#!/usr/bin/env python3
"""Check C89 declaration placement in generated bytes Clinic wrappers."""
import re
import sys
from pathlib import Path

if len(sys.argv) != 2:
    raise SystemExit("usage: vc6-bytes-clinic-c89.test.py bytesobject.c.h")
source = Path(sys.argv[1]).read_text()
checks = {
    "bytes_decode(PyBytesObject *self, PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames)": (
        "encoding_length", "errors_length"),
    "bytes_new(PyTypeObject *type, PyObject *args, PyObject *kwargs)": (
        "encoding_length", "errors_length"),
}
for signature, names in checks.items():
    start = source.index(signature)
    body_start = source.index("\n{\n", start) + 2
    body_end = source.index("\n}", body_start)
    body = source[body_start:body_end]
    unpack = re.search(r"^\s*(?:args|fastargs) = _PyArg_UnpackKeywords", body, re.MULTILINE)
    if unpack is None:
        raise SystemExit(signature.split("(", 1)[0] + ": argument unpack statement missing")
    opening = body[:unpack.start()]
    execution = body[unpack.end():]
    for name in names:
        declaration = "Py_ssize_t " + name + ";"
        if opening.count(declaration) != 1 or body.count(declaration) != 1:
            raise SystemExit(signature.split("(", 1)[0] + ": " + name + " must be declared once before argument unpacking")
        if re.search(r"\bPy_ssize_t\s+" + re.escape(name) + r"\b", execution):
            raise SystemExit(signature.split("(", 1)[0] + ": late declaration remains for " + name)
    for name in names:
        if "&" + name not in execution:
            raise SystemExit(signature.split("(", 1)[0] + ": original UTF-8 length use missing for " + name)
print("bytes Clinic C89 declaration placement: PASS")