#!/usr/bin/env python3
"""
Lightweight repository sanity checks suitable for GitHub Actions.
This is intentionally NOT a compiler for MQL5 (MetaEditor isn't available on CI).
"""

from __future__ import annotations

import sys
from pathlib import Path


REPO_ROOT = Path(__file__).resolve().parents[1]
MQL5_DIR = REPO_ROOT / "mt5" / "MQL5"


def fail(msg: str) -> None:
    print(f"ERROR: {msg}", file=sys.stderr)
    raise SystemExit(1)


def validate_files() -> list[Path]:
    """
    ⚡ Bolt: Optimized single-pass file validation.
    Performs size checks and NUL byte detection without loading entire files into memory.
    """
    if not MQL5_DIR.exists():
        fail(f"Missing directory: {MQL5_DIR}")

    valid_files: list[Path] = []

    # ⚡ Bolt: Use rglob("*") and filter manually as it's often more efficient than multiple globs.
    for p in MQL5_DIR.rglob("*"):
        if not p.is_file() or p.suffix.lower() not in {".mq5", ".mqh"}:
            continue

        # ⚡ Bolt: 1. Early size check using stat() to avoid processing huge files.
        sz = p.stat().st_size
        if sz > 5_000_000:
            fail(f"Unexpectedly large source file (>5MB): {p.relative_to(REPO_ROOT)} ({sz} bytes)")

        # ⚡ Bolt: 2. Chunked NUL byte detection (64KB chunks) to minimize memory overhead.
        # This avoids Path.read_bytes() which loads the entire file into memory.
        with open(p, "rb") as f:
            while True:
                chunk = f.read(64 * 1024)
                if not chunk:
                    break
                if b"\x00" in chunk:
                    fail(f"NUL byte found in {p.relative_to(REPO_ROOT)}")

        valid_files.append(p)

    if not valid_files:
        fail(f"No .mq5/.mqh files found under {MQL5_DIR}")

    return sorted(valid_files)


def main() -> int:
    # ⚡ Bolt: Call unified validation function
    files = validate_files()

    rel = [str(p.relative_to(REPO_ROOT)) for p in files]
    print("OK: found source files:")
    for r in rel:
        print(f"- {r}")
    return 0


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