/**
 * @license Licensed under the Apache License, Version 2.0 (the "License"):
 *          http://www.apache.org/licenses/LICENSE-2.0
 *
 * @fileoverview Ajax calls to the Ardublockly Server python program.
 */
'use strict';

/** Create a name space for the application. */
var ArdublocklyServer = {};

/**
 * Reads JSON data from the server and forwards formatted JavaScript object.
 * @param {!string} url Location for the JSON data.
 * @param {!function} jsonDataCb Callback with JSON object or null for error.
 */
ArdublocklyServer.getJson = function(url, callback) {
  ArdublocklyServer.sendRequest(url, 'GET', 'application/json', null, callback);
};

/**
 * Sends JSON data to the ArduBlocklyServer.
 * @param {!string} url Requestor URL.
 * @param {!string} json JSON string.
 * @param {!function} callback Request callback function.
 */
ArdublocklyServer.putJson = function(url, json, callback) {
  ArdublocklyServer.sendRequest(url, 'PUT', 'application/json', json, callback);
};

/**
 * Sends a request to the Ardubloockly Server that returns a JSON response.
 * @param {!string} url Requestor URL.
 * @param {!string} method HTTP method.
 * @param {!string} contentType HTTP content type.
 * @param {string} jsonObjSend JavaScript object to be parsed into JSON to send.
 * @param {!function} cb Request callback function, takes a single input for a
 *     parsed JSON object.
 */
ArdublocklyServer.sendRequest = function(
    url, method, contentType, jsonObjSend, cb) {
  var request = ArdublocklyServer.createRequest();

  // The data received is JSON, so it needs to be converted into the right
  // format to be displayed in the page.
  var onReady = function() {
    if (request.readyState == 4) {
      if (request.status == 200) {
        var jsonObjReceived = null;
        try {
          jsonObjReceived = JSON.parse(request.responseText);
        } catch(e) {
          console.error('Incorrectly formatted JSON data from ' + url);
          throw e;
        }
        cb(jsonObjReceived);
      } else {
        // return a null element which will be dealt with in the front end
        cb(null);
      }
    }
  };

  try {
    request.open(method, url, true);
    request.setRequestHeader('Content-type', contentType);
    request.onreadystatechange = onReady;
    request.send(JSON.stringify(jsonObjSend));
  } catch (e) {
    // Nullify callback to indicate error
    cb(null);
    throw e;
  }
};

/** @return {XMLHttpRequest} An XML HTTP Request multi-browser compatible. */
ArdublocklyServer.createRequest = function() {
  var request = null;
  try {
    // Firefox, Chrome, IE7+, Opera, Safari
    request = new XMLHttpRequest();
  }
  catch (e) {
    // IE6 and earlier
    try {
      request = new ActiveXObject('Msxml2.XMLHTTP');
    }
    catch (e) {
      try {
        request = new ActiveXObject('Microsoft.XMLHTTP');
      }
      catch (e) {
        throw 'Your browser does not support AJAX. You will not be able to' +
              'use all of Ardublockly features.';
        request = null;
      }
    }
  }
  return request;
};

/**
 * Creates an HTML element based on the JSON data received from the server.
 * @param {!string} json_data A string containing the JSON data to be parsed.
 * @return {!element} An HTML element, which type depends on the JSON 'element'
 *                    key (currently only text input or drop down).
 */
ArdublocklyServer.jsonToIdeModal = function(jsonObj) {
  if (!jsonObj) return null;

  var elTitle = document.createElement('h4');
  elTitle.className = (jsonObj && jsonObj.success) ? 'arduino_dialog_success' :
                                                     'arduino_dialog_failure';
  var elStdOp = document.createElement('span');
  elStdOp.className = 'arduino_dialog_out';
  var elErrOp = document.createElement('span');
  elErrOp.className = 'arduino_dialog_out_error';

  // Add the Standard and Error outputs
  var ideData = jsonObj.ide_data;
  if (ideData && (ideData.std_output !== undefined) && 
      (ideData.err_output !== undefined)) {
    elStdOp.innerHTML = ideData.std_output.split('\n').join('<br />');
    elErrOp.innerHTML = ideData.err_output.split('\n').join('<br />');
  } else {
    console.error(jsonObj);
    console.error('The IDE out JSON response does not have valid "ide_data".');
  }

  if (jsonObj.errors) {
    // Prepare error message
    elTitle.innerHTML = Ardublockly.getLocalStr('arduinoOpErrorTitle');
    var errStr = [];
    for (var i = 0; i < jsonObj.errors.length; i++) {
      var errorContext = 'Unrecognised error.';
      try {
        errorContext = Ardublockly.getLocalStr(
            'arduinoOpErrorIdContext_' + jsonObj.errors[i].id);
      } catch (e) {
        // Swallow the exception, could be expanded to try to figure out issue
      }
      errStr.push('\nError id ' + jsonObj.errors[i].id + ': ' + errorContext);
    }
    elErrOp.innerHTML += '<br />' + errStr.join('<br />');
  } else if (jsonObj.success && jsonObj.ide_mode) {
    // Format a successful response
    if (jsonObj.ide_mode == 'upload') {
      elTitle.innerHTML = Ardublockly.getLocalStr('arduinoOpUploadedTitle');
    } else if (jsonObj.ide_mode == 'verify') {
      elTitle.innerHTML = Ardublockly.getLocalStr('arduinoOpVerifiedTitle');
    } else if (jsonObj.ide_mode == 'open') {
      elTitle.innerHTML = Ardublockly.getLocalStr('arduinoOpOpenedTitle');
      // This is a corner case where we also add to the stand out
      elStdOp.innerHTML += Ardublockly.getLocalStr('arduinoOpOpenedBody');
    } else {
      elTitle.innerHTML = Ardublockly.getLocalStr('arduinoOpErrorTitle');
    }
  } else {
    console.error(jsonObj);
    console.error('Unexpected response format, printed above.');
  }

  var element = document.createElement('div');
  element.appendChild(elTitle);
  element.appendChild(elStdOp);
  element.appendChild(elErrOp);
  return element;
};

ArdublocklyServer.jsonToHtmlTextInput = function(jsonObj) {
  var element = null;
  if (jsonObj) {
    // Simple text input
    element = document.createElement('input');
    element.setAttribute('type', 'text');
    element.style.cssText = '';
    if (jsonObj.errors) {
      element.setAttribute('value', '');
      element.style.cssText = 'border-bottom: 1px solid #f75c51;' +
                              'box-shadow: 0 1px 0 0 #d73c30;';
    } else {
      element.setAttribute('value', jsonObj.selected || '');
    }
  }
  return element;
};

ArdublocklyServer.jsonToHtmlDropdown = function(jsonObj) {
  var element = null;
  if (!jsonObj) {
    console.error('Invalid JSON received from server.');
  } else if(jsonObj.errors) {
    console.error('There are errors in the JSON response from server.');
    console.error(jsonObj);
  } else {
    // Drop down list of unknown length with a selected item
    element = document.createElement('select');
    element.name = jsonObj.settings_type;
    for (var i = 0; i < jsonObj.options.length; i++) {
      if (jsonObj.options[i].value && jsonObj.options[i].display_text) {
        var option = document.createElement('option');
        option.value = jsonObj.options[i].value;
        option.text = jsonObj.options[i].display_text;
        // Check selected option and mark it
        if (jsonObj.selected) {
          option.selected = jsonObj.options[i].value == jsonObj.selected;
        }
        element.appendChild(option);
      } else {
        console.error('Missing required JSON keys for Drop Down conversion.');
      }
    }
  }
  return element;
};

/**
 * Gets the current Compiler location from the ArdublocklyServer settings.
 * @param {!function} callback Callback function for the server request, must
 *     have one argument to receive the JSON response.
 */
ArdublocklyServer.requestCompilerLocation = function(callback) {
  ArdublocklyServer.getJson('/settings/compiler', callback);
};

/**
 * Sends a string to the Ardublockly Server for a the Arduino IDE executable
 * path.
 * @param {!function} callback Callback function for the server request, must
 *     have one argument to receive the JSON response.
 */
ArdublocklyServer.setCompilerLocation = function(new_path, callback) {
    ArdublocklyServer.putJson(
      '/settings/compiler', {"new_value": new_path}, callback);
};

/**
 * Gets the current Sketch location from the Ardublockly Server settings.
 * @param {!function} callback Callback function for the server request, must
 *     have one argument to receive the JSON response.
 */
ArdublocklyServer.requestSketchLocation = function(callback) {
   ArdublocklyServer.getJson('/settings/sketch', callback);
};

/**
 * Sends a string to the Ardublockly Server for a the Arduino sketch folder.
 * @param {!string} new_path New Sketch location path..
 * @param {!function} callback Callback function for the server request, must
 *     have one argument to receive the JSON response.
 */
ArdublocklyServer.setSketchLocation = function(new_path, callback) {
  ArdublocklyServer.putJson(
      '/settings/sketch', {"new_value": new_path}, callback);
};

/**
 * Request to the Ardublockly Server to return JSON data containing all
 * available target Arduino Boards, and the selected one in the settings.
 * The data is then processed into an HTML element and sent to the callback
 * function as an argument.
 * @param {!function} callback Callback function for the server request, must
 *     have one argument to receive the JSON response.
 */
ArdublocklyServer.requestArduinoBoards = function(callback) {
  ArdublocklyServer.getJson('/settings/board', callback);
};

/**
 * Sends the inputted Arduino Board type to the Ardublockly Server Settings.
 * The new settings menu for the Board type is then processed into an HTML
 * element and sent to the callback function as an argument.
 * @param {!string} new_board Indicates which board has been selected.
 * @param {!function} callback Callback function for the server request, must
 *     have one argument to receive the JSON response.
 */
ArdublocklyServer.setArduinoBoard = function(new_board, callback) {
  ArdublocklyServer.putJson(
      '/settings/board', {"new_value": new_board}, callback);
};

/**
 * Request to the Ardublockly Server to return JSON data containing all
 * available serial ports in the computer, and the selected one in the
 * settings. The data is then processed into an HTML element and sent to the
 * callback function as an argument.
 * @param {!function} callback Callback function for the server request, must
 *     have one argument to receive the JSON response.
 */
ArdublocklyServer.requestSerialPorts = function(callback) {
  ArdublocklyServer.getJson('/settings/serial', callback);
};

/**
 * Sends the inputted Serial Port to the Ardublockly Server Settings. The new
 * settings menu for the Serial Port is then processed into an HTML element
 * and sent to the callback function as an argument.
 * @param {!string} new_port Indicates which port has been selected.
 * @param {!function} callback Callback function for the server request, must
 *     have one argument to receive the JSON response.
 */
ArdublocklyServer.setSerialPort = function(new_port, callback) {
  ArdublocklyServer.putJson(
      '/settings/serial', {"new_value": new_port}, callback);
};

/**
 * Gets the current IDE setting from the Ardublockly Server settings. The new
 * settings menu for the IDE options is then processed into an HTML element
 * and sent to the callback function as an argument.
 * @param {!function} callback Callback function for the server request, must
 *     have one argument to receive the JSON response.
 */
ArdublocklyServer.requestIdeOptions = function(callback) {
  ArdublocklyServer.getJson('/settings/ide', callback);
};

/**
 * Sends the inputted IDE option to the Ardublockly Server Settings. The new
 * settings menu for the IDE options is then processed into an HTML element
 * and sent to the callback function as an argument.
 * @param {!string} ide_option Indicates which option has been selected.
 * @param {!function} callback Callback function for the server request, must
 *     have one argument to receive the JSON response.
 */
ArdublocklyServer.setIdeOptions = function(ide_option, callback) {
  ArdublocklyServer.putJson(
      '/settings/ide', {"new_value": ide_option}, callback);
};


/**
 * Sends the Arduino code to the ArdublocklyServer to be processed as defined
 * by the settings.
 * @param {!string} code Arduino code in a single string format.
 * @param {!function} callback Callback function for the server request, must
 *     have one argument to receive the JSON response.
 */
ArdublocklyServer.sendSketchToServer = function(code, callback) {
  ArdublocklyServer.sendRequest(
      '/code', 'POST', 'application/json', {"sketch_code": code}, callback);
};