"""
Database module for handling conversation persistence using Supabase.
"""

import os
import json
from datetime import datetime
import requests
from dotenv import load_dotenv

# Load environment variables
load_dotenv()

class SupabaseClient:
    def __init__(self):
        """Initialize Supabase client with credentials from environment variables."""
        self.supabase_url = os.getenv('SUPABASE_URL')
        self.supabase_key = os.getenv('SUPABASE_KEY')
        
        if not self.supabase_url or not self.supabase_key:
            raise ValueError("Supabase credentials not found in environment variables. "
                            "Please set SUPABASE_URL and SUPABASE_KEY.")
    
    def _make_request(self, method, endpoint, data=None, params=None):
        """Make a request to Supabase API."""
        url = f"{self.supabase_url}{endpoint}"
        headers = {
            "apikey": self.supabase_key,
            "Authorization": f"Bearer {self.supabase_key}",
            "Content-Type": "application/json",
            "Prefer": "return=representation"
        }
        
        if method == "GET":
            response = requests.get(url, headers=headers, params=params)
        elif method == "POST":
            response = requests.post(url, headers=headers, json=data)
        elif method == "PUT":
            response = requests.put(url, headers=headers, json=data)
        elif method == "DELETE":
            response = requests.delete(url, headers=headers, params=params)
        else:
            raise ValueError(f"Unsupported method: {method}")
        
        return response

    def create_conversation(self, consultation_id):
        """Create a new conversation record in the database."""
        data = {
            "consultation_id": consultation_id,
            "created_at": datetime.now().isoformat(),
            "is_active": True
        }
        
        response = self._make_request(
            "POST", 
            "/rest/v1/conversations", 
            data=data
        )
        
        if response.status_code not in (200, 201):
            raise Exception(f"Failed to create conversation: {response.text}")
        
        return response.json()
    
    def save_message(self, consultation_id, message):
        """Save a single message to the database."""
        # Normalize message format for database storage
        message_data = {
            "consultation_id": consultation_id,
            "role": message.get("role"),
            "content": message.get("content"),
            "timestamp": datetime.now().isoformat()
        }
        
        # Handle additional fields
        if "explanation" in message:
            message_data["explanation"] = message.get("explanation")
        
        # Store follow-up questions
        if "follow_up_questions" in message:
            message_data["follow_up_questions"] = message.get("follow_up_questions")
        
        if "evidence" in message:
            # Convert evidence to string for storage
            try:
                message_data["evidence"] = json.dumps(message.get("evidence"))
            except Exception as e:
                # If JSON serialization fails, store as empty array
                message_data["evidence"] = "[]"
                print(f"Failed to serialize evidence: {str(e)}")
        
        try:
            response = self._make_request(
                "POST", 
                "/rest/v1/messages", 
                data=message_data
            )
            
            if response.status_code not in (200, 201):
                print(f"Failed to save message: Status {response.status_code}, Response: {response.text}")
                # Attempt to log the message that failed to save
                print(f"Message data: {json.dumps(message_data)}")
                return None
            
            return response.json()
        except Exception as e:
            print(f"Exception saving message to database: {str(e)}")
            # Attempt to log the message that failed to save
            print(f"Message data: {json.dumps(message_data)}")
            return None
    
    def get_conversation_history(self, consultation_id):
        """Retrieve full conversation history for a given consultation ID."""
        params = {
            "consultation_id": f"eq.{consultation_id}",
            "order": "timestamp.asc",
            "limit": "25"  # Explicitly set a high limit for messages - 10000, if needed. 
        }
        
        try:
            response = self._make_request(
                "GET", 
                "/rest/v1/messages", 
                params=params
            )
            
            if response.status_code != 200:
                print(f"Failed to retrieve conversation history: Status {response.status_code}, Response: {response.text}")
                return []
            
            # Convert database format back to application format
            messages = response.json()
            print(f"Retrieved {len(messages)} messages from database for consultation {consultation_id}")
            
            history = []
            
            for msg in messages:
                message_dict = {
                    "role": msg["role"],
                    "content": msg["content"]
                }
                
                if msg.get("explanation"):
                    message_dict["explanation"] = msg["explanation"]
                
                if msg.get("follow_up_questions"):
                    message_dict["follow_up_questions"] = msg["follow_up_questions"]
                
                if msg.get("evidence"):
                    # Parse evidence JSON string back to object
                    try:
                        message_dict["evidence"] = json.loads(msg["evidence"])
                    except Exception as e:
                        print(f"Failed to parse evidence JSON: {str(e)}")
                        message_dict["evidence"] = []
                
                history.append(message_dict)
            
            return history
        
        except Exception as e:
            print(f"Exception retrieving conversation history: {str(e)}")
            return []
    
    def delete_conversation(self, consultation_id):
        """Delete a completed conversation from the database."""
        # First delete all messages
        msg_params = {"consultation_id": f"eq.{consultation_id}"}
        self._make_request("DELETE", "/rest/v1/messages", params=msg_params)
        
        # Then delete conversation record
        conv_params = {"consultation_id": f"eq.{consultation_id}"}
        response = self._make_request("DELETE", "/rest/v1/conversations", params=conv_params)
        
        if response.status_code != 200:
            raise Exception(f"Failed to delete conversation: {response.text}")
        
        return True
        
    def get_active_conversations(self):
        """Get list of active conversations."""
        params = {
            "is_active": "eq.true",
            "order": "created_at.desc"
        }
        
        response = self._make_request(
            "GET", 
            "/rest/v1/conversations", 
            params=params
        )
        
        if response.status_code != 200:
            raise Exception(f"Failed to retrieve active conversations: {response.text}")
        
        return response.json()

# Initialize database client
def get_db_client():
    """Get database client instance."""
    return SupabaseClient()