window.onload=function() {
  var url = "/" + window.location.search.substring(1);
  var xmlHttp = null;

  if (typeof XMLHttpRequest != 'undefined') { xmlHttp = new XMLHttpRequest(); }
  if (!xmlHttp ) {
    try { xmlHttp  = new ActiveXObject("Msxml2.XMLHTTP");
    } catch(e) {
      try { xmlHttp  = new ActiveXObject("Microsoft.XMLHTTP");
      } catch(e) { xmlHttp = null; }
    }
  }

  if (xmlHttp) {
    xmlHttp.open('GET', url, true);
    xmlHttp.onreadystatechange = function () { if( xmlHttp.readyState == 4 ) { handleComplete(xmlHttp); } };
    if( xmlHttp.overrideMimeType != null ) {
      xmlHttp.overrideMimeType('text/plain; charset=x-user-defined');
    }
    xmlHttp.send(null);
  }

  document.getElementById( "content" ).innerHTML = "<p><b>Fetching Mailbox... " + url + " (this may take a while, please be patient...)</b><br/></p>";
}

function handleComplete(transport) {
  switch ( transport.status ) {
    case 200: case 304:
      parsemail(transport.responseText);
      break;
    default:
      alert( "Oech" + transport.status + " " + transport.responseText );
      break;
  } 
}

var myStates = {
 nothingRead            : 0,
 inSinglePartMailHeader : 1,
 inMultiPartMailHeader  : 2,
 inSinglePartMailBody   : 3,
 inMultiPartMailBody    : 4,
 inMultiPartHeader      : 5,
 inMultiPartBody        : 6
};

function enlarge( id ) {
  var img = document.getElementById( id );
  var w = img.getAttribute( "width" );

  if( w == "200" || w == "200px" ) {
    img.setAttribute( "width", null );
  } else {
    img.setAttribute( "width", "200px" );
  }
}

function parsemail(mail) {
  var imgNr = 0, mailNr = 0, myState = myStates.nothingRead;

  var myContentType, myContentEncoding, myContentTransferEncoding;
  var multiPartDivider = "";
  var myMultiContentEncoding, myMultiContentTransferEncoding;
  var myMultiContentType, myMultiFilename;

  var myMail, myMailHeader, myMailBody;
  var myBodyContent = "";
  var myContainer = document.createDocumentFragment( );

  var lines = mail.split( "\n" );

  for(var i = 0; i < lines.length; i++ ) {
    line=lines[i];

    if( "From " == line.substring(0,5) ) {
      switch( myState ) {
        case myStates.inSinglePartMailBody:
          myMail.appendChild( myMailBody ); // Fall through
        default:
          myContainer.appendChild( myMail );
          break;
        case myStates.nothingRead:
          break;
      }

      myState = myStates.inSinglePartMailHeader;
      mailNr++;
      myMail = document.createElement( "div" );
      myMail.setAttribute( "id", "eMail" + mailNr );
      myMail.setAttribute( "class", "eMail" );
      myMailHeader = document.createElement( "div" );
      myMailHeader.setAttribute( "id", "eMailHeader" + mailNr );
      myMailHeader.setAttribute( "class", "eMailHeader" );
    }

    if( myState == myStates.inSinglePartMailHeader || myState == myStates.inMultiPartMailHeader ) {

      if( line == "" ) {
        myState += 2; // in*PartMailHeader -> in*PartMailBody
        myMail.appendChild( myMailHeader );
        myMailBody = document.createElement( "div" );
        myMailBody.setAttribute( "id", "eMailBody" + mailNr );
        myMailBody.setAttribute( "class", "eMailBody" );
        myBodyContent = "";
        continue;
      }

      // Header unfolding
      while( i < lines.length-1 && lines[i+1].match( /^\s+/ ) ) {
        line += lines[++i];
      }

      // Header lines may contain encoded words
      line = decode_header( line );

      // Display all header lines
      var textElement = document.createElement( "div" );
      textElement.appendChild( document.createTextNode( line ) );

      // Highlight important header lines
      if( line.match( /^From:|^To:/ ) ) {
        var refElement = document.createElement( "a" );
        refElement.setAttribute( "href", "mailto:" + line.replace( /^From:|^To: (.*)/, "$1" ) );
        refElement.appendChild( textElement );
        textElement = refElement;
        textElement.setAttribute( "class", "eMailHeaderVisible" );
      } else if ( line.match( /^Subject:|^Date:/ ) ) {
        textElement.setAttribute( "class", "eMailHeaderVisible" );
      } else {
        textElement.setAttribute( "class", "eMailHeaderInvisible" );
      }
      myMailHeader.appendChild( textElement );

      // Detect Content-Type and Content-Transfer-Encoding
      if( line.match( /^Content-Type:/ ) ) {
        myContentType = line.replace( /^Content-Type:\s*(.*?);?.*$/i, "$1" );
        myContentEncoding = line.replace( /^Content-Type:\s*.*?;.*charset=\"?(.*?)\"?(?:;|$).*/i, "$1" ).toLowerCase();
      } else if( line.match( /Content-Transfer-Encoding:/i ) ) {
        myContentTransferEncoding = line.replace( /Content-Transfer-Encoding:\s*(.*)/i, "$1" ).toLowerCase();
      }

      // Check for MIME Mail
      if( line.match( /Content-Type:\s*multipart.*boundary=.*/i ) ) {
        myState = myStates.inMultiPartMailHeader;
        multiPartDivider = line.replace( /.*boundary=\"?(.*?)\"?$/gi, "--$1" );
      }
    }

    if( myState >= myStates.inMultiPartMailBody ) {
      if( line == multiPartDivider || line == multiPartDivider + "--" ) {
        if( myState == myStates.inMultiPartBody ) {
          if( myMultiContentType.match( /image*/i ) ) {
            var myImage = document.createElement( "img" );
            var myImageId = "img"+imgNr;
            var myImageHint = document.createElement( "p" );

            var myDataURIPrefix = "data:" + myMultiContentType + ";";
            if( myMultiContentTransferEncoding == "base64" ) {
              myDataURIPrefix += "base64";
            }

            imgNr++;

            myImageHint.appendChild( document.createTextNode( "Click to enlarge image " + myMultiFilename + ":" ) );
            myImageHint.setAttribute( "class", "data-uri-image-hint" );

            myImage.setAttribute( "src",     myDataURIPrefix + "," + myBodyContent );
            myImage.setAttribute( "alt",     myMultiFilename );
            myImage.setAttribute( "class",   "data-uri-image" );
            myImage.setAttribute( "width",   "200px" );
            myImage.setAttribute( "id",      myImageId );
            myImage.setAttribute( "onClick", 'enlarge( "'+ myImage.id + '" )' );

            myMailBody.appendChild( myImageHint );
            myMailBody.appendChild( myImage );

          } else if( myMultiContentType.match( /text.plain/i ) ) {
            var myText = document.createElement( "pre" );
            myText.appendChild( document.createTextNode( myBodyContent ) );
            myText.setAttribute( "class", "eMailPlaintext" );
            myMailBody.appendChild( myText );
          } else if( myMultiContentType.match( /text.html/i ) ) {
            var myHTML = document.createElement( "div" );
            myHTML.innerHTML = myBodyContent;
            myMailBody.appendChild( myHTML );
          } else if( myMultiContentType.match( /text*/i ) ) {
            var myText = document.createElement( "div" );
            myText.appendChild( document.createTextNode( myBodyContent ) );
            myMailBody.appendChild( myText );
          } else {
            var myDownload = document.createElement( "div" );
            myDownload.setAttribute( "class", "data-uri-download" );
            myDownload.appendChild( document.createTextNode( "This email contains an attachement of the type " + myMultiContentType +". Right-Click to download it. ") );

            var myDataURIPrefix = "data:" + myMultiContentType + ";";
            if( myMultiContentTransferEncoding == "base64" ) {
              myDataURIPrefix += "base64";
            }

            var myRef = document.createElement( "a" );
            myRef.setAttribute( "href", myDataURIPrefix + "," + myBodyContent );
            myRef.setAttribute( "type", myMultiContentType );
            myRef.appendChild( document.createTextNode( myMultiFilename ) );

            myDownload.appendChild( myRef );
            myMailBody.appendChild( myDownload );
          }
          myMail.appendChild( myMailBody );
        }

        myState = myStates.inMultiPartHeader;
        myMultiContentType = "text/plain;"
        myMultiContentTransferEncoding = "";
        myMultiFilename = "document";

      } else {
        if( myState == myStates.inMultiPartHeader ) {
          if( line == "" ) {
            myState = myStates.inMultiPartBody;
            myBodyContent = "";
            continue;
          }

          // Header unfolding
          while( i < lines.length-1 && lines[i+1].match( /^\s+/ ) ) {
            line += lines[++i];
          }

          // Header lines may contain encoded words
          line = decode_header( line );

          if( line.match( /Content-Type:/ ) ) {
            myMultiContentType = line.replace( /Content-Type:\s*(.*?);.*/, "$1" ).toLowerCase();
            myMultiContentEncoding = line.replace( /Content-Type:\s*.*?;.*charset=\"?(.*?)\"?(?:;|$).*/i, "$1" ).toLowerCase();
          } else if( line.match( /Content-Transfer-Encoding:/i ) ) {
            myMultiContentTransferEncoding = line.replace( /Content-Transfer-Encoding:\s*(.*?)/, "$1" ).toLowerCase();
          }

          if( line.match( /.*name=/ ) ) {
            myMultiFilename = line.replace( /.*name="(.*)"/, "$1" );
          }
        } else {
          if( myMultiContentTransferEncoding == "quoted-printable" ) {
            line = decode_quotedprintable( line );
          }

          myBodyContent += decode_charsets( line, myMultiContentEncoding ) + "\n";
        }
      }
    }

    if( myState == myStates.inSinglePartMailBody ) {
      var textElement = document.createElement( "div" );

      if( myContentTransferEncoding == "quoted-printable" ) {
        line = decode_quotedprintable( line );
      }
      textElement.appendChild( document.createTextNode( decode_charsets( line, myContentEncoding ) ) );
      myMailBody.appendChild( textElement );
    }
  }

  switch( myState ) {
  case myStates.inMultiPartBody:
  case myStates.inSinglePartMailBody:
    myMail.appendChild( myMailBody );
  default:
    myContainer.appendChild( myMail );
    break;
  case myStates.nothingRead:
    myContainer.appendChild( document.createTextNode( "Your mailbox is empty. This can either mean that no email has been received yet, or that your email has been fetched and deleted already. You may want to try to reload." ) );
    break;
  }

  var div = document.createElement( "div" );
  div.setAttribute( "id", "content" );
  div.appendChild( myContainer );
  var vspace = document.createElement( "div" );
  vspace.setAttribute( "class", "vspace" );
  div.appendChild( vspace );

  var old_content = document.getElementById( "content" );
  old_content.parentNode.replaceChild( div, old_content );
}