class Whiteboard {
  constructor() {
    this.canvas = document.getElementById('whiteboard');
    this.ctx = this.canvas.getContext('2d');
    this.isDrawing = false;
    this.setupCanvas();
    this.setupEventListeners();
  }

  setupCanvas() {
    const resize = () => {
      this.canvas.width = window.innerWidth;
      this.canvas.height = window.innerHeight;
      
      this.ctx.strokeStyle = '#000';
      this.ctx.lineWidth = 2;
      this.ctx.lineCap = 'round';
      this.ctx.lineJoin = 'round';
    };

    window.addEventListener('resize', resize);
    resize();
  }

  setupEventListeners() {
    this.canvas.addEventListener('mousedown', this.startDrawing.bind(this));
    this.canvas.addEventListener('mousemove', this.draw.bind(this));
    this.canvas.addEventListener('mouseup', this.stopDrawing.bind(this));
    this.canvas.addEventListener('mouseout', this.stopDrawing.bind(this));

    this.canvas.addEventListener('touchstart', (e) => {
      e.preventDefault();
      const touch = e.touches[0];
      const mouseEvent = new MouseEvent('mousedown', {
        clientX: touch.clientX,
        clientY: touch.clientY
      });
      this.canvas.dispatchEvent(mouseEvent);
    });

    this.canvas.addEventListener('touchmove', (e) => {
      e.preventDefault();
      const touch = e.touches[0];
      const mouseEvent = new MouseEvent('mousemove', {
        clientX: touch.clientX,
        clientY: touch.clientY
      });
      this.canvas.dispatchEvent(mouseEvent);
    });

    this.canvas.addEventListener('touchend', (e) => {
      e.preventDefault();
      const mouseEvent = new MouseEvent('mouseup', {});
      this.canvas.dispatchEvent(mouseEvent);
    });

    document.getElementById('processBtn').addEventListener('click', this.processDrawing.bind(this));
    document.getElementById('clearBtn').addEventListener('click', this.clearCanvas.bind(this));
  }

  startDrawing(e) {
    this.isDrawing = true;
    const rect = this.canvas.getBoundingClientRect();
    const x = e.clientX - rect.left;
    const y = e.clientY - rect.top;
    this.ctx.beginPath();
    this.ctx.moveTo(x, y);
  }

  draw(e) {
    if (!this.isDrawing) return;
    const rect = this.canvas.getBoundingClientRect();
    const x = e.clientX - rect.left;
    const y = e.clientY - rect.top;
    this.ctx.lineTo(x, y);
    this.ctx.stroke();
  }

  stopDrawing() {
    this.isDrawing = false;
  }

  clearCanvas() {
    this.ctx.clearRect(0, 0, this.canvas.width, this.canvas.height);
  }

  processDrawing() {
    const imageData = this.canvas.toDataURL('image/png');
    console.log('Processing drawing...');
    console.log(imageData.substring(0, 100) + '...');
  }
}

document.addEventListener('DOMContentLoaded', () => {
  new Whiteboard();
});