#!/usr/bin/env python3
"""
Remove JD-Core decompiler noise from Java sources under maven-*:

  - Line prefix comments: /*    */ and /* N */ (line numbers)
  - Trailing metadata block: /* Location: ... JD-Core Version: ... */

Does not strip normal Javadoc /** ... */ or arbitrary block comments.
"""
from __future__ import annotations

import argparse
import re
import sys
from pathlib import Path

RE_LINE_EMPTY_PREFIX = re.compile(r"^/\* +\*/\s*")
RE_LINE_NUM_PREFIX = re.compile(r"^/\* \d+ \*/\s*")
# Ends with line like " */" (space + */) after "* JD-Core Version: ..."
RE_TAIL_META = re.compile(
    r"(?:^|\n)/\* Location:.*?\n\s*\*/\s*",
    re.DOTALL,
)


def strip_content(text: str) -> str:
    text = text.replace("\r\n", "\n").replace("\r", "\n")
    lines = text.split("\n")
    stripped = []
    for line in lines:
        line = RE_LINE_EMPTY_PREFIX.sub("", line)
        line = RE_LINE_NUM_PREFIX.sub("", line)
        stripped.append(line)
    joined = "\n".join(stripped)
    joined = RE_TAIL_META.sub("\n", joined)
    if joined and not joined.endswith("\n"):
        joined += "\n"
    return joined


def process_file(path: Path, dry_run: bool) -> bool:
    raw = path.read_text(encoding="utf-8", errors="replace")
    new = strip_content(raw)
    raw_norm = raw.replace("\r\n", "\n").replace("\r", "\n")
    if raw_norm and not raw_norm.endswith("\n"):
        raw_norm += "\n"
    if new == raw_norm:
        return False
    if not dry_run:
        path.write_text(new, encoding="utf-8", newline="\n")
    return True


def main() -> int:
    ap = argparse.ArgumentParser(description=__doc__)
    ap.add_argument(
        "roots",
        nargs="*",
        type=Path,
        help="Optional roots (default: all maven-* under repo root next to scripts/)",
    )
    ap.add_argument("--dry-run", action="store_true", help="Report only, do not write")
    args = ap.parse_args()

    script_dir = Path(__file__).resolve().parent
    repo = script_dir.parent

    if args.roots:
        roots = [Path(p).resolve() for p in args.roots]
    else:
        roots = sorted(repo.glob("maven-*"))
        roots = [p for p in roots if p.is_dir()]

    changed = 0
    scanned = 0
    for root in roots:
        if not root.exists():
            print(f"skip missing: {root}", file=sys.stderr)
            continue
        for path in root.rglob("*.java"):
            if "/target/" in str(path).replace("\\", "/"):
                continue
            scanned += 1
            if process_file(path, args.dry_run):
                changed += 1
                if args.dry_run:
                    print(f"would update: {path}")

    print(f"Scanned: {scanned} Java files under {len(roots)} root(s)")
    print(f"{'Would change' if args.dry_run else 'Changed'}: {changed} file(s)")
    return 0


if __name__ == "__main__":
    sys.exit(main())