// @flow

import { NativeModules } from "react-native";
const PermissionsIOS = NativeModules.ReactNativePermissions;

type Status = "authorized" | "denied" | "restricted" | "undetermined";
type Rationale = { title: string, message: string };
type CheckOptions = string | { type: string };
type RequestOptions = string | { type: string, rationale?: Rationale };

const permissionTypes = [
  "location",
  "camera",
  "microphone",
  "photo",
  "contacts",
  "event",
  "reminder",
  "bluetooth",
  "notification",
  "backgroundRefresh",
  "speechRecognition",
  "mediaLibrary",
  "motion",
];

const DEFAULTS = {
  location: "whenInUse",
  notification: ["alert", "badge", "sound"],
};

class ReactNativePermissions {
  canOpenSettings: () => Promise<boolean> = () =>
    PermissionsIOS.canOpenSettings();

  openSettings: () => Promise<*> = () => PermissionsIOS.openSettings();

  getTypes: () => Array<string> = () => permissionTypes;

  check = (permission: string, options?: CheckOptions): Promise<Status> => {
    if (!permissionTypes.includes(permission)) {
      const error = new Error(
        `ReactNativePermissions: ${permission} is not a valid permission type on iOS`,
      );

      return Promise.reject(error);
    }

    let type;

    if (typeof options === "string") {
      type = options;
    } else if (options && options.type) {
      type = options.type;
    }

    return PermissionsIOS.getPermissionStatus(
      permission,
      type || DEFAULTS[permission],
    );
  };

  request = (permission: string, options?: RequestOptions): Promise<Status> => {
    if (!permissionTypes.includes(permission)) {
      const error = new Error(
        `ReactNativePermissions: ${permission} is not a valid permission type on iOS`,
      );

      return Promise.reject(error);
    }

    if (permission == "backgroundRefresh") {
      const error = new Error(
        "ReactNativePermissions: You cannot request backgroundRefresh",
      );

      return Promise.reject(error);
    }

    let type;

    if (typeof options === "string") {
      type = options;
    } else if (options && options.type) {
      type = options.type;
    }

    return PermissionsIOS.requestPermission(
      permission,
      type || DEFAULTS[permission],
    );
  };

  checkMultiple = (permissions: Array<string>): Promise<{ [string]: string }> =>
    Promise.all(permissions.map(permission => this.check(permission))).then(
      result =>
        result.reduce((acc, value, index) => {
          const name = permissions[index];
          acc[name] = value;
          return acc;
        }, {}),
    );
}

export default new ReactNativePermissions();