"""
daemon.py - Background polling loop for scheduled tasks

Override poll_callback() with your domain-specific logic.
"""

import os
import time
import logging
from datetime import datetime

import core.postgres as postgres
import core.notifications as notifications

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

POLL_INTERVAL = int(os.environ.get("POLL_INTERVAL", 60))


def check_medication_reminders():
    """Check for medications due now and send notifications."""
    try:
        from datetime import date as date_type
        meds = postgres.select("medications", where={"active": True})
        now = datetime.now()
        current_time = now.strftime("%H:%M")
        current_day = now.strftime("%a").lower()  # "mon","tue", etc.
        today = now.date()
        today_str = today.isoformat()

        for med in meds:
            freq = med.get("frequency", "daily")

            # Skip as_needed -- no scheduled reminders for PRN
            if freq == "as_needed":
                continue

            # Day-of-week check for specific_days
            if freq == "specific_days":
                days = med.get("days_of_week", [])
                if current_day not in days:
                    continue

            # Interval check for every_n_days
            if freq == "every_n_days":
                start = med.get("start_date")
                interval = med.get("interval_days")
                if start and interval:
                    start_d = start if isinstance(start, date_type) else datetime.strptime(str(start), "%Y-%m-%d").date()
                    if (today - start_d).days < 0 or (today - start_d).days % interval != 0:
                        continue
                else:
                    continue

            # Time check
            times = med.get("times", [])
            if current_time not in times:
                continue

            # Already taken today? Check by created_at date
            logs = postgres.select("med_logs", where={"medication_id": med["id"], "action": "taken"})
            already_taken = any(
                log.get("scheduled_time") == current_time
                and str(log.get("created_at", ""))[:10] == today_str
                for log in logs
            )
            if already_taken:
                continue

            user_settings = notifications.getNotificationSettings(med["user_uuid"])
            if user_settings:
                msg = f"Time to take {med['name']} ({med['dosage']} {med['unit']})"
                notifications._sendToEnabledChannels(user_settings, msg)
    except Exception as e:
        logger.error(f"Error checking medication reminders: {e}")


def check_routine_reminders():
    """Check for scheduled routines due now and send notifications."""
    try:
        now = datetime.now()
        current_time = now.strftime("%H:%M")
        current_day = now.strftime("%a").lower()
        schedules = postgres.select("routine_schedules", where={"remind": True})

        for schedule in schedules:
            if current_time != schedule.get("time"):
                continue
            days = schedule.get("days", [])
            if current_day not in days:
                continue

            routine = postgres.select_one("routines", {"id": schedule["routine_id"]})
            if not routine:
                continue

            user_settings = notifications.getNotificationSettings(routine["user_uuid"])
            if user_settings:
                msg = f"Time to start your routine: {routine['name']}"
                notifications._sendToEnabledChannels(user_settings, msg)
    except Exception as e:
        logger.error(f"Error checking routine reminders: {e}")


def check_refills():
    """Check for medications running low on refills."""
    try:
        meds = postgres.select("medications")
        for med in meds:
            qty = med.get("quantity_remaining")
            if qty is not None and qty <= 7:
                user_settings = notifications.getNotificationSettings(med["user_uuid"])
                if user_settings:
                    msg = f"Low on {med['name']}: only {qty} doses remaining. Time to refill!"
                    notifications._sendToEnabledChannels(user_settings, msg)
    except Exception as e:
        logger.error(f"Error checking refills: {e}")


def poll_callback():
    """Called every POLL_INTERVAL seconds."""
    check_medication_reminders()
    check_routine_reminders()
    check_refills()


def daemon_loop():
    logger.info("Scheduler daemon starting")
    while True:
        try:
            poll_callback()
        except Exception as e:
            logger.error(f"Poll callback error: {e}")
        time.sleep(POLL_INTERVAL)


if __name__ == "__main__":
    daemon_loop()