from datetime import datetime, timedelta
from icalendar import Calendar, Event
from pathlib import Path
import pytz


async def create_calendar_event(
    title: str,
    start: str,
    end: str,
    description: str = '',
    location: str = ''
) -> dict:
    """
    Create ICS calendar event
    
    Args:
        title: Event title
        start: Start datetime (ISO format or natural language)
        end: End datetime (ISO format or natural language)
        description: Event description
        location: Event location
        
    Returns:
        Dict with ICS file path
    """
    try:
        # Parse dates
        start_dt = parse_datetime(start)
        end_dt = parse_datetime(end)
        
        # Create calendar
        cal = Calendar()
        cal.add('prodid', '-//LifeAdmin AI//lifeadmin.ai//')
        cal.add('version', '2.0')
        
        # Create event
        event = Event()
        event.add('summary', title)
        event.add('dtstart', start_dt)
        event.add('dtend', end_dt)
        event.add('description', description)
        if location:
            event.add('location', location)
        event.add('dtstamp', datetime.now(pytz.UTC))
        
        # Generate unique ID
        import uuid
        event.add('uid', str(uuid.uuid4()))
        
        cal.add_component(event)
        
        # Save to file
        output_path = f"data/outputs/event_{datetime.now().strftime('%Y%m%d_%H%M%S')}.ics"
        Path(output_path).parent.mkdir(parents=True, exist_ok=True)
        
        with open(output_path, 'wb') as f:
            f.write(cal.to_ical())
        
        return {
            'success': True,
            'output_path': output_path,
            'event': {
                'title': title,
                'start': start_dt.isoformat(),
                'end': end_dt.isoformat(),
                'description': description
            }
        }
        
    except Exception as e:
        return {'error': str(e), 'success': False}


def parse_datetime(dt_string: str) -> datetime:
    """Parse datetime from various formats"""
    try:
        # Try ISO format
        return datetime.fromisoformat(dt_string.replace('Z', '+00:00'))
    except:
        pass
    
    try:
        # Try common formats
        for fmt in ['%Y-%m-%d %H:%M', '%Y-%m-%d', '%m/%d/%Y %H:%M', '%m/%d/%Y']:
            try:
                dt = datetime.strptime(dt_string, fmt)
                return pytz.UTC.localize(dt)
            except:
                continue
    except:
        pass
    
    # Default to now
    return datetime.now(pytz.UTC)


async def create_multiple_events(events: list) -> dict:
    """Create multiple calendar events from a list"""
    results = []
    for event_data in events:
        result = await create_calendar_event(**event_data)
        results.append(result)
    
    successful = sum(1 for r in results if r.get('success'))
    
    return {
        'success': True,
        'total_events': len(events),
        'successful': successful,
        'results': results
    }