/* -*- mode: java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
/* copyright 2012 mozilla foundation
 *
 * licensed under the apache license, version 2.0 (the "license");
 * you may not use this file except in compliance with the license.
 * you may obtain a copy of the license at
 *
 *     http://www.apache.org/licenses/license-2.0
 *
 * unless required by applicable law or agreed to in writing, software
 * distributed under the license is distributed on an "as is" basis,
 * without warranties or conditions of any kind, either express or implied.
 * see the license for the specific language governing permissions and
 * limitations under the license.
 */
/* globals vbarray, pdfjs */

'use strict';

// initializing pdfjs global object here, it case if we need to change/disable
// some pdf.js features, e.g. range requests
if (typeof pdfjs === 'undefined') {
  (typeof window !== 'undefined' ? window : this).pdfjs = {};
}

// checking if the typed arrays are supported
// support: ios<6.0 (subarray), ie<10, android<4.0
(function checktypedarraycompatibility() {
  if (typeof uint8array !== 'undefined') {
    // support: ios<6.0
    if (typeof uint8array.prototype.subarray === 'undefined') {
        uint8array.prototype.subarray = function subarray(start, end) {
          return new uint8array(this.slice(start, end));
        };
        float32array.prototype.subarray = function subarray(start, end) {
          return new float32array(this.slice(start, end));
        };
    }

    // support: android<4.1
    if (typeof float64array === 'undefined') {
      window.float64array = float32array;
    }
    return;
  }

  function subarray(start, end) {
    return new typedarray(this.slice(start, end));
  }

  function setarrayoffset(array, offset) {
    if (arguments.length < 2) {
      offset = 0;
    }
    for (var i = 0, n = array.length; i < n; ++i, ++offset) {
      this[offset] = array[i] & 0xff;
    }
  }

  function typedarray(arg1) {
    var result, i, n;
    if (typeof arg1 === 'number') {
      result = [];
      for (i = 0; i < arg1; ++i) {
        result[i] = 0;
      }
    } else if ('slice' in arg1) {
      result = arg1.slice(0);
    } else {
      result = [];
      for (i = 0, n = arg1.length; i < n; ++i) {
        result[i] = arg1[i];
      }
    }

    result.subarray = subarray;
    result.buffer = result;
    result.bytelength = result.length;
    result.set = setarrayoffset;

    if (typeof arg1 === 'object' && arg1.buffer) {
      result.buffer = arg1.buffer;
    }
    return result;
  }

  window.uint8array = typedarray;
  window.int8array = typedarray;

  // we don't need support for set, bytelength for 32-bit array
  // so we can use the typedarray as well
  window.uint32array = typedarray;
  window.int32array = typedarray;
  window.uint16array = typedarray;
  window.float32array = typedarray;
  window.float64array = typedarray;
})();

// url = url || webkiturl
// support: safari<7, android 4.2+
(function normalizeurlobject() {
  if (!window.url) {
    window.url = window.webkiturl;
  }
})();

// object.defineproperty()?
// support: android<4.0, safari<5.1
(function checkobjectdefinepropertycompatibility() {
  if (typeof object.defineproperty !== 'undefined') {
    var definepropertypossible = true;
    try {
      // some browsers (e.g. safari) cannot use defineproperty() on dom objects
      // and thus the native version is not sufficient
      object.defineproperty(new image(), 'id', { value: 'test' });
      // ... another test for android gb browser for non-dom objects
      var test = function test() {};
      test.prototype = { get id() { } };
      object.defineproperty(new test(), 'id',
        { value: '', configurable: true, enumerable: true, writable: false });
    } catch (e) {
      definepropertypossible = false;
    }
    if (definepropertypossible) {
      return;
    }
  }

  object.defineproperty = function objectdefineproperty(obj, name, def) {
    delete obj[name];
    if ('get' in def) {
      obj.__definegetter__(name, def['get']);
    }
    if ('set' in def) {
      obj.__definesetter__(name, def['set']);
    }
    if ('value' in def) {
      obj.__definesetter__(name, function objectdefinepropertysetter(value) {
        this.__definegetter__(name, function objectdefinepropertygetter() {
          return value;
        });
        return value;
      });
      obj[name] = def.value;
    }
  };
})();


// no xmlhttprequest#response?
// support: ie<11, android <4.0
(function checkxmlhttprequestresponsecompatibility() {
  var xhrprototype = xmlhttprequest.prototype;
  var xhr = new xmlhttprequest();
  if (!('overridemimetype' in xhr)) {
    // ie10 might have response, but not overridemimetype
    // support: ie10
    object.defineproperty(xhrprototype, 'overridemimetype', {
      value: function xmlhttprequestoverridemimetype(mimetype) {}
    });
  }
  if ('responsetype' in xhr) {
    return;
  }

  // the worker will be using xhr, so we can save time and disable worker.
  pdfjs.disableworker = true;

  object.defineproperty(xhrprototype, 'responsetype', {
    get: function xmlhttprequestgetresponsetype() {
      return this._responsetype || 'text';
    },
    set: function xmlhttprequestsetresponsetype(value) {
      if (value === 'text' || value === 'arraybuffer') {
        this._responsetype = value;
        if (value === 'arraybuffer' &&
            typeof this.overridemimetype === 'function') {
          this.overridemimetype('text/plain; charset=x-user-defined');
        }
      }
    }
  });

  // support: ie9
  if (typeof vbarray !== 'undefined') {
    object.defineproperty(xhrprototype, 'response', {
      get: function xmlhttprequestresponseget() {
        if (this.responsetype === 'arraybuffer') {
          return new uint8array(new vbarray(this.responsebody).toarray());
        } else {
          return this.responsetext;
        }
      }
    });
    return;
  }

  object.defineproperty(xhrprototype, 'response', {
    get: function xmlhttprequestresponseget() {
      if (this.responsetype !== 'arraybuffer') {
        return this.responsetext;
      }
      var text = this.responsetext;
      var i, n = text.length;
      var result = new uint8array(n);
      for (i = 0; i < n; ++i) {
        result[i] = text.charcodeat(i) & 0xff;
      }
      return result.buffer;
    }
  });
})();

// window.btoa (base64 encode function) ?
// support: ie<10
(function checkwindowbtoacompatibility() {
  if ('btoa' in window) {
    return;
  }

  var digits =
    'abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789+/=';

  window.btoa = function windowbtoa(chars) {
    var buffer = '';
    var i, n;
    for (i = 0, n = chars.length; i < n; i += 3) {
      var b1 = chars.charcodeat(i) & 0xff;
      var b2 = chars.charcodeat(i + 1) & 0xff;
      var b3 = chars.charcodeat(i + 2) & 0xff;
      var d1 = b1 >> 2, d2 = ((b1 & 3) << 4) | (b2 >> 4);
      var d3 = i + 1 < n ? ((b2 & 0xf) << 2) | (b3 >> 6) : 64;
      var d4 = i + 2 < n ? (b3 & 0x3f) : 64;
      buffer += (digits.charat(d1) + digits.charat(d2) +
                 digits.charat(d3) + digits.charat(d4));
    }
    return buffer;
  };
})();

// window.atob (base64 encode function)?
// support: ie<10
(function checkwindowatobcompatibility() {
  if ('atob' in window) {
    return;
  }

  // https://github.com/davidchambers/base64.js
  var digits =
    'abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz0123456789+/=';
  window.atob = function (input) {
    input = input.replace(/=+$/, '');
    if (input.length % 4 === 1) {
      throw new error('bad atob input');
    }
    for (
      // initialize result and counters
      var bc = 0, bs, buffer, idx = 0, output = '';
      // get next character
      buffer = input.charat(idx++);
      // character found in table?
      // initialize bit storage and add its ascii value
      ~buffer && (bs = bc % 4 ? bs * 64 + buffer : buffer,
        // and if not first of each 4 characters,
        // convert the first 8 bits to one ascii character
        bc++ % 4) ? output += string.fromcharcode(255 & bs >> (-2 * bc & 6)) : 0
    ) {
      // try to find character in table (0-63, not found => -1)
      buffer = digits.indexof(buffer);
    }
    return output;
  };
})();

// function.prototype.bind?
// support: android<4.0, ios<6.0
(function checkfunctionprototypebindcompatibility() {
  if (typeof function.prototype.bind !== 'undefined') {
    return;
  }

  function.prototype.bind = function functionprototypebind(obj) {
    var fn = this, headargs = array.prototype.slice.call(arguments, 1);
    var bound = function functionprototypebindbound() {
      var args = headargs.concat(array.prototype.slice.call(arguments));
      return fn.apply(obj, args);
    };
    return bound;
  };
})();

// htmlelement dataset property
// support: ie<11, safari<5.1, android<4.0
(function checkdatasetproperty() {
  var div = document.createelement('div');
  if ('dataset' in div) {
    return; // dataset property exists
  }

  object.defineproperty(htmlelement.prototype, 'dataset', {
    get: function() {
      if (this._dataset) {
        return this._dataset;
      }

      var dataset = {};
      for (var j = 0, jj = this.attributes.length; j < jj; j++) {
        var attribute = this.attributes[j];
        if (attribute.name.substring(0, 5) !== 'data-') {
          continue;
        }
        var key = attribute.name.substring(5).replace(/\-([a-z])/g,
          function(all, ch) {
            return ch.touppercase();
          });
        dataset[key] = attribute.value;
      }

      object.defineproperty(this, '_dataset', {
        value: dataset,
        writable: false,
        enumerable: false
      });
      return dataset;
    },
    enumerable: true
  });
})();

// htmlelement classlist property
// support: ie<10, android<4.0, ios<5.0
(function checkclasslistproperty() {
  var div = document.createelement('div');
  if ('classlist' in div) {
    return; // classlist property exists
  }

  function changelist(element, itemname, add, remove) {
    var s = element.classname || '';
    var list = s.split(/\s+/g);
    if (list[0] === '') {
      list.shift();
    }
    var index = list.indexof(itemname);
    if (index < 0 && add) {
      list.push(itemname);
    }
    if (index >= 0 && remove) {
      list.splice(index, 1);
    }
    element.classname = list.join(' ');
    return (index >= 0);
  }

  var classlistprototype = {
    add: function(name) {
      changelist(this.element, name, true, false);
    },
    contains: function(name) {
      return changelist(this.element, name, false, false);
    },
    remove: function(name) {
      changelist(this.element, name, false, true);
    },
    toggle: function(name) {
      changelist(this.element, name, true, true);
    }
  };

  object.defineproperty(htmlelement.prototype, 'classlist', {
    get: function() {
      if (this._classlist) {
        return this._classlist;
      }

      var classlist = object.create(classlistprototype, {
        element: {
          value: this,
          writable: false,
          enumerable: true
        }
      });
      object.defineproperty(this, '_classlist', {
        value: classlist,
        writable: false,
        enumerable: false
      });
      return classlist;
    },
    enumerable: true
  });
})();

// check console compatibility
// in older ie versions the console object is not available
// unless console is open.
// support: ie<10
(function checkconsolecompatibility() {
  if (!('console' in window)) {
    window.console = {
      log: function() {},
      error: function() {},
      warn: function() {}
    };
  } else if (!('bind' in console.log)) {
    // native functions in ie9 might not have bind
    console.log = (function(fn) {
      return function(msg) { return fn(msg); };
    })(console.log);
    console.error = (function(fn) {
      return function(msg) { return fn(msg); };
    })(console.error);
    console.warn = (function(fn) {
      return function(msg) { return fn(msg); };
    })(console.warn);
  }
})();

// check onclick compatibility in opera
// support: opera<15
(function checkonclickcompatibility() {
  // workaround for reported opera bug dsk-354448:
  // onclick fires on disabled buttons with opaque content
  function ignoreiftargetdisabled(event) {
    if (isdisabled(event.target)) {
      event.stoppropagation();
    }
  }
  function isdisabled(node) {
    return node.disabled || (node.parentnode && isdisabled(node.parentnode));
  }
  if (navigator.useragent.indexof('opera') !== -1) {
    // use browser detection since we cannot feature-check this bug
    document.addeventlistener('click', ignoreiftargetdisabled, true);
  }
})();

// checks if possible to use url.createobjecturl()
// support: ie
(function checkonblobsupport() {
  // sometimes ie loosing the data created with createobjecturl(), see #3977
  if (navigator.useragent.indexof('trident') >= 0) {
    pdfjs.disablecreateobjecturl = true;
  }
})();

// checks if navigator.language is supported
(function checknavigatorlanguage() {
  if ('language' in navigator) {
    return;
  }
  pdfjs.locale = navigator.userlanguage || 'en-us';
})();

(function checkrangerequests() {
  // safari has issues with cached range requests see:
  // https://github.com/mozilla/pdf.js/issues/3260
  // last tested with version 6.0.4.
  // support: safari 6.0+
  var issafari = object.prototype.tostring.call(
                  window.htmlelement).indexof('constructor') > 0;

  // older versions of android (pre 3.0) has issues with range requests, see:
  // https://github.com/mozilla/pdf.js/issues/3381.
  // make sure that we only match webkit-based android browsers,
  // since firefox/fennec works as expected.
  // support: android<3.0
  var regex = /android\s[0-2][^\d]/;
  var isoldandroid = regex.test(navigator.useragent);

  if (issafari || isoldandroid) {
    pdfjs.disablerange = true;
    pdfjs.disablestream = true;
  }
})();

// check if the browser supports manipulation of the history.
// support: ie<10, android<4.2
(function checkhistorymanipulation() {
  // android 2.x has so buggy pushstate support that it was removed in
  // android 3.0 and restored as late as in android 4.2.
  // support: android 2.x
  if (!history.pushstate || navigator.useragent.indexof('android 2.') >= 0) {
    pdfjs.disablehistory = true;
  }
})();

// support: ie<11, chrome<21, android<4.4, safari<6
(function checksetpresenceinimagedata() {
  // ie < 11 will use window.canvaspixelarray which lacks set function.
  if (window.canvaspixelarray) {
    if (typeof window.canvaspixelarray.prototype.set !== 'function') {
      window.canvaspixelarray.prototype.set = function(arr) {
        for (var i = 0, ii = this.length; i < ii; i++) {
          this[i] = arr[i];
        }
      };
    }
  } else {
    // old chrome and android use an inaccessible canvaspixelarray prototype.
    // because we cannot feature detect it, we rely on user agent parsing.
    var polyfill = false, versionmatch;
    if (navigator.useragent.indexof('chrom') >= 0) {
      versionmatch = navigator.useragent.match(/chrom(e|ium)\/([0-9]+)\./);
      // chrome < 21 lacks the set function.
      polyfill = versionmatch && parseint(versionmatch[2]) < 21;
    } else if (navigator.useragent.indexof('android') >= 0) {
      // android < 4.4 lacks the set function.
      // android >= 4.4 will contain chrome in the user agent,
      // thus pass the chrome check above and not reach this block.
      polyfill = /android\s[0-4][^\d]/g.test(navigator.useragent);
    } else if (navigator.useragent.indexof('safari') >= 0) {
      versionmatch = navigator.useragent.
        match(/version\/([0-9]+)\.([0-9]+)\.([0-9]+) safari\//);
      // safari < 6 lacks the set function.
      polyfill = versionmatch && parseint(versionmatch[1]) < 6;
    }

    if (polyfill) {
      var contextprototype = window.canvasrenderingcontext2d.prototype;
      contextprototype._createimagedata = contextprototype.createimagedata;
      contextprototype.createimagedata = function(w, h) {
        var imagedata = this._createimagedata(w, h);
        imagedata.data.set = function(arr) {
          for (var i = 0, ii = this.length; i < ii; i++) {
            this[i] = arr[i];
          }
        };
        return imagedata;
      };
    }
  }
})();

// support: ie<10, android<4.0, ios
(function checkrequestanimationframe() {
  function fakerequestanimationframe(callback) {
    window.settimeout(callback, 20);
  }

  var isios = /(ipad|iphone|ipod)/g.test(navigator.useragent);
  if (isios) {
    // requestanimationframe on ios is broken, replacing with fake one.
    window.requestanimationframe = fakerequestanimationframe;
    return;
  }
  if ('requestanimationframe' in window) {
    return;
  }
  window.requestanimationframe =
    window.mozrequestanimationframe ||
    window.webkitrequestanimationframe ||
    fakerequestanimationframe;
})();

(function checkcanvassizelimitation() {
  var isios = /(ipad|iphone|ipod)/g.test(navigator.useragent);
  var isandroid = /android/g.test(navigator.useragent);
  if (isios || isandroid) {
    // 5mp
    pdfjs.maxcanvaspixels = 5242880;
  }
})();

// disable fullscreen support for certain problematic configurations.
// support: ie11+ (when embedded).
(function checkfullscreensupport() {
  var isembeddedie = (navigator.useragent.indexof('trident') >= 0 &&
                      window.parent !== window);
  if (isembeddedie) {
    pdfjs.disablefullscreen = true;
  }
})();