#!/usr/bin/env python3
"""Reject executable v1 compatibility paths and symbols from the v2 tree."""

from __future__ import annotations

import argparse
import re
import sys
from pathlib import Path

LEGACY_PATHS = (
    Path("backend/app"),
    Path("backend/backup"),
    Path("backend/tests"),
    Path("frontend/src/api/client.ts"),
)
SCAN_ROOTS = (Path("backend/src"), Path("frontend/src"), Path("openapi"))
TEXT_SUFFIXES = {".json", ".py", ".ts", ".tsx", ".yaml", ".yml"}
FORBIDDEN = (
    re.compile(r"/api/v1(?:/|\b)"),
    re.compile(r"\blegacy_(?:reader|importer?|converter?)\b", re.IGNORECASE),
    re.compile(r"\btimestamp_directory\b", re.IGNORECASE),
    re.compile(r"\b(?:app\.main|backup\.engine)\b"),
)


def scan(root: Path) -> list[str]:
    findings: list[str] = []
    for relative in LEGACY_PATHS:
        if (root / relative).exists():
            findings.append(f"legacy path exists: {relative}")

    for relative_root in SCAN_ROOTS:
        scan_root = root / relative_root
        if not scan_root.exists():
            continue
        for path in sorted(scan_root.rglob("*")):
            if not path.is_file() or path.suffix not in TEXT_SUFFIXES:
                continue
            try:
                text = path.read_text(encoding="utf-8")
            except (OSError, UnicodeError) as error:
                findings.append(f"cannot read {path.relative_to(root)}: {error}")
                continue
            for pattern in FORBIDDEN:
                if pattern.search(text):
                    findings.append(
                        f"forbidden symbol {pattern.pattern!r}: {path.relative_to(root)}"
                    )
    return findings


def main() -> int:
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("root", nargs="?", default=".", type=Path)
    args = parser.parse_args()
    root = args.root.resolve()
    findings = scan(root)
    if findings:
        print("v1 compatibility scan failed:", file=sys.stderr)
        for finding in findings:
            print(f"- {finding}", file=sys.stderr)
        return 1
    print("v1 compatibility scan: OK")
    return 0


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