from flask import current_app
from datetime import datetime, timedelta
from typing import List, Dict
import pandas as pd
from backend.models.schedule import Schedule

class ScheduleService:
    """Service for managing post scheduling."""
    
    def __init__(self):
        self.supabase = current_app.supabase
    
    def get_user_schedules(self, user_id: str) -> List[Dict]:
        """
        Get all schedules for a user.
        
        Args:
            user_id (str): User ID
            
        Returns:
            List[Dict]: List of schedules
        """
        try:
            response = (
                self.supabase
                .table("Scheduling")
                .select("*, Social_network(id_utilisateur, social_network, account_name)")
                .execute()
            )
            
            # Filter schedules for the user
            schedules = []
            for item in response.data:
                if item.get('Social_network', {}).get('id_utilisateur') == user_id:
                    schedule = Schedule.from_dict({
                        'id': item['id'],
                        'social_account_id': item['id_social'],
                        'schedule_time': item['schedule_time'],
                        'adjusted_time': item['adjusted_time'],
                        'created_at': item['created_at']
                    })
                    schedules.append(schedule.to_dict())
            
            return schedules
            
        except Exception as e:
            # Log the error for debugging
            print(f"[ERROR] Failed to fetch schedules: {str(e)}")
            # Return empty list instead of raising exception
            return []
    
    def create_schedule(self, user_id: str, social_network: str, schedule_time: str, days: List[str]) -> Dict:
        """
        Create a new schedule.
        
        Args:
            user_id (str): User ID
            social_network (str): Social account ID (as string)
            schedule_time (str): Schedule time in format "HH:MM"
            days (List[str]): List of days to schedule
            
        Returns:
            Dict: Created schedule
        """
        try:
            # Validate that social_network is a valid ID
            if not social_network or not isinstance(social_network, str):
                raise Exception("Invalid social account ID provided")
            
            # Try to convert social_network to int for database query
            try:
                social_account_id = int(social_network)
            except ValueError:
                raise Exception(f"Invalid social account ID format: {social_network}. Expected a numeric ID.")
            
            # Get social account - verify it belongs to the current user
            account_response = (
                self.supabase
                .table("Social_network")
                .select("id, id_utilisateur")
                .eq("id", social_account_id)
                .execute()
            )
            
            if not account_response.data:
                raise Exception("Social account not found")
            
            # Verify the account belongs to the current user
            account = account_response.data[0]
            if str(account.get('id_utilisateur')) != str(user_id):
                raise Exception("Social account not found or unauthorized")
            
            social_account_id = account['id']
            
            # Create schedules for each day
            created_schedules = []
            
            for day in days:
                # Format schedule time
                formatted_schedule = f"{day} {schedule_time}"
                
                # Calculate adjusted time (5 minutes before for content generation)
                adjusted_time = self._calculate_adjusted_time(formatted_schedule)
                
                # Insert schedule
                response = (
                    self.supabase
                    .table("Scheduling")
                    .insert({
                        "id_social": social_account_id,
                        "schedule_time": formatted_schedule,
                        "adjusted_time": adjusted_time
                    })
                    .execute()
                )
                
                if response.data:
                    schedule = Schedule.from_dict({
                        'id': response.data[0]['id'],
                        'social_account_id': response.data[0]['id_social'],
                        'schedule_time': response.data[0]['schedule_time'],
                        'adjusted_time': response.data[0]['adjusted_time'],
                        'created_at': response.data[0]['created_at']
                    })
                    created_schedules.append(schedule.to_dict())
            
            return {
                'success': True,
                'schedules': created_schedules,
                'message': f'Schedule created successfully for {len(created_schedules)} day(s)'
            }
            
        except Exception as e:
            raise Exception(f"Failed to create schedule: {str(e)}")
    
    def delete_schedule(self, schedule_id: str) -> Dict:
        """
        Delete a schedule.
        
        Args:
            schedule_id (str): Schedule ID
            
        Returns:
            Dict: Deletion result
        """
        try:
            response = (
                self.supabase
                .table("Scheduling")
                .delete()
                .eq("id", schedule_id)
                .execute()
            )
            
            if response.data:
                return {
                    'success': True,
                    'message': 'Schedule deleted successfully'
                }
            else:
                return {
                    'success': False,
                    'message': 'Schedule not found'
                }
                
        except Exception as e:
            raise Exception(f"Failed to delete schedule: {str(e)}")
    
    def _calculate_adjusted_time(self, schedule_time: str) -> str:
        """
        Calculate adjusted time for content generation (5 minutes before schedule).
        
        Args:
            schedule_time (str): Original schedule time
            
        Returns:
            str: Adjusted time
        """
        # Parse schedule time
        parts = schedule_time.strip().split()
        if len(parts) != 2 or ':' not in parts[1]:
            return schedule_time
        
        day, time_part = parts
        try:
            hour, minute = map(int, time_part.split(':'))
            # Subtract 5 minutes for content generation
            adjusted_minute = minute - 5
            adjusted_hour = hour
            
            if adjusted_minute < 0:
                adjusted_minute += 60
                adjusted_hour -= 1
                if adjusted_hour < 0:
                    adjusted_hour += 24
            
            return f"{day} {adjusted_hour:02d}:{adjusted_minute:02d}"
        except ValueError:
            return schedule_time
    
    def get_all_schedules(self) -> pd.DataFrame:
        """
        Get all schedules for the scheduler.
        
        Returns:
            pd.DataFrame: DataFrame with all schedules
        """
        try:
            response = (
                self.supabase
                .table("Scheduling")
                .select("*, Social_network(id_utilisateur, account_name)")
                .execute()
            )
            
            # Normalize the data
            data = response.data
            df = pd.json_normalize(data)
            
            if not df.empty:
                df = df.rename(columns={
                    "Social_network.id_utilisateur": "user_id",
                    "Social_network.account_name": "social_network"
                })
                
                # Select relevant columns
                cols = ["id", "id_social", "user_id", "schedule_time", "social_network", "adjusted_time", "created_at"]
                df = df[[c for c in cols if c in df.columns]]
            
            return df
            
        except Exception as e:
            raise Exception(f"Failed to fetch all schedules: {str(e)}")