"""
modules/calendar.py — FRIDAY Calendar Manager

Active calendar management:
- Add events/reminders
- Upcoming events check
- Time tracking
- Meeting reminders
"""

import json
import os
import time
from datetime import datetime, timedelta
from config import DATA_DIR


CAL_FILE = os.path.join(DATA_DIR, "calendar.json")


def _load() -> dict:
    if not os.path.exists(CAL_FILE):
        return {"events": []}
    try:
        with open(CAL_FILE, "r") as f:
            return json.load(f)
    except Exception:
        return {"events": []}


def _save(data: dict):
    with open(CAL_FILE, "w") as f:
        json.dump(data, f, indent=2)


def add_event(title: str, when: str = "", duration: int = 60) -> str:
    """Add calendar event."""
    data = _load()

    # Simple time parsing
    event_time = time.time()
    if "today" in when.lower():
        pass  # today
    elif "tomorrow" in when.lower():
        event_time += 86400
    elif "monday" in when.lower():
        # Find next Monday
        days_ahead = (7 - datetime.now().weekday() + 0) % 7
        if days_ahead == 0:
            days_ahead = 7
        event_time += days_ahead * 86400
    elif "week" in when.lower():
        event_time += 7 * 86400

    data.setdefault("events", []).append({
        "title": title,
        "time": event_time,
        "duration": duration,
    })

    _save(data)
    return f"Event: {title}, added."


def get_upcoming(limit: int = 5) -> list:
    """Get upcoming events."""
    data = _load()
    now = time.time()

    upcoming = [e for e in data.get("events", []) if e.get("time", 0) > now]
    upcoming.sort(key=lambda x: x.get("time", 0))

    return upcoming[:limit]


def view_today() -> str:
    """View today's events."""
    data = _load()
    now = time.time()
    today_start = now - (now % 86400)
    today_end = today_start + 86400

    today_events = []
    for e in data.get("events", []):
        t = e.get("time", 0)
        if today_start <= t < today_end:
            dt = datetime.fromtimestamp(t)
            time_str = dt.strftime("%I:%M")
            today_events.append(f"{time_str} - {e['title']}")

    if not today_events:
        return "Nothing scheduled today."

    return "Today: " + ", ".join(today_events)


def check_reminders() -> list:
    """Check if any reminders due."""
    import threading
    data = _load()
    now = time.time()
    due = []

    for e in data.get("events", []):
        t = e.get("time", 0)
        if t <= now < t + 300:  # within 5 min window
            due.append(e)

    return due


# ── Voice Commands ────────────────────────────────────────────

def handle_command(command: str, speak) -> bool:
    """Handle calendar commands."""
    c = command.lower()

    # Add event
    if "schedule" in c or "add event" in c or "remind me" in c:
        title = c.replace("schedule", "").replace("add event", "").replace("remind me to", "").strip()
        if title:
            when = c  # Could parse more
            msg = add_event(title, when)
            speak(msg)
            return True

    # Today's schedule
    if "today" in c and ("schedule" in c or "events" in c or "what" in c):
        msg = view_today()
        speak(msg)
        return True

    # Upcoming
    if "upcoming" in c or "next" in c:
        events = get_upcoming()
        if events:
            lines = [datetime.fromtimestamp(e['time']).strftime("%a %I:%M") + " " + e['title'] for e in events[:3]]
            speak("Upcoming: " + ", ".join(lines))
        else:
            speak("No upcoming events.")
        return True

    # Check reminders
    if "check reminders" in c or "alerts" in c:
        reminders = check_reminders()
        if reminders:
            for r in reminders:
                speak(f"REMINDER: {r['title']}")
        else:
            speak("No reminders due.")
        return True

    return False