/**
 * @license
 * Copyright 2019 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
 *
 *   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.
 */

export interface RemoteConfig {
  /**
   * Defines configuration for the Remote Config SDK.
   */
  settings: Settings;

  /**
   * Object containing default values for configs.
   */
  defaultConfig: { [key: string]: string | number | boolean };

  /**
   * The Unix timestamp in milliseconds of the last <i>successful</i> fetch, or negative one if
   * the {@link RemoteConfig} instance either hasn't fetched or initialization
   * is incomplete.
   */
  fetchTimeMillis: number;

  /**
   * The status of the last fetch <i>attempt</i>.
   */
  lastFetchStatus: FetchStatus;

  /**
   * Makes the last fetched config available to the getters.
   * Returns a promise which resolves to true if the current call activated the fetched configs.
   * If the fetched configs were already activated, the promise will resolve to false.
   */
  activate(): Promise<boolean>;

  /**
   * Ensures the last activated config are available to the getters.
   */
  ensureInitialized(): Promise<void>;

  /**
   * Fetches and caches configuration from the Remote Config service.
   */
  fetch(): Promise<void>;

  /**
   * Performs fetch and activate operations, as a convenience.
   * Returns a promise which resolves to true if the current call activated the fetched configs.
   * If the fetched configs were already activated, the promise will resolve to false.
   */
  fetchAndActivate(): Promise<boolean>;

  /**
   * Gets all config.
   */
  getAll(): { [key: string]: Value };

  /**
   * Gets the value for the given key as a boolean.
   *
   * Convenience method for calling <code>remoteConfig.getValue(key).asBoolean()</code>.
   */
  getBoolean(key: string): boolean;

  /**
   * Gets the value for the given key as a number.
   *
   * Convenience method for calling <code>remoteConfig.getValue(key).asNumber()</code>.
   */
  getNumber(key: string): number;

  /**
   * Gets the value for the given key as a String.
   *
   * Convenience method for calling <code>remoteConfig.getValue(key).asString()</code>.
   */
  getString(key: string): string;

  /**
   * Gets the {@link Value} for the given key.
   */
  getValue(key: string): Value;

  /**
   * Defines the log level to use.
   */
  setLogLevel(logLevel: LogLevel): void;
}

/**
 * Indicates the source of a value.
 *
 * <ul>
 *   <li>"static" indicates the value was defined by a static constant.</li>
 *   <li>"default" indicates the value was defined by default config.</li>
 *   <li>"remote" indicates the value was defined by fetched config.</li>
 * </ul>
 */
export type ValueSource = 'static' | 'default' | 'remote';

/**
 * Wraps a value with metadata and type-safe getters.
 */
export interface Value {
  /**
   * Gets the value as a boolean.
   *
   * The following values (case-insensitive) are interpreted as true:
   * "1", "true", "t", "yes", "y", "on". Other values are interpreted as false.
   */
  asBoolean(): boolean;

  /**
   * Gets the value as a number. Comparable to calling <code>Number(value) || 0</code>.
   */
  asNumber(): number;

  /**
   * Gets the value as a string.
   */
  asString(): string;

  /**
   * Gets the {@link ValueSource} for the given key.
   */
  getSource(): ValueSource;
}

/**
 * Defines configuration options for the Remote Config SDK.
 */
export interface Settings {
  /**
   * Defines the maximum age in milliseconds of an entry in the config cache before
   * it is considered stale. Defaults to 43200000 (Twelve hours).
   */
  minimumFetchIntervalMillis: number;

  /**
   * Defines the maximum amount of milliseconds to wait for a response when fetching
   * configuration from the Remote Config server. Defaults to 60000 (One minute).
   */
  fetchTimeoutMillis: number;
}

/**
 * Summarizes the outcome of the last attempt to fetch config from the Firebase Remote Config server.
 *
 * <ul>
 *   <li>"no-fetch-yet" indicates the {@link RemoteConfig} instance has not yet attempted
 *       to fetch config, or that SDK initialization is incomplete.</li>
 *   <li>"success" indicates the last attempt succeeded.</li>
 *   <li>"failure" indicates the last attempt failed.</li>
 *   <li>"throttle" indicates the last attempt was rate-limited.</li>
 * </ul>
 */
export type FetchStatus = 'no-fetch-yet' | 'success' | 'failure' | 'throttle';

/**
 * Defines levels of Remote Config logging.
 */
export type LogLevel = 'debug' | 'error' | 'silent';

declare module '@firebase/component' {
  interface NameServiceMapping {
    'remoteConfig-compat': RemoteConfig;
  }
}