manifold/web/components/use-save-shares.ts
2022-05-02 12:16:36 -04:00

58 lines
1.5 KiB
TypeScript

import { Binary, CPMM, DPM, FullContract } from '../../common/contract'
import { Bet } from '../../common/bet'
import { useEffect, useState } from 'react'
import _ from 'lodash'
export const useSaveShares = (
contract: FullContract<CPMM | DPM, Binary>,
userBets: Bet[] | undefined
) => {
const [savedShares, setSavedShares] = useState<
| {
yesShares: number
noShares: number
yesFloorShares: number
noFloorShares: number
}
| undefined
>()
const [yesBets, noBets] = _.partition(
userBets ?? [],
(bet) => bet.outcome === 'YES'
)
const [yesShares, noShares] = [
_.sumBy(yesBets, (bet) => bet.shares),
_.sumBy(noBets, (bet) => bet.shares),
]
const yesFloorShares = Math.round(yesShares) === 0 ? 0 : Math.floor(yesShares)
const noFloorShares = Math.round(noShares) === 0 ? 0 : Math.floor(noShares)
useEffect(() => {
// Save yes and no shares to local storage.
const savedShares = localStorage.getItem(`${contract.id}-shares`)
if (!userBets && savedShares) {
setSavedShares(JSON.parse(savedShares))
}
if (userBets) {
const updatedShares = { yesShares, noShares }
localStorage.setItem(
`${contract.id}-shares`,
JSON.stringify(updatedShares)
)
}
}, [contract.id, userBets, noShares, yesShares])
if (userBets) return { yesShares, noShares, yesFloorShares, noFloorShares }
return (
savedShares ?? {
yesShares: 0,
noShares: 0,
yesFloorShares: 0,
noFloorShares: 0,
}
)
}