import os
from fastapi import FastAPI, Header, HTTPException
from fastapi.middleware.cors import CORSMiddleware
from supabase import create_client, Client
from jose import jwt, JWTError
from dotenv import load_dotenv

# Load environment variables from .env file for local development
load_dotenv()

# --- Configuration ---
# These will be set as "Secrets" in your Hugging Face Space settings
SUPABASE_URL = os.getenv("SUPABASE_URL")
SUPABASE_SERVICE_KEY = os.getenv("SUPABASE_SERVICE_ROLE_KEY")
JWT_SECRET_KEY = os.getenv("JWT_SECRET_KEY")
ALGORITHM = "HS256"

# --- Initialization ---
app = FastAPI()

@app.get("/")
def read_root():
    return {"status": "ok", "message": "Itinerary API is running"}

# Initialize Supabase client with the service role key for admin access
try:
    supabase: Client = create_client(SUPABASE_URL, SUPABASE_SERVICE_KEY)
except Exception as e:
    print(f"Error initializing Supabase client: {e}")
    supabase = None

# Configure CORS (Cross-Origin Resource Sharing)
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=False,
    allow_methods=["*"],
    allow_headers=["*"],
)

# --- API Endpoint (MODIFIED to fetch all itineraries) ---
@app.get("/get-itinerary")
async def get_itinerary_data(authorization: str = Header(...)):
    """
    Verifies the user's custom JWT and fetches ALL their itineraries from Supabase.
    """
    if not supabase:
        raise HTTPException(status_code=500, detail="Database connection not configured.")

    try:
        # 1. Extract token from "Bearer <token>" header
        token_type, token = authorization.split()
        if token_type.lower() != "bearer":
            raise HTTPException(status_code=401, detail="Invalid token type")

        # 2. Verify and decode the JWT
        payload = jwt.decode(token, JWT_SECRET_KEY, algorithms=[ALGORITHM])
        
        # 3. Extract user ID
        user_id = payload.get("user_id")
        if user_id is None:
            raise HTTPException(status_code=401, detail="User ID not found in token payload")
        
        # 4. Query Supabase for all itineraries, newest first
        # We removed .single() and .limit(1) to get a list
        # We also added "id" and "created_at" to help the frontend
        response = supabase.table("itineraries") \
            .select("id, created_at, itinerary_data") \
            .eq("user_id", user_id) \
            .order("created_at", desc=True) \
            .execute()

        # 5. Return the list of data
        return response.data

    except JWTError:
        raise HTTPException(status_code=401, detail="Could not validate credentials")
    except HTTPException as e:
        # Re-raise HTTPExceptions to preserve status code and detail
        raise e
    except Exception as e:
        # Catch any other unexpected errors
        print(f"An unexpected error occurred: {e}")
        raise HTTPException(status_code=500, detail="Internal server error")

@app.delete("/itinerary/{itinerary_id}")
async def delete_itinerary(itinerary_id: str, authorization: str = Header(...)): # 🎯 MODIFIED: Changed int to str
    """
    Deletes a specific itinerary, ensuring the user owns it.
    """
    if not supabase:
        raise HTTPException(status_code=500, detail="Database connection not configured.")

    try:
        # First, verify the user's token to get their ID
        token_type, token = authorization.split()
        if token_type.lower() != "bearer":
            raise HTTPException(status_code=401, detail="Invalid token type")
        
        payload = jwt.decode(token, JWT_SECRET_KEY, algorithms=[ALGORITHM])
        user_id = payload.get("user_id")
        if user_id is None:
            raise HTTPException(status_code=401, detail="User ID not found in token payload")

        # Securely delete the itinerary by matching both its ID and the user's ID
        response = supabase.table("itineraries").delete().match({
            "id": itinerary_id,
            "user_id": user_id
        }).execute()

        if not response.data:
            raise HTTPException(status_code=404, detail="Itinerary not found or you do not have permission to delete it.")

        return {"message": "Itinerary deleted successfully"}

    except JWTError:
        raise HTTPException(status_code=401, detail="Could not validate credentials")
    except Exception as e:
        print(f"An unexpected error occurred: {e}")
        raise HTTPException(status_code=500, detail="Internal server error")