betting

A Rust crate to manage twitch-style bets (aka Parimutuel betting)

use bets::{Bets, BetError, Amount};

fn bet_demo() -> Result<(), BetError> {
    let bets = Bets::new("bets.db").unwrap();
    // Create 3 accounts on server 1 with 100 starting coins
    bets.create_account(1u64, 0u64, 100u64).unwrap();
    bets.create_account(1u64, 1u64, 100u64).unwrap();
    bets.create_account(1u64, 2u64, 100u64).unwrap();
    // Create a bet with 2 outcomes
    bets.create_bet(
        1u64, 1u64,
        "Who will win the Rocket League 1v1 ?",
        &vec!["Alice", "Bob"],
    ).unwrap();
    // Alice bets on herself (option with id 0) with 10 coins
    bets.bet_on(1u64, 0u64, 0u64, 10).unwrap();
    // Bob bets on himself (option with id 1) with 40 coins
    bets.bet_on(1u64, 1u64, 1u64, 40).unwrap();
    // Charlie bets on Alice with half of his coins (50)
    bets.bet_on(1u64, 0u64, 2u64, 0.5).unwrap();
    // asserts that the money is gone from their accounts
    assert_eq!(bets.balance(1u64, 0u64).unwrap(), 90);
    assert_eq!(bets.balance(1u64, 1u64).unwrap(), 60);
    assert_eq!(bets.balance(1u64, 2u64).unwrap(), 50);
    // lock the bet
    bets.lock_bet(1u64).unwrap();
    // ...
    // Rocket league 1v1 occurs
    // ...
    // Alice ended up winning ! we resolve the bet with option of id 0
    bets.resolve(1u64, 0u64).unwrap();
    // The winning side gets 10 + 40 + 50 = 100 coins
    // split proportionally among the betters
    // Alice had bet 10 out of 60 of this option, she wins 100*(10/60) = 16.6 rounded to 17
    assert_eq!(bets.balance(1u64, 0u64).unwrap(), 107);
    // Bob doesn't win anything since he bet on the wrong option
    assert_eq!(bets.balance(1u64, 1u64).unwrap(), 60);
    // Charlie had bet 50 out of 60 of this option, he wins 100*(50/60) = 83.3 rounded to 83
    assert_eq!(bets.balance(1u64, 2u64).unwrap(), 133);
    Ok(());
}

fn main() {
    if let Err(why) = bet_demo() {
        println!("{:?}", why);
    }
}