///<reference path="../../headers/common.d.ts" />

import _ from "lodash";
import moment from "moment";
import * as dateMath from "./datemath";

var spans = {
  s: { display: "second" },
  m: { display: "minute" },
  h: { display: "hour" },
  d: { display: "day" },
  w: { display: "week" },
  M: { display: "month" },
  y: { display: "year" }
};

var rangeOptions = [
  { from: "now/d", to: "now/d", display: "Today", section: 2 },
  { from: "now/d", to: "now", display: "Today so far", section: 2 },
  { from: "now/w", to: "now/w", display: "This week", section: 2 },
  { from: "now/w", to: "now", display: "This week so far", section: 2 },
  { from: "now/M", to: "now/M", display: "This month", section: 2 },
  { from: "now/M", to: "now", display: "This month so far", section: 2 },
  { from: "now/y", to: "now/y", display: "This year", section: 2 },
  { from: "now/y", to: "now", display: "This year so far", section: 2 },

  { from: "now-1d/d", to: "now-1d/d", display: "Yesterday", section: 1 },
  {
    from: "now-2d/d",
    to: "now-2d/d",
    display: "Day before yesterday",
    section: 1
  },
  {
    from: "now-7d/d",
    to: "now-7d/d",
    display: "This day last week",
    section: 1
  },
  { from: "now-1w/w", to: "now-1w/w", display: "Previous week", section: 1 },
  { from: "now-1M/M", to: "now-1M/M", display: "Previous month", section: 1 },
  { from: "now-1y/y", to: "now-1y/y", display: "Previous year", section: 1 },

  { from: "now-5m", to: "now", display: "Last 5 minutes", section: 3 },
  { from: "now-15m", to: "now", display: "Last 15 minutes", section: 3 },
  { from: "now-30m", to: "now", display: "Last 30 minutes", section: 3 },
  { from: "now-1h", to: "now", display: "Last 1 hour", section: 3 },
  { from: "now-3h", to: "now", display: "Last 3 hours", section: 3 },
  { from: "now-6h", to: "now", display: "Last 6 hours", section: 3 },
  { from: "now-12h", to: "now", display: "Last 12 hours", section: 3 },
  { from: "now-24h", to: "now", display: "Last 24 hours", section: 3 },

  { from: "now-2d", to: "now", display: "Last 2 days", section: 0 },
  { from: "now-7d", to: "now", display: "Last 7 days", section: 0 },
  { from: "now-30d", to: "now", display: "Last 30 days", section: 0 },
  { from: "now-90d", to: "now", display: "Last 90 days", section: 0 },
  { from: "now-6M", to: "now", display: "Last 6 months", section: 0 },
  { from: "now-1y", to: "now", display: "Last 1 year", section: 0 },
  { from: "now-2y", to: "now", display: "Last 2 years", section: 0 },
  { from: "now-5y", to: "now", display: "Last 5 years", section: 0 }
];

var absoluteFormat = "MMM D, YYYY HH:mm:ss";

var rangeIndex = {};
_.each(rangeOptions, function(frame) {
  rangeIndex[frame.from + " to " + frame.to] = frame;
});

export function getRelativeTimesList(timepickerSettings, currentDisplay) {
  var groups = _.groupBy(rangeOptions, (option: any) => {
    option.active = option.display === currentDisplay;
    return option.section;
  });

  // _.each(timepickerSettings.time_options, (duration: string) => {
  //   let info = describeTextRange(duration);
  //   if (info.section) {
  //     groups[info.section].push(info);
  //   }
  // });

  return groups;
}

function formatDate(date) {
  return date.format(absoluteFormat);
}

// handles expressions like
// 5m
// 5m to now/d
// now/d to now
// now/d
// if no to <expr> then to now is assumed
export function describeTextRange(expr: any) {
  let isLast = expr.indexOf("+") !== 0;
  if (expr.indexOf("now") === -1) {
    expr = (isLast ? "now-" : "now") + expr;
  }

  let opt = rangeIndex[expr + " to now"];
  if (opt) {
    return opt;
  }

  if (isLast) {
    opt = { from: expr, to: "now" };
  } else {
    opt = { from: "now", to: expr };
  }

  let parts = /^now([-+])(\d+)(\w)/.exec(expr);
  if (parts) {
    let unit = parts[3];
    let amount = parseInt(parts[2]);
    let span = spans[unit];
    if (span) {
      opt.display = isLast ? "Last " : "Next ";
      opt.display += amount + " " + span.display;
      opt.section = span.section;
      if (amount > 1) {
        opt.display += "s";
      }
    }
  } else {
    opt.display = opt.from + " to " + opt.to;
    opt.invalid = true;
  }

  return opt;
}

export function describeTimeRange(range) {
  var option = rangeIndex[range.from.toString() + " to " + range.to.toString()];
  if (option) {
    return option.display;
  }

  if (moment.isMoment(range.from) && moment.isMoment(range.to)) {
    return formatDate(range.from) + " to " + formatDate(range.to);
  }

  if (moment.isMoment(range.from)) {
    var toMoment = dateMath.parse(range.to, true);
    return formatDate(range.from) + " to " + toMoment.fromNow();
  }

  if (moment.isMoment(range.to)) {
    var from = dateMath.parse(range.from, false);
    return from.fromNow() + " to " + formatDate(range.to);
  }

  if (range.to.toString() === "now") {
    var res = describeTextRange(range.from);
    return res.display;
  }

  return range.from.toString() + " to " + range.to.toString();
}