/*************************************************************************
http.request() function
====================
The http.request() function will fetch a web address asynchronously (on a
separate thread)and pass the URL's response to a callback function
which will be executed synchronously (on the main thread).  In this
way, http.request() can be used to fetch web content without blocking the
main thread of execution.

Parameters
----------

 * request: The request details either a plain URL e.g. "http://scriptcraft.js/sample.json" or an object with the following properties...

   - url: The URL of the request.
   - method: Should be one of the standard HTTP methods, GET, POST, PUT, DELETE (defaults to GET).
   - params: A Javascript object with name-value pairs. This is for supplying parameters to the server.

 * callback: The function to be called when the Web request has completed. This function takes the following parameters...
   - responseCode: The numeric response code from the server. If the server did not respond with 200 OK then the response parameter will be undefined.
   - response: A string (if the response is of type text) or object containing the HTTP response body.

Example
-------
The following example illustrates how to use http.request to make a request to a JSON web service and evaluate its response...

    var jsResponse;
    http.request("http://scriptcraftjs.org/sample.json",function(responseCode, responseBody){
        jsResponse = eval("(" + responseBody +  ")");
    });

... The following example illustrates a more complex use-case POSTing parameters to a CGI process on a server...

    http.request({ url: "http://pixenate.com/pixenate/pxn8.pl",
                   method: "POST",
                   params: {script: "[]"}
                 }, function( responseCode, responseBody){
          var jsObj = eval("(" + responseBody + ")");
      });

***/
var http = http || {};

http.request = function( request, callback)
{
    var paramsToString = function(params){
        var result = "";
        var paramNames = [];
        for (var i in params){
            paramNames.push(i);
        }
        for (var i = 0;i < paramNames.length;i++){
            result += paramNames[i] + "=" + encodeURI(params[paramNames[i]]);
            if (i < paramNames.length-1)
                result += "&";
        }
        return result;
    };
    
    server.scheduler.runTaskAsynchronously(__plugin,function() 
    {
        var url, paramsAsString, conn, requestMethod;
        if (typeof request === "string"){
            url = request;
            requestMethod = "GET";
        }else{
            paramsAsString = paramsToString(request.params);
            requestMethod = request.method || "GET";
            if (requestMethod == "GET" && request.params){
                // append each parameter to the URL
                url = request.url + "?" + paramsAsString;
            }
        }
        conn = new java.net.URL(url).openConnection();
        conn.requestMethod = requestMethod;
        conn.doOutput = true;
        conn.instanceFollowRedirects = false;

        if (conn.requestMethod == "POST"){
            conn.doInput = true;
            // put each parameter in the outputstream
            conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); 
            conn.setRequestProperty("charset", "utf-8");
            conn.setRequestProperty("Content-Length", "" + paramsAsString.length);
            conn.useCaches =false ;
            wr = new java.io.DataOutputStream(conn.getOutputStream ());
            wr.writeBytes(paramsAsString);
            wr.flush();
            wr.close();
        }
        var rc = conn.responseCode;
        var response;
        var stream;
        if (rc == 200){
            stream = conn.getInputStream();
            response = new java.util.Scanner(stream).useDelimiter("\\A").next();
        }
        server.scheduler.runTask(__plugin,function(){
            callback(rc,response);
        });
    });
};