/**
 * @author alteredq / http://alteredqualia.com/
 * @author mr.doob / http://mrdoob.com/
 */

export default {
  canvas: !!window.CanvasRenderingContext2D,
  webgl: (function() {
    try {
      var canvas = document.createElement('canvas');

      return !!(window.WebGLRenderingContext && (canvas.getContext('webgl') || canvas.getContext('experimental-webgl')));
    } catch(e) {
      return false;
    }
  })(),

  workers: !!window.Worker,
  fileapi: window.File && window.FileReader && window.FileList && window.Blob,

  getWebGLErrorMessage: function() {
    var element = document.createElement('div');
    element.id = 'webgl-error-message';
    element.style.fontFamily = 'monospace';
    element.style.fontSize = '13px';
    element.style.fontWeight = 'normal';
    element.style.textAlign = 'center';
    element.style.background = '#fff';
    element.style.color = '#000';
    element.style.padding = '1.5em';
    element.style.width = '400px';
    element.style.margin = '5em auto 0';

    if(!this.webgl) {
      element.innerHTML = window.WebGLRenderingContext ? [
        'Your graphics card does not seem to support <a href="http://khronos.org/webgl/wiki/Getting_a_WebGL_Implementation" style="color:#000000">WebGL</a>.<br />',
        'Find out how to get it <a href="http://get.webgl.org/" style="color:#000000">here</a>.'
      ].join('\n') : [
        'Your browser does not seem to support <a href="http://khronos.org/webgl/wiki/Getting_a_WebGL_Implementation" style="color:#000000">WebGL</a>.<br/>',
        'Find out how to get it <a href="http://get.webgl.org/" style="color:#000000">here</a>.'
      ].join('\n');
    }

    return element;
  },

  addGetWebGLMessage: function(parameters) {
    var parent, id, element;

    parameters = parameters || {};

    parent = parameters.parent !== undefined ? parameters.parent : document.body;
    id = parameters.id !== undefined ? parameters.id : 'oldie';

    element = this.getWebGLErrorMessage();
    element.id = id;

    parent.appendChild(element);
  }
};