//! `h5rs dump` and `h5rs ls` of HDF5 2.0 native complex numbers (datatype
//! class 11), against the output of h5dump 2.2.0 and h5ls 2.2.0 (the Debian
//! h5dump CI installs, 1.14.x, predates the type). The h5dump output is
//! stored next to the fixture; see
//! `crates/clawhdf5/tests/fixtures/gen_native_complex.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 its lines, with the data lines (`(i): ...`) replaced
/// by their index, and the data values in order.
fn split(ddl: &str) -> (Vec<String>, Vec<String>) {
    let (mut frame, mut data) = (Vec::new(), Vec::new());
    for line in ddl.lines() {
        match line.split_once("):") {
            Some((idx, body)) if idx.trim_start().starts_with('(') => {
                frame.push(format!("{idx}):"));
                // Values are split at `, `; array elements come bracketed.
                data.extend(
                    body.split(", ")
                        .map(|s| s.trim().trim_matches(|c| c == '[' || c == ']' || c == ','))
                        .map(str::trim)
                        .filter(|s| !s.is_empty() && *s != "{")
                        .map(String::from),
                );
            }
            _ => {
                let t = line.trim().trim_end_matches(',');
                if t.ends_with('i') || t.parse::<f64>().is_ok() {
                    // A compound member's value on its own line.
                    data.push(t.to_string());
                } else {
                    frame.push(line.to_string());
                }
            }
        }
    }
    (frame, data)
}

/// `a+bi`, `a-bi` or `a+-bi` as its two parts (a real number as one).
fn parts(v: &str) -> Vec<f64> {
    let Some(z) = v.strip_suffix('i') else {
        return vec![v.parse().unwrap()];
    };
    let b = z.as_bytes();
    let at = (1..b.len())
        .find(|&k| (b[k] == b'+' || b[k] == b'-') && !matches!(b[k - 1], b'e' | b'E' | b'+'))
        .unwrap_or_else(|| panic!("not a complex value: {v}"));
    let (re, im) = z.split_at(at);
    let im = im.strip_prefix('+').unwrap_or(im);
    vec![re.parse().unwrap(), im.parse().unwrap()]
}

#[test]
fn dump_matches_h5dump_2_2() {
    let path = fixture("native_complex_hdf5_2.h5");
    let ours = h5rs(&["dump", path.to_str().unwrap()]);
    let reference = std::fs::read_to_string(fixture("native_complex_hdf5_2.ddl")).unwrap();
    let (mut our_frame, our_data) = split(&ours);
    let (mut ref_frame, ref_data) = split(&reference);
    // The first line names the file as it was given.
    our_frame.remove(0);
    ref_frame.remove(0);
    // Everything but the values is h5dump's byte for byte: the types print
    // as H5T_COMPLEX_IEEE_F64LE, H5T_ARRAY { [2] H5T_COMPLEX_IEEE_F32LE }, ...
    assert_eq!(our_frame, ref_frame);
    assert_eq!(our_data.len(), ref_data.len(), "{our_data:?}\n{ref_data:?}");
    assert_eq!(our_data.len(), 36);
    // Values: h5dump prints `%g` (6 digits), inf/nan, and the binary16
    // parts it has no C type for as `<re>+<im>i` (`1+-2i`); h5rs prints
    // the shortest round-trip string and Inf/NaN, joined the same way.
    for (i, (o, r)) in our_data.iter().zip(&ref_data).enumerate() {
        assert_eq!(o.contains("+-"), r.contains("+-"), "[{i}] {o} vs {r}");
        let (op, rp) = (parts(o), parts(r));
        assert_eq!(op.len(), rp.len(), "[{i}] {o} vs {r}");
        for (x, y) in op.iter().zip(&rp) {
            let same = if y.is_nan() || y.is_infinite() {
                x.is_nan() == y.is_nan() && (y.is_nan() || x == y)
            } else {
                *x as f32 == *y as f32 || (x - y).abs() <= 5e-6 * y.abs()
            };
            assert!(same, "[{i}] h5rs {o}, h5dump {r}");
            assert_eq!(
                x.is_sign_negative(),
                y.is_sign_negative(),
                "[{i}] {o} vs {r}"
            );
        }
    }
}

#[test]
fn ls_describes_complex_like_h5ls_2_2() {
    let path = fixture("native_complex_hdf5_2.h5");
    // h5ls 2.2.0 -v, `Type:` of the types it has no native C name for (it
    // prints `native double _Complex` for the others, as it prints `native
    // double` where h5rs prints `IEEE 64-bit little-endian float`).
    for (name, long) in [
        (
            "c128be",
            "complex number of\n                   IEEE 64-bit big-endian float",
        ),
        (
            "c128",
            "complex number of\n                   IEEE 64-bit little-endian float",
        ),
        (
            "c32",
            "complex number of\n                   IEEE 16-bit little-endian float",
        ),
        (
            "array",
            "[2] complex number of\n                   IEEE 32-bit little-endian float",
        ),
    ] {
        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()]);
    for (name, short) in [
        ("c64", "complex64"),
        ("c128", "complex128"),
        ("c128be", "complex128-be"),
        ("c32", "complex32"),
        ("scalar", "complex128"),
        ("array", "array[2]<complex64>"),
        ("compound", "compound{z: complex128, k: int64}"),
    ] {
        assert!(
            listing
                .lines()
                .any(|l| l.starts_with(&format!("{name} ")) && l.ends_with(&format!(" {short}"))),
            "{name}:\n{listing}"
        );
    }
}

#[test]
fn json_dump_uses_the_r_i_compound() {
    // hdf5-json (h5json 2.0.0) has no complex class: the type is written as
    // the `{r, i}` compound h5py uses, the values as `[re, im]` pairs.
    let path = fixture("native_complex_hdf5_2.h5");
    let j: serde_json::Value =
        serde_json::from_str(&h5rs(&["dump", "--json", path.to_str().unwrap()])).unwrap();
    let ds = j["datasets"]
        .as_object()
        .unwrap()
        .values()
        .find(|d| d["alias"][0] == "/scalar")
        .unwrap();
    assert_eq!(ds["type"]["class"], "H5T_COMPOUND");
    assert_eq!(ds["type"]["fields"][0]["name"], "r");
    assert_eq!(ds["type"]["fields"][1]["type"]["base"], "H5T_IEEE_F64LE");
    assert_eq!(ds["value"], serde_json::json!([2.5, -0.5]));
}

#[test]
fn diff_compares_complex_values() {
    let path = fixture("native_complex_hdf5_2.h5");
    let p = path.to_str().unwrap();
    // Same values, different byte order: no differences.
    let out = Command::new(env!("CARGO_BIN_EXE_h5rs"))
        .args(["diff", p, p, "/c128", "/c128be"])
        .output()
        .unwrap();
    assert!(out.status.success(), "{out:?}");
    // One element differs in its imaginary part: one difference, exit
    // status 1, as h5diff 2.2.0 reports it.
    let out = Command::new(env!("CARGO_BIN_EXE_h5rs"))
        .args(["diff", "-r", p, p, "/c128", "/c128x"])
        .output()
        .unwrap();
    assert_eq!(out.status.code(), Some(1), "{out:?}");
    let text = String::from_utf8_lossy(&out.stdout);
    assert!(text.contains("1 difference(s) found"), "{text}");
    // h5diff 2.2.0: `[ 1 1 ]  0+1i  1+1i  1+0i`.
    let row = text.lines().find(|l| l.starts_with("[ 1 1 ]")).unwrap();
    assert_eq!(
        row.split_whitespace().collect::<Vec<_>>(),
        ["[", "1", "1", "]", "0+1i", "1+1i", "1+0i"]
    );
}