import rng from './rng.js';
import { unsafeStringify } from './stringify.js';
const _state = {};
function v1(options, buf, offset) {
    let bytes;
    const isV6 = options?._v6 ?? false;
    if (options) {
        const optionsKeys = Object.keys(options);
        if (optionsKeys.length === 1 && optionsKeys[0] === '_v6') {
            options = undefined;
        }
    }
    if (options) {
        bytes = v1Bytes(options.random ?? options.rng?.() ?? rng(), options.msecs, options.nsecs, options.clockseq, options.node, buf, offset);
    }
    else {
        const now = Date.now();
        const rnds = rng();
        updateV1State(_state, now, rnds);
        bytes = v1Bytes(rnds, _state.msecs, _state.nsecs, isV6 ? undefined : _state.clockseq, isV6 ? undefined : _state.node, buf, offset);
    }
    return buf ?? unsafeStringify(bytes);
}
export function updateV1State(state, now, rnds) {
    state.msecs ??= -Infinity;
    state.nsecs ??= 0;
    if (now === state.msecs) {
        state.nsecs++;
        if (state.nsecs >= 10000) {
            state.node = undefined;
            state.nsecs = 0;
        }
    }
    else if (now > state.msecs) {
        state.nsecs = 0;
    }
    else if (now < state.msecs) {
        state.node = undefined;
    }
    if (!state.node) {
        state.node = rnds.slice(10, 16);
        state.node[0] |= 0x01;
        state.clockseq = ((rnds[8] << 8) | rnds[9]) & 0x3fff;
    }
    state.msecs = now;
    return state;
}
function v1Bytes(rnds, msecs, nsecs, clockseq, node, buf, offset = 0) {
    if (rnds.length < 16) {
        throw new Error('Random bytes length must be >= 16');
    }
    if (!buf) {
        buf = new Uint8Array(16);
        offset = 0;
    }
    else {
        if (offset < 0 || offset + 16 > buf.length) {
            throw new RangeError(`UUID byte range ${offset}:${offset + 15} is out of buffer bounds`);
        }
    }
    msecs ??= Date.now();
    nsecs ??= 0;
    clockseq ??= ((rnds[8] << 8) | rnds[9]) & 0x3fff;
    if (node == null) {
        node = rnds.slice(10, 16);
        node[0] |= 0x01;
    }
    msecs += 12219292800000;
    const t = (msecs & 0xfffffff) * 10000 + nsecs;
    const tl = t >>> 0;
    buf[offset++] = (tl >>> 24) & 0xff;
    buf[offset++] = (tl >>> 16) & 0xff;
    buf[offset++] = (tl >>> 8) & 0xff;
    buf[offset++] = tl & 0xff;
    const tmh = (((msecs / 0x10000000) | 0) * 625 + ((t / 0x100000000) | 0)) & 0xfffffff;
    buf[offset++] = (tmh >>> 8) & 0xff;
    buf[offset++] = tmh & 0xff;
    buf[offset++] = ((tmh >>> 24) & 0xf) | 0x10;
    buf[offset++] = (tmh >>> 16) & 0xff;
    buf[offset++] = (clockseq >>> 8) | 0x80;
    buf[offset++] = clockseq & 0xff;
    for (let n = 0; n < 6; ++n) {
        buf[offset++] = node[n];
    }
    return buf;
}
export default v1;