@thi.ng/date/relative.js

Datetime types, relative dates, math, iterators, composable formatters, locales

import {
  DAY,
  HOUR,
  MINUTE,
  SECOND
} from "./api.js";
import { ensureEpoch } from "./checks.js";
import { dateTime, ensureDateTime } from "./datetime.js";
import { EN_LONG, EN_SHORT } from "./i18n/en.js";
const parseRelative = (offset, base) => {
  offset = offset.toLowerCase();
  const epoch = dateTime(base);
  switch (offset) {
    case "today":
      return epoch;
    case "tomorrow":
      epoch.incDay();
      return epoch;
    case "yesterday":
      epoch.decDay();
      return epoch;
    default: {
      let idx = __findIndex(EN_SHORT.days, offset);
      if (idx < 0) {
        idx = __findIndex(EN_LONG.days, offset);
      }
      if (idx >= 0) {
        do {
          epoch.incDay();
        } while (epoch.toDate().getDay() != idx);
        return epoch;
      }
      const match = /^(an? |next |[-+]?\d+\s?)((ms|milli(?:(s?|seconds?)))|s(?:(ecs?|econds?))?|min(?:(s|utes?))?|h(?:ours?)?|d(?:ays?)?|w(?:eeks?)?|mo(?:nths?)?|q(?:uarters?)?|y(?:ears?)?)(\s+ago)?$/.exec(
        offset
      );
      return match ? relative(
        __parseNum(match[1], !!match[7]),
        __parsePeriod(match[2]),
        base
      ) : void 0;
    }
  }
};
const __findIndex = (items, x) => items.findIndex((y) => y.toLowerCase() === x);
const __parseNum = (x, past) => (x === "next " || x === "a " || x === "an " ? 1 : Number(x)) * (past ? -1 : 1);
const __parsePeriod = (x) => {
  x = x !== "s" && x !== "ms" && x.endsWith("s") ? x.substring(0, x.length - 1) : x;
  return {
    ms: "t",
    milli: "t",
    millisecond: "t",
    sec: "s",
    second: "s",
    min: "m",
    minute: "m",
    hour: "h",
    day: "d",
    week: "w",
    mo: "M",
    month: "M",
    quarter: "q",
    year: "y"
  }[x] || x;
};
const relative = (num, period, base = dateTime()) => dateTime(base).add(num, period);
const difference = (a, b) => ensureEpoch(a) - ensureEpoch(b);
const absDifference = (a, b) => Math.abs(difference(a, b));
const decomposeDifference = (a, b = /* @__PURE__ */ new Date()) => {
  const dur = ensureEpoch(a) - ensureEpoch(b);
  let abs = Math.abs(dur);
  const milli = abs % SECOND;
  abs -= milli;
  const sec = abs % MINUTE;
  abs -= sec;
  const min = abs % HOUR;
  abs -= min;
  const hour = abs % DAY;
  abs -= hour;
  const parts = [
    Math.sign(dur),
    0,
    // year
    0,
    // month
    0,
    // day
    hour / HOUR,
    min / MINUTE,
    sec / SECOND,
    milli
  ];
  if (!abs) return parts;
  const diff = (a2, b2) => {
    const months2 = (b2.y - a2.y) * 12 + (b2.M - a2.M);
    const bstart = +a2.add(months2, "M");
    let frac = +b2 - bstart;
    frac /= frac < 0 ? bstart - +a2.add(months2 - 1, "M") : +a2.add(months2 + 1, "M") - bstart;
    return -(months2 + frac) || 0;
  };
  const aa = ensureDateTime(a, "d");
  const bb = ensureDateTime(b, "d");
  const months = Math.abs(aa.d < bb.d ? -diff(bb, aa) : diff(aa, bb)) | 0;
  const days = (start, end) => Math.abs(
    +start.withPrecision("d").add(months, "M") - +end.withPrecision("d")
  ) / DAY;
  parts[1] = months / 12 | 0;
  parts[2] = months % 12;
  parts[3] = dur < 0 ? days(aa, bb) : days(bb, aa);
  return parts;
};
export {
  absDifference,
  decomposeDifference,
  difference,
  parseRelative,
  relative
};