#!/usr/bin/env python3
"""
CLI entry point: find and remove orphaned mod folders from downloads/.

An orphan is a downloads/{group}/@ModName folder that is no longer referenced
by any group in comparison.json.  These accumulate when presets change and
the pipeline is re-run without cleaning up old folders.

Usage:
    python clean_orphans.py               # list orphans, ask for confirmation
    python clean_orphans.py --dry-run     # list orphans, do not delete
    python clean_orphans.py --yes         # list and delete without prompting
"""
from __future__ import annotations

import argparse
import json
import os
import shutil
import sys

from arma_modlist_tools.cleaner import find_orphan_folders
from arma_modlist_tools.compat import fix_console_encoding
from arma_modlist_tools.config import load_config
from arma_modlist_tools.linker import _is_junction, remove_junction

fix_console_encoding()

_UNITS = ("B", "KB", "MB", "GB", "TB")


def _fmt_size(n: int) -> str:
    for unit in _UNITS:
        if n < 1024:
            return f"{n:.1f} {unit}"
        n /= 1024
    return f"{n:.1f} PB"


def main() -> None:
    parser = argparse.ArgumentParser(
        description="Find and remove orphaned mod folders from downloads/."
    )
    parser.add_argument(
        "--dry-run",
        action="store_true",
        help="List orphans but do not delete anything.",
    )
    parser.add_argument(
        "--yes", "-y",
        action="store_true",
        help="Delete without prompting for confirmation.",
    )
    args = parser.parse_args()

    cfg = load_config()

    if not cfg.comparison.exists():
        print(f"ERROR: {cfg.comparison} not found. Run compare_modlists.py first.")
        sys.exit(1)

    comparison = json.loads(cfg.comparison.read_text(encoding="utf-8"))

    print(f"\nScanning {cfg.downloads} for orphaned mod folders...\n")
    orphans = find_orphan_folders(cfg.downloads, comparison)

    if not orphans:
        print("  No orphans found. Your downloads folder is clean.")
        print()
        return

    total_size = sum(o["size"] for o in orphans)
    print(f"  {'Group':<28}  {'Folder':<32}  Size")
    print(f"  {'-'*28}  {'-'*32}  {'-'*10}")
    for o in orphans:
        print(f"  {o['group']:<28}  {o['name']:<32}  {_fmt_size(o['size'])}")

    print()
    print(f"  {len(orphans)} orphan(s) found — {_fmt_size(total_size)} total")
    print()

    if args.dry_run:
        print("  --dry-run: nothing deleted.")
        print()
        return

    if not args.yes:
        answer = input("  Delete all orphans? [y/N] ").strip().lower()
        if answer not in ("y", "yes"):
            print("  Aborted.")
            print()
            return

    deleted = 0
    freed = 0
    errors = 0
    for o in orphans:
        p = o["path"]
        try:
            if _is_junction(p):
                # Safety: never rmtree a junction — use remove_junction() which
                # calls os.rmdir() and removes only the pointer, not the target.
                ok, err = remove_junction(p)
                if not ok:
                    print(f"  ERROR: could not remove junction {p.name}: {err}")
                    errors += 1
                    continue
            else:
                shutil.rmtree(p)
            deleted += 1
            freed += o["size"]
            print(f"  Deleted: {o['group']}/{o['name']}")
        except Exception as e:
            print(f"  ERROR: {p.name}: {e}")
            errors += 1

    print()
    print(f"  Done: {deleted} deleted, freed {_fmt_size(freed)}"
          + (f", {errors} error(s)" if errors else ""))
    print()

    if errors:
        sys.exit(1)


if __name__ == "__main__":
    main()