(function(root, factory) {
  if (typeof define === 'function' && define.amd) {
    // AMD. Register as an anonymous module.
    define(['superagent', 'querystring'], factory);
  } else if (typeof module === 'object' && module.exports) {
    // CommonJS-like environments that support module.exports, like Node.
    module.exports = factory(require('logtown').getLogger('orbipay-paymentsapi-client/src/ApiClient'), require('superagent'), require('querystring'), require('./CommonUtil'), require('crypto'));
  } else {
    // Browser globals (root is window)
    if (!root.OrbipayPaymentsapiClient) {
      root.OrbipayPaymentsapiClient = {};
    }
    root.OrbipayPaymentsapiClient.ApiClient = factory(root.superagent, root.querystring);
  }
}(this, function(logger, superagent, querystring, CommonUtil, crypto) {
  'use strict';

  /**
   * @module ApiClient
   */

  /**
   * <h3 style="color:red"> This class subject to change without prior notice, Please dont use this class directly. </h3>

   * Manages low level client-server communications, parameter marshalling, etc. There should not be any need for an
   * application to use this class directly - the *Api and model classes provide the public API for the service. The
   * contents of this file should be regarded as internal but are documented for completeness.
   * @alias module:ApiClient
   * @class
   */
  var exports = function(clientSignatureKey, basePath, clientApiKey, authScheme) {
    /**
     * The base URL against which to resolve every API call's (relative) path.
     * @type {String}
     * @default https://api.orbipay.com/payments/v1
     */
    this.basePath = basePath;

    /**
     * The authentication methods to be included for all API calls.
     * @type {Array.<String>}
     */
    this.authentications = {
    };
    /**
     * The default HTTP headers to be included for all API calls.
     * @type {Array.<String>}
     * @default {}
     */
    this.defaultHeaders = {};

    /**
     * The default HTTP timeout for all API calls.
     * @type {Number}
     * @default 60
     */
    this.timeout = 60;

    /**
     * If set to false an additional timestamp parameter is added to all API GET calls to
     * prevent browser caching
     * @type {Boolean}
     * @default true
     */
    this.cache = true;

    /**
     * If set to true, the client will save the cookies from each server
     * response, and return them in the next request.
     * @default false
     */
    this.enableCookies = false;

    /*
     * Used to save and return cookies in a node.js (non-browser) setting,
     * if this.enableCookies is set to true.
     */
    if (typeof window === 'undefined') {
      this.agent = new superagent.agent();
    }

    /*
     * Allow user to override superagent agent
     */
    this.requestAgent = null;

    this.clientSignatureKey = clientSignatureKey;
    this.clientApiKey = clientApiKey;
    this.authScheme = authScheme;

  };

  /**
   * Returns a string representation for an actual parameter.
   * @param param The actual parameter.
   * @returns {String} The string representation of <code>param</code>.
   */
  exports.prototype.paramToString = function(param) {
    if (param === undefined || param === null) {
      return '';
    }
    if (param instanceof Date) {
      return param.toJSON();
    }
    return param.toString();
  };

  /**
   * Builds full URL by appending the given path to the base URL and replacing path parameter place-holders with parameter values.
   * NOTE: query parameters are not handled here.
   * @param {String} path The path to append to the base URL.
   * @param {Object} pathParams The parameter values to append.
   * @returns {String} The encoded path with parameter values substituted.
   */
  exports.prototype.buildUrl = function(path, pathParams) {
    if (!path.match(/^\//)) {
      path = '/' + path;
    }
    var url = this.basePath + path;
    var _this = this;
    url = url.replace(/\{([\w-]+)\}/g, function(fullMatch, key) {
      var value;
      if (pathParams.hasOwnProperty(key)) {
        value = _this.paramToString(pathParams[key]);
	if(exports.isEmptyString(value)){
          logger.error('Missing the required parameter ' + key);
          throw new Error('Missing the required parameter ' + key);
        }
      } else {
        value = fullMatch;
      }
      return encodeURIComponent(value);
    });
    return url;
  };

  /**
   * Checks whether the given content type represents JSON.<br>
   * JSON content type examples:<br>
   * <ul>
   * <li>application/json</li>
   * <li>application/json; charset=UTF8</li>
   * <li>APPLICATION/JSON</li>
   * </ul>
   * @param {String} contentType The MIME content type to check.
   * @returns {Boolean} <code>true</code> if <code>contentType</code> represents JSON, otherwise <code>false</code>.
   */
  exports.prototype.isJsonMime = function(contentType) {
    return Boolean(contentType != null && contentType.match(/^application\/json(;.*)?$/i));
  };

  /**
   * Chooses a content type from the given array, with JSON preferred; i.e. return JSON if included, otherwise return the first.
   * @param {Array.<String>} contentTypes
   * @returns {String} The chosen content type, preferring JSON.
   */
  exports.prototype.jsonPreferredMime = function(contentTypes) {
    for (var i = 0; i < contentTypes.length; i++) {
      if (this.isJsonMime(contentTypes[i])) {
        return contentTypes[i];
      }
    }
    return contentTypes[0];
  };

  /**
   * Checks whether the given parameter value represents file-like content.
   * @param param The parameter to check.
   * @returns {Boolean} <code>true</code> if <code>param</code> represents a file.
   */
  exports.prototype.isFileParam = function(param) {
    // fs.ReadStream in Node.js and Electron (but not in runtime like browserify)
    if (typeof require === 'function') {
      var fs;
      try {
        fs = require('fs');
      } catch (err) {}
      if (fs && fs.ReadStream && param instanceof fs.ReadStream) {
        return true;
      }
    }
    // Buffer in Node.js
    if (typeof Buffer === 'function' && param instanceof Buffer) {
      return true;
    }
    // Blob in browser
    if (typeof Blob === 'function' && param instanceof Blob) {
      return true;
    }
    // File in browser (it seems File object is also instance of Blob, but keep this for safe)
    if (typeof File === 'function' && param instanceof File) {
      return true;
    }
    return false;
  };

  /**
   * Normalizes parameter values:
   * <ul>
   * <li>remove nils</li>
   * <li>keep files and arrays</li>
   * <li>format to string with `paramToString` for other cases</li>
   * </ul>
   * @param {Object.<String, Object>} params The parameters as object properties.
   * @returns {Object.<String, Object>} normalized parameters.
   */
  exports.prototype.normalizeParams = function(params) {
    var newParams = {};
    for (var key in params) {
      if (params.hasOwnProperty(key) && params[key] != undefined && params[key] != null) {
        var value = params[key];
        if (this.isFileParam(value) || Array.isArray(value)) {
          newParams[key] = value;
        } else {
          newParams[key] = this.paramToString(value);
        }
      }
    }
    return newParams;
  };

  /**
   * Enumeration of collection format separator strategies.
   * @enum {String}
   * @readonly
   */
  exports.CollectionFormatEnum = {
    /**
     * Comma-separated values. Value: <code>csv</code>
     * @const
     */
    CSV: ',',
    /**
     * Space-separated values. Value: <code>ssv</code>
     * @const
     */
    SSV: ' ',
    /**
     * Tab-separated values. Value: <code>tsv</code>
     * @const
     */
    TSV: '\t',
    /**
     * Pipe(|)-separated values. Value: <code>pipes</code>
     * @const
     */
    PIPES: '|',
    /**
     * Native array. Value: <code>multi</code>
     * @const
     */
    MULTI: 'multi'
  };

  /**
   * Builds a string representation of an array-type actual parameter, according to the given collection format.
   * @param {Array} param An array parameter.
   * @param {module:ApiClient.CollectionFormatEnum} collectionFormat The array element separator strategy.
   * @returns {String|Array} A string representation of the supplied collection, using the specified delimiter. Returns
   * <code>param</code> as is if <code>collectionFormat</code> is <code>multi</code>.
   */
  exports.prototype.buildCollectionParam = function buildCollectionParam(param, collectionFormat) {
    if (param == null) {
      return null;
    }
    switch (collectionFormat) {
      case 'csv':
        return param.map(this.paramToString).join(',');
      case 'ssv':
        return param.map(this.paramToString).join(' ');
      case 'tsv':
        return param.map(this.paramToString).join('\t');
      case 'pipes':
        return param.map(this.paramToString).join('|');
      case 'multi':
        // return the array directly as SuperAgent will handle it as expected
        return param.map(this.paramToString);
      default:
        throw new Error('Unknown collection format: ' + collectionFormat);
    }
  };

  /**
   * Applies authentication headers to the request.
   * @param {Object} request The request object created by a <code>superagent()</code> call.
   * @param {Array.<String>} authNames An array of authentication method names.
   */
  exports.prototype.applyAuthToRequest = function(request, authNames) {
    var _this = this;
    authNames.forEach(function(authName) {
      var auth = _this.authentications[authName];
      switch (auth.type) {
        case 'basic':
          if (auth.username || auth.password) {
            request.auth(auth.username || '', auth.password || '');
          }
          break;
        case 'apiKey':
          if (auth.apiKey) {
            var data = {};
            if (auth.apiKeyPrefix) {
              data[auth.name] = auth.apiKeyPrefix + ' ' + auth.apiKey;
            } else {
              data[auth.name] = auth.apiKey;
            }
            if (auth['in'] === 'header') {
              request.set(data);
            } else {
              request.query(data);
            }
          }
          break;
        case 'oauth2':
          if (auth.accessToken) {
            request.set({'Authorization': 'Bearer ' + auth.accessToken});
          }
          break;
        default:
          throw new Error('Unknown authentication type: ' + auth.type);
      }
    });
  };

  /**
   * Deserializes an HTTP response body into a value of the specified type.
   * @param {Object} response A SuperAgent response object.
   * @param {(String|Array.<String>|Object.<String, Object>|Function)} returnType The type to return. Pass a string for simple types
   * or the constructor function for a complex type. Pass an array containing the type name to return an array of that type. To
   * return an object, pass an object with one property whose name is the key type and whose value is the corresponding value type:
   * all properties on <code>data<code> will be converted to this type.
   * @returns A value of the specified type.
   */
  exports.prototype.deserialize = function deserialize(response, returnType) {
    if (response == null || returnType == null || response.status == 204) {
      return null;
    }
    // Rely on SuperAgent for parsing response body.
    // See http://visionmedia.github.io/superagent/#parsing-response-bodies
    var data = response.body;
    if (data == null || (typeof data === 'object' && typeof data.length === 'undefined' && !Object.keys(data).length)) {
      // SuperAgent does not always produce a body; use the unparsed response as a fallback
      data = response.text;
    }
    return exports.convertToType(data, returnType);
  };

  /**
   * Callback function to receive the result of the operation.
   * @callback module:ApiClient~callApiCallback
   * @param {String} error Error message, if any.
   * @param data The data returned by the service call.
   * @param {String} response The complete HTTP response.
   */

  /**
   * Invokes the REST service using the supplied settings and parameters.
   * @param {String} path The base URL to invoke.
   * @param {String} httpMethod The HTTP method to use.
   * @param {Object.<String, String>} pathParams A map of path parameters and their values.
   * @param {Object.<String, Object>} queryParams A map of query parameters and their values.
   * @param {Object.<String, Object>} collectionQueryParams A map of collection query parameters and their values.
   * @param {Object.<String, Object>} headerParams A map of header parameters and their values.
   * @param {Object.<String, Object>} formParams A map of form parameters and their values.
   * @param {Object} bodyParam The value to pass as the request body.
   * @param {Array.<String>} authNames An array of authentication type names.
   * @param {Array.<String>} contentTypes An array of request MIME types.
   * @param {Array.<String>} accepts An array of acceptable response MIME types.
   * @param {(String|Array|ObjectFunction)} returnType The required type to return; can be a string for simple types or the
   * constructor for a complex type.
   * @param {module:ApiClient~callApiCallback} callback The callback function.
   * @returns {Object} The SuperAgent request object.
   */
  exports.prototype.callApi = function callApi(path, httpMethod, pathParams,
      queryParams, headerParams, formParams, bodyParam, authNames, contentTypes, accepts,
      returnType, callback) {

    var _this = this;
    var url = this.buildUrl(path, pathParams);
    logger.debug('HTTP URL: ' + url);
    logger.debug('HTTP Method: ' + httpMethod);
    
    // added by us    

    var resourcePath = this.resourcePath(path, pathParams);
    
    if(this.clientApiKey == null || this.clientApiKey == ''){
    	this.clientApiKey = headerParams['client_key'];
    }
    
    if(this.authScheme == null || this.authScheme == '' || this.authScheme == 'OPAY1-HMAC-SHA256'){
	    var authorizationData = exports.computeOPAY1HMACSHA256Hash(resourcePath, httpMethod, queryParams, headerParams, formParams, bodyParam, this.clientSignatureKey);
	    var clientHash = authorizationData['hash'];
	    headerParams['Authorization'] = 'OPAY1-HMAC-SHA256 Credential=' + this.clientApiKey + ',Signature=' + clientHash.trim() + '';
    }else if(this.authScheme == 'OPAY2-HMAC-SHA256'){
    	var authorizationData = exports.computeOPAY2HMACSHA256Hash(headerParams['client_key'], this.clientApiKey,this.clientSignatureKey, headerParams['timestamp']);
	    var clientHash = authorizationData['hash'];
	    headerParams['Authorization'] = 'OPAY2-HMAC-SHA256 Credential=' + this.clientApiKey + ',Signature=' + clientHash.trim() + '';
    }else if(this.authScheme == 'OPAY3-HMAC-SHA256'){
	    headerParams['Authorization'] = 'OPAY3-HMAC-SHA256 Credential=' + this.clientApiKey;
    }else{
    	logger.debug('invalid auth_scheme received');
    	throw new Error('invalid auth_scheme received');
    }
    headerParams['User-Agent'] = 'orbipay-paymentsapi-client/1.13.0/Node';

    var request = superagent(httpMethod, url);
    // apply authentications
    this.applyAuthToRequest(request, authNames);

    // set query parameters
    if (httpMethod.toUpperCase() === 'GET' && this.cache === false) {
        queryParams['_'] = new Date().getTime();
    }
    request.query(this.normalizeParams(queryParams));
    logger.debug('Query Params: ', JSON.stringify(queryParams));
    // set header parameters
    request.set(this.defaultHeaders).set(this.normalizeParams(headerParams));
    logger.debug('Request Headers: ', JSON.stringify(headerParams));

    logger.debug('Request Body: ', JSON.stringify(bodyParam, CommonUtil.maskSensitiveInfo));

    // set requestAgent if it is set by user
    if (this.requestAgent) {
      request.agent(this.requestAgent);
    }

    if (process.env['ORBIPAY_PAYMENTS_API_TIMEOUT_SECONDS']) {
    this.timeout = process.env['ORBIPAY_PAYMENTS_API_TIMEOUT_SECONDS'];
		logger.debug('HTTP TIMEOUT in seconds : ' + this.timeout);
    }
    else{
        logger.warn('Timeout environment variable, ORBIPAY_PAYMENTS_API_TIMEOUT_SECONDS is not found setting default value in seconds: ', this.timeout);
    }

    request.timeout(this.timeout*1000);

    var contentType = this.jsonPreferredMime(contentTypes);
    if (contentType) {
      // Issue with superagent and multipart/form-data (https://github.com/visionmedia/superagent/issues/746)
      if(contentType !== 'multipart/form-data') {
        request.type(contentType);
      }
    } else if (!request.header['Content-Type']) {
      request.type('application/json');
    }

    if (contentType === 'application/x-www-form-urlencoded') {
      request.send(querystring.stringify(this.normalizeParams(formParams)));
    } else if (contentType === 'multipart/form-data') {
      var _formParams = this.normalizeParams(formParams);
      for (var formParamKey in _formParams) {
        if (_formParams.hasOwnProperty(formParamKey)) {
          if (this.isFileParam(_formParams[formParamKey])) {
            // file field
            request.attach(formParamKey, _formParams[formParamKey]);
          } else {
            request.field(formParamKey, _formParams[formParamKey]);
          }
        }
      }
    } else if (bodyParam) {
      request.send(bodyParam);
    }

    var accept = this.jsonPreferredMime(accepts);
    if (accept) {
      request.accept(accept);
    }

    if (returnType === 'Blob') {
      request.responseType('blob');
    } else if (returnType === 'String') {
      request.responseType('string');
    }

    // Attach previously saved cookies, if enabled
    if (this.enableCookies){
      if (typeof window === 'undefined') {
        this.agent.attachCookies(request);
      }
      else {
        request.withCredentials();
      }
    }


    if (callback) {
	  logger.info('Sending Request to Service');
          request.end(function (error, response) {
              var data = null;
              if (!error) {
                  try {
                      data = _this.deserialize(response, returnType);
		      logger.info('Receive Response from Service : HTTP Status Code :', response.status);
		      logger.debug('HTTP Response Body :', JSON.stringify(data, CommonUtil.maskSensitiveInfo));
                      if (_this.enableCookies && typeof window === 'undefined') {
                          _this.agent.saveCookies(response);
                      }
                  } catch (err) {
                      error = err;
                  }
              }

              if (error) {
		  	logger.info('Receive Response from Service : HTTP Status Code :', error.status);
                  logger.error('HTTP Error code :', error.code);
                  logger.error('HTTP Error errno :', error.errno);
                  logger.error('HTTP Error message :', error.message);
                  if(response && response.text) {
                      logger.debug('HTTP Response Body :', response.text);
                  }
                  else{
                      logger.warn('HTTP Body is not received ');
                  }
              }
              response = response || {};
              logger.debug('Response Headers :', JSON.stringify(response['header']));
              if(response['header']) {
                  logger.info('request_uuid :', response['header']['request_uuid']);
              }
              callback(error, data, response);
          });
      }

    return request;
  };

  /**
   * Parses an ISO-8601 string representation of a date value.
   * @param {String} str The date value as a string.
   * @returns {Date} The parsed date object.
   */
  exports.parseDate = function(str) {
    return new Date(str.replace(/T/i, ' '));
  };

  /**
   * Converts a value to the specified type.
   * @param {(String|Object)} data The data to convert, as a string or object.
   * @param {(String|Array.<String>|Object.<String, Object>|Function)} type The type to return. Pass a string for simple types
   * or the constructor function for a complex type. Pass an array containing the type name to return an array of that type. To
   * return an object, pass an object with one property whose name is the key type and whose value is the corresponding value type:
   * all properties on <code>data<code> will be converted to this type.
   * @returns An instance of the specified type or null or undefined if data is null or undefined.
   */
  exports.convertToType = function(data, type) {
    if (data === null || data === undefined)
      return data;

    switch (type) {
      case 'Boolean':
        return Boolean(data);
      case 'Integer':
        return parseInt(data, 10);
      case 'Number':
        return parseFloat(data);
      case 'String':
        if(typeof data === 'string'){
            return String(data);
        }
        else{
          return data;
        }
      case 'Date':
        return this.parseDate(String(data));
      case 'Blob':
      	return data;
      default:
        if (type === Object) {
          // generic object, return directly
          return data;
        } else if (typeof type === 'function') {
          // for model type like: User
          return type.constructFromObject(data);
        } else if (Array.isArray(type)) {
          // for array type like: ['String']
          var itemType = type[0];
          return data.map(function(item) {
            return exports.convertToType(item, itemType);
          });
        } else if (typeof type === 'object') {
          // for plain object type like: {'String': 'Integer'}
          var keyType, valueType;
          for (var j in type) {
            if (type.hasOwnProperty(j)) {
              keyType = j;
              valueType = type[j];
              break;
            }
          }
          var result = {};
          for (var k in data) {
            if (data.hasOwnProperty(k)) {
              var key = exports.convertToType(k, keyType);
              var value = exports.convertToType(data[k], valueType);
              result[key] = value;
            }
          }
          return result;
        } else {
          // for unknown type, return the data directly
          return data;
        }
    }
  };

  /**
   * Constructs a new map or array model from REST data.
   * @param data {Object|Array} The REST data.
   * @param obj {Object|Array} The target object or array.
   */
  exports.constructFromObject = function(data, obj, itemType) {
    if (Array.isArray(data)) {
      for (var i = 0; i < data.length; i++) {
        if (data.hasOwnProperty(i))
          obj[i] = exports.convertToType(data[i], itemType);
      }
    } else {
      for (var k in data) {
        if (data.hasOwnProperty(k))
          obj[k] = exports.convertToType(data[k], itemType);
      }
    }
  };

  exports.prototype.resourcePath = function (path, pathParams) {
        if (!path.match(/^\//)) {
            path = '/' + path;
        }
        var url = path;
        var _this = this;
        url = url.replace(/{([\w-]+)}/g, function (fullMatch, key) {
            var value;
            if (pathParams.hasOwnProperty(key)) {
                value = _this.paramToString(pathParams[key]);
            } else {
                value = fullMatch;
            }
            return encodeURIComponent(value);
        });
        return url;
  };

  exports.getFormString = function (params) {
        var key;
        var response = {};
        var paramString = '';
        var logArray = [];

        for (key in params) {
            if (params.hasOwnProperty(key)) {
                var value = params[key];
                if (Array.isArray(value)) {
                    for (var k in value) {
                        if (value.hasOwnProperty(k)) {
                            var v = value[k];
                            if (!exports.isNullOrUndefined(v)) {
                                paramString = paramString + (key.trim() + '=' + v) + '&';
                                logArray.push({
                                    'key': key,
                                    'value': v
                                });
                            }
                        }
                    }
                } else {
                    if (!exports.isNullOrUndefined(value)) {
                        paramString = paramString + (key + '=' + value) + '&';
                        logArray.push({
                            'key': key,
                            'value': value
                        });
                    }
                }
            }
        }
        response['paramString'] = paramString.substring(0, paramString.length - 1);
        response['logArray'] = logArray;

        return response;
    };


    exports.isNullOrUndefined = function (data) {
        return (typeof(data) === 'undefined' || data === null);
    };


    exports.isEmptyString = function (string) {
        return (string === undefined || string === null || string === '');
    };

  exports.getQueryString = function (inparams) {
        var key;
        var trimmedValue;
        var paramString = '';
        var filteredKeys = [];
        var params = {};

        for (key in inparams) {
            if (inparams.hasOwnProperty(key) && !exports.isEmptyString(key) && !exports.isEmptyString(key.trim()) && inparams[key] !== undefined && inparams[key] !== null) {
                params[key.trim()] = inparams[key];
                filteredKeys.push(key.trim());
            }
        }

        //sorting Keys
        filteredKeys.sort();

        for (var i = 0; i < filteredKeys.length; i++) {
            key = filteredKeys[i];
            var value = params[key];
            if (Array.isArray(value)) {

                value = value.map(Function.prototype.call, String.prototype.trim);

                //sorting values
                value.sort();

                for (var k in value) {
                    if (value.hasOwnProperty(k)) {
                        var v = value[k];
                        if (!exports.isEmptyString(v)) {
                            trimmedValue = v.trim();
                            if (!exports.isEmptyString(trimmedValue)) {
                                paramString = paramString + (key.trim() + '=' + trimmedValue) + '&';
                            }
                        }
                    }
                }

            } else {
                if (!exports.isEmptyString(value)) {
                    trimmedValue = value.trim();
                    if (!exports.isEmptyString(trimmedValue)) {
                        paramString = paramString + (key.trim() + '=' + trimmedValue) + '&';
                    }
                }
            }
        }
        return paramString.substring(0, paramString.length - 1);
  };
  
  exports.getHeaderString = function (inparams) {
        var key;
        var trimmedValue;
        var paramString = '';
        var filteredKeys = [];
        var params = {};

        for (key in inparams) {
            if (inparams.hasOwnProperty(key) && !exports.isEmptyString(key) && !exports.isEmptyString(key.trim()) && exports.isValidHeaderParam(key.trim()) && inparams[key] !== undefined && inparams[key] !== null) {
                params[key.trim()] = inparams[key];
                filteredKeys.push(key.trim());
            }
        }

        //sorting Keys
        filteredKeys.sort();

        for (var i = 0; i < filteredKeys.length; i++) {
            key = filteredKeys[i];
            var value = params[key];
            if (!exports.isEmptyString(value)) {
                trimmedValue = value.trim();
                if (!exports.isEmptyString(trimmedValue)) {
                    paramString = paramString + (key.trim() + '=' + trimmedValue) + '&';
                }
            }
        }
        return paramString.substring(0, paramString.length - 1);
  };

  exports.computeOPAY1HMACSHA256Hash = function (resourcePath, method, queryParams, headerParams, formParams, body, signatureKey) {
        if(signatureKey == null || signatureKey == '' ){
            throw new Error('Invalid value for secret');
        }
        var textToHash = '';
        textToHash = textToHash + method.toUpperCase() + ':';
        textToHash = textToHash + '/payments/v1' + decodeURIComponent(resourcePath) + ':';
        textToHash = textToHash + exports.getQueryString(queryParams) + ':';
        textToHash = textToHash + exports.getHeaderString(headerParams) + ':';

        if (exports.isNonEmptyObject(body)) {
            textToHash = textToHash + JSON.stringify(body);
            logger.debug('HTTP Request Body :', JSON.stringify(body, CommonUtil.maskSensitiveInfo));
        } else {
            var formData = exports.getFormString(formParams);
            textToHash = textToHash + formData['paramString'];
            logger.debug('Form Params :', CommonUtil.maskSensitiveFormParams(formData['logArray']));
        }

        var hash = exports.generateHmacHash(signatureKey, textToHash).trim();

        var response = {};

        response['hash'] = hash;
        return response;
    };
    
	 exports.computeOPAY2HMACSHA256Hash = function (clientKey, apiKey, secretKey, timestamp) {

            if(secretKey == null || secretKey == '' ){
                throw new Error('Invalid value for secret');
            }

	    var textToHash = '';
	    textToHash = textToHash + clientKey + ':';
	    textToHash = textToHash + apiKey + ':';
	    textToHash = textToHash + secretKey + ':';
	    textToHash = textToHash + timestamp;
	
	    var hash = exports.generateHmacHash(secretKey, textToHash).trim();
	
	    var response = {};
	
	    response['hash'] = hash;
	    return response;
	  };
    

    exports.isNonEmptyObject = function (obj) {
        return (obj !== null && typeof obj === 'object' && Object.keys(obj).length > 0);
    };

    exports.generateHmacHash = function (key, text) {
        return crypto.createHmac('sha256', new Buffer(key, 'utf-8')).update(new Buffer(text, 'utf-8')).digest('base64');
    };


    exports.isValidHeaderParam = function (headerParam) {
        return ['product' , 'trace_id' , 'idempotent_request_key' , 'channel' , 'requestor' , 'client_key' , 'X-OPAY-Headers' , 'requestor_type' , 'timestamp'].indexOf(headerParam) !== -1;
    };
    
  /**
   * The default API client implementation.
   * @type {module:ApiClient}
   */
  exports.instance = new exports();

  return exports;
}));