auction.rs

use core::fmt;
use sha2::{ Sha256, Digest };
use std::{
    error::Error,
    fmt::{Debug, Display},
    io,
};

#[derive(Debug, Clone, Copy)]
struct AuctionDetails {}

#[derive(Debug, Clone)]
enum HashError<'a> {
    Error_message(&'a str),
}

trait Auction {
    fn commit<T: Display>(a: T, b: T) -> Result<Vec<Vec<u8>>, HashError<'static>>;
    fn open<T: Display>(
        input: T,
        commitment: Vec<u8>
    ) -> Result<bool, HashError<'static>>;
}

impl Auction for AuctionDetails {
    fn commit<T: Display>(a: T, b: T) -> Result<Vec<Vec<u8>>, HashError<'static>> {
        let mut hash_vector = Vec::new();
    
        let a_hash = hash_fn(a);
        let b_hash = hash_fn(b);

        hash_vector.push(a_hash);
        hash_vector.push(b_hash);

        Ok(hash_vector)
    }

    fn open<T: Display>(
        input: T,
        commitment: Vec<u8>,
    ) -> Result<bool, HashError<'static>> {
        let input_hash = hash_fn(input);

        if input_hash == commitment {
            Ok(true)
        } else {
            Err(HashError::Error_message("Commitment hash discrepancy"))
        }
    }
}

fn hash_fn<T: Display>(input: T) -> Vec<u8> {
    let mut hasher = Sha256::new();

    hasher.update(input.to_string());
    let hash = hasher.finalize();

    hash.to_vec()
}

fn main() {
    let mut input = String::new();

    println!("Enter first bid: ");
    io::stdin()
        .read_line(&mut input)
        .expect("failed to read line");
    let first_bid: u8 = input.trim().parse().expect("Pls enter a valid number");
    input.clear();

    println!("Enter second bid: ");
    io::stdin()
        .read_line(&mut input)
        .expect("failed to read line");
    let second_bid: u8 = input.trim().parse().expect("Please enter a valid number");

    let bid_hashes: Vec<Vec<u8>> =
        AuctionDetails::commit(first_bid, second_bid).expect("commit function failed");

        let first_bid_commit = bid_hashes.clone()[0].to_vec();
        let second_bid_commit = bid_hashes.clone()[1].to_vec();

        let first_bid_open = AuctionDetails::open(first_bid, first_bid_commit).unwrap();
        println!("First bid hash reveal: {}", first_bid_open);

        let second_bid_open = AuctionDetails::open(second_bid, second_bid_commit).unwrap();
        println!("Second bid reveal: {}", second_bid_open);

}