rating javascript

function RatingStar(fiveStar, fourStar, threeStar, twoStar, oneStar)  {
	this.fiveStar = fiveStar;
	this.fourStar = fourStar;
	this.threeStar = threeStar;
	this.twoStar = twoStar;
	this.oneStar = oneStar;
	this.rating = 0;
}

RatingStar.prototype.setRating = function() {

   // calculate rating
   const sumFiveStar = this.fiveStar.reduce((a, c) => a + c, 0)
   const sumFourStar = this.fourStar.reduce((a, c) => a + c, 0)
   const sumThreeStar = this.threeStar.reduce((a, c) => a + c, 0)
   const sumTwoStar = this.twoStar.reduce((a, c) => a + c, 0)
   const sumOneStar = this.oneStar.reduce((a, c) => a + c, 0)

   // get count people give rating star
   const countFiveStart = this.fiveStar.length + 1
   const countFourStart = this.fourStar.length + 1
   const countThreeStart = this.threeStar.length + 1
   const countTwoStart = this.twoStar.length + 1
   const countOneStart = this.oneStar.length + 1

   // mutiply rating with diference rating star
   const multiplyFiveStar = Math.floor(sumFiveStar) * 5
   const multiplyFourStar = Math.floor(sumFourStar) * 4
   const multiplyThreeStar = Math.floor(sumThreeStar) * 3
   const multiplyTwoStar = Math.floor(sumTwoStar) * 2
   const multiplyOneStar = Math.floor(sumOneStar) * 1

   // sum rating
   const ratingStarBeforeSum = Math.floor(sumFiveStar + sumFourStar + sumThreeStar + sumTwoStar + sumOneStar)
   const ratingStarAfterSum = (multiplyFiveStar + multiplyFourStar + multiplyThreeStar + multiplyTwoStar + multiplyOneStar)
   const totalPeopleGiveRating = (countFiveStart + countFourStart + countThreeStart + countTwoStart + countOneStart)

   // final rating
   const fiveStarPersen = `${Math.floor((multiplyFiveStar / 100))}%`
   const fourStarPersen = `${Math.floor((multiplyFourStar / 100))}%`
   const threeStarPersen = `${Math.floor((multiplyThreeStar / 100))}%`
   const twoStarPersen = `${Math.floor((multiplyTwoStar / 100))}%`
   const oneStarPersen = `${Math.floor((multiplyOneStar / 100))}%`

   const totalRating = +parseFloat((ratingStarAfterSum / ratingStarBeforeSum)).toFixed(1)
   return {
   	fiveStar: {
   	  persen: fiveStarPersen,
   	  total: multiplyFiveStar,
   	  peopleGiveRating: countFiveStart
   	},
   	fourStar: {
   	  persen: fourStarPersen,
   	  total: multiplyFourStar,
   	  peopleGiveRating: countFourStart
   	},
   	threeStar : {
   	  persen: threeStarPersen,
   	  total: multiplyThreeStar,
   	  peopleGiveRating: countThreeStart
   	},
   	twoStar: {
   	  persen: twoStarPersen,
   	  total: multiplyTwoStar,
   	  peopleGiveRating: countTwoStart
   	},
   	oneStar: {
   	  persen: twoStarPersen,
   	  total: multiplyOneStar,
   	  peopleGiveRating: countTwoStart
   	},
   	totalPeopleGiveRating,
   	totalRating
   }
}

RatingStar.prototype.getRating = function() {

	const data = this.setRating()

	if(data.totalRating > 0 && data.totalRating == 1 && data.totalRating < 2) {
		this.rating = 1

	} else if(data.totalRating > 1 && data.totalRating == 2 && data.totalRating < 3) {
		this.rating = 2

	} else if(data.totalRating > 2 && data.totalRating == 3 && data.totalRating < 4) {
		this.rating = 3

	} else if(data.totalRating > 3 && data.totalRating == 4 && data.totalRating < 5) {
		this.rating = 4

	} else if(data.totalRating > 4 && data.totalRating == 5 && data.totalRating >= 5) {
		this.rating = 5

	} else if(data.totalRating > 0 && data.totalRating < 1) {
		this.rating = 1.5

	} else if(data.totalRating > 1 && data.totalRating < 2) {
		this.rating = 2.5

	} else if(data.totalRating > 2 && data.totalRating < 3) {
		this.rating = 3.5

	} else if(data.totalRating > 3 && data.totalRating < 4) {
		this.rating = 4.5

	} else if(data.totalRating > 4 && data.totalRating < 5) {
		this.rating = 5.5

	} else {
		rating = 'tidak ada rating'
	}

	return Object.assign(data, {ratingStar: this.rating})	
}

// example dummy data
const fiveStar = [5, 5, 5, 5, 5, 5 , 5, 5] 
const fourStar = [4, 4.5 ,4, 4, 4.5, 4.5, 4, 4.5, 4.5, 4.5, 4, 4.5, 4]  
const threeStar = [3, 3, 3.5]
const twoStar = [2, 2, 2, 2.5, 2.5, 2, 2, 2.5, 2.5] 
const oneStar = [1.5, 1.5 ,1, 1.5, 1.5, 1, 1, 1, 1, 1.5] 

const data = new RatingStar(fiveStar, fourStar, threeStar, twoStar, oneStar)
console.log(data.getRating())

// output
// {
//   fiveStar: { persen: '2%', total: 200, peopleGiveRating: 9 },
//   fourStar: { persen: '2%', total: 220, peopleGiveRating: 14 },
//   threeStar: { persen: '0%', total: 27, peopleGiveRating: 4 },
//   twoStar: { persen: '0%', total: 40, peopleGiveRating: 10 },
//   oneStar: { persen: '0%', total: 12, peopleGiveRating: 10 },
//   totalPeopleGiveRating: 48,
//   totalRating: 3.6,
//   ratingStar: 4.5
// }