const BASE32_CODES = '0123456789bcdefghjkmnpqrstuvwxyz';
const BASE32_CODES_DICT = {};
for (let i = 0; i < BASE32_CODES.length; i++) {
    BASE32_CODES_DICT[BASE32_CODES.charAt(i)] = i;
}
const MIN_LAT = -90;
const MAX_LAT = 90;
const MIN_LON = -180;
const MAX_LON = 180;
// Adapted from ngeohash decode_bbox
export function getGeohashBounds(geohash) {
    let isLon = true;
    let maxLat = MAX_LAT;
    let minLat = MIN_LAT;
    let maxLon = MAX_LON;
    let minLon = MIN_LON;
    let mid;
    let hashValue = 0;
    for (let i = 0, l = geohash.length; i < l; i++) {
        const code = geohash[i].toLowerCase();
        hashValue = BASE32_CODES_DICT[code];
        for (let bits = 4; bits >= 0; bits--) {
            const bit = (hashValue >> bits) & 1;
            if (isLon) {
                mid = (maxLon + minLon) / 2;
                if (bit === 1) {
                    minLon = mid;
                }
                else {
                    maxLon = mid;
                }
            }
            else {
                mid = (maxLat + minLat) / 2;
                if (bit === 1) {
                    minLat = mid;
                }
                else {
                    maxLat = mid;
                }
            }
            isLon = !isLon;
        }
    }
    return [minLat, minLon, maxLat, maxLon];
}
export function getGeohashPolygon(geohash) {
    const [s, w, n, e] = getGeohashBounds(geohash);
    return [e, n, e, s, w, s, w, n, e, n];
}