#!/usr/bin/env python3
"""Source-level C89 and ownership-order check for bytearray_join."""
import re
import sys
from pathlib import Path

if len(sys.argv) != 2:
    raise SystemExit("usage: vc6-bytearray-join-c89.test.py bytearrayobject.c")
source = Path(sys.argv[1]).read_text()
signature = "bytearray_join(PyByteArrayObject *self, PyObject *iterable_of_bytes)"
start = source.index(signature)
body_start = source.index("{", start)
body_end = source.index("\n}", body_start)
body = source[body_start + 1:body_end]

if not body.lstrip().startswith("PyObject *ret;"):
    raise SystemExit("ret must be declared in bytearray_join's opening declaration group")
if len(re.findall(r"\bPyObject\s*\*\s*ret\s*;", body)) != 1:
    raise SystemExit("bytearray_join must declare ret exactly once")
if re.search(r"\bPyObject\s*\*\s*ret\s*=", body):
    raise SystemExit("bytearray_join must assign ret separately from its declaration")
pattern = re.compile(
    r"self->ob_exports\+\+;.*?"
    r"ret\s*=\s*stringlib_bytes_join\(\s*\(PyObject\*\)self,\s*"
    r"iterable_of_bytes\s*\);\s*"
    r"self->ob_exports--;\s*(?://[^\n]*\s*)?return ret;",
    re.DOTALL,
)
if not pattern.search(body):
    raise SystemExit("bytearray_join export/join/unexport/return order changed")
print("bytearray_join C89 declaration and export order: PASS")