// Copyright © 2024 Mikhail Hogrefe
//
// This file is part of Malachite.
//
// Malachite is free software: you can redistribute it and/or modify it under the terms of the GNU
// Lesser General Public License (LGPL) as published by the Free Software Foundation; either version
// 3 of the License, or (at your option) any later version. See <https://www.gnu.org/licenses/>.

use malachite_base::iterators::prefix_to_string;
use malachite_base::num::basic::traits::Zero;
use malachite_nz::natural::Natural;
use malachite_q::exhaustive::exhaustive_rationals_with_denominator_range_to_infinity;
use malachite_q::Rational;
use std::str::FromStr;

fn helper(d: &str, a: &str, out: &str) {
    assert_eq!(
        prefix_to_string(
            exhaustive_rationals_with_denominator_range_to_infinity(
                Natural::from_str(d).unwrap(),
                Rational::from_str(a).unwrap()
            ),
            20
        ),
        out
    );
}

#[test]
fn test_exhaustive_rationals_with_denominator_range_to_infinity() {
    helper(
        "1",
        "0",
        "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, ...]",
    );
    helper(
        "2",
        "0",
        "[1/2, 3/2, 5/2, 7/2, 9/2, 11/2, 13/2, 15/2, 17/2, 19/2, 21/2, 23/2, 25/2, 27/2, 29/2, \
        31/2, 33/2, 35/2, 37/2, 39/2, ...]",
    );
    helper(
        "3",
        "0",
        "[1/3, 2/3, 4/3, 5/3, 7/3, 8/3, 10/3, 11/3, 13/3, 14/3, 16/3, 17/3, 19/3, 20/3, 22/3, \
        23/3, 25/3, 26/3, 28/3, 29/3, ...]",
    );
    helper(
        "4",
        "0",
        "[1/4, 3/4, 5/4, 7/4, 9/4, 11/4, 13/4, 15/4, 17/4, 19/4, 21/4, 23/4, 25/4, 27/4, 29/4, \
        31/4, 33/4, 35/4, 37/4, 39/4, ...]",
    );
    helper(
        "5",
        "0",
        "[1/5, 2/5, 3/5, 4/5, 6/5, 7/5, 8/5, 9/5, 11/5, 12/5, 13/5, 14/5, 16/5, 17/5, 18/5, 19/5, \
        21/5, 22/5, 23/5, 24/5, ...]",
    );
    helper(
        "6",
        "0",
        "[1/6, 5/6, 7/6, 11/6, 13/6, 17/6, 19/6, 23/6, 25/6, 29/6, 31/6, 35/6, 37/6, 41/6, 43/6, \
        47/6, 49/6, 53/6, 55/6, 59/6, ...]",
    );

    helper(
        "1",
        "1/2",
        "[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, ...]",
    );
    helper(
        "2",
        "1/2",
        "[1/2, 3/2, 5/2, 7/2, 9/2, 11/2, 13/2, 15/2, 17/2, 19/2, 21/2, 23/2, 25/2, 27/2, 29/2, \
        31/2, 33/2, 35/2, 37/2, 39/2, ...]",
    );
    helper(
        "3",
        "1/2",
        "[2/3, 4/3, 5/3, 7/3, 8/3, 10/3, 11/3, 13/3, 14/3, 16/3, 17/3, 19/3, 20/3, 22/3, 23/3, \
        25/3, 26/3, 28/3, 29/3, 31/3, ...]",
    );
    helper(
        "4",
        "1/2",
        "[3/4, 5/4, 7/4, 9/4, 11/4, 13/4, 15/4, 17/4, 19/4, 21/4, 23/4, 25/4, 27/4, 29/4, 31/4, \
        33/4, 35/4, 37/4, 39/4, 41/4, ...]",
    );
    helper(
        "5",
        "1/2",
        "[3/5, 4/5, 6/5, 7/5, 8/5, 9/5, 11/5, 12/5, 13/5, 14/5, 16/5, 17/5, 18/5, 19/5, 21/5, \
        22/5, 23/5, 24/5, 26/5, 27/5, ...]",
    );
    helper(
        "6",
        "1/2",
        "[5/6, 7/6, 11/6, 13/6, 17/6, 19/6, 23/6, 25/6, 29/6, 31/6, 35/6, 37/6, 41/6, 43/6, 47/6, \
        49/6, 53/6, 55/6, 59/6, 61/6, ...]",
    );

    helper(
        "1",
        "245850922/78256779",
        "[4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, ...]",
    );
    helper(
        "2",
        "245850922/78256779",
        "[7/2, 9/2, 11/2, 13/2, 15/2, 17/2, 19/2, 21/2, 23/2, 25/2, 27/2, 29/2, 31/2, 33/2, 35/2, \
        37/2, 39/2, 41/2, 43/2, 45/2, ...]",
    );
    helper(
        "3",
        "245850922/78256779",
        "[10/3, 11/3, 13/3, 14/3, 16/3, 17/3, 19/3, 20/3, 22/3, 23/3, 25/3, 26/3, 28/3, 29/3, \
        31/3, 32/3, 34/3, 35/3, 37/3, 38/3, ...]",
    );
    helper(
        "4",
        "245850922/78256779",
        "[13/4, 15/4, 17/4, 19/4, 21/4, 23/4, 25/4, 27/4, 29/4, 31/4, 33/4, 35/4, 37/4, 39/4, \
        41/4, 43/4, 45/4, 47/4, 49/4, 51/4, ...]",
    );
    helper(
        "5",
        "245850922/78256779",
        "[16/5, 17/5, 18/5, 19/5, 21/5, 22/5, 23/5, 24/5, 26/5, 27/5, 28/5, 29/5, 31/5, 32/5, \
        33/5, 34/5, 36/5, 37/5, 38/5, 39/5, ...]",
    );
    helper(
        "6",
        "245850922/78256779",
        "[19/6, 23/6, 25/6, 29/6, 31/6, 35/6, 37/6, 41/6, 43/6, 47/6, 49/6, 53/6, 55/6, 59/6, \
        61/6, 65/6, 67/6, 71/6, 73/6, 77/6, ...]",
    );

    helper(
        "1",
        "-245850922/78256779",
        "[0, 1, -1, 2, -2, 3, -3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, ...]",
    );
    helper(
        "2",
        "-245850922/78256779",
        "[1/2, -1/2, 3/2, -3/2, 5/2, -5/2, 7/2, 9/2, 11/2, 13/2, 15/2, 17/2, 19/2, 21/2, 23/2, \
        25/2, 27/2, 29/2, 31/2, 33/2, ...]",
    );
    helper(
        "3",
        "-245850922/78256779",
        "[1/3, -1/3, 2/3, -2/3, 4/3, -4/3, 5/3, -5/3, 7/3, -7/3, 8/3, -8/3, 10/3, 11/3, 13/3, \
        14/3, 16/3, 17/3, 19/3, 20/3, ...]",
    );
    helper(
        "4",
        "-245850922/78256779",
        "[1/4, -1/4, 3/4, -3/4, 5/4, -5/4, 7/4, -7/4, 9/4, -9/4, 11/4, -11/4, 13/4, 15/4, 17/4, \
        19/4, 21/4, 23/4, 25/4, 27/4, ...]",
    );
    helper(
        "5",
        "-245850922/78256779",
        "[1/5, -1/5, 2/5, -2/5, 3/5, -3/5, 4/5, -4/5, 6/5, -6/5, 7/5, -7/5, 8/5, -8/5, 9/5, -9/5, \
        11/5, -11/5, 12/5, -12/5, ...]",
    );
    helper(
        "6",
        "-245850922/78256779",
        "[1/6, -1/6, 5/6, -5/6, 7/6, -7/6, 11/6, -11/6, 13/6, -13/6, 17/6, -17/6, 19/6, 23/6, \
        25/6, 29/6, 31/6, 35/6, 37/6, 41/6, ...]",
    );
}

#[test]
#[should_panic]
fn exhaustive_rationals_with_denominator_range_to_infinity_fail() {
    exhaustive_rationals_with_denominator_range_to_infinity(
        Natural::ZERO,
        Rational::from_unsigneds(1u32, 3),
    );
}