#!/usr/bin/env python3

from pathlib import Path
import sys
from datetime import datetime
from tempfile import mkdtemp

SCRATCH_DIR = Path.home() / "scratch"
WEEK_SCRATCH = SCRATCH_DIR / datetime.now().strftime("%Y/%U")

(SCRATCH_DIR / "current").unlink()
(SCRATCH_DIR / "current").symlink_to(WEEK_SCRATCH)


def scratch_maintenance():
    if not WEEK_SCRATCH.is_dir():
        WEEK_SCRATCH.mkdir(exist_ok=True)
    for p in WEEK_SCRATCH.iterdir():
        if p.is_dir() and len(list(p.iterdir())) == 0:
            sys.stderr.write(f"removing: {p}\n")
            p.rmdir()


def make_temp() -> Path:
    return Path(mkdtemp(prefix=datetime.now().strftime("%d") + ".", dir=WEEK_SCRATCH))


def make_named(name: str) -> Path:
    d = WEEK_SCRATCH / name
    d.mkdir(exist_ok=True)
    return d


def return_last() -> Path:
    dirs = [d for d in WEEK_SCRATCH.iterdir() if d.is_dir()]
    if len(dirs) == 0:
        sys.stderr.write("no directores. exiting...")

    return sorted(dirs, key=lambda p: p.stat().st_mtime, reverse=True)[0]


def main():
    scratch_maintenance()

    if len(sys.argv) > 2:
        sys.exit("unexpected number of arguments")

    elif len(sys.argv) > 1:
        name = sys.argv[1]
        if name == ["last", "l"]:
            d = return_last()
        elif name in ["current", "c"]:
            d = WEEK_SCRATCH
        else:
            d = make_named(name)
    else:
        d = make_temp()

    print(d)


if __name__ == "__main__":
    main()