/*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:[],
      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,
      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);
    $(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) {
      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 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));
    }

    // 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 xhr = new XMLHttpRequest(),
            upload = xhr.upload,
            file = files[e.target.index],
            index = e.target.index,
            start_time = new Date().getTime(),
            boundary = '------multipartformboundary' + (new Date()).getTime(),
            global_progress_index = global_progress.length,
            builder,
            newName = rename(file.name),
            mime = file.type;
        // 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;
        }

        if (typeof newName === "string") {
          builder = getBuilder(newName, e.target.result, mime, boundary);
        } else {
          builder = getBuilder(file.name, e.target.result, mime, boundary);
        }

        upload.index = index;
        upload.file = file;
        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(), true);
	    } else {
	    	xhr.open("POST", opts.url, 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();

        opts.uploadStarted(index, file, files_count);

        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 = opts.uploadFinished(index, file, serverResponse, timeDiff, xhr);
            filesDone++;

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

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

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

            if (filesDone === (files_count - filesRejected)) {
              afterAll();
            }
            if (result === false) {
              stop_loop = true;
            }
          

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

      // 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);