Skill: Payout Calculation

When to Use

Use this skill when changing:

• •how payouts are computed
• •rounding/precision rules
• •discrepancy detection behavior
• •the format of payout strings shown to users

Source of Truth (Code)

• •src/App.js: calculatePayouts

Inputs / State (Current)

The calculator uses:

• •players: array of { name, startStack, endStack } (stacks are user-entered and often stored as strings)
• •coinValue: number (chip value -> money conversion)
• •selectedCurrency: object with symbol (used for display)

Algorithm (Current)

calculatePayouts does the following:

1. •Normalizes empty startStack/endStack values to "0".
2. •Recomputes totalStartingStack and totalEndingStack.
3. •If totals differ, shows a discrepancy modal with the discrepancy value converted using coinValue.
4. •Computes per-player:
   • •startingValue = startStack * coinValue
   • •endingValue = endStack * coinValue
   • •result = endingValue - startingValue
5. •Builds a list of payout instructions by matching winners (result > 0) with losers (result < 0):
   • •Greedy settlement: for each winner, iterate losers and transfer min(winnerRemaining, abs(loserRemaining)).
   • •Produces strings like: "<loser> should pay <winner> <symbol><amount>".
6. •Stores { playerResults, payouts, currency } into results state and opens the results dialog.

Rounding / Precision Notes

• •The code uses parseFloat and toFixed(2) for display.
• •If you change money math, explicitly document rounding and equality expectations.

Common Changes

• •Change payout string format: update calculatePayouts and ensure ResultsDisplay/share features still match.
• •Support alternative settlement strategies (min transactions, grouping): document tradeoffs and add tests if introduced.

Debugging Checklist

• •Reproduce with a small 2-player example (one winner/one loser).
• •Test multi-player cases with multiple winners/losers.
• •Verify discrepancy behavior when totals are off by small amounts (floating point).