module AppliciousUtils
  module ViewHelpers

    #  Creates an instance of a plupload S3 file uploader
    ###
    # required parameters:
    ###
    #  key                       s3 'path' to uploaded files
    #
    ###
    # optional parameters:
    ###
    #  s3_config_filename        filename of s3 config yaml file (full path), defaults to "#{RAILS_ROOT}/config/amazon_s3.yml"
    #
    #  content_type              binary/octet-stream
    #
    #  acl                       public-read
    #
    #  expiration_date           10.hours.from_now.utc.iso8601
    #
    #  max_filesize              2.megabytes

    def s3_uploader(options = {})
      options[:s3_config_filename] ||= "#{Rails.root}/config/amazon_s3.yml"
      config = YAML.load_file(options[:s3_config_filename])[Rails.env].symbolize_keys
      bucket            = config[:bucket_name]
      access_key_id     = config[:access_key_id]
      secret_access_key = config[:secret_access_key]

      options[:key] ||= 'test'  # folder on AWS to store file in
      options[:acl] ||= 'public-read'
      options[:expiration_date] ||= 10.hours.from_now.utc.iso8601
      options[:max_filesize] ||= 500.megabytes
      options[:content_type] ||= 'image/' # Videos would be binary/octet-stream
      options[:filter_title] ||= 'Images'
      options[:filter_extentions] ||= 'jpg,jpeg,gif,png,bmp'

      id = options[:id] ? "_#{options[:id]}" : ''

      policy = Base64.encode64(
        "{'expiration': '#{options[:expiration_date]}',
          'conditions': [
            {'bucket': '#{bucket}'},
            {'acl': '#{options[:acl]}'},
            {'success_action_status': '201'},
            ['content-length-range', 0, #{options[:max_filesize]}],
            ['starts-with', '$key', ''],
            ['starts-with', '$Content-Type', ''],
            ['starts-with', '$name', ''],
            ['starts-with', '$Filename', '']
          ]
        }").gsub(/\n|\r/, '')

      signature = Base64.encode64(
                    OpenSSL::HMAC.digest(
                      OpenSSL::Digest::Digest.new('sha1'),
                      secret_access_key, policy)).gsub("\n","")

      out = ""

      out << javascript_tag("$(function() {

        /*
         * S3 Uploader instance
        */
        // image uploader via plupload
          var uploader = new plupload.Uploader({
              runtimes : 'html5,flash,silverlight',
              browse_button : 'pickfiles',
              max_file_size : '500mb',
              url : 'http://#{bucket}.s3.amazonaws.com/',
              flash_swf_url: 'applicious/plupload/plupload.flash.swf',
              silverlight_xap_url: '/applicious/plupload/plupload.silverlight.xap',
              init : {
                FilesAdded: function(up, files) {
                  plupload.each(files, function(file) {
                    if (up.files.length > 1) {
                      up.removeFile(file);
                    }
                  });
                  if (up.files.length >= 1) {
                    $('#pickfiles').fadeOut('slow');
                  }
                },
                FilesRemoved: function(up, files) {
                  if (up.files.length < 1) {
                    $('#pickfiles').fadeIn('slow');
                  }
                }
              },
              multi_selection: false,
              multipart: true,
              multipart_params: {
                'key': 'test/${filename}',
                'Filename': '${filename}', // adding this to keep consistency across the runtimes
          			'acl': '#{options[:acl]}',
          			'Content-Type': '#{options[:content_type]}',
          			'success_action_status': '201',
          			'AWSAccessKeyId' : '#{access_key_id}',		
          			'policy': '#{policy}',
          			'signature': '#{signature}'
               },
              filters : [
                  {title : '#{options[:filter_title]}', extensions : '#{options[:filter_extentions]}'}
              ],
              file_data_name: 'file'
          });
        
          // instantiates the uploader
          uploader.init();
        
          // shows the progress bar and kicks off uploading
          uploader.bind('FilesAdded', function(up, files) {
              $('#progress_bar .ui-progress').css('width', '5%');
              $('span.ui-label').show();
        
              // start the uploader after the progress bar shows
              $('#progress_bar').show(function () {               
                uploader.start();
              });
          });

          // binds progress to progress bar
          uploader.bind('UploadProgress', function(up, file) {
              if(file.percent < 100){
                  $('#progress_bar .ui-progress').css('width', file.percent+'%');
              }
              else {
                  $('#progress_bar .ui-progress').css('width', '100%');
                  $('span.ui-label').text('Complete');
              }                               
          });

          // shows error object in the browser console (for now)
          uploader.bind('Error', function(up, error) {
            // unfortunately PLUpload gives some extremely vague 
            // Flash error messages so you have to use WireShark
            // for debugging them (read the README)
          
            alert('There was an error.  Check the browser console log for more info');
            console.log('Expand the error object below to see the error. Use WireShark to debug.');
          
            console.log(error);
          });
      
      });")
  
    end
  end
end