#!/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"),
    Path("config"),
    Path(".github/workflows"),
)
SCAN_FILES = (
    Path("backend/Dockerfile"),
    Path("frontend/Dockerfile"),
    Path("frontend/nginx.conf"),
    Path("frontend/vite.config.ts"),
    Path("docker-compose.yml"),
    Path("compose.yaml"),
    Path("backend/pyproject.toml"),
    Path("frontend/package.json"),
)
TEXT_SUFFIXES = {".json", ".py", ".toml", ".ts", ".tsx", ".yaml", ".yml"}
FORBIDDEN = (
    re.compile(r"/api/v1(?:/|\b)"),
    re.compile(
        r"\b(?:legacy|v1)[_-]?(?:database|db|payload|backup)?[_-]?(?:reader|importer?|converter?)\b",
        re.IGNORECASE,
    ),
    re.compile(
        r"\b(?:read|open|load|import|convert)[_-]?(?:legacy|v1)[_-]?(?:database|db|payload|backup)\b",
        re.IGNORECASE,
    ),
    re.compile(r"[\"']backup_tool\.db[\"']", re.IGNORECASE),
    re.compile(r"%Y-%m-%d_%H%M%S"),
    re.compile(r"\btimestamp[_-]?(?:directory|parser)\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}")

    candidates = {root / relative for relative in SCAN_FILES if (root / relative).is_file()}
    for relative_root in SCAN_ROOTS:
        scan_root = root / relative_root
        if scan_root.exists():
            candidates.update(
                path
                for path in scan_root.rglob("*")
                if path.is_file() and path.suffix in TEXT_SUFFIXES
            )

    for path in sorted(candidates):
        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())