/*
  Copyright (c) 2003-2004 Jan-Klaas Kollhof
  
  This file is part of the JavaScript o lait library(jsolait).
  
  jsolait is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.
 
  This software is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU Lesser General Public License for more details.
 
  You should have received a copy of the GNU Lesser General Public License
  along with this software; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

/**
    Provides an JSON-RPC imlementation.
*/
Module("jsonrpc", "0.3.2", function(mod){
    
    var lang = importModule("lang");
    var tokens =  lang.tokens;
    
    var ObjectBuffer=Class("ObjectBuffer", function(publ, supr){
        publ.init=function(){
            this.data="";
        }
        publ.getObjects=function(data){
            this.data += data;
            var t = new lang.Tokenizer(this.data);
            var brCnt= 0;
            var objects = [];
            var readCnt = 0
            while(! t.finished()){
                var n = t.next();
                if(n.type != tokens.ERR){
                    if(n.value == "{"){
                        brCnt+=1;
                    }else if(n.value == "}"){
                        brCnt-=1;
                        if(brCnt==0){
                            var s = this.data.slice(readCnt, n.pos+1);
                            readCnt += s.length;
                            objects.push(s);
                        }
                    }
                }else{
                    break;
                }
            }
            this.data = this.data.slice(readCnt);
            return objects;
        }
    })
    
    var nameAllowed=function(name){
        return name.match(/^[a-zA-Z]\w*$/) != null;
    }
    
    var getMethodByName=function(obj, name){
        try{//to get a method by asking the service
            obj = obj._getMethodByName(name)
        }catch(e){
            var names = name.split(".");
            for(var i=0;i<names.length;i++){
                name = names[i];
                if(nameAllowed(name)){
                    obj = obj[name];
                }
            }
        }
        return obj;
    }
    
    var Response=Class("Response", function(publ, supr){
        publ.init=function(id, result, error){
            this.id=id;
            this.result = result;
            this.error = error;
        }
        publ._toJSON=function(){
            var p = [lang.objToJson(this.id), lang.objToJson(this.result),lang.objToJson(this.error)];
            return '{"id":' + p[0] + ', "result":' + p[1] + ', "error":' + p[2] + "}";
        }
    })
    
    var Request=Class("Request", function(publ, supr){
        publ.init=function(id, method, params){
            this.id=id;
            this.method = method;
            this.params = params;
        }
        publ._toJSON=function(){
            var p = [lang.objToJson(this.id), lang.objToJson(this.method),lang.objToJson(this.params)];
            return '{"id":' + p[0] + ', "method":' + p[1] + ', "params":' + p[2] + "}";
        }
    })
    
    var Notification=Class("Notification", function(publ, supr){
        publ.init=function(method, params){
            this.method = method;
            this.params = params;
        }
        publ._toJSON=function(){
            var p = [lang.objToJson(this.method),lang.objToJson(this.params)];
            return '{"method":' + p[0] + ', "params":' + p[1] + "}";
        }
    })
    
    var ResponseHandler=Class("ResponseHandler", function(publ, supr){
        publ.init=function(callback){
            this.callback=callback;
        }
        publ.handleResponse=function(resp){
            this.callback(resp.result, resp.error);
        }
    })
    
    var RPCLib = Class("RPCLib", function(publ, supr){
        
    })
    
    var BaseConnectionHandler = Class("BaseConnectionHandler",  function(publ, supr){
        publ.init=function(service){
            this.service = service;
            this.jsonParser = new lang.JSONParser();
            this.jsonParser.addLib(new RPCLib(), "rpc", []);
            this.respHandlers = [];
            this.objBuffer = new ObjectBuffer();
        }
                
        publ.addResponseHandler=function(cb){
            var id=1;
            while(this.respHandlers[""+id] ){
                id+=1;
            }
            id="" + id;
            this.respHandlers[id] = new ResponseHandler(cb);
            return id;
        }
        
        publ.send = function(data){
        }
        
        publ.sendNotify = function(name, args){
            var n = new Notification(name, args);
            n = this.jsonParser.objToJson(n);
            this.send(n)
        }
        
        publ.sendRequest = function(name, args, callback){
            var id = this.addResponseHandler(callback);
            var r = new Request(id, name, args);
            r = this.jsonParser.objToJson(r);
            this.send(r);
        }
        
        publ.sendResponse = function(id, result, error){
            var r = new Response(id, result, error);
            r = this.jsonParser.objToJson(r);
            this.send(r);
        }
        
        publ.handleRequest = function(req){
            var name = req.method;
            var params = req.params;
            var id=req.id;
            if(this.service[name]){
                try{
                    var rslt = this.service[name].apply(this.service,params);
                    this.sendResponse(id, rslt, null)
                }catch(e){
                    this.sendResponse(id, null, new ApplicationError("" + e))
                }
            }else{
                this.sendResponse(id, null, new MethodNotFound());
            }
        }
        
        publ.handleNotification = function(notif){
            if(this.service[notif.method]){
                try{
                    this.service[notif.method].apply(this.service, notif.params);
                }catch(e){
                }
            }
        }
        
        publ.handleResponse = function(resp){
            var id=resp.id;
            var h = this.respHandlers[id];
            h.handleResponse(resp)
            delete this.respHandlers[id]
        }
        
        publ.handleData = function(data){
            var objs = this.objBuffer.getObjects(data);
            for(var i=0;i<objs.length;i++){
                try{
                    var obj = this.jsonParser.jsonToObj(objs[i]);
                }catch(e){
                    throw "Not well formed";
                }
                if(obj.method != null){ 
                    if(obj.id != null){
                        this.handleRequest(new Request(obj.id, obj.method, obj.params));
                    }else{
                        this.handleNotification(new Notification(obj.method, obj.params));
                    }
                }else if(obj.id != null){
                     this.handleResponse(new Response(obj.id, obj.result, obj.error));
                }else{
                   throw "Unknown Data";
                }
            }
        }
    })
    
    var SocketConnectionHandler = Class("SocketConnectionHandler", BaseConnectionHandler, function(publ, supr){
        publ.init=function(socket, localService){
            this.socket = socket;
            socket.addEventListener("connectionData", this, false);
            supr(this).init( localService);
        }
        
        publ.handleEvent=function(evt){
            this.handleData(evt.data);
        }
        
        publ.send=function(data){
            this.socket.send(data);
        }
        
        publ.close=function(data){
            this.socket.close();
        }
    })
    
    var HTTPConnectionHandler = Class("HTTPConnectionHandler", BaseConnectionHandler, function(publ, supr){
        var urllib;
        publ.init=function(url, localService){
            urllib=importModule("urllib");
            this.url = url;
            supr(this).init( localService);
        }
                
        publ.handleData = function(data){
            try{
                var obj = this.jsonParser.jsonToObj(data);
            }catch(e){
                throw "Not well formed";
            }
            if(obj.id != null){
                return obj;
            }else{
                throw "Unknown Data (No id property found)";
            }  
        }
        
        publ.sendRequest = function(name, args, callback){
            var sync = false;
            if(typeof callback != "function"){//see if it is sync
                args.push(callback); 
                sync=true;
            }
            var data = new Request("httpReq", name, args);
            data = this.jsonParser.objToJson(data);
            if(sync){
                var rsp = urllib.postURL(this.url, data, [["Content-Type", "text/plain"]]);
                rsp = this.handleData(rsp.responseText);
                if(rsp.error){
                    throw rsp.error;
                }else{
                    return rsp.result;
                }
            }else{//async connection uses the respHandler to handle the repsonse
                var self = this;
                urllib.postURL(this.url, data, [["Content-Type", "text/plain"]], function(rsp){
                    try{
                        rsp = self.handleData(rsp.responseText);
                    }catch(e){
                        callback(null,e);
                        return;
                    }
                    callback(rsp.result, rsp.error);
                });
            }
        }
        
        publ.sendNotify = function(name, args){
            var data = new Notification(name, args);
            data = this.jsonParser.objToJson(data);
            urllib.postURL(this.url, data, [["Content-Type", "text/plain"]], function(rsp){});
        }
    })
    
    var PeerObject=Class("PeerObject", function(publ, supr){
        publ.init=function(name, conn){
            var fn=function(){
                var args=[];
                for(var i=0;i<arguments.length;i++){
                    args[i] = arguments[i];
                }
                var cb=args.pop();
                return conn.sendRequest(name, args, cb);
            }
            return fn;
        }
    })
     
    var PeerNotifyObject=Class("PeerNotifyObject", function(publ, supr){
        publ.init=function(name, conn){
            var fn=function(){
                var args=[];
                for(var i=0;i<arguments.length;i++){
                    args[i] = arguments[i];
                }
                conn.sendNotify(name, args);
            }
            return fn;
        }
    })
    
    var BasePeer = Class("BasePeer", function(publ, supr){
        publ.init=function(conn, methodNames){
            this._conn = conn;
            this.notify = new PeerObject("notify", conn);
            this._add(methodNames);
        }
        
        var setupPeerMethod=function(root, methodName, conn, MethClass){
            var names = methodName.split(".");
            var obj = root;
            for(var n=0;n<names.length-1;n++){
                var name = names[n];
                if(obj[name]){
                    obj = obj[name];
                }else{
                    obj[name] = new Object();
                    obj = obj[name];
                }
            }
            var name = names[names.length-1];
            if(obj[name]){
            }else{
                var mth = new MethClass(methodName, conn);
                obj[name] = mth;
            }
        }
        
        publ._add = function(methodNames){
            for(var i=0;i<methodNames.length;i++){
                setupPeerMethod(this, methodNames[i], this._conn, PeerObject);
                setupPeerMethod(this.notify, methodNames[i], this._conn, PeerNotifyObject);
            }
        }
    })
    
    
    mod.ServiceProxy = Class("ServiceProxy", BasePeer, function(publ, supr){
        publ.init = function(url, methodNames, localService){
            var n = url.match(/^jsonrpc:\/\/(.*:\d*)$/);
            if(n!=null){//is it  json-rpc over TCP protocoll 
                var hostaddr = n[1];
                try{
                    var socket = createConnection();
                }catch(e){
                    throw "Can't create a socket connection."
                }
                socket.connect(hostaddr);
                supr(this).init( new SocketConnectionHandler(socket, localService), methodNames);
            }else{//or is it json-rpc over http
                supr(this).init( new HTTPConnectionHandler(url, localService), methodNames);
            }
        }
    })
})