#!/usr/bin/env python3
"""Fail when a change set mixes Terraform with deployable application files.

Workflow, docs, and gate-script changes may travel with either side.
"""

from __future__ import annotations

import argparse
import sys

APP_ROOTS = (
    "src/",
    "public/",
    "pages/",
    "config/",
)

APP_FILES = {
    "index.html",
    "vite.config.ts",
    "vitest.config.ts",
}


def is_terraform_path(path: str) -> bool:
    return path == "terraform" or path.startswith("terraform/")


def is_app_path(path: str) -> bool:
    normalized = path.replace("\\", "/")
    if normalized in APP_FILES:
        return True
    if normalized in {"src", "public", "pages", "config"}:
        return True
    if normalized.startswith(APP_ROOTS):
        return True
    if normalized.startswith("tsconfig"):
        return True
    return normalized.startswith(".env")


def isolation_violation(paths: list[str]) -> tuple[list[str], list[str]] | None:
    terraform_files = sorted({path for path in paths if is_terraform_path(path)})
    app_files = sorted({path for path in paths if is_app_path(path)})
    if terraform_files and app_files:
        return terraform_files, app_files
    return None


def main() -> int:
    parser = argparse.ArgumentParser()
    parser.add_argument(
        "paths",
        nargs="*",
        help="Changed paths. Omit and pass newline-separated paths on stdin.",
    )
    args = parser.parse_args()
    paths = list(args.paths)
    if not paths and not sys.stdin.isatty():
        paths = [line.strip() for line in sys.stdin if line.strip()]
    violation = isolation_violation(paths)
    if violation is None:
        print("PASS: application and Terraform changes are isolated")
        return 0
    terraform_files, app_files = violation
    print("FAIL: do not mix deployable application files with terraform/", file=sys.stderr)
    print("terraform:", file=sys.stderr)
    for path in terraform_files:
        print(f"  {path}", file=sys.stderr)
    print("application:", file=sys.stderr)
    for path in app_files:
        print(f"  {path}", file=sys.stderr)
    return 1


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