import os
from datetime import datetime, timedelta
from typing import List, Optional, Dict, Any
from dotenv import load_dotenv
from supabase import create_client, Client
from cache import cache  # Import Redis cache
import uuid

load_dotenv()

SUPABASE_URL = os.getenv("SUPABASE_URL")
SUPABASE_KEY = os.getenv("SUPABASE_KEY")

class Database:
    def __init__(self):
        self.client = None
        if SUPABASE_URL and SUPABASE_KEY:
            try:
                self.client: Client = create_client(SUPABASE_URL, SUPABASE_KEY)
            except Exception as e:
                print(f"Failed to initialize Supabase client: {e}")
        
        # In-memory mock storage
        self.mock_users = [
            {"contact_number": "5550101", "name": "Alice Test", "created_at": datetime.now().isoformat()},
            {"contact_number": "9730102", "name": "Naresh", "created_at": datetime.now().isoformat()}
        ]
        self.mock_appointments = [
             {
                "id": "mock_apt_1",
                "contact_number": "555-0101",
                "appointment_time": "2026-01-22T10:00:00",
                "status": "confirmed",
                "purpose": "Checkup",
                "created_at": datetime.now().isoformat()
            }
        ]
        self.mock_summaries = []
        self.mock_chat_messages = []
        self.cache = cache
        
        # Initialize Mock Slots (Next 10 days)
        self.mock_slots = []
        base_time = datetime.now().replace(minute=0, second=0, microsecond=0)
        for d in range(1, 11):
            day = base_time + timedelta(days=d)
            for h in [9, 10, 14, 16]:
                slot_time = day.replace(hour=h).isoformat()
                self.mock_slots.append({"slot_time": slot_time, "is_booked": False})

    def get_available_slots(self) -> List[str]:
        """Get list of available slot times."""
        if self.client:
            try:
                response = self.client.table("appointment_slots")\
                    .select("slot_time")\
                    .eq("is_booked", False)\
                    .gt("slot_time", datetime.now().isoformat())\
                    .order("slot_time")\
                    .execute()
                return [row["slot_time"] for row in response.data]
            except Exception as e:
                print(f"Error fetching slots from DB: {e}")
        
        # Mock fallback
        # Filter mock slots that are in future and not booked
        now_str = datetime.now().isoformat()
        return [s["slot_time"] for s in self.mock_slots if not s["is_booked"] and s["slot_time"] > now_str]

    def get_user(self, contact_number: str) -> Optional[Dict[str, Any]]:
        """Check if a user exists by contact number (with caching)."""
        # Normalize input: remove non-digit characters
        contact_number = "".join(filter(str.isdigit, str(contact_number)))
        
        # Try cache first
        cache_key = f"user:{contact_number}"
        cached_user = self.cache.get(cache_key)
        if cached_user:
            return cached_user
        
        if self.client:
            try:
                response = self.client.table("users").select("*").eq("contact_number", contact_number).execute()
                if response.data:
                    user = response.data[0]
                    # Cache for 1 hour
                    self.cache.set(cache_key, user, ttl=3600)
                    return user
            except Exception as e:
                print(f"Error fetching user from DB (falling back to mock): {e}")
        
        # Mock implementation fallback
        for user in self.mock_users:
            if user["contact_number"] == contact_number:
                return user
        return None

    def create_user(self, contact_number: str, name: str = "Unknown") -> Optional[Dict[str, Any]]:
        """Create a new user."""
        if self.client:
            try:
                data = {"contact_number": contact_number, "name": name}
                # Use upsert to handle potential race conditions or existing users
                response = self.client.table("users").upsert(data).execute()
                if response.data:
                    return response.data[0]
            except Exception as e:
                print(f"Error creating user in DB (falling back to mock): {e}")

        # Mock implementation fallback
        new_user = {"contact_number": contact_number, "name": name, "created_at": datetime.now().isoformat()}
        self.mock_users.append(new_user)
        return new_user
    
    def get_user_appointments(self, contact_number: str) -> List[Dict[str, Any]]:
        """Fetch past and upcoming appointments for a user."""
        if self.client:
            try:
                response = self.client.table("appointments")\
                    .select("*")\
                    .eq("contact_number", contact_number)\
                    .order("appointment_time", desc=True)\
                    .execute()
                return response.data
            except Exception as e:
                print(f"Error fetching appointments from DB (falling back to mock): {e}")
        
        # Mock implementation fallback
        return [
            apt for apt in self.mock_appointments 
            if apt["contact_number"] == contact_number and apt["status"] != "cancelled"
        ]

    def check_slot_availability(self, appointment_time: datetime) -> bool:
        """Check if a slot is valid and available."""
        time_str = appointment_time.isoformat()
        
        if self.client:
            try:
                # Check appointment_slots table for validity and availability
                response = self.client.table("appointment_slots")\
                    .select("*")\
                    .eq("slot_time", time_str)\
                    .eq("is_booked", False)\
                    .execute()
                
                return len(response.data) > 0
            except Exception as e:
                print(f"Error checking availability in DB (falling back to mock): {e}")

        # Mock fallback
        for slot in self.mock_slots:
            if slot["slot_time"] == time_str:
                return not slot["is_booked"]
        return False

    def book_appointment(self, contact_number: str, appointment_time: str, purpose: str = "General") -> Optional[Dict[str, Any]]:
        """Book an appointment and mark slot as booked."""
        if self.client:
            try:
                # 1. Insert into appointments
                data = {
                    "contact_number": contact_number,
                    "appointment_time": appointment_time,
                    "status": "confirmed",
                    "purpose": purpose
                }
                response = self.client.table("appointments").insert(data).execute()
                
                # 2. Mark slot as booked
                self.client.table("appointment_slots")\
                    .update({"is_booked": True})\
                    .eq("slot_time", appointment_time)\
                    .execute()

                if response.data:
                    return response.data[0]
            except Exception as e:
                print(f"Error booking appointment in DB (falling back to mock): {e}")
        
        # Mock implementation fallback
        import random
        apt_id = f"APT-{random.randint(1000, 9999)}"
        new_apt = {
            "id": apt_id,
            "contact_number": contact_number,
            "appointment_time": appointment_time,
            "status": "confirmed",
            "purpose": purpose,
            "created_at": datetime.now().isoformat()
        }
        self.mock_appointments.append(new_apt)
        
        # Mark mock slot as booked
        for slot in self.mock_slots:
            if slot["slot_time"] == appointment_time:
                slot["is_booked"] = True
                
        return new_apt

    def cancel_appointment(self, appointment_id: str) -> bool:
        """Cancel an appointment."""
        if self.client:
            try:
                response = self.client.table("appointments")\
                    .update({"status": "cancelled"})\
                    .eq("id", appointment_id)\
                    .execute()
                return True
            except Exception as e:
                print(f"Error cancelling appointment in DB (falling back to mock): {e}")

        # Mock implementation fallback
        for apt in self.mock_appointments:
            if apt["id"] == appointment_id:
                apt["status"] = "cancelled"
                return True
        return False

    def modify_appointment(self, appointment_id: str, new_time: str) -> bool:
        """Modify appointment time."""
        if self.client:
            try:
                response = self.client.table("appointments")\
                    .update({"appointment_time": new_time})\
                    .eq("id", appointment_id)\
                    .execute()
                return True
            except Exception as e:
                print(f"Error modifying appointment in DB (falling back to mock): {e}")

        # Mock implementation fallback
        for apt in self.mock_appointments:
            if apt["id"] == appointment_id:
                apt["appointment_time"] = new_time
                return True
        return False

    def save_summary(self, contact_number: str, summary: str) -> bool:
        """Save the conversation summary."""
        if self.client:
            try:
                data = {
                    "contact_number": contact_number,
                    "summary": summary,
                    "created_at": datetime.now().isoformat()
                }
                # Assuming a 'conversations' table exists
                self.client.table("conversations").insert(data).execute()
                return True
            except Exception as e:
                print(f"Error saving summary in DB (falling back to mock): {e}")

        # Mock implementation fallback
        print(f"Mock saving summary for {contact_number}: {summary}")
        self.mock_summaries.append({
            "contact_number": contact_number,
            "summary": summary,
            "created_at": datetime.now().isoformat()
        })
        return True
    
    def save_chat_message(self, session_id: str, contact_number: str, role: str, content: str, tool_name: str = None, tool_args: dict = None) -> bool:
        """Save a single chat message to the database"""
        if self.client:
            try:
                data = {
                    "session_id": session_id,
                    "contact_number": contact_number,
                    "role": role,
                    "content": content,
                    "tool_name": tool_name,
                    "tool_args": tool_args,
                    "created_at": datetime.now().isoformat()
                }
                self.client.table("chat_messages").insert(data).execute()
                return True
            except Exception as e:
                print(f"Error saving chat message to DB (falling back to mock): {e}")
        
        # Mock fallback
        self.mock_chat_messages.append({
            "session_id": session_id,
            "contact_number": contact_number,
            "role": role,
            "content": content,
            "tool_name": tool_name,
            "tool_args": tool_args,
            "created_at": datetime.now().isoformat()
        })
        return True
    
    def save_chat_transcript(self, session_id: str, contact_number: str, messages: list) -> bool:
        """Save entire chat transcript (batch insert)"""
        if not messages:
            return False
        
        if self.client:
            try:
                # Prepare batch data
                data = []
                for msg in messages:
                    data.append({
                        "session_id": session_id,
                        "contact_number": contact_number,
                        "role": msg.get("role"),
                        "content": msg.get("content"),
                        "tool_name": msg.get("tool_name"),
                        "tool_args": msg.get("tool_args"),
                        "created_at": datetime.now().isoformat()
                    })
                
                # Batch insert
                self.client.table("chat_messages").insert(data).execute()
                print(f"✅ Saved {len(data)} chat messages to database")
                return True
            except Exception as e:
                print(f"Error saving chat transcript to DB (falling back to mock): {e}")
        
        # Mock fallback
        for msg in messages:
            self.mock_chat_messages.append({
                "session_id": session_id,
                "contact_number": contact_number,
                "role": msg.get("role"),
                "content": msg.get("content"),
                "tool_name": msg.get("tool_name"),
                "tool_args": msg.get("tool_args"),
                "created_at": datetime.now().isoformat()
            })
        print(f"Mock saved {len(messages)} chat messages")
        return True
    
    def get_chat_history(self, contact_number: str, limit: int = 100) -> list:
        """Get chat history for a user"""
        if self.client:
            try:
                response = self.client.table("chat_messages")\
                    .select("*")\
                    .eq("contact_number", contact_number)\
                    .order("created_at", desc=True)\
                    .limit(limit)\
                    .execute()
                return response.data if response.data else []
            except Exception as e:
                print(f"Error fetching chat history: {e}")
        
        # Mock fallback
        return [msg for msg in self.mock_chat_messages if msg["contact_number"] == contact_number][-limit:]

# Hardcoded slots for the 'fetch_slots' requirement
AVAILABLE_SLOTS = [
    "2026-01-22T09:00:00",
    "2026-01-22T10:00:00",
    "2026-01-22T14:00:00",
    "2026-01-23T11:00:00",
    "2026-01-23T15:00:00"
]