// Eryn Wells <eryn@erynwells.me>

use rand::{rngs::StdRng, RngCore, SeedableRng};

pub struct RandomNumberGenerator {
    rng: StdRng,
}

impl RandomNumberGenerator {
    /// A default value for hashing chess games.
    ///
    /// This value is the SHA-256 hash of a PGN I downloaded from the internet
    /// of the six games Kasparov played against Deep Blue in 1996.
    #[rustfmt::skip]
    const DEFAULT_SEED_VALUE: [u8; 32] = [
        0x22, 0x0b, 0xae, 0xd5, 0xc5, 0xb8, 0x20, 0xb1,
        0xee, 0x05, 0x4b, 0x72, 0x73, 0x4c, 0x1a, 0xf9,
        0xc2, 0xb7, 0x5d, 0x87, 0xc8, 0xa9, 0x44, 0x87,
        0x01, 0xda, 0xdb, 0xe0, 0x8e, 0xf8, 0xe8, 0x77,
    ];

    #[must_use]
    pub fn new(seed: <StdRng as SeedableRng>::Seed) -> Self {
        let rng = StdRng::from_seed(seed);

        Self { rng }
    }

    #[must_use]
    pub fn rand(&mut self) -> &mut StdRng {
        &mut self.rng
    }

    pub fn next_u64(&mut self) -> u64 {
        self.rng.next_u64()
    }
}

impl Default for RandomNumberGenerator {
    fn default() -> Self {
        let rng = StdRng::from_seed(Self::DEFAULT_SEED_VALUE);
        Self { rng }
    }
}