shootismoke/common

import { LatLng } from '../../types';
import { fetchAndDecode } from '../../util/fetch';
import { AqicnData, AqicnResponse } from './validation';

/**
 * Check if the response we get from aqicn is `{"status": "error", "msg": "..."}`,
 * if yes, return an error.
 */
function checkError({ status, data, msg }: AqicnResponse): AqicnData {
    if (status === 'ok' && typeof data === 'object') {
        return data;
    } else {
        throw new Error(msg || (data as string));
    }
}

export interface AqicnOptions {
    /**
     * Aqicn token
     * @see https://aqicn.org/data-platform/token/#/
     */
    token: string;
}

/**
 * Fetch the closest station to the user's current position
 *
 * @param gps - Latitude and longitude of the user's current position
 */
export function fetchByGps(
    gps: LatLng,
    options: AqicnOptions
): Promise<AqicnData> {
    if (!options || !options.token) {
        throw new Error('AqiCN requires a token');
    }

    const { latitude, longitude } = gps;

    return fetchAndDecode<AqicnResponse>(
        `https://api.waqi.info/feed/geo:${latitude};${longitude}/?token=${options.token}`
    ).then(checkError);
}

/**
 * Fetch data by station
 *
 * @param stationId - The station ID to search
 */
export async function fetchByStation(
    stationId: string,
    options: AqicnOptions
): Promise<AqicnData> {
    if (!options || !options.token) {
        throw new Error('AqiCN requires a token');
    }

    return fetchAndDecode<AqicnResponse>(
        `https://api.waqi.info/feed/@${stationId}/?token=${options.token}`
    ).then(checkError);
}