#!/usr/bin/env python3
"""Check type_set_bases's loop index declaration and initialization timing."""
import re
from pathlib import Path

source = Path("cpython/Objects/typeobject.c").read_text()
match = re.search(
    r"\nstatic int\ntype_set_bases\(PyTypeObject \*type, PyObject \*new_bases, void \*context\)\n\{(.*?)\n\}",
    source,
    re.S,
)
assert match, "type_set_bases definition missing"
body = re.sub(r"/\*.*?\*/|//[^\n]*", "", match.group(1), flags=re.S)
assert re.match(
    r"\s*Py_ssize_t n;\s*Py_ssize_t i;\s*PyTypeObject \*new_base;\s*PyObject \*old_bases;\s*PyTypeObject \*old_base;\s*PyObject \*temp;\s*int res;\s*if\b",
    body,
), (
    "type_set_bases: Py_ssize_t i; must follow n in the opening declarations"
)
assert len(re.findall(r"\bPy_ssize_t\s+n\b", body)) == 1, (
    "type_set_bases: declare n exactly once"
)
assert len(re.findall(r"\bn\s*=\s*PyTuple_GET_SIZE\(new_bases\)", body)) == 1, (
    "type_set_bases: read the new_bases size into n exactly once"
)
validation = body.split("new_base = best_base(new_bases);", 1)[0]
assert len(re.findall(r"\bPy_ssize_t\s+i\b", validation)) == 1, "declare i exactly once"
assert len(re.findall(r"\bi\s*=(?!=)", validation)) == 1, "initialize i exactly once"
assert not re.search(r"for\s*\(\s*Py_ssize_t\s+i\b", validation), "C99 loop index declaration remains"
expected = """
    Py_ssize_t n;
    Py_ssize_t i;
    PyTypeObject *new_base;
    PyObject *old_bases;
    PyTypeObject *old_base;
    PyObject *temp;
    int res;
    if (!check_set_special_type_attr(type, new_bases, "__bases__")) {
        return -1;
    }
    assert(new_bases != NULL);

    if (!PyTuple_Check(new_bases)) {
        PyErr_Format(PyExc_TypeError,
             "can only assign tuple to %s.__bases__, not %s",
                 type->tp_name, Py_TYPE(new_bases)->tp_name);
        return -1;
    }
    if (PyTuple_GET_SIZE(new_bases) == 0) {
        PyErr_Format(PyExc_TypeError,
             "can only assign non-empty tuple to %s.__bases__, not ()",
                 type->tp_name);
        return -1;
    }
    n = PyTuple_GET_SIZE(new_bases);
    for (i = 0; i < n; i++) {
"""
assert body.split()[:len(expected.split())] == expected.split(), (
    "type_set_bases: preserve validation, empty-tuple guard, n assignment timing, "
    "and index initialization at the original loop point"
)
print("type_set_bases loop index C89 declaration and unchanged evaluation order: PASS")