#!/usr/bin/env python3
"""Generate wolfram-cpp owned-handle typedefs from wolfram's wf_*_free set.

Scans the wolfram C public headers for ``void wf_<T>_free(wf_<T> *...)`` and
emits a header declaring ``wolfram::unique_handle<wf_<T>, wf_<T>_free>`` typedefs
plus the ``#include``s needed to make those symbols visible. This mirrors the
project convention of generating C-adjacent code from the C headers with Python.

Usage:
    python3 tools/gen_owners.py <wolfram-include-dir> <output.hpp>
"""
import re
import sys
from pathlib import Path

# Match `void wf_<T>_free(wf_<T> *name)`. The backreference ensures the freed
# type matches the function prefix. Excludes `wf_*_json_free(char*)` (strings).
HEADER_RE = re.compile(
    r"void\s+wf_([A-Za-z0-9_]+)_free\s*\(\s*wf_\1\s*\*\s*\w+\s*\)"
)


def main() -> int:
    inc_dir = Path(sys.argv[1] if len(sys.argv) > 1 else "include/wolfram")
    out = Path(sys.argv[2]) if len(sys.argv) > 2 else Path("generated_owners.hpp")

    types: dict[str, str] = {}
    includes: set[str] = set()
    # Recursively scan all .h files (including oauth/, repo/ subdirectories)
    for h in sorted(inc_dir.rglob("*.h")):
        # Skip the json-enhanced vendored copy — it duplicates json.h symbols.
        if "json-enhanced" in h.parts:
            continue
        text = h.read_text(encoding="utf-8", errors="ignore")
        for m in HEADER_RE.finditer(text):
            t = m.group(1)
            if t not in types:
                rel = h.relative_to(inc_dir)
                inc = f"wolfram/{rel.as_posix()}"
                types[t] = inc
                includes.add(inc)

    lines = [
        "/* Generated by cpp/wolfram-cpp/tools/gen_owners.py; do not edit. */",
        "#ifndef WOLFRAM_CPP_GENERATED_OWNERS_HPP",
        "#define WOLFRAM_CPP_GENERATED_OWNERS_HPP",
        "",
    ]
    for inc in sorted(includes):
        lines.append(f'#include <{inc}>')
    lines += [
        "",
        '#include "wolfram/unique_handle.hpp"',
        "",
        "namespace wolfram {",
        "",
    ]
    for t in sorted(types):
        lines.append(f"using wf_{t}_handle = unique_handle<wf_{t}, wf_{t}_free>;")
    lines += [
        "",
        "} // namespace wolfram",
        "",
        "#endif",
    ]
    out.write_text("\n".join(lines) + "\n", encoding="utf-8")
    print(f"wrote {out}: {len(types)} owned handles from {len(includes)} headers")
    return 0


if __name__ == "__main__":
    raise SystemExit(main())