/**
 * Copyright Google LLC
 *
 * 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
 *
 *     https://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.
 */

// [START apps_script_data_studio_build_get_config]
/**
 * Builds the Community Connector config.
 * @return {Config} The Community Connector config.
 * @see https://developers.google.com/apps-script/reference/data-studio/config
 */
function getConfig() {
  const cc = DataStudioApp.createCommunityConnector();
  const config = cc.getConfig();

  config
    .newInfo()
    .setId("instructions")
    .setText("Enter npm package names to fetch their download count.");

  config
    .newTextInput()
    .setId("package")
    .setName("Enter a single package name.")
    .setHelpText("for example, googleapis or lighthouse")
    .setPlaceholder("googleapis")
    .setAllowOverride(true);

  config.setDateRangeRequired(true);

  return config.build();
}
// [END apps_script_data_studio_build_get_config]

// [START apps_script_data_studio_build_get_fields]
/**
 * Builds the Community Connector fields object.
 * @return {Fields} The Community Connector fields.
 * @see https://developers.google.com/apps-script/reference/data-studio/fields
 */
function getFields() {
  const cc = DataStudioApp.createCommunityConnector();
  const fields = cc.getFields();
  const types = cc.FieldType;
  const aggregations = cc.AggregationType;

  fields
    .newDimension()
    .setId("packageName")
    .setName("Package Name")
    .setType(types.TEXT);

  fields
    .newDimension()
    .setId("day")
    .setName("Day")
    .setType(types.YEAR_MONTH_DAY);

  fields
    .newMetric()
    .setId("downloads")
    .setName("Downloads")
    .setType(types.NUMBER)
    .setAggregation(aggregations.SUM);

  return fields;
}

/**
 * Builds the Community Connector schema.
 * @param {object} request The request.
 * @return {object} The schema.
 */
function getSchema(request) {
  const fields = getFields().build();
  return { schema: fields };
}
// [END apps_script_data_studio_build_get_fields]

// [START apps_script_data_studio_build_get_data]
/**
 * Constructs an object with values as rows.
 * @param {Fields} requestedFields The requested fields.
 * @param {object[]} response The response.
 * @param {string} packageName The package name.
 * @return {object} An object containing rows with values.
 */
function responseToRows(requestedFields, response, packageName) {
  // Transform parsed data and filter for requested fields
  return response.map((dailyDownload) => {
    const row = [];
    for (const field of requestedFields.asArray()) {
      switch (field.getId()) {
        case "day":
          row.push(dailyDownload.day.replace(/-/g, ""));
          break;
        case "downloads":
          row.push(dailyDownload.downloads);
          break;
        case "packageName":
          row.push(packageName);
          break;
        default:
          row.push("");
      }
    }
    return { values: row };
  });
}

/**
 * Gets the data for the community connector
 * @param {object} request The request.
 * @return {object} The data.
 */
function getData(request) {
  const requestedFieldIds = request.fields.map((field) => field.name);
  const requestedFields = getFields().forIds(requestedFieldIds);

  // Fetch and parse data from API
  const url = [
    "https://api.npmjs.org/downloads/range/",
    request.dateRange.startDate,
    ":",
    request.dateRange.endDate,
    "/",
    request.configParams.package,
  ];
  const response = UrlFetchApp.fetch(url.join(""));
  const parsedResponse = JSON.parse(response).downloads;
  const rows = responseToRows(
    requestedFields,
    parsedResponse,
    request.configParams.package,
  );

  return {
    schema: requestedFields.build(),
    rows: rows,
  };
}
// [END apps_script_data_studio_build_get_data]

// [START apps_script_data_studio_build_get_auth_type]
/**
 * Gets the Auth type.
 * @return {object} The auth type.
 */
function getAuthType() {
  const cc = DataStudioApp.createCommunityConnector();
  return cc.newAuthTypeResponse().setAuthType(cc.AuthType.NONE).build();
}
// [END apps_script_data_studio_build_get_auth_type]