//****************************************************************************
// Licence:
// 1. Keep this copyright notice.
// 2. Keep attribution to any authors listed above, including yourself
// 3. Use it for free.
//****************************************************************************
// Log of changes:
//
// 0.5 - 16 Mar 2005: HttpResponse Headers improved
// 0.4 - 15 Mar 2005: HttpRequest and OpenEx added by esskar
// 0.3 - 15 Mar 2005: Header usage fixed by esskar
// 0.2 - 15 Mar 2005: Copyright included by esskar
// 0.1 - 14 Mar 2005: Project started by Sascha Kiefer (esskar)
//
//****************************************************************************

var HTTPERROR_SUCCESS       = 0;
var HTTPERROR_INVALIDOBJECT = 1;
var HTTPERROR_CALLBACK      = 2;
var HTTPERROR_OPEN          = 3;

function Http(Interface) {
   //Properties
   this.Version = '0.5';
   this.IsAsync = false;
   this.Interface = Interface;
   this.LastException = '';

   if(this.Interface == null) {
       if(typeof XMLHttpRequest != 'undefined') {
           /* try this first; maybe MS
              will implement it someday :) */
           this.Interface = new XMLHttpRequest();
       }

       if(this.Interface == null) {
           var axos = new Array( // newest on top
               'MSXML2.XMLHTTP.4.0',
               'MSXML2.XMLHTTP.3.0',
               'MSXML2.XMLHTTP',
               'Microsoft.XMLHTTP'
           );

           for(var i = 0; this.Interface == null && i < axos.length; i++ ) {
               try {
                   this.Interface = new ActiveXObject(axos[i]);
               } catch(e) {
                   this.LastException = e;
                   this.Interface = null;
               }
           }
       }
   }

   //Methods
   this.IsValid = CallHttpIsValid;
   this.Get = CallHttpGet;
   this.Post = CallHttpPost;
   this.Open = CallHttpOpen;
   this.OpenEx = CallHttpOpenEx;
   this.SetHeader = CallHttpSetHeader;
   this.GetResponse = CallHttpGetResponse;
}

function CallHttpIsValid() {
   return this.Interface != null;
}

function HttpRequest() {
   this.Method = 'GET';
   this.Url = '';
   this.Headers = new Array();
   this.Body = null;
   this.Callback = null;
}


function CallHttpOpenEx(req) {
   return this.Open(
       req.Method,
       req.Url,
       req.Body,
       req.Callback,
       req.Headers
   );
}

function CallHttpOpen(method, url, data, callback, headers) {
   if(this.IsValid()) {
       if(!method) method = 'GET';
       if(!data)   data   = null;
       if(this.IsAsync) {
           if(typeof callback != 'function')
               return HTTPERROR_CALLBACK;

           this.Interface.onreadystatechange = callback;
       }

       try {
           this.Interface.open(method, url, this.IsAsync);
       } catch(e) { // probably: 'access is denied'
           this.LastException = e;
           return HTTPERROR_OPEN;
       }

       // Send userdefined headers
       if(headers != null) {
           for(var header in headers) {
               this.SetHeader(header, headers[header]);
           }
       }

       this.Interface.send(data);

       return HTTPERROR_SUCCESS;
   }

   return HTTPERROR_INVALIDOBJECT;
}

function CallHttpGet(url, callback, headers) {
   return this.Open('GET', url, null, callback, headers);
}

function CallHttpPost(url, data, callback, headers) {
   return this.Open('POST', url, data, callback, headers);
}

function CallHttpSetHeader(headername, headervalue) {
   if(!this.IsValid())
       return false;

   var retval = true;
   try {
       this.Interface.setRequestHeader(headername, headervalue);
   } catch(e) {
       retval = false;
       this.LastException = e;
   }

   return retval;
}

function HttpResponse() {
    this.Status = 0;
    this.StatusText = '';
    this.Headers = new Array;
    this.Body = '';
    this.Text = '';
    this.Xml = '';

    this.SetHeaderString = CallHttpResponseSetHeaderString;
}

function CallHttpResponseSetHeaderString(string) {
    if(!string) string = '';

    var lines = string.split("\n");
    for(var i = 0; i < lines.length; i++) {
        var header = lines[i].split(": ");
        if(header.length >= 2) {
            var headername  = header.shift();
            var headervalue = header.join(": ");

            this.Headers[headername] = headervalue;
        }
    }
}

function CallHttpGetResponse() {
    if(this.Interface.readyState != 4)
        return null;

    var res = new HttpResponse();

    res.Status      = this.Interface.status;
    res.StatusText  = typeof this.Interface.statusText == 'undefined'
                        ? ''
                        : this.Interface.statusText;
    res.Body        = typeof this.Interface.responseBody == 'undefined'
                        ? ''
                        : this.Interface.responseBody;
    res.Text        = typeof this.Interface.responseText == 'undefined'
                        ? ''
                        : this.Interface.responseText;
    res.Xml         = this.Interface.responseXML == null
                        ? ''
                        : this.Interface.responseXML.xml;

    res.SetHeaderString(this.Interface.getAllResponseHeaders());

    return res;
}