use ark_ff::{
    biginteger::{BigInteger, BigInteger256},
    fields::{
        fp6_3over2::Fp6Parameters, FftField, FftParameters, Field, FpParameters, PrimeField,
        SquareRootField,
    },
    One, UniformRand, Zero,
};
use ark_serialize::{buffer_bit_byte_size, CanonicalSerialize};
use ark_std::rand::Rng;
use ark_std::test_rng;
use core::{
    cmp::Ordering,
    ops::{AddAssign, MulAssign, SubAssign},
};

use crate::{Fq, Fq12, Fq2, Fq6, Fq6Parameters, FqParameters, Fr};
use ark_algebra_test_templates::fields::*;

pub(crate) const ITERATIONS: usize = 5;

#[test]
fn test_fr() {
    let mut rng = test_rng();
    for _ in 0..ITERATIONS {
        let a: Fr = rng.gen();
        let b: Fr = rng.gen();
        field_test(a, b);
        primefield_test::<Fr>();
        sqrt_field_test(b);
        let byte_size = a.serialized_size();
        field_serialization_test::<Fr>(byte_size);
    }
}

#[test]
fn test_fq() {
    let mut rng = test_rng();
    for _ in 0..ITERATIONS {
        let a: Fq = rng.gen();
        let b: Fq = rng.gen();
        field_test(a, b);
        primefield_test::<Fq>();
        sqrt_field_test(a);
        let byte_size = a.serialized_size();
        let (_, buffer_size) = buffer_bit_byte_size(Fq::size_in_bits());
        assert_eq!(byte_size, buffer_size);
        field_serialization_test::<Fq>(byte_size);
    }
}

#[test]
fn test_fq2() {
    let mut rng = test_rng();
    for _ in 0..ITERATIONS {
        let a: Fq2 = rng.gen();
        let b: Fq2 = rng.gen();
        field_test(a, b);
        sqrt_field_test(a);
    }
    frobenius_test::<Fq2, _>(Fq::characteristic(), 13);
    let byte_size = Fq2::zero().serialized_size();
    field_serialization_test::<Fq2>(byte_size);
}

#[test]
fn test_fq6() {
    let mut rng = test_rng();
    for _ in 0..ITERATIONS {
        let g: Fq6 = rng.gen();
        let h: Fq6 = rng.gen();
        field_test(g, h);
    }
    frobenius_test::<Fq6, _>(Fq::characteristic(), 13);
    let byte_size = Fq6::zero().serialized_size();
    field_serialization_test::<Fq6>(byte_size);
}

#[test]
fn test_fq12() {
    let mut rng = test_rng();
    for _ in 0..ITERATIONS {
        let g: Fq12 = rng.gen();
        let h: Fq12 = rng.gen();
        field_test(g, h);
    }
    frobenius_test::<Fq12, _>(Fq::characteristic(), 13);
    let byte_size = Fq12::zero().serialized_size();
    field_serialization_test::<Fq12>(byte_size);
}

#[test]
fn test_fq_repr_from() {
    assert_eq!(BigInteger256::from(100), BigInteger256([100, 0, 0, 0]));
}

#[test]
fn test_fq_repr_is_odd() {
    assert!(!BigInteger256::from(0).is_odd());
    assert!(BigInteger256::from(0).is_even());
    assert!(BigInteger256::from(1).is_odd());
    assert!(!BigInteger256::from(1).is_even());
    assert!(!BigInteger256::from(324834872).is_odd());
    assert!(BigInteger256::from(324834872).is_even());
    assert!(BigInteger256::from(324834873).is_odd());
    assert!(!BigInteger256::from(324834873).is_even());
}

#[test]
fn test_fq_repr_is_zero() {
    assert!(BigInteger256::from(0).is_zero());
    assert!(!BigInteger256::from(1).is_zero());
    assert!(!BigInteger256([0, 0, 1, 0]).is_zero());
}

#[test]
fn test_fq_repr_num_bits() {
    let mut a = BigInteger256::from(0);
    assert_eq!(0, a.num_bits());
    a = BigInteger256::from(1);
    for i in 1..257 {
        assert_eq!(i, a.num_bits());
        a.mul2();
    }
    assert_eq!(0, a.num_bits());
}

#[test]
fn test_fq_add_assign() {
    // Test associativity

    let mut rng = ark_std::test_rng();

    for _ in 0..1000 {
        // Generate a, b, c and ensure (a + b) + c == a + (b + c).
        let a = Fq::rand(&mut rng);
        let b = Fq::rand(&mut rng);
        let c = Fq::rand(&mut rng);

        let mut tmp1 = a;
        tmp1.add_assign(&b);
        tmp1.add_assign(&c);

        let mut tmp2 = b;
        tmp2.add_assign(&c);
        tmp2.add_assign(&a);

        assert_eq!(tmp1, tmp2);
    }
}

#[test]
fn test_fq_sub_assign() {
    let mut rng = ark_std::test_rng();

    for _ in 0..1000 {
        // Ensure that (a - b) + (b - a) = 0.
        let a = Fq::rand(&mut rng);
        let b = Fq::rand(&mut rng);

        let mut tmp1 = a;
        tmp1.sub_assign(&b);

        let mut tmp2 = b;
        tmp2.sub_assign(&a);

        tmp1.add_assign(&tmp2);
        assert!(tmp1.is_zero());
    }
}

#[test]
fn test_fq_mul_assign() {
    let mut rng = ark_std::test_rng();

    for _ in 0..1000000 {
        // Ensure that (a * b) * c = a * (b * c)
        let a = Fq::rand(&mut rng);
        let b = Fq::rand(&mut rng);
        let c = Fq::rand(&mut rng);

        let mut tmp1 = a;
        tmp1.mul_assign(&b);
        tmp1.mul_assign(&c);

        let mut tmp2 = b;
        tmp2.mul_assign(&c);
        tmp2.mul_assign(&a);

        assert_eq!(tmp1, tmp2);
    }

    for _ in 0..1000000 {
        // Ensure that r * (a + b + c) = r*a + r*b + r*c

        let r = Fq::rand(&mut rng);
        let mut a = Fq::rand(&mut rng);
        let mut b = Fq::rand(&mut rng);
        let mut c = Fq::rand(&mut rng);

        let mut tmp1 = a;
        tmp1.add_assign(&b);
        tmp1.add_assign(&c);
        tmp1.mul_assign(&r);

        a.mul_assign(&r);
        b.mul_assign(&r);
        c.mul_assign(&r);

        a.add_assign(&b);
        a.add_assign(&c);

        assert_eq!(tmp1, a);
    }
}

#[test]
fn test_fq_squaring() {
    let mut rng = ark_std::test_rng();

    for _ in 0..1000000 {
        // Ensure that (a * a) = a^2
        let a = Fq::rand(&mut rng);

        let mut tmp = a;
        tmp.square_in_place();

        let mut tmp2 = a;
        tmp2.mul_assign(&a);

        assert_eq!(tmp, tmp2);
    }
}

#[test]
fn test_fq_inverse() {
    assert!(Fq::zero().inverse().is_none());

    let mut rng = ark_std::test_rng();

    let one = Fq::one();

    for _ in 0..1000 {
        // Ensure that a * a^-1 = 1
        let mut a = Fq::rand(&mut rng);
        let ainv = a.inverse().unwrap();
        a.mul_assign(&ainv);
        assert_eq!(a, one);
    }
}

#[test]
fn test_fq_double_in_place() {
    let mut rng = ark_std::test_rng();

    for _ in 0..1000 {
        // Ensure doubling a is equivalent to adding a to itself.
        let mut a = Fq::rand(&mut rng);
        let mut b = a;
        b.add_assign(&a);
        a.double_in_place();
        assert_eq!(a, b);
    }
}

#[test]
fn test_fq_negate() {
    {
        let a = -Fq::zero();

        assert!(a.is_zero());
    }

    let mut rng = ark_std::test_rng();

    for _ in 0..1000 {
        // Ensure (a - (-a)) = 0.
        let mut a = Fq::rand(&mut rng);
        let b = -a;
        a.add_assign(&b);

        assert!(a.is_zero());
    }
}

#[test]
fn test_fq_pow() {
    let mut rng = ark_std::test_rng();

    for i in 0..1000 {
        // Exponentiate by various small numbers and ensure it consists with repeated
        // multiplication.
        let a = Fq::rand(&mut rng);
        let target = a.pow(&[i]);
        let mut c = Fq::one();
        for _ in 0..i {
            c.mul_assign(&a);
        }
        assert_eq!(c, target);
    }

    for _ in 0..1000 {
        // Exponentiating by the modulus should have no effect in a prime field.
        let a = Fq::rand(&mut rng);

        assert_eq!(a, a.pow(Fq::characteristic()));
    }
}

#[test]
fn test_fq_sqrt() {
    let mut rng = ark_std::test_rng();

    assert_eq!(Fq::zero().sqrt().unwrap(), Fq::zero());

    for _ in 0..1000 {
        // Ensure sqrt(a^2) = a or -a
        let a = Fq::rand(&mut rng);
        let nega = -a;
        let mut b = a;
        b.square_in_place();

        let b = b.sqrt().unwrap();

        assert!(a == b || nega == b);
    }

    for _ in 0..1000 {
        // Ensure sqrt(a)^2 = a for random a
        let a = Fq::rand(&mut rng);

        if let Some(mut tmp) = a.sqrt() {
            tmp.square_in_place();

            assert_eq!(a, tmp);
        }
    }
}

#[test]
fn test_fq_num_bits() {
    assert_eq!(FqParameters::MODULUS_BITS, 254);
    assert_eq!(FqParameters::CAPACITY, 253);
}

#[test]
fn test_fq_root_of_unity() {
    assert_eq!(FqParameters::TWO_ADICITY, 1);
    assert_eq!(
        Fq::multiplicative_generator().pow([
            0x9e10460b6c3e7ea3,
            0xcbc0b548b438e546,
            0xdc2822db40c0ac2e,
            0x183227397098d014,
        ]),
        Fq::two_adic_root_of_unity()
    );
    assert_eq!(
        Fq::two_adic_root_of_unity().pow([1 << FqParameters::TWO_ADICITY]),
        Fq::one()
    );
    assert!(Fq::multiplicative_generator().sqrt().is_none());
}

#[test]
fn test_fq_ordering() {
    // BigInteger256's ordering is well-tested, but we still need to make sure the
    // Fq elements aren't being compared in Montgomery form.
    for i in 0..100 {
        assert!(Fq::from(BigInteger256::from(i + 1)) > Fq::from(BigInteger256::from(i)));
    }
}

#[test]
fn test_fq_legendre() {
    use ark_ff::fields::LegendreSymbol::*;

    assert_eq!(QuadraticResidue, Fq::one().legendre());
    assert_eq!(Zero, Fq::zero().legendre());
    assert_eq!(
        QuadraticResidue,
        Fq::from(BigInteger256::from(4)).legendre()
    );
    assert_eq!(
        QuadraticNonResidue,
        Fq::from(BigInteger256::from(5)).legendre()
    );
}

#[test]
fn test_fq2_ordering() {
    let mut a = Fq2::new(Fq::zero(), Fq::zero());
    let mut b = a.clone();

    assert!(a.cmp(&b) == Ordering::Equal);
    b.c0.add_assign(&Fq::one());
    assert!(a.cmp(&b) == Ordering::Less);
    a.c0.add_assign(&Fq::one());
    assert!(a.cmp(&b) == Ordering::Equal);
    b.c1.add_assign(&Fq::one());
    assert!(a.cmp(&b) == Ordering::Less);
    a.c0.add_assign(&Fq::one());
    assert!(a.cmp(&b) == Ordering::Less);
    a.c1.add_assign(&Fq::one());
    assert!(a.cmp(&b) == Ordering::Greater);
    b.c0.add_assign(&Fq::one());
    assert!(a.cmp(&b) == Ordering::Equal);
}

#[test]
fn test_fq2_basics() {
    assert_eq!(Fq2::new(Fq::zero(), Fq::zero(),), Fq2::zero());
    assert_eq!(Fq2::new(Fq::one(), Fq::zero(),), Fq2::one());
    assert!(Fq2::zero().is_zero());
    assert!(!Fq2::one().is_zero());
    assert!(!Fq2::new(Fq::zero(), Fq::one(),).is_zero());
}

#[test]
fn test_fq2_legendre() {
    use ark_ff::fields::LegendreSymbol::*;

    assert_eq!(Zero, Fq2::zero().legendre());
    // i^2 = -1
    let mut m1 = -Fq2::one();
    assert_eq!(QuadraticResidue, m1.legendre());
    m1 = Fq6Parameters::mul_fp2_by_nonresidue(&m1);
    assert_eq!(QuadraticNonResidue, m1.legendre());
}

#[test]
fn test_fq6_mul_by_1() {
    let mut rng = ark_std::test_rng();

    for _ in 0..1000 {
        let c1 = Fq2::rand(&mut rng);
        let mut a = Fq6::rand(&mut rng);
        let mut b = a;

        a.mul_by_1(&c1);
        b.mul_assign(&Fq6::new(Fq2::zero(), c1, Fq2::zero()));

        assert_eq!(a, b);
    }
}

#[test]
fn test_fq6_mul_by_01() {
    let mut rng = ark_std::test_rng();

    for _ in 0..1000 {
        let c0 = Fq2::rand(&mut rng);
        let c1 = Fq2::rand(&mut rng);
        let mut a = Fq6::rand(&mut rng);
        let mut b = a;

        a.mul_by_01(&c0, &c1);
        b.mul_assign(&Fq6::new(c0, c1, Fq2::zero()));

        assert_eq!(a, b);
    }
}

#[test]
fn test_fq12_mul_by_014() {
    let mut rng = ark_std::test_rng();

    for _ in 0..1000 {
        let c0 = Fq2::rand(&mut rng);
        let c1 = Fq2::rand(&mut rng);
        let c5 = Fq2::rand(&mut rng);
        let mut a = Fq12::rand(&mut rng);
        let mut b = a;

        a.mul_by_014(&c0, &c1, &c5);
        b.mul_assign(&Fq12::new(
            Fq6::new(c0, c1, Fq2::zero()),
            Fq6::new(Fq2::zero(), c5, Fq2::zero()),
        ));

        assert_eq!(a, b);
    }
}

#[test]
fn test_fq12_mul_by_034() {
    let mut rng = ark_std::test_rng();

    for _ in 0..1000 {
        let c0 = Fq2::rand(&mut rng);
        let c3 = Fq2::rand(&mut rng);
        let c4 = Fq2::rand(&mut rng);
        let mut a = Fq12::rand(&mut rng);
        let mut b = a;

        a.mul_by_034(&c0, &c3, &c4);
        b.mul_assign(&Fq12::new(
            Fq6::new(c0, Fq2::zero(), Fq2::zero()),
            Fq6::new(c3, c4, Fq2::zero()),
        ));

        assert_eq!(a, b);
    }
}