/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2015 Ziver Koc
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

package zutil.net.ws.rest;

import zutil.converter.Converter;
import zutil.io.StringOutputStream;
import zutil.net.http.HttpHeader;
import zutil.net.http.HttpPage;
import zutil.net.http.HttpPrintStream;
import zutil.net.ws.WSInterface;
import zutil.net.ws.WSMethodDef;
import zutil.net.ws.WSParameterDef;
import zutil.net.ws.WebServiceDef;
import zutil.parser.json.JSONObjectOutputStream;

import java.io.IOException;
import java.util.List;
import java.util.Map;

/**
 * User: Ziver
 */
public class RESTHttpPage implements HttpPage {

    /** The object that the functions will be invoked from **/
    private WebServiceDef wsDef;
    /** This instance of the web service class is used if session is disabled **/
    private WSInterface ws;


    public RESTHttpPage(WSInterface wsObject ){
        this.ws = wsObject;
        this.wsDef = new WebServiceDef(ws.getClass());
    }


    @Override
    public void respond(HttpPrintStream out,
                        HttpHeader headers,
                        Map<String, Object> session,
                        Map<String, String> cookie,
                        Map<String, String> request) throws IOException {
        try {
            out.println(
                    execute(headers.getRequestURL(), request));
        } catch (Throwable throwable) {
            throw new IOException(throwable);
        }
    }


    protected String execute(String targetMethod, Map<String, String> input) throws Exception {
        if (wsDef.hasMethod(targetMethod)) {
            // Parse request
            WSMethodDef m = wsDef.getMethod(targetMethod);
            Object[] inputParams = prepareInputParams(m, input);

            // Invoke
            Object ret = m.invoke(ws, inputParams);

            // Generate Response
            StringOutputStream strBuffer = new StringOutputStream();
            JSONObjectOutputStream out = new JSONObjectOutputStream(strBuffer);
            out.enableMetaData(false);
            out.writeObject(ret);
            out.close();
            return strBuffer.toString();
        }
        return "{error: \"Unknown target: "+targetMethod+"\"}";
    }

    private Object[] prepareInputParams(WSMethodDef methodDef, Map<String, String> input){
        List<WSParameterDef> inputParamDefs = methodDef.getInputs();
        Object[] inputParams = new Object[inputParamDefs.size()];

        // Get the parameter values
        for (int i=0; i<inputParamDefs.size(); i++){
            WSParameterDef param = inputParamDefs.get(i);
            if (input.containsKey(param.getName())){
                inputParams[i] = Converter.fromString(
                        input.get(param.getName()),
                        param.getParamClass());
            }
        }
        return inputParams;
    }
}
