(function () {
  if (!window.cet || !window.cet.microservices || !window.cet.microservices.apiready) {
    window.cet = window.cet || {};
    cet.microservices = cet.microservices || {};

    let apiready = new Promise(function (resolve, reject) {
      var scriptElement = document.createElement("script");
      scriptElement.addEventListener('load', resolve);
      scriptElement.addEventListener('error', reject);
      var origin = document.currentScript.src.split('/', 3).join('/');
      scriptElement.src = origin + "/provider/ApiProvider.js?8dc3062e1069100";
      document.head.appendChild(scriptElement);
    });
    cet.microservices.apiready = apiready;
  }
  let selfUrl = document.currentScript.src;
  cet.microservices.apiready.then(() => {
    cet.microservices.api.system.addService(selfUrl);
  });
})();
window.cet = window.cet || {};
window.cet.microservices = window.cet.microservices || {};

cet.microservices.dashboardapi = (function () {
  // in order to call 'safe' api safely, make sure accessmanagement is loaded:
  var safeApiReady = cet.microservices.apiready.then(() => {
    if (cet.accessmanagement)
      return Promise.resolve();
    else
      return cet.microservices.api.loadApi("/accessmngapi/provider/accessmanagement.js", "apigateway");
  });

  const settings = {
    apiUrl: "/dashboardapi/"
  };

  const isDevEnvironment = (location.host.indexOf('.dev') > 0 || location.host.indexOf('.testing') > 0);

  /*------------------------------------------------------------------------------*/
  /* Build URL query from the given payload object. */
  const buildQueryFromPayload = function (payload) {
    if (payload && typeof payload === 'object') {
      var str = [];

      for (var p in payload) {
        if (payload.hasOwnProperty(p)) {
          if (Array.isArray(payload[p])) {
            for (var i = 0; i < payload[p].length; i++) {
              str.push(encodeURIComponent(p) + "=" + encodeURIComponent(payload[p][i]));
            }
          } else {
            str.push(encodeURIComponent(p) + "=" + encodeURIComponent(payload[p]));
          }
        }
      }

      return str.length > 0 ? '?' + str.join('&') : '';
    }

    return '';
  };

  /*------------------------------------------------------------------------------*/
  /* Validate single parameter. */
  const validateParameter = function (pName, pValue) {
    if ((typeof pValue === 'string' && pValue.trim().length === 0) ||
      (Array.isArray(pValue) && pValue.length === 0)) {
      return pName + ' cannot be empty';
    }

    return '';
  };

  /*------------------------------------------------------------------------------*/
  /* Validate request object. */
  const validateRequest = function (request, relevantParameters) {
    if (!request) {
      return 'request data is missing';
    }

    for (var i = 0; i < relevantParameters.length; i++) {
      var param = relevantParameters[i];
      var paramParts = param.split('.');

      var subRequest = request;

      if (paramParts.length > 1) {
        for (var p = 0; p < paramParts.length - 1; p++) {
          subRequest = subRequest && subRequest[paramParts[p]];
          param = paramParts[p + 1];
        }
      }

      if (!subRequest || !subRequest.hasOwnProperty(param)) {
        return relevantParameters[i] + ' is missing';
      } else {
        var error = validateParameter(relevantParameters[i], subRequest[param]);

        if (error) {
          return error;
        }
      }
    }

    return '';
  };

  /*------------------------------------------------------------------------------*/
  const processRequest = (request) => {
    var promise = new Promise(function (resolve, reject) {
      var validationErrorMsg = request.validationParams ? validateRequest(request.data, request.validationParams) : '';
      if (validationErrorMsg) {
        if (isDevEnvironment) {
          throw new Error({ name: 'ProviderValidationError', message: validationErrorMsg });
        }
        reject({ name: 'ProviderValidationError', message: validationErrorMsg });
      } else {
        safeApiReady.then(async () => {
          try {
            var result = null;

            if (request.type === 'get') {
              result = await cetms.safe.get(request.URL + buildQueryFromPayload(request.data));
            } else if (request.type === 'post') {
              result = await cetms.safe.post(request.URL, request.data);
            }

            resolve(result);
          } catch (error) {
            reject(error);
          }
        }).catch(error => {
          reject(error);
        });
      }
    });

    return promise;
  };

  //#region Teachers

  /*------------------------------------------------------------------------------*/
  const getTeacherStudents = (requestData) => {
    return processRequest({
      type: 'get',
      URL: settings.apiUrl + 'Teachers/GetStudents',
      data: requestData,
      validationParams: ['teacherId']
    });
  };

  /*------------------------------------------------------------------------------*/
  const getTeacherTasks = (requestData) => {
    return processRequest({
      type: 'get',
      URL: settings.apiUrl + 'Teachers/GetTasks',
      data: requestData,
      validationParams: ['teacherId']
    });
  };

  /*------------------------------------------------------------------------------*/
  const getTeacherLightTasks = (requestData) => {
    return processRequest({
      type: 'get',
      URL: settings.apiUrl + 'Teachers/GetLightTasks',
      data: requestData,
      validationParams: ['teacherId']
    });
  };

  /*------------------------------------------------------------------------------*/
  const getTeacherFullTask = (requestData) => {
    return processRequest({
      type: 'get',
      URL: settings.apiUrl + 'Teachers/GetFullTask',
      data: requestData,
      validationParams: ['teacherId', 'taskId']
    });
  };

  /*------------------------------------------------------------------------------*/
  const getTeacherTasksByIds = (requestData) => {
    return processRequest({
      type: 'post',
      URL: settings.apiUrl + 'Teachers/GetTasksByIds',
      data: requestData,
      validationParams: ['teacherId', 'taskIds']
    });
  };

  //#endregion

  //#region Students

  /*------------------------------------------------------------------------------*/

  const getStudentTasks = (requestData) => {
    return processRequest({
      type: 'get',
      URL: settings.apiUrl + 'Students/GetTasks',
      data: requestData,
      validationParams: ['studentId']
    });
  };

  /*------------------------------------------------------------------------------*/

  //#endregion

  return {
    'teachers': {
      getStudents: getTeacherStudents,
      getTasks: getTeacherTasks,
      getLightTasks: getTeacherLightTasks,
      getFullTask: getTeacherFullTask,
      getTasksByIds: getTeacherTasksByIds
    },
    'students': {
      getTasks: getStudentTasks
    }
  };
})();