#!/usr/bin/env python3
"""Am I free to leave the Long Day Factory yet?

Time served = (now - startTime) - lunchBreak
You are free once time served reaches 4 hours.

Exit codes:
  0  calculation done (see FREE / NOT FREE in output)
  2  lunch times missing and no decision flag passed -> ask the user
  3  startTime missing -> user must run long-day-start
"""
import json
import sys
from datetime import datetime, timedelta, time
from pathlib import Path

SENTENCE = timedelta(hours=4)
DEFAULT_LUNCH_OUT = time(11, 30)
DEFAULT_LUNCH_IN = time(12, 30)
F = Path.home() / "long-day-factory.json"


def parse(ts):
    return datetime.fromisoformat(ts) if ts else None


def fmt_delta(td):
    secs = int(td.total_seconds())
    sign = "-" if secs < 0 else ""
    secs = abs(secs)
    h, m = secs // 3600, (secs % 3600) // 60
    return f"{sign}{h}h{m:02d}m"


def main():
    flag = sys.argv[1] if len(sys.argv) > 1 else ""

    if not F.exists():
        print("No ~/long-day-factory.json found. Run long-day-start first.")
        sys.exit(3)

    data = json.loads(F.read_text())
    start = parse(data.get("startTime"))
    lunch_out = parse(data.get("lunchTime"))
    lunch_in = parse(data.get("backToWork"))

    if start is None:
        print("startTime is not set. Run long-day-start first.")
        sys.exit(3)

    now = datetime.now(start.tzinfo)

    # Resolve the lunch break.
    note = ""
    if lunch_out and lunch_in:
        lunch_break = lunch_in - lunch_out
        if lunch_break.total_seconds() < 0:
            lunch_break = timedelta(0)
            note = "(backToWork is before lunchTime — treating lunch as 0)"
    elif flag == "--default-lunch":
        d = start.date()
        lunch_out = datetime.combine(d, DEFAULT_LUNCH_OUT, tzinfo=start.tzinfo)
        lunch_in = datetime.combine(d, DEFAULT_LUNCH_IN, tzinfo=start.tzinfo)
        data["lunchTime"] = lunch_out.isoformat()
        data["backToWork"] = lunch_in.isoformat()
        F.write_text(json.dumps(data, indent=2) + "\n")
        lunch_break = lunch_in - lunch_out
        note = "(assumed the standard 11:30-12:30 lunch and saved it)"
    elif flag == "--flat-hour":
        lunch_break = timedelta(hours=1)
        note = "(assumed a flat 1h lunch, not saved)"
    else:
        missing = []
        if not lunch_out:
            missing.append("lunchTime")
        if not lunch_in:
            missing.append("backToWork")
        print("NEEDS_LUNCH_DECISION: missing " + ", ".join(missing))
        sys.exit(2)

    served = (now - start) - lunch_break
    remaining = SENTENCE - served

    print(f"Clocked in:   {start.isoformat()}")
    print(f"Lunch break:  {fmt_delta(lunch_break)} {note}".rstrip())
    print(f"Time served:  {fmt_delta(served)}")

    if remaining.total_seconds() <= 0:
        print("Status:       FREE")
        print(f"Overtime:     {fmt_delta(-remaining)}")
    else:
        eta = now + remaining
        print("Status:       NOT FREE")
        print(f"Remaining:    {fmt_delta(remaining)}")
        print(f"Parole at:    {eta.strftime('%H:%M')}")


if __name__ == "__main__":
    main()