//  DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
//
//   Copyright 2016-2018 Pascal ECHEMANN.
//
//   Licensed under the Apache License, Version 2.0 (the "License");
//   you may not use this file except in compliance with the License.
//   You may obtain a copy of the License at
//
//       http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the License is distributed on an "AS IS" BASIS,
//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//   See the License for the specific language governing permissions and
//   limitations under the License.

import {HttpRequest, HttpResponse} from "jec-exchange";
import {LogLevel, HttpStatusCode} from "jec-commons";
import {SandcatLoggerProxy} from "../logging/SandcatLoggerProxy";
import {SandcatLocaleManager} from "../i18n/SandcatLocaleManager";

/**
 * A helper class that creates and returns a function used as callback handler
 * by <code>ResourceJsletProxy</code> implementations.
 */
export class ResponseHandlerBuilder {

  //////////////////////////////////////////////////////////////////////////////
  // Constructor function
  //////////////////////////////////////////////////////////////////////////////

  /**
   * Creates a new <code>ResponseHandlerBuilder</code> instance.
   */
  constructor() {}

  //////////////////////////////////////////////////////////////////////////////
  // Public methods
  //////////////////////////////////////////////////////////////////////////////

  /**
   * Creates and returns a new callback handler for a
   * <code>ResourceJsletProxy</code> implementation.
   * 
   * @param {HttpRequest} req the HTTP request for the current HTTP transaction.
   * @param {HttpResponse} res the HTTP response for the current HTTP
   *                           transaction.
   * @param {Function} exit the function used by the container to handle
   *                        asynchronous answers for this jslet.
   * @return {Function} a new callback handler function. 
   */
  public build(req:HttpRequest, res:HttpResponse,
          exit:(req:HttpRequest, res:HttpResponse, data:any) => void):Function {
    const handler:Function = (data?:any, err?:any, status?:HttpStatusCode)=>{
        if(err) {
          //TODO: build a better error process:
          SandcatLoggerProxy.getInstance().log(
            SandcatLocaleManager.getInstance().get("errors.sandcat", err),
            LogLevel.ERROR
          );
          exit(
            req,
            res.sendStatus(status || HttpStatusCode.INTERNAL_SERVER_ERROR),
            null
          );
        } else {
          if(status) res.status(status);
          //console.log(data)
          res.send(data)
          exit(req, res, null);
        }
      };
    return handler;
  }
};