miniconf 0.21.0

use miniconf::{Indices, KeyError, Packed, Path, Shape, Tree, TreeSchema, TreeSerialize};
mod common;

#[derive(Tree, Default)]
struct Settings {
    a: f32,
    b: [f32; 2],
}

#[test]
fn packed() {
    // Check empty being too short
    let info = Settings::SCHEMA.get(Packed::EMPTY).unwrap();
    assert_eq!((info.depth, info.schema.is_leaf()), (0, false));

    // Check path-packed round trip.
    for iter_path in Settings::SCHEMA
        .nodes::<Path<String>, 2>()
        .map(Result::unwrap)
    {
        let packed: Packed = Settings::SCHEMA.transcode(iter_path.as_ref()).unwrap();
        let path: Path<String> = Settings::SCHEMA.transcode(packed).unwrap();
        assert_eq!(path, iter_path);
        println!(
            "{path:?} {iter_path:?}, {:#06b} {} {:?}",
            packed.get() >> 60,
            packed.into_lsb(),
            Settings::SCHEMA.get(iter_path.as_ref()).unwrap().depth
        );
    }
    println!(
        "{:?}",
        Settings::SCHEMA
            .nodes::<Packed, 2>()
            .map(|p| p.unwrap().into_lsb())
            .collect::<Vec<_>>()
    );

    // Check that Packed `marker + 0b0` is equivalent to `/a`
    let a = Packed::from_lsb(0b10.try_into().unwrap());
    let path: Path<String> = Settings::SCHEMA.transcode(a).unwrap();
    assert_eq!(Settings::SCHEMA.get(a).unwrap().depth, 1);
    assert_eq!(path.as_ref(), "/a");
}

#[test]
fn top() {
    #[derive(Tree)]
    struct S {
        baz: [i32; 1],
        foo: i32,
    }
    assert_eq!(
        S::SCHEMA
            .nodes::<Path<String>, 2>()
            .map(|p| p.unwrap().into_inner())
            .collect::<Vec<_>>(),
        ["/baz/0", "/foo"]
    );
    assert_eq!(
        S::SCHEMA
            .nodes::<Indices<_>, 2>()
            .map(|p| p.unwrap())
            .collect::<Vec<_>>(),
        [Indices::new([0, 0], 2), Indices::new([1, 0], 1)]
    );
    let p: Packed = S::SCHEMA.transcode([1usize]).unwrap();
    assert_eq!(
        (p.into_lsb().get(), S::SCHEMA.get([1usize]).unwrap().depth),
        (0b11, 1)
    );
    assert_eq!(
        S::SCHEMA
            .nodes::<Packed, 2>()
            .map(|p| p.unwrap().into_lsb().get())
            .collect::<Vec<_>>(),
        [0b100, 0b11]
    );
}

#[test]
fn zero_key() {
    assert_eq!(
        Option::<()>::SCHEMA
            .nodes::<Packed, 2>()
            .next()
            .unwrap()
            .unwrap()
            .into_lsb()
            .get(),
        0b1
    );

    assert_eq!(
        <[usize; 1]>::SCHEMA
            .nodes::<Packed, 2>()
            .next()
            .unwrap()
            .unwrap()
            .into_lsb()
            .get(),
        0b10
    );

    // Check the corner case of a len=1 index where (len - 1) = 0 and zero bits would be required to encode.
    // Hence the Packed values for len=1 and len=2 are the same.
    let a11 = [[0]];
    let a22 = [[0; 2]; 2];
    let mut buf = [0u8; 100];
    let mut ser = serde_json_core::ser::Serializer::new(&mut buf);
    for (depth, result) in [
        Err(KeyError::TooShort.into()),
        Err(KeyError::TooShort.into()),
        Ok(()),
    ]
    .iter()
    .enumerate()
    {
        assert_eq!(
            TreeSerialize::serialize_by_key(
                &a11,
                Packed::from_lsb((0b1 << depth).try_into().unwrap()),
                &mut ser
            ),
            *result
        );
        assert_eq!(
            TreeSerialize::serialize_by_key(
                &a22,
                Packed::from_lsb((0b1 << depth).try_into().unwrap()),
                &mut ser
            ),
            *result
        );
    }
}

#[test]
fn size() {
    // The max width claims below only apply to 32 bit architectures

    // Play with the worst cases for 32 bit Packed
    // Bit-hungriest type would be [T; 0] or () but (a) those are forbidden (internal without leaves) and (b) they don't have any keys
    // so won't recurse in Transcode or consume from Keys
    // Then [T; 1] which takes one bit per level (not 0 bits, to distinguish empty Packed)
    // Worst case for a 32 bit usize we need 31 array levels (marker bit).
    type A31 = [[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[(); 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1];
        1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1]; 1];
    assert_eq!(core::mem::size_of::<A31>(), 0);
    let packed = Packed::new_from_lsb(1 << 31).unwrap();
    let path = A31::SCHEMA.transcode::<Path<String>>(packed).unwrap();
    assert_eq!(A31::SCHEMA.get(packed).unwrap().depth, 31);
    assert_eq!(path.as_ref().len(), 2 * 31);
    const META: Shape = A31::SCHEMA.shape();
    assert_eq!(META.max_bits, 31);
    assert_eq!(META.max_depth, 31);
    assert_eq!(META.count.get(), 1usize.pow(31));
    assert_eq!(META.max_length, 31);

    // Another way to get to 32 bit is to take 15 length-3 (2 bit) levels and one length-1 (1 bit) level to fill it, needing (3**15 ~ 14 M) storage.
    // With the unit as type, we need 0 storage but can't do much.
    type A16 = [[[[[[[[[[[[[[[[(); 3]; 3]; 3]; 3]; 3]; 3]; 3]; 3]; 3]; 3]; 3]; 3]; 3]; 3]; 3]; 1];
    assert_eq!(core::mem::size_of::<A16>(), 0);
    let packed = Packed::new_from_lsb(1 << 31).unwrap();
    let path = A16::SCHEMA.transcode::<Path<String>>(packed).unwrap();
    assert_eq!(A16::SCHEMA.get(packed).unwrap().depth, 16);
    assert_eq!(path.as_ref().len(), 2 * 16);
    const META16: Shape = A16::SCHEMA.shape();
    assert_eq!(META16.max_bits, 31);
    assert_eq!(META16.max_depth, 16);
    assert_eq!(META16.count.get(), 3usize.pow(15));
    assert_eq!(META16.max_length, 16);
}