const d3 = require('d3');

function UTC(dttm) {
  return new Date(
    dttm.getUTCFullYear(),
    dttm.getUTCMonth(),
    dttm.getUTCDate(),
    dttm.getUTCHours(),
    dttm.getUTCMinutes(),
    dttm.getUTCSeconds()
  );
}
export const tickMultiFormat = d3.time.format.multi([
  [
    '.%L',
    function (d) {
      return d.getMilliseconds();
    },
  ],
  // If there are millisections, show  only them
  [
    ':%S',
    function (d) {
      return d.getSeconds();
    },
  ],
  // If there are seconds, show only them
  [
    '%a %b %d, %I:%M %p',
    function (d) {
      return d.getMinutes() !== 0;
    },
  ],
  // If there are non-zero minutes, show Date, Hour:Minute [AM/PM]
  [
    '%a %b %d, %I %p',
    function (d) {
      return d.getHours() !== 0;
    },
  ],
  // If there are hours that are multiples of 3, show date and AM/PM
  [
    '%a %b %d',
    function (d) {
      return d.getDate() !== 1;
    },
  ],
  // If not the first of the month, do "month day, year."
  [
    '%B %Y',
    function (d) {
      return d.getMonth() !== 0 && d.getDate() === 1;
    },
  ],
  // If the first of the month, do "month day, year."
  [
    '%Y',
    function () {
      return true;
    },
  ],  // fall back on month, year
]);
export const formatDate = function (dttm) {
  const d = UTC(new Date(dttm));
  // d = new Date(d.getTime() - 1 * 60 * 60 * 1000);
  return tickMultiFormat(d);
};
export const timeFormatFactory = function (d3timeFormat) {
  const f = d3.time.format(d3timeFormat);
  return function (dttm) {
    const d = UTC(new Date(dttm));
    return f(d);
  };
};