import json
import os
from datetime import datetime
from typing import List, Dict, Optional

class ScheduleManager:
    def __init__(self, schedules_path: str = "/app/schedules.json"):
        self.schedules_path = schedules_path
        self.schedules = self._load_schedules()

    def _load_schedules(self) -> List[Dict]:
        """Load schedules from JSON file."""
        if os.path.exists(self.schedules_path):
            try:
                with open(self.schedules_path, 'r') as f:
                    return json.load(f)
            except json.JSONDecodeError:
                return []
        return []

    def save_schedules(self):
        """Save schedules to JSON file."""
        os.makedirs(os.path.dirname(self.schedules_path), exist_ok=True)
        with open(self.schedules_path, 'w') as f:
            json.dump(self.schedules, f, indent=2)
            f.write("\n")

    def add_schedule(self, schedule: Dict) -> Dict:
        """Add a new schedule."""
        schedule_id = max([s['id'] for s in self.schedules], default=0) + 1
        new_schedule = {
            'id': schedule_id,
            'time': schedule['time'],
            'book': schedule.get('book'),
            'enabled': schedule.get('enabled', True),
        }
        self.schedules.append(new_schedule)
        self.save_schedules()
        return new_schedule

    def update_schedule(self, schedule_id: int, updates: Dict) -> Optional[Dict]:
        """Update an existing schedule."""
        for i, schedule in enumerate(self.schedules):
            if schedule['id'] == schedule_id:
                self.schedules[i].update(updates)
                self.save_schedules()
                return self.schedules[i]
        return None

    def delete_schedule(self, schedule_id: int) -> bool:
        """Delete a schedule."""
        for i, schedule in enumerate(self.schedules):
            if schedule['id'] == schedule_id:
                self.schedules.pop(i)
                self.save_schedules()
                return True
        return False

    def get_schedule(self, schedule_id: int) -> Optional[Dict]:
        """Get a specific schedule."""
        for schedule in self.schedules:
            if schedule['id'] == schedule_id:
                return schedule
        return None

    def list_schedules(self) -> List[Dict]:
        """List all schedules."""
        return self.schedules

    def get_enabled_schedules(self) -> List[Dict]:
        """Get all enabled schedules."""
        return [s for s in self.schedules if s.get('enabled', True)]

    def is_schedule_ready(self, schedule: Dict) -> bool:
        """Check if a schedule is ready to be sent."""
        schedule_time = datetime.fromisoformat(schedule['time'].replace('Z', '+00:00'))
        current_time = datetime.now()
        return current_time >= schedule_time