Split date range overlaps into chunks (javascript)

Question

I came up with a concept, but am having trouble converting it into code.

Here's a picture to better help explain my idea: da picture

Can't tell by the picture, but there can be gaps between dates as well.

Not to make it an XY-problem, here's why I need to do this. I have array of date ranges and bonuses and I want to create an array of non overlapping dates with sum of bonuses.

I'm trying to split overlaps into chucks that do not overlap anymore. Came across a package called moment-range. Is there perhaps a name for this what I'm trying to succeed? "Projecting date ranges onto linear ...something"

Final code below

const _ = require('lodash')
const Moment = require('moment')
const MomentRange = require('moment-range')

const moment = MomentRange.extendMoment(Moment);

let bonuses = [
  {start: new Date('Jan 15, 2018 23:00:00 GMT+0200'), end: new Date('Jan 18, 2018 23:59:59 GMT+0200'), bonus: 30, preSale: true},
  {start: new Date('Jan 17, 2018 00:00:00 GMT+0200'), end: new Date('Jan 29, 2018 13:00:00 GMT+0200'), bonus: 25, preSale: true},
  {start: new Date('Feb 12, 2018 00:00:00 GMT+0200'), end: new Date('Feb 18, 2018 23:59:59 GMT+0200'), bonus: 20, preSale: false},
  {start: new Date('Feb 19, 2018 00:00:00 GMT+0200'), end: new Date('Feb 27, 2018 23:59:59 GMT+0200'), bonus: 15, preSale: false},
  {start: new Date('Feb 26, 2018 00:00:00 GMT+0200'), end: new Date('Mar 4, 2018 23:59:59 GMT+0200'), bonus: 10, preSale: false},
  {start: new Date('Mar 5, 2018 00:00:00 GMT+0200'), end: new Date('Mar 11, 2018 23:59:59 GMT+0200'), bonus: 5, preSale: false},
]

_.map(bonuses, o => o.range = moment.range(o.start, o.end))

let dates = []
_.each(bonuses, o => {
  dates.push(o.start)
  dates.push(o.end)
})

dates.sort(function(a, b) {
  return a-b
})

let ranges = []
for(let i=1; i<dates.length; i++) {
  ranges.push({
    start: dates[i-1],
    end: dates[i],
    range: moment.range(dates[i-1], dates[i])
  })
}

for (let range of ranges) {
  range.bonus = 0
  for (let bonus of bonuses) {
    if (range.range.intersect(bonus.range)) {
      range.bonus += bonus.bonus
    }
  }
}

_.each(ranges, r => console.log(r.start, ' - ', r.end, '  => ', r.bonus))

Well from the picture, I’d say you simple put all of your start and end times into an array, sort them ... and there you have the “boundaries” for all your target intervals …? — CBroe, May 30 '18 at 11:17
@CBroe I updated the question, what do you suggest I do now? — keeeenion, May 30 '18 at 13:47

score 3 · Accepted Answer · answered May 30 '18 at 11:38

3

var dates = [];
bonuses.forEach(item => {
    dates.push(item.start);
    dates.push(item.end);
});
dates.sort();
var ranges = [];
for(var i=1;i<dates.length;i++){
    ranges.push({
        start: dates[i-1], 
        end: dates[i]
    });
}
console.log(ranges);

answered May 30 '18 at 11:38

Ronn Wilder

1,228
9
13

Sorry for not noticing already, this is exactly what I need. Thank you :) – keeeenion Jun 02 '18 at 01:14
If dates contain duplicates, you need dates=[...new Set(dates)]; before dates.sort – pkExec Nov 10 '22 at 12:46

score 1 · Answer 2 · answered May 30 '18 at 11:36

Something like this?

var min = Infinity;
var max = 0;
var bonuses = [
    { start: new Date('Jan 15, 2018 23:00:00 GMT+0200'), end: new Date('Jan 18, 2018 23:59:59 GMT+0200'), bonus: 30, intersects: false },
    { start: new Date('Jan 16, 2018 00:00:00 GMT+0200'), end: new Date('Jan 29, 2018 13:00:00 GMT+0200'), bonus: 25, intersects: false },
    { start: new Date('Feb 12, 2018 00:00:00 GMT+0200'), end: new Date('Feb 18, 2018 23:59:59 GMT+0200'), bonus: 20, intersects: false },
    { start: new Date('Feb 19, 2018 00:00:00 GMT+0200'), end: new Date('Feb 29, 2018 23:59:59 GMT+0200'), bonus: 15, intersects: false },
    { start: new Date('Feb 26, 2018 00:00:00 GMT+0200'), end: new Date('Mar 4, 2018 23:59:59 GMT+0200'), bonus: 10, intersects: false },
    { start: new Date('Mar 5, 2018 00:00:00 GMT+0200'), end: new Date('Mar 11, 2018 23:59:59 GMT+0200'), bonus: 5, intersects: false }
];
bonuses
    .map(function (a, index) {
    if (a.start.getTime() < min) {
        min = a.start.getTime();
    }
    if (a.end.getTime() < min) {
        min = a.end.getTime();
    }
    if (a.start.getTime() > max) {
        max = a.start.getTime();
    }
    if (a.end.getTime() > max) {
        max = a.end.getTime();
    }
    for (var i = index + 1; i < bonuses.length; i++) {
        var b = bonuses[i];
        if (b.start.getTime() < a.start.getTime() && b.end.getTime() > a.start.getTime() ||
            a.start.getTime() < b.start.getTime() && a.end.getTime() > b.start.getTime()) {
            bonuses[i].intersects = true;
            a.intersects = true;
        }
    }
    return a;
});
var tileSize = 20;
var canvas = document.body.appendChild(document.createElement("canvas"));
canvas.width = 800;
canvas.height = bonuses.length * tileSize;
var ctx = canvas.getContext("2d");
bonuses.forEach(function (bonus, index) {
    var start = (bonus.start.getTime() - min) / (max - min);
    var end = (bonus.end.getTime() - min) / (max - min);
    ctx.fillStyle = bonus.intersects ? "red" : "green";
    ctx.fillRect(canvas.width * start, tileSize * index, canvas.width * (end - start), tileSize);
    ctx.strokeRect(canvas.width * start, tileSize * index, canvas.width * (end - start), tileSize);
});

It sure helps with visualisation, but does not really help with me problem. — keeeenion, May 30 '18 at 13:51

Split date range overlaps into chunks (javascript)

2 Answers2