import requests
import json
import os
from typing import Dict, List, Any, Optional, Tuple
from datetime import datetime, timedelta
import pytz

from utils.logging import setup_logger
from utils.error_handling import handle_exceptions, IntegrationError
from utils.storage import load_data, save_data

# Initialize logger
logger = setup_logger(__name__)

class GoogleCalendarIntegration:
    """Google Calendar API integration for event synchronization"""
    
    def __init__(self, credentials: Optional[Dict[str, Any]] = None):
        """Initialize Google Calendar integration
        
        Args:
            credentials: Google API credentials (optional)
        """
        self.base_url = "https://www.googleapis.com/calendar/v3"
        self.credentials = credentials
        self.token = credentials.get("access_token") if credentials else None
        self.refresh_token = credentials.get("refresh_token") if credentials else None
        self.token_expiry = credentials.get("expiry") if credentials else None
        self.headers = {}
        
        if self.token:
            self.headers["Authorization"] = f"Bearer {self.token}"
    
    @handle_exceptions
    def set_credentials(self, credentials: Dict[str, Any]) -> None:
        """Set Google API credentials
        
        Args:
            credentials: Google API credentials
        """
        self.credentials = credentials
        self.token = credentials.get("access_token")
        self.refresh_token = credentials.get("refresh_token")
        self.token_expiry = credentials.get("expiry")
        
        if self.token:
            self.headers["Authorization"] = f"Bearer {self.token}"
    
    @handle_exceptions
    def refresh_access_token(self) -> bool:
        """Refresh the access token using the refresh token
        
        Returns:
            True if token refresh is successful, False otherwise
        """
        # In a real implementation, this would use the refresh token to get a new access token
        # For demo purposes, we'll just return False
        logger.warning("Token refresh not implemented in demo")
        return False
    
    @handle_exceptions
    def test_connection(self) -> bool:
        """Test Google Calendar API connection
        
        Returns:
            True if connection is successful, False otherwise
        """
        try:
            # Check if token is expired
            if self.token_expiry and datetime.fromisoformat(self.token_expiry) < datetime.now():
                # Try to refresh token
                if not self.refresh_access_token():
                    return False
            
            response = requests.get(
                f"{self.base_url}/users/me/calendarList",
                headers=self.headers
            )
            return response.status_code == 200
        except Exception as e:
            logger.error(f"Google Calendar connection test failed: {str(e)}")
            return False
    
    @handle_exceptions
    def get_calendars(self) -> List[Dict[str, Any]]:
        """Get user calendars
        
        Returns:
            List of calendars
        """
        response = requests.get(
            f"{self.base_url}/users/me/calendarList",
            headers=self.headers
        )
        
        if response.status_code != 200:
            raise IntegrationError(f"Failed to get calendars: {response.text}")
        
        calendars = response.json().get("items", [])
        return [{
            "id": calendar.get("id"),
            "name": calendar.get("summary"),
            "description": calendar.get("description"),
            "timezone": calendar.get("timeZone"),
            "primary": calendar.get("primary", False),
            "color": calendar.get("backgroundColor")
        } for calendar in calendars]
    
    @handle_exceptions
    def get_events(self, calendar_id: str, start_time: datetime = None, 
                  end_time: datetime = None, max_results: int = 100) -> List[Dict[str, Any]]:
        """Get calendar events
        
        Args:
            calendar_id: Calendar ID
            start_time: Start time for events (optional)
            end_time: End time for events (optional)
            max_results: Maximum number of events to return
            
        Returns:
            List of events
        """
        params = {
            "maxResults": max_results,
            "singleEvents": True,
            "orderBy": "startTime"
        }
        
        if start_time:
            params["timeMin"] = start_time.isoformat() + "Z"  # RFC3339 timestamp
        
        if end_time:
            params["timeMax"] = end_time.isoformat() + "Z"  # RFC3339 timestamp
        
        response = requests.get(
            f"{self.base_url}/calendars/{calendar_id}/events",
            headers=self.headers,
            params=params
        )
        
        if response.status_code != 200:
            raise IntegrationError(f"Failed to get events: {response.text}")
        
        events = response.json().get("items", [])
        return [self._format_event(event) for event in events]
    
    @handle_exceptions
    def create_event(self, calendar_id: str, summary: str, start: Dict[str, Any], 
                    end: Dict[str, Any], description: str = None, location: str = None, 
                    attendees: List[Dict[str, str]] = None) -> Dict[str, Any]:
        """Create a new calendar event
        
        Args:
            calendar_id: Calendar ID
            summary: Event summary/title
            start: Event start time (dict with 'dateTime' or 'date')
            end: Event end time (dict with 'dateTime' or 'date')
            description: Event description (optional)
            location: Event location (optional)
            attendees: List of attendees (optional)
            
        Returns:
            Created event data
        """
        data = {
            "summary": summary,
            "start": start,
            "end": end
        }
        
        if description:
            data["description"] = description
        
        if location:
            data["location"] = location
        
        if attendees:
            data["attendees"] = attendees
        
        response = requests.post(
            f"{self.base_url}/calendars/{calendar_id}/events",
            headers=self.headers,
            json=data
        )
        
        if response.status_code not in [200, 201]:
            raise IntegrationError(f"Failed to create event: {response.text}")
        
        event = response.json()
        return self._format_event(event)
    
    @handle_exceptions
    def update_event(self, calendar_id: str, event_id: str, summary: str = None, 
                    start: Dict[str, Any] = None, end: Dict[str, Any] = None, 
                    description: str = None, location: str = None) -> Dict[str, Any]:
        """Update an existing calendar event
        
        Args:
            calendar_id: Calendar ID
            event_id: Event ID
            summary: Event summary/title (optional)
            start: Event start time (optional)
            end: Event end time (optional)
            description: Event description (optional)
            location: Event location (optional)
            
        Returns:
            Updated event data
        """
        data = {}
        
        if summary is not None:
            data["summary"] = summary
        
        if start is not None:
            data["start"] = start
        
        if end is not None:
            data["end"] = end
        
        if description is not None:
            data["description"] = description
        
        if location is not None:
            data["location"] = location
        
        response = requests.patch(
            f"{self.base_url}/calendars/{calendar_id}/events/{event_id}",
            headers=self.headers,
            json=data
        )
        
        if response.status_code != 200:
            raise IntegrationError(f"Failed to update event: {response.text}")
        
        event = response.json()
        return self._format_event(event)
    
    @handle_exceptions
    def delete_event(self, calendar_id: str, event_id: str) -> bool:
        """Delete a calendar event
        
        Args:
            calendar_id: Calendar ID
            event_id: Event ID
            
        Returns:
            True if deletion is successful
        """
        response = requests.delete(
            f"{self.base_url}/calendars/{calendar_id}/events/{event_id}",
            headers=self.headers
        )
        
        if response.status_code not in [200, 204]:
            raise IntegrationError(f"Failed to delete event: {response.text}")
        
        return True
    
    @handle_exceptions
    def convert_events_to_tasks(self, calendar_id: str, days: int = 7) -> List[Dict[str, Any]]:
        """Convert Google Calendar events to MONA tasks
        
        Args:
            calendar_id: Calendar ID
            days: Number of days to look ahead
            
        Returns:
            List of tasks
        """
        # Get events for the next 'days' days
        start_time = datetime.now(pytz.UTC)
        end_time = start_time + timedelta(days=days)
        
        events = self.get_events(calendar_id, start_time, end_time)
        
        tasks = []
        for event in events:
            # Skip all-day events
            if "date" in event.get("start", {}):
                continue
            
            # Convert event to task format
            start_time = datetime.fromisoformat(event["start"].get("dateTime", "").replace("Z", "+00:00"))
            
            task = {
                "id": f"gcal-event-{event['id']}",
                "title": event["summary"],
                "description": event.get("description", ""),
                "status": "todo",
                "priority": "medium",  # Default priority
                "created_at": event.get("created", datetime.now().isoformat()),
                "updated_at": event.get("updated", datetime.now().isoformat()),
                "due_date": start_time.isoformat(),
                "source": "google_calendar",
                "source_id": event["id"],
                "source_url": event.get("htmlLink", ""),
                "metadata": {
                    "calendar_id": calendar_id,
                    "location": event.get("location", ""),
                    "start": event["start"],
                    "end": event["end"],
                    "attendees": event.get("attendees", [])
                }
            }
            
            tasks.append(task)
        
        return tasks
    
    @handle_exceptions
    def sync_tasks_to_events(self, tasks: List[Dict[str, Any]], calendar_id: str) -> List[Dict[str, Any]]:
        """Sync MONA tasks to Google Calendar events
        
        Args:
            tasks: List of tasks to sync
            calendar_id: Calendar ID
            
        Returns:
            List of synced tasks with updated metadata
        """
        synced_tasks = []
        
        for task in tasks:
            # Skip tasks that are already synced with Google Calendar
            if task.get("source") == "google_calendar":
                synced_tasks.append(task)
                continue
            
            # Skip tasks without due dates
            if not task.get("due_date"):
                synced_tasks.append(task)
                continue
            
            # Create event from task
            due_date = datetime.fromisoformat(task["due_date"].replace("Z", "+00:00"))
            end_date = due_date + timedelta(hours=1)  # Default 1-hour event
            
            event_data = {
                "summary": task["title"],
                "description": task.get("description", ""),
                "start": {
                    "dateTime": due_date.isoformat(),
                    "timeZone": "UTC"
                },
                "end": {
                    "dateTime": end_date.isoformat(),
                    "timeZone": "UTC"
                }
            }
            
            # Create event
            event = self.create_event(
                calendar_id=calendar_id,
                summary=event_data["summary"],
                start=event_data["start"],
                end=event_data["end"],
                description=event_data["description"]
            )
            
            # Update task with Google Calendar metadata
            task.update({
                "source": "google_calendar",
                "source_id": event["id"],
                "source_url": event.get("htmlLink", ""),
                "metadata": {
                    "calendar_id": calendar_id,
                    "start": event["start"],
                    "end": event["end"]
                }
            })
            
            synced_tasks.append(task)
        
        return synced_tasks
    
    def _format_event(self, event: Dict[str, Any]) -> Dict[str, Any]:
        """Format event data for consistent output
        
        Args:
            event: Raw event data from API
            
        Returns:
            Formatted event data
        """
        return {
            "id": event.get("id"),
            "summary": event.get("summary"),
            "description": event.get("description"),
            "location": event.get("location"),
            "start": event.get("start"),
            "end": event.get("end"),
            "created": event.get("created"),
            "updated": event.get("updated"),
            "status": event.get("status"),
            "htmlLink": event.get("htmlLink"),
            "attendees": event.get("attendees", []),
            "organizer": event.get("organizer")
        }