#!/usr/bin/env python3
"""Fail when production Python files exceed the configured line budget.

The gate is intentionally narrow:
- it only checks the `atlasbot/` package tree;
- it treats each file independently;
- it keeps the threshold explicit so CI can ratchet without guesswork.
"""

from __future__ import annotations

import argparse
from pathlib import Path


def _count_lines(path: Path) -> int:
    """Return the physical line count for `path`.

    Input:
    - `path`: a readable Python source file.

    Output:
    - The number of newline-delimited lines in the file.
    """

    return len(path.read_text(encoding="utf-8").splitlines())


def _iter_python_files(root: Path) -> list[Path]:
    """List production Python files under `root`.

    Input:
    - `root`: repository package root to scan.

    Output:
    - Sorted Python file paths, excluding bytecode and hidden caches.
    """

    return sorted(
        path
        for path in root.rglob("*.py")
        if path.is_file() and "__pycache__" not in path.parts and ".venv" not in path.parts
    )


def main() -> int:
    """Run the size gate and return a process exit code."""

    parser = argparse.ArgumentParser()
    parser.add_argument("--root", default="atlasbot")
    parser.add_argument("--max-lines", type=int, default=500)
    args = parser.parse_args()

    root = Path(args.root)
    violations: list[tuple[int, Path]] = []
    for path in _iter_python_files(root):
        lines = _count_lines(path)
        if lines > args.max_lines:
            violations.append((lines, path))

    if violations:
        for lines, path in sorted(violations, reverse=True):
            print(f"{path}: {lines} lines (limit {args.max_lines})")
        return 1
    return 0


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