import { stringifyNumber } from '../../stringify/stringifyNumber.mjs';

/** Internal types handle bigint as number, because TS can't figure it out. */
function parseSexagesimal(str, asBigInt) {
  const sign = str[0];
  const parts = sign === '-' || sign === '+' ? str.substring(1) : str;
  const num = n => asBigInt ? BigInt(n) : Number(n);
  const res = parts.replace(/_/g, '').split(':').reduce((res, p) => res * num(60) + num(p), num(0));
  return sign === '-' ? num(-1) * res : res;
}
/**
 * hhhh:mm:ss.sss
 *
 * Internal types handle bigint as number, because TS can't figure it out.
 */
function stringifySexagesimal(node) {
  let {
    value
  } = node;
  let num = n => n;
  if (typeof value === 'bigint') num = n => BigInt(n);else if (isNaN(value) || !isFinite(value)) return stringifyNumber(node);
  let sign = '';
  if (value < 0) {
    sign = '-';
    value *= num(-1);
  }
  const _60 = num(60);
  const parts = [value % _60]; // seconds, including ms
  if (value < 60) {
    parts.unshift(0); // at least one : is required
  } else {
    value = (value - parts[0]) / _60;
    parts.unshift(value % _60); // minutes
    if (value >= 60) {
      value = (value - parts[0]) / _60;
      parts.unshift(value); // hours
    }
  }

  return sign + parts.map(n => n < 10 ? '0' + String(n) : String(n)).join(':').replace(/000000\d*$/, '') // % 60 may introduce error
  ;
}

const intTime = {
  identify: value => typeof value === 'bigint' || Number.isInteger(value),
  default: true,
  tag: 'tag:yaml.org,2002:int',
  format: 'TIME',
  test: /^[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+$/,
  resolve: (str, _onError, {
    intAsBigInt
  }) => parseSexagesimal(str, intAsBigInt),
  stringify: stringifySexagesimal
};
const floatTime = {
  identify: value => typeof value === 'number',
  default: true,
  tag: 'tag:yaml.org,2002:float',
  format: 'TIME',
  test: /^[-+]?[0-9][0-9_]*(?::[0-5]?[0-9])+\.[0-9_]*$/,
  resolve: str => parseSexagesimal(str, false),
  stringify: stringifySexagesimal
};
const timestamp = {
  identify: value => value instanceof Date,
  default: true,
  tag: 'tag:yaml.org,2002:timestamp',
  // If the time zone is omitted, the timestamp is assumed to be specified in UTC. The time part
  // may be omitted altogether, resulting in a date format. In such a case, the time part is
  // assumed to be 00:00:00Z (start of day, UTC).
  test: RegExp('^([0-9]{4})-([0-9]{1,2})-([0-9]{1,2})' +
  // YYYY-Mm-Dd
  '(?:' +
  // time is optional
  '(?:t|T|[ \\t]+)' +
  // t | T | whitespace
  '([0-9]{1,2}):([0-9]{1,2}):([0-9]{1,2}(\\.[0-9]+)?)' +
  // Hh:Mm:Ss(.ss)?
  '(?:[ \\t]*(Z|[-+][012]?[0-9](?::[0-9]{2})?))?' +
  // Z | +5 | -03:30
  ')?$'),
  resolve(str) {
    const match = str.match(timestamp.test);
    if (!match) throw new Error('!!timestamp expects a date, starting with yyyy-mm-dd');
    const [, year, month, day, hour, minute, second] = match.map(Number);
    const millisec = match[7] ? Number((match[7] + '00').substr(1, 3)) : 0;
    let date = Date.UTC(year, month - 1, day, hour || 0, minute || 0, second || 0, millisec);
    const tz = match[8];
    if (tz && tz !== 'Z') {
      let d = parseSexagesimal(tz, false);
      if (Math.abs(d) < 30) d *= 60;
      date -= 60000 * d;
    }
    return new Date(date);
  },
  stringify: ({
    value
  }) => value.toISOString().replace(/((T00:00)?:00)?\.000Z$/, '')
};

export { floatTime, intTime, timestamp };
