/*global jQuery:false, alert:false */

/*
 * Default text - jQuery plugin for html5 dragging files from desktop to browser
 *
 * Author: Weixi Yen
 *
 * Email: [Firstname][Lastname]@gmail.com
 *
 * Copyright (c) 2010 Resopollution
 *
 * Licensed under the MIT license:
 *   http://www.opensource.org/licenses/mit-license.php
 *
 * Project home:
 *   http://www.github.com/weixiyen/jquery-filedrop
 *
 * Version:  0.1.0
 *
 * Features:
 *      Allows sending of extra parameters with file.
 *      Works with Firefox 3.6+
 *      Future-compliant with HTML5 spec (will work with Webkit browsers and IE9)
 * Usage:
 *  See README at project homepage
 *
 */
;(function($) {

  jQuery.event.props.push("dataTransfer");

  var default_opts = {
      fallback_id: '',
      url: '',
      refresh: 1000,
      paramname: 'userfile',
      allowedfiletypes:[],
      raw_droppable:[],
      maxfiles: 25,           // Ignored if queuefiles is set > 0
      maxfilesize: 1,         // MB file size limit
      queuefiles: 0,          // Max files before queueing (for large volume uploads)
      queuewait: 200,         // Queue wait time if full
      data: {},
      headers: {},
      drop: empty,
      rawDrop: empty,
      dragStart: empty,
      dragEnter: empty,
      dragOver: empty,
      dragLeave: empty,
      docEnter: empty,
      docOver: empty,
      docLeave: empty,
      beforeEach: empty,
      afterAll: empty,
      rename: empty,
      error: function(err, file, i, status) {
        alert(err);
      },
      uploadStarted: empty,
      uploadFinished: empty,
      progressUpdated: empty,
      globalProgressUpdated: empty,
      speedUpdated: empty
      },
      errors = ["BrowserNotSupported", "TooManyFiles", "FileTooLarge", "FileTypeNotAllowed", "NotFound", "NotReadable", "AbortError", "ReadError"],
      doc_leave_timer, stop_loop = false,
      files_count = 0,
      files;

  $.fn.filedrop = function(options) {
    var opts = $.extend({}, default_opts, options),
        global_progress = []
        // Humbug modification: keep a pointer to the object that the function
        // was invoked on.
        caller = this;

    this.on('drop', drop).on('dragstart', opts.dragStart).on('dragenter', dragEnter).on('dragover', dragOver).on('dragleave', dragLeave);
    this.on('paste', paste);

    $(document).on('drop', docDrop).on('dragenter', docEnter).on('dragover', docOver).on('dragleave', docLeave);

    $('#' + opts.fallback_id).change(function(e) {
      opts.drop(e);
      files = e.target.files;
      files_count = files.length;
      upload();
    });

    function drop(e) {

      function has_type(dom_stringlist, type) {
        var j;
        for (j = 0; j < dom_stringlist.length; j++) {
          if (dom_stringlist[j] === type) {
            return true;
          }
        }
        return false;
      }

      if (e.dataTransfer.files.length === 0) {
        var i;
        for (i = 0; i < opts.raw_droppable.length; i++) {
          var type = opts.raw_droppable[i];
          if (has_type(e.dataTransfer.types, type)) {
            opts.rawDrop(e.dataTransfer.getData(type));
            return false;
          }
        }
      }

      if( opts.drop.call(this, e) === false ) return false;
      files = e.dataTransfer.files;
      if (files === null || files === undefined || files.length === 0) {
        opts.error(errors[0]);
        return false;
      }
      files_count = files.length;
      upload();
      e.preventDefault();
      return false;
    }

    function paste(event) {
      if (event.originalEvent.clipboardData === undefined ||
          event.originalEvent.clipboardData.items === undefined) {
        return;
      }

      // Check if any of the items are strings, and if they are,
      // then return, since we want the default browser behavior
      // to deal with those.

      var itemsLength = event.originalEvent.clipboardData.items.length;

      for (var i = 0; i <  itemsLength; i++) {
        if (event.originalEvent.clipboardData.items[i].kind === "string") {
          return;
        }
      }

      // Take the first image pasted in the clipboard
      var match_re = /image.*/;
      var item;
      $.each(event.originalEvent.clipboardData.items, function (idx, this_event) {
        if (this_event.type.match(match_re)) {
          item = this_event;
          return false;
        }
      });

      if (item === undefined) {
        return;
      }

      // Call the user callback to initialize the drop event
      if( opts.drop.call(this, event) === false ) return false;

      // Read the data of the drop in as binary data, and send it to the server
      var data = item.getAsFile();
      var reader = new FileReader();
      reader.onload = function(event) {
          function finished_callback(serverResponse, timeDiff, xhr) {
            return opts.uploadFinished(-1, undefined, serverResponse, timeDiff, xhr);
          }

          var url_params = "?mimetype=" + encodeURIComponent(data.type);
          do_xhr("pasted_image", event.target.result, data.type, {}, url_params, finished_callback, function () {});
      };
      reader.readAsBinaryString(data);
    }

    function getBuilder(filename, filedata, mime, boundary) {
      var dashdash = '--',
          crlf = '\r\n',
          builder = '';

      if (opts.data) {
        var params = $.param(opts.data).replace(/\+/g, '%20').split(/&/);

        $.each(params, function() {
          var pair = this.split("=", 2),
              name = decodeURIComponent(pair[0]),
              val  = decodeURIComponent(pair[1]);

          builder += dashdash;
          builder += boundary;
          builder += crlf;
          builder += 'Content-Disposition: form-data; name="' + name + '"';
          builder += crlf;
          builder += crlf;
          builder += val;
          builder += crlf;
        });
      }

      builder += dashdash;
      builder += boundary;
      builder += crlf;
      builder += 'Content-Disposition: form-data; name="' + opts.paramname + '"';
      builder += '; filename="' + filename + '"';
      builder += crlf;

      builder += 'Content-Type: ' + mime;
      builder += crlf;
      builder += crlf;

      builder += filedata;
      builder += crlf;

      builder += dashdash;
      builder += boundary;
      builder += dashdash;
      builder += crlf;
      return builder;
    }

    function progress(e) {
      if (e.lengthComputable) {
        var percentage = Math.round((e.loaded * 100) / e.total);
        if (this.currentProgress !== percentage) {

          this.currentProgress = percentage;
          opts.progressUpdated(this.index, this.file, this.currentProgress);

          global_progress[this.global_progress_index] = this.currentProgress;
          globalProgress();

          var elapsed = new Date().getTime();
          var diffTime = elapsed - this.currentStart;
          if (diffTime >= opts.refresh) {
            var diffData = e.loaded - this.startData;
            var speed = diffData / diffTime; // KB per second
            opts.speedUpdated(this.index, this.file, speed);
            this.startData = e.loaded;
            this.currentStart = elapsed;
          }
        }
      }
    }

    function globalProgress() {
      if (global_progress.length === 0) {
        return;
      }

      var total = 0, index;
      for (index in global_progress) {
        if(global_progress.hasOwnProperty(index)) {
          total = total + global_progress[index];
        }
      }

      opts.globalProgressUpdated(Math.round(total / global_progress.length));
    }

    function do_xhr(filename, filedata, mime, upload_args, extra_url_args, finished_callback, on_error) {
      var xhr                   = new XMLHttpRequest(),
          start_time            = new Date().getTime(),
          global_progress_index = global_progress.length,
          boundary              = '------multipartformboundary' + (new Date()).getTime(),
          upload                = xhr.upload;

      // Humbug modification: Shunt the XHR into the parent object so we
      // can interrupt it later.
      caller.data("filedrop_xhr", xhr);

      if (opts.withCredentials) {
        xhr.withCredentials = opts.withCredentials;
      }

      var builder = builder = getBuilder(filename, filedata, mime, boundary);

      upload = $.extend(upload, upload_args);
      upload.downloadStartTime = start_time;
      upload.currentStart = start_time;
      upload.currentProgress = 0;
      upload.global_progress_index = global_progress_index;
      upload.startData = 0;
      upload.addEventListener("progress", progress, false);

      // Allow url to be a method
      if (jQuery.isFunction(opts.url)) {
        xhr.open("POST", opts.url() + extra_url_args, true);
      } else {
        xhr.open("POST", opts.url + extra_url_args, true);
      }

      xhr.setRequestHeader('content-type', 'multipart/form-data; boundary=' + boundary);

      // Add headers
      $.each(opts.headers, function(k, v) {
        xhr.setRequestHeader(k, v);
      });

      xhr.sendAsBinary(builder);

      global_progress[global_progress_index] = 0;
      globalProgress();

      xhr.onload = function() {
        var serverResponse = null;

        if (xhr.responseText) {
          try {
            serverResponse = jQuery.parseJSON(xhr.responseText);
          }
          catch (e) {
            serverResponse = xhr.responseText;
          }
        }

        var now = new Date().getTime(),
            timeDiff = now - start_time,
            result = finished_callback(serverResponse, timeDiff, xhr);

          // Make sure the global progress is updated
          global_progress[global_progress_index] = 100;
          globalProgress();

          if (result === false) {
            stop_loop = true;
          }

        // Pass any errors to the error option
        if (xhr.status < 200 || xhr.status > 299) {
          on_error(xhr.statusText, xhr.status);
        }
      };

    }

    // Respond to an upload
    function upload() {
      stop_loop = false;

      if (!files) {
        opts.error(errors[0]);
        return false;
      }

      if (opts.allowedfiletypes.push && opts.allowedfiletypes.length) {
        for(var fileIndex = files.length;fileIndex--;) {
          if(!files[fileIndex].type || $.inArray(files[fileIndex].type, opts.allowedfiletypes) < 0) {
            opts.error(errors[3], files[fileIndex]);
            return false;
          }
        }
      }

      var filesDone = 0,
          filesRejected = 0;

      if (files_count > opts.maxfiles && opts.queuefiles === 0) {
        opts.error(errors[1]);
        return false;
      }

      // Define queues to manage upload process
      var workQueue = [];
      var processingQueue = [];
      var doneQueue = [];

      // Add everything to the workQueue
      for (var i = 0; i < files_count; i++) {
        workQueue.push(i);
      }

      // Helper function to enable pause of processing to wait
      // for in process queue to complete
      var pause = function(timeout) {
        setTimeout(process, timeout);
        return;
      };

      // Process an upload, recursive
      var process = function() {

        var fileIndex;

        if (stop_loop) {
          return false;
        }

        // Check to see if are in queue mode
        if (opts.queuefiles > 0 && processingQueue.length >= opts.queuefiles) {
          return pause(opts.queuewait);
        } else {
          // Take first thing off work queue
          fileIndex = workQueue[0];
          workQueue.splice(0, 1);

          // Add to processing queue
          processingQueue.push(fileIndex);
        }

        try {
          if (beforeEach(files[fileIndex]) !== false) {
            if (fileIndex === files_count) {
              return;
            }
            var reader = new FileReader(),
                max_file_size = 1048576 * opts.maxfilesize;

            reader.index = fileIndex;
            if (files[fileIndex].size > max_file_size) {
              opts.error(errors[2], files[fileIndex], fileIndex);
              // Remove from queue
              processingQueue.forEach(function(value, key) {
                if (value === fileIndex) {
                  processingQueue.splice(key, 1);
                }
              });
              filesRejected++;
              return true;
            }

            reader.onerror = function(e) {
                switch(e.target.error.code) {
                    case e.target.error.NOT_FOUND_ERR:
                        opts.error(errors[4]);
                        return false;
                    case e.target.error.NOT_READABLE_ERR:
                        opts.error(errors[5]);
                        return false;
                    case e.target.error.ABORT_ERR:
                        opts.error(errors[6]);
                        return false;
                    default:
                        opts.error(errors[7]);
                        return false;
                };
            };

            reader.onloadend = !opts.beforeSend ? send : function (e) {
              opts.beforeSend(files[fileIndex], fileIndex, function () { send(e); });
            };

            reader.readAsBinaryString(files[fileIndex]);

          } else {
            filesRejected++;
          }
        } catch (err) {
          // Remove from queue
          processingQueue.forEach(function(value, key) {
            if (value === fileIndex) {
              processingQueue.splice(key, 1);
            }
          });
          opts.error(errors[0]);
          return false;
        }

        // If we still have work to do,
        if (workQueue.length > 0) {
          process();
        }
      };

      var send = function(e) {

        var fileIndex = ((typeof(e.srcElement) === "undefined") ? e.target : e.srcElement).index;

        // Sometimes the index is not attached to the
        // event object. Find it by size. Hack for sure.
        if (e.target.index === undefined) {
          e.target.index = getIndexBySize(e.total);
        }

        var file = files[e.target.index],
            index = e.target.index;

        function finished_callback(serverResponse, timeDiff, xhr) {
          filesDone++;
          var result = opts.uploadFinished(index, file, serverResponse, timeDiff, xhr);

          if (filesDone === (files_count - filesRejected)) {
            afterAll();
          }

          // Remove from processing queue
          processingQueue.forEach(function(value, key) {
            if (value === fileIndex) {
              processingQueue.splice(key, 1);
            }
          });

          // Add to donequeue
          doneQueue.push(fileIndex);

          return result;
        }

        function on_error(status_text, status) {
          opts.error(status_text, file, fileIndex, status);
        }

        var fileName,
            fileData = e.target.result;
        if (typeof newName === "string") {
          fileName = newName;
        } else {
          fileName = file.name;
        }

        var extra_opts = { file: files[e.target.index],
                           index: e.target.index };

        do_xhr(fileName, fileData, file.type, extra_opts, "", finished_callback, on_error);

      };

      // Initiate the processing loop
      process();
    }

    function getIndexBySize(size) {
      for (var i = 0; i < files_count; i++) {
        if (files[i].size === size) {
          return i;
        }
      }

      return undefined;
    }

    function rename(name) {
      return opts.rename(name);
    }

    function beforeEach(file) {
      return opts.beforeEach(file);
    }

    function afterAll() {
      return opts.afterAll();
    }

    function dragEnter(e) {
      clearTimeout(doc_leave_timer);
      e.preventDefault();
      opts.dragEnter.call(this, e);
    }

    function dragOver(e) {
      clearTimeout(doc_leave_timer);
      e.preventDefault();
      opts.docOver.call(this, e);
      opts.dragOver.call(this, e);
    }

    function dragLeave(e) {
      clearTimeout(doc_leave_timer);
      opts.dragLeave.call(this, e);
      e.stopPropagation();
    }

    function docDrop(e) {
      e.preventDefault();
      opts.docLeave.call(this, e);
      return false;
    }

    function docEnter(e) {
      clearTimeout(doc_leave_timer);
      e.preventDefault();
      opts.docEnter.call(this, e);
      return false;
    }

    function docOver(e) {
      clearTimeout(doc_leave_timer);
      e.preventDefault();
      opts.docOver.call(this, e);
      return false;
    }

    function docLeave(e) {
      doc_leave_timer = setTimeout((function(_this) {
        return function() {
          opts.docLeave.call(_this, e);
        };
      })(this), 200);
    }

    return this;
  };

  function empty() {}

  try {
    if (XMLHttpRequest.prototype.sendAsBinary) {
        return;
    }
    XMLHttpRequest.prototype.sendAsBinary = function(datastr) {
      function byteValue(x) {
        return x.charCodeAt(0) & 0xff;
      }
      var ords = Array.prototype.map.call(datastr, byteValue);
      var ui8a = new Uint8Array(ords);
      this.send(ui8a.buffer);
    };
  } catch (e) {}

})(jQuery);