atst/js/components/charts/budget_chart.js
2019-01-24 09:38:43 -05:00

190 lines
5.8 KiB
JavaScript

import {
format,
isWithinRange,
addMonths,
isSameMonth,
getMonth,
} from 'date-fns'
import { abbreviateDollars, formatDollars } from '../../lib/dollars'
const TOP_OFFSET = 20
const BOTTOM_OFFSET = 70
const CHART_HEIGHT = 360
export default {
name: 'budget-chart',
props: {
currentMonth: String,
expirationDate: String,
months: Object,
budget: String,
},
data: function() {
const heightScale =
this.budget / (CHART_HEIGHT - TOP_OFFSET - BOTTOM_OFFSET)
return {
numMonths: 10,
focusedMonthPosition: 4,
height: CHART_HEIGHT,
heightScale,
budgetHeight: CHART_HEIGHT - BOTTOM_OFFSET - this.budget / heightScale,
baseHeight: CHART_HEIGHT - BOTTOM_OFFSET,
width: 0,
displayedMonths: [],
spendPath: '',
projectedPath: '',
displayBudget: formatDollars(parseFloat(this.budget)),
}
},
mounted: function() {
this._setDisplayedMonths()
this._setMetrics()
addEventListener('load', this._setMetrics)
addEventListener('resize', this._setMetrics)
},
methods: {
_setMetrics: function() {
this.width = this.$refs.panel.clientWidth
this.spendPath = ''
this.projectedPath = ''
let lastSpend = 0
let lastSpendPoint = ''
for (let i = 0; i < this.numMonths; i++) {
const {
metrics,
budget,
rollingAverage,
cumulativeTotal,
} = this.displayedMonths[i]
const blockWidth = this.width / this.numMonths
const blockX = blockWidth * i
const spend = budget && budget.spend ? budget.spend : rollingAverage
const barHeight = spend / this.heightScale
lastSpend = spend
const cumulativeY =
this.height - cumulativeTotal / this.heightScale - BOTTOM_OFFSET
const cumulativeX = blockX + blockWidth / 2
const cumulativePoint = `${cumulativeX} ${cumulativeY}`
this.displayedMonths[i].metrics = Object.assign(metrics, {
blockWidth,
blockX,
barHeight,
barWidth: 30,
barX: blockX + (blockWidth / 2 - 15),
barY: this.height - barHeight - BOTTOM_OFFSET,
cumulativeR: 2.5,
cumulativeY,
cumulativeX,
})
if (budget && budget.spend) {
this.spendPath += this.spendPath === '' ? 'M' : ' L'
this.spendPath += cumulativePoint
lastSpendPoint = cumulativePoint
} else if (lastSpendPoint !== '') {
this.projectedPath +=
this.projectedPath === '' ? `M${lastSpendPoint} L` : ' L'
this.projectedPath += cumulativePoint
}
}
},
_setDisplayedMonths: function() {
const [month, year] = this.currentMonth.split('/')
const [expYear, expMonth, expDate] = this.expirationDate.split('-') // assumes format 'YYYY-MM-DD'
const monthsRange = []
const monthsBack = this.focusedMonthPosition + 1
const monthsForward = this.numMonths - this.focusedMonthPosition - 1
// currently focused date
const current = new Date(year, month)
// starting date of the chart
const start = addMonths(current, -monthsBack)
// ending date of the chart
const end = addMonths(start, this.numMonths + 1)
// expiration date
const expires = new Date(expYear, expMonth - 1, expDate)
// is the expiration date within the displayed date range?
const expirationWithinRange = isWithinRange(expires, start, end)
let rollingAverage = 0
let cumulativeTotal = 0
for (let i = 0; i < this.numMonths; i++) {
const date = addMonths(start, i)
const dateMinusOne = addMonths(date, -1)
const dateMinusTwo = addMonths(date, -2)
const dateMinusThree = addMonths(date, -3)
const index = format(date, 'MM/YYYY')
const indexMinusOne = format(dateMinusOne, 'MM/YYYY')
const indexMinusTwo = format(dateMinusTwo, 'MM/YYYY')
const indexMinusThree = format(dateMinusThree, 'MM/YYYY')
const budget = this.months[index] || null
const spendAmount = budget ? budget.spend : rollingAverage
const spendMinusOne = this.months[indexMinusOne]
? this.months[indexMinusOne].spend
: rollingAverage
const spendMinusTwo = this.months[indexMinusTwo]
? this.months[indexMinusTwo].spend
: rollingAverage
const spendMinusThree = this.months[indexMinusThree]
? this.months[indexMinusThree].spend
: rollingAverage
const isExpirationMonth = isSameMonth(date, expires)
if (budget && budget.cumulative) {
cumulativeTotal = budget.cumulative
} else {
cumulativeTotal += spendAmount
}
rollingAverage =
(spendAmount + spendMinusOne + spendMinusTwo + spendMinusThree) / 4
monthsRange.push({
budget,
rollingAverage,
cumulativeTotal,
isExpirationMonth,
spendAmount: formatDollars(spendAmount),
abbreviatedSpend: abbreviateDollars(spendAmount),
cumulativeAmount: formatDollars(cumulativeTotal),
abbreviatedCumulative: abbreviateDollars(cumulativeTotal),
date: {
monthIndex: format(date, 'M'),
month: format(date, 'MMM'),
year: format(date, 'YYYY'),
},
showYear: isExpirationMonth || i === 0 || getMonth(date) === 0,
isHighlighted: this.currentMonth === index,
metrics: {
blockWidth: 0,
blockX: 0,
barHeight: 0,
barWidth: 0,
barX: 0,
barY: 0,
cumulativeY: 0,
cumulativeX: 0,
cumulativeR: 0,
},
})
}
this.displayedMonths = monthsRange
},
},
}