#!/usr/bin/env python3
"""Check C89 declaration placement in immutable stringlib partitions."""
import sys
from pathlib import Path

if len(sys.argv) != 2:
    raise SystemExit("usage: vc6-stringlib-partition-c89.test.py partition.h")
source = Path(sys.argv[1]).read_text()
expected_orders = {
    "partition": (
        "Py_INCREF(str_obj);",
        "empty = (PyObject*)STRINGLIB_GET_EMPTY();",
        "assert(empty != NULL);",
        "Py_INCREF(empty);",
        "PyTuple_SET_ITEM(out, 1, empty);",
        "Py_INCREF(empty);",
        "PyTuple_SET_ITEM(out, 2, empty);",
    ),
    "rpartition": (
        "empty = (PyObject*)STRINGLIB_GET_EMPTY();",
        "assert(empty != NULL);",
        "Py_INCREF(empty);",
        "PyTuple_SET_ITEM(out, 0, empty);",
        "Py_INCREF(empty);",
        "PyTuple_SET_ITEM(out, 1, empty);",
        "Py_INCREF(str_obj);",
        "PyTuple_SET_ITEM(out, 2, (PyObject*) str_obj);",
    ),
}
for name, order in expected_orders.items():
    signature = "STRINGLIB(" + name + ")("
    start = source.index(signature)
    body_start = source.index("\n{\n", start) + 2
    body_end = source.index("\n}\n", body_start)
    body = source[body_start:body_end]
    opening, no_match = body.split("    if (pos < 0)", 1)
    if "#if !STRINGLIB_MUTABLE\n    PyObject *empty;\n#endif" not in opening:
        raise SystemExit(name + ": empty must be declared in the C89 entry declaration group")
    if body.count("PyObject *empty;") != 1 or "PyObject *empty =" in body:
        raise SystemExit(name + ": empty must have one separate declaration")
    branch_start = no_match.index("#else")
    branch_end = no_match.index("#endif", branch_start)
    branch = no_match[branch_start:branch_end]
    cursor = 0
    for statement in order:
        position = branch.find(statement, cursor)
        if position < 0:
            raise SystemExit(name + ": empty reference-count / tuple insertion order changed")
        cursor = position + len(statement)
print("stringlib partition C89 declarations and ownership order: PASS")