => `${randomChoice(vars)}${randomChoice(ops)}${randomChoice(vars)}`,
      () =>
        `(${randomChoice(vars)}${randomChoice(ops)}${randomChoice(vars)})%${randomChoice(numbers)}`,
      () =>
        `${randomChoice(vars)}${randomChoice(shifts)}${Math.floor(Math.random() * 8)}`,
      () =>
        `(${randomChoice(vars)}*${randomChoice(vars)})%${randomChoice(numbers)}`,
      () => `${randomChoice(vars)}^${randomChoice(vars)}^${randomChoice(vars)}`,
    ];

    // 70% chance to pick from presets, 30% chance to generate dynamic
    if (Math.random() < 0.7) {
      return randomChoice(presets);
    } else {
      return randomChoice(dynamicExpressions)();
    }
  }
}