//! `h5rs dump` and `h5rs ls` of the small floats libhdf5 2.x predefines
//! (bfloat16, FP8 E4M3/E5M2, FP6 E2M3/E3M2, FP4 E2M1), against the output
//! of h5dump 2.2.0 and h5ls 2.2.0 stored next to the fixture (the Debian
//! h5dump CI installs, 1.14.x, predates these types). See
//! `crates/clawhdf5/tests/fixtures/gen_mx_floats.py`.

use std::path::PathBuf;
use std::process::Command;

fn fixture(name: &str) -> PathBuf {
    PathBuf::from(env!("CARGO_MANIFEST_DIR"))
        .join("../clawhdf5/tests/fixtures")
        .join(name)
}

fn h5rs(args: &[&str]) -> String {
    let out = Command::new(env!("CARGO_BIN_EXE_h5rs"))
        .args(args)
        .output()
        .unwrap();
    assert!(out.status.success(), "h5rs {args:?}: {out:?}");
    String::from_utf8(out.stdout).unwrap()
}

/// Split a dump into the lines outside `DATA { ... }` blocks and the values
/// inside them, per block.
fn split(ddl: &str) -> (Vec<&str>, Vec<Vec<String>>) {
    let (mut frame, mut data) = (Vec::new(), Vec::new());
    let mut values: Option<Vec<String>> = None;
    for line in ddl.lines() {
        match &mut values {
            None if line.trim() == "DATA {" => values = Some(Vec::new()),
            None => frame.push(line),
            Some(v) if line.trim() == "}" => {
                data.push(std::mem::take(v));
                values = None;
            }
            Some(v) => {
                let (_, body) = line.split_once("):").expect("an indexed data line");
                v.extend(
                    body.split(',')
                        .map(str::trim)
                        .filter(|s| !s.is_empty())
                        .map(String::from),
                );
            }
        }
    }
    (frame, data)
}

#[test]
fn dump_matches_h5dump_2_2() {
    let path = fixture("mx_floats_hdf5_2_2.h5");
    let ours = h5rs(&["dump", path.to_str().unwrap()]);
    let reference = std::fs::read_to_string(fixture("mx_floats_hdf5_2_2.ddl")).unwrap();
    let (our_frame, our_data) = split(&ours);
    let (ref_frame, ref_data) = split(&reference);
    // Everything but the values is h5dump's byte for byte: the datatypes
    // print as H5T_FLOAT_BFLOAT16LE, H5T_FLOAT_F4E2M1, ...
    assert_eq!(our_frame, ref_frame);
    assert_eq!(our_data.len(), 17);
    assert_eq!(our_data.len(), ref_data.len());
    // Values: h5dump prints `%g` (6 significant digits) and inf/-inf/nan/
    // -nan; h5rs prints the shortest string that round-trips and Inf/-Inf/NaN.
    for (block, (ours, theirs)) in our_data.iter().zip(&ref_data).enumerate() {
        assert_eq!(ours.len(), theirs.len(), "block {block}");
        for (i, (o, r)) in ours.iter().zip(theirs).enumerate() {
            let o: f64 = o.parse().unwrap();
            let r: f64 = r.parse().unwrap();
            let same = if r.is_nan() || r.is_infinite() {
                o.is_nan() == r.is_nan() && (r.is_nan() || o == r)
            } else {
                // Both round to the same f32 (a bfloat16 subnormal prints
                // as its shortest f32 string, `9.1835e-41`, fewer digits
                // than h5dump's), or agree to h5dump's 6 digits.
                o as f32 == r as f32 || (o - r).abs() <= 5e-6 * r.abs()
            };
            assert!(same, "block {block}[{i}]: h5rs {o}, h5dump {r}");
        }
    }
}

#[test]
fn ls_names_small_floats_like_h5ls_2_2() {
    let path = fixture("mx_floats_hdf5_2_2.h5");
    // h5ls 2.2.0 -v, `Type:` line of each dataset.
    for (name, long, short) in [
        ("bf16le", "bfloat16 16-bit little-endian float", "bfloat16"),
        ("bf16be", "bfloat16 16-bit big-endian float", "bfloat16-be"),
        ("f8e4m3", "FP8 E4M3 8-bit float", "float8-e4m3"),
        ("f8e5m2", "FP8 E5M2 8-bit float", "float8-e5m2"),
        ("f6e2m3", "FP6 E2M3 6-bit float", "float6-e2m3"),
        ("f6e3m2", "FP6 E3M2 6-bit float", "float6-e3m2"),
        ("f4e2m1", "FP4 E2M1 4-bit float", "float4-e2m1"),
    ] {
        let target = format!("{}/{name}", path.display());
        let verbose = h5rs(&["ls", "-v", &target]);
        assert!(
            verbose.contains(&format!("    Type:      {long}\n")),
            "{name}:\n{verbose}"
        );
        let listing = h5rs(&["ls", path.to_str().unwrap()]);
        assert!(
            listing
                .lines()
                .any(|l| l.starts_with(&format!("{name} ")) && l.ends_with(&format!(" {short}"))),
            "{name}:\n{listing}"
        );
    }
}