95 lines
2.7 KiB
TypeScript
95 lines
2.7 KiB
TypeScript
import * as _ from 'lodash'
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import { Contract } from './contract'
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import { filterDefined } from './util/array'
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import { addObjects } from './util/object'
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export const getRecommendedContracts = (
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contractsById: { [contractId: string]: Contract },
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yourBetOnContractIds: string[]
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) => {
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const contracts = Object.values(contractsById)
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const yourContracts = filterDefined(
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yourBetOnContractIds.map((contractId) => contractsById[contractId])
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)
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const yourContractIds = new Set(yourContracts.map((c) => c.id))
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const notYourContracts = contracts.filter((c) => !yourContractIds.has(c.id))
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const yourWordFrequency = contractsToWordFrequency(yourContracts)
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const otherWordFrequency = contractsToWordFrequency(notYourContracts)
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const words = _.union(
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Object.keys(yourWordFrequency),
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Object.keys(otherWordFrequency)
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)
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const yourWeightedFrequency = _.fromPairs(
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_.map(words, (word) => {
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const [yourFreq, otherFreq] = [
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yourWordFrequency[word] ?? 0,
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otherWordFrequency[word] ?? 0,
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]
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const score = yourFreq / (yourFreq + otherFreq + 0.0001)
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return [word, score]
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})
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)
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// console.log(
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// 'your weighted frequency',
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// _.sortBy(_.toPairs(yourWeightedFrequency), ([, freq]) => -freq)
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// )
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const scoredContracts = contracts.map((contract) => {
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const wordFrequency = contractToWordFrequency(contract)
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const score = _.sumBy(Object.keys(wordFrequency), (word) => {
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const wordFreq = wordFrequency[word] ?? 0
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const weight = yourWeightedFrequency[word] ?? 0
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return wordFreq * weight
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})
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return {
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contract,
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score,
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}
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})
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return _.sortBy(scoredContracts, (scored) => -scored.score).map(
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(scored) => scored.contract
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)
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}
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const contractToText = (contract: Contract) => {
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const { description, question, tags, creatorUsername } = contract
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return `${creatorUsername} ${question} ${tags.join(' ')} ${description}`
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}
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const getWordsCount = (text: string) => {
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const normalizedText = text.replace(/[^a-zA-Z]/g, ' ').toLowerCase()
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const words = normalizedText.split(' ').filter((word) => word)
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const counts: { [word: string]: number } = {}
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for (const word of words) {
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if (counts[word]) counts[word]++
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else counts[word] = 1
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}
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return counts
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}
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const toFrequency = (counts: { [word: string]: number }) => {
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const total = _.sum(Object.values(counts))
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return _.mapValues(counts, (count) => count / total)
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}
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const contractToWordFrequency = (contract: Contract) =>
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toFrequency(getWordsCount(contractToText(contract)))
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const contractsToWordFrequency = (contracts: Contract[]) => {
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const frequencySum = contracts
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.map(contractToWordFrequency)
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.reduce(addObjects, {})
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return toFrequency(frequencySum)
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}
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