/**
 * CSPRNG Fisher-Yates shuffle.
 *
 * Only works on lists up to 255 elements.
 */
function cryptoShuffle(l) {
    for (let i = l.length - 1; i > 0; i--) {
        let value = new Uint8Array([0]);
        crypto.getRandomValues(value);
        while (value[0] > i) {
            crypto.getRandomValues(value);
        }

        let temp = l[i];
        l[i] = l[value[0]];
        l[value[0]] = temp;
    }

    return l;
}

window.cryptoShuffle = cryptoShuffle;

function proveRegions(regions) {
    // Construct prover coins
    let coins = [];

    let regionNames = Object.keys(regions.keys());
    for (let x = 0; x < 20; x++) {
        let psi = cryptoShuffle(regionNames).join("");
    }

    // Construct verifier coins
    let hasher = new jsSHA("SHA3-256", "TEXT");
    hasher.update(JSON.stringify(regions));

    // Construct prover proofs
}