wisesplit/pages/index.tsx
2022-10-24 02:10:52 -05:00

117 lines
3 KiB
TypeScript

import { atom, PrimitiveAtom, useAtom } from "jotai";
import { selectAtom } from "jotai/utils";
import type { NextPage } from "next";
import { useState } from "react";
import EditBox from "../components/EditBox";
import ReceiptItem, { IReceiptItem } from "../components/ReceiptItem";
import Totals from "../components/Totals";
import parseInput, { ParsedInputDisplay } from "../lib/parseInput";
const totalAtom = atom(0);
const receiptAtom = atom<PrimitiveAtom<IReceiptItem>[]>([]);
const receiptTotalAtom = atom((get) => {
const totalValue = get(totalAtom);
const receipt = get(receiptAtom);
const totals = new Map();
let subtotalSum = 0;
for (const itemAtom of receipt) {
const item = get(itemAtom);
const price = get(item.price);
const splitBetween = get(item.splitBetween);
const numSplitters = splitBetween.length;
if (numSplitters == 0) continue;
const eachPrice = price / numSplitters;
subtotalSum += price;
for (const personAtom of splitBetween) {
const person = get(personAtom);
const personName = person.name;
let accum = totals.get(personName) || 0;
accum += eachPrice;
totals.set(personName, accum);
}
}
if (subtotalSum == 0) return totals;
const newTotals = new Map();
const proportion = totalValue / subtotalSum;
for (const [person, value] of totals.entries()) {
newTotals.set(person, value * proportion);
}
return newTotals;
});
const Home: NextPage = () => {
const [receipt, setReceipt] = useAtom(receiptAtom);
const [total] = useAtom(receiptTotalAtom);
const [input, setInput] = useState("");
const formatter = new Intl.NumberFormat("en-US", {
style: "currency",
currency: "USD",
});
const add = (e) => {
e.preventDefault();
let parsed = parseInput(input);
console.log(parsed);
const price = atom(parsed.price || 0);
const splitBetween = atom(
[...parsed.splitBetween].map((a) => atom({ name: a }))
);
setReceipt((prev) => [
...prev,
atom<IReceiptItem>({ name: parsed.itemName, price, splitBetween }),
]);
setInput("");
return false;
};
return (
<main>
<h2>Items</h2>
<div>
Receipt Total:
<EditBox valueAtom={totalAtom} />
</div>
<form onSubmit={add}>
<ParsedInputDisplay input={input} />
<input
type="text"
placeholder="Add item..."
onInput={(e) => setInput(e.target.value)}
value={input}
/>
</form>
<ul>
{receipt.map((itemAtom, i) => {
return (
<li key={`receiptItem-${i}`}>
<ReceiptItem itemAtom={itemAtom} />
</li>
);
})}
</ul>
<div>
Total breakdown:
<ul>
{[...total.entries()].map(([person, value], i) => (
<li key={`breakdown-${i}`}>
<b>{person}</b>: {formatter.format(value)}
</li>
))}
</ul>
</div>
</main>
);
};
export default Home;