import 'dart:html';
import 'package:browserloop/game/Game.dart';
import 'package:browserloop/game/LoopExample.dart';
import 'package:browserloop/src/03-VariableTimestep.dart';
import 'package:browserloop/src/04-FixedLoopVariableRender.dart';
import 'package:browserloop/src/02-AnimationFrameWhile.dart';

List<Example> examples = [
  Example("While Loop Example", "#while_loop"),
  Example("Fixed Update, Variable Render", "#fixed_variable"),
  Example("Variable Timestep", "#variable_timestep")
];
LoopExample active;

class Example {
  final String query;
  final String name;
  CanvasElement canvas = CanvasElement(width: 480, height: 480);
  LoopExample loop;

  Example(this.name, this.query);
}

void main() {
  examples.forEach((ex) {
    resetExample(ex);
  });
}

void appendToDOM(Example example) {
  querySelector(example.query).append(example.canvas);
  example.canvas.onClick.forEach(activate);
  print("${example.query} appended to DOM");
}

void removeFromDOM(Example example) {
  querySelector(example.query).children.clear();
  print("${example.query} removed from DOM");
}

void resetExample(Example ex) {
  removeFromDOM(ex);
  if (ex.loop != null) ex.loop.stop();
  ex.canvas =
      new CanvasElement(width: ex.canvas.width, height: ex.canvas.height);
  createPlaceholder(ex);
  appendToDOM(ex);
}

void createPlaceholder(Example ex) {
  if (ex.canvas == null) return;

  // Clear Canvas
  CanvasRenderingContext2D ctx = ex.canvas.context2D;
  Point c = Point(ex.canvas.width / 2, ex.canvas.height / 2);
  ctx.setFillColorRgb(255, 150, 10);
  ctx.fillRect(0, 0, ex.canvas.width, ex.canvas.height);

  // Draw Play Button
  ctx.beginPath();
  ctx.moveTo(c.x - 25, c.y - 25);
  ctx.lineTo(c.x + 25, c.y + 25);
  ctx.lineTo(c.x - 25, c.y + 75);
  ctx.closePath();
  ctx.lineWidth = 10;
  ctx.setStrokeColorRgb(155, 155, 155);
  ctx.setFillColorRgb(255, 255, 255);
  ctx.stroke();
  ctx.fill();

  // Draw Text
  ctx.fillText(ex.name, c.x - ctx.measureText(ex.name).width / 2, c.y - 50);

  print("${ex.query} placeholder created");
}

void activate(MouseEvent e) {
  if (e.target is! CanvasElement) return;
  CanvasElement c = (e.target as CanvasElement);

  examples.forEach((Example ex) {
    if (ex.canvas == c) {
      resetExample(ex);
      switch (ex.query) {
        case "#while_loop":
          ex.loop = new WhileLoop(new Game(ex.canvas));
          break;
        case "#fixed_variable":
          ex.loop = new FixedLoopVariableRender(new Game(ex.canvas));
          break;
        case "#variable_timestep":
          ex.loop = new VariableTimestep(new Game(ex.canvas));
          break;
      }
      if (ex.canvas != ex.loop.game.canvas) ex.loop.game.canvas = ex.canvas;
      querySelector(ex.query).append(new ButtonElement()
        ..text = "start"
        ..onClick.listen((e) {
          ex.loop.stop();
          ex.loop.start();
        }));
      querySelector(ex.query).append(new ButtonElement()
        ..text = "stop"
        ..onClick.listen((e) {
          ex.loop.stop();
        }));
//    querySelector('#reset').onClick.listen((e) => ex.loop.game.reset());
//    querySelector('#plus').onClick.listen((e) => _changeGrid(-5));
//    querySelector('#minus').onClick.listen((e) => _changeGrid(5));
    } else {
      resetExample(ex);
    }
  });
}