import os
from fastapi import FastAPI, HTTPException, Request, Response
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import RedirectResponse, HTMLResponse
import gradio as gr
import requests
import logging
import time
import aiohttp
import asyncio
from typing import Optional, Dict, Any
from passlib.context import CryptContext
from passlib.exc import UnknownHashError
from pydantic import BaseModel

# ======================
# Configuration
# ======================

logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
)
logger = logging.getLogger(__name__)

# Password hashing
pwd_context = CryptContext(
    schemes=["bcrypt"],
    deprecated="auto"
)

# Environment variables (fallback to hardcoded values if not set)
BACKEND_URL = os.getenv("BACKEND_URL", "https://rocketfarmstudios-cps-api.hf.space")
ADMIN_EMAIL = os.getenv("ADMIN_EMAIL", "yakdhanali97@gmail.com")
ADMIN_PASSWORD = os.getenv("ADMIN_PASSWORD", "123456")

# ======================
# Models
# ======================

class DoctorCreate(BaseModel):
    full_name: str
    email: str
    license_number: str
    password: str
    specialty: str

# ======================
# Token Management
# ======================

class TokenManager:
    def __init__(self):
        self.token: Optional[str] = None
        self.last_refresh: float = 0
        self.expires_in: int = 3600  # Default expiry
        self.lock = asyncio.Lock()

    async def _make_login_request(self) -> Optional[str]:
        """Make the login request with proper error handling"""
        login_payload = {
            "username": ADMIN_EMAIL,
            "password": ADMIN_PASSWORD,
            "device_token": "admin-console"
        }

        try:
            async with aiohttp.ClientSession() as session:
                async with session.post(
                    f"{BACKEND_URL}/auth/login",
                    json=login_payload,
                    timeout=aiohttp.ClientTimeout(total=10)
                ) as response:
                    if response.status == 200:
                        data = await response.json()
                        return data.get("access_token")
                    else:
                        error = await response.text()
                        logger.error(f"Login failed: {response.status} - {error}")
                        return None
        except Exception as e:
            logger.error(f"Login request error: {str(e)}")
            return None

    async def refresh_token(self) -> str:
        """Obtain a new token with retry logic"""
        async with self.lock:  # Prevent multiple concurrent refreshes
            for attempt in range(3):
                token = await self._make_login_request()
                if token:
                    self.token = token
                    self.last_refresh = time.time()
                    logger.info("Successfully refreshed admin token")
                    return token
                
                wait_time = min(5, (attempt + 1) * 2)  # Exponential backoff with max 5s
                logger.warning(f"Attempt {attempt + 1} failed, retrying in {wait_time}s...")
                await asyncio.sleep(wait_time)

            raise HTTPException(
                status_code=500,
                detail="Failed to obtain admin token after multiple attempts"
            )

    async def get_token(self) -> str:
        """Get current valid token, refreshing if needed"""
        if not self.token or (time.time() - self.last_refresh) > (self.expires_in - 60):
            return await self.refresh_token()
        return self.token

token_manager = TokenManager()

# ======================
# FastAPI App
# ======================

app = FastAPI(
    title="Medical Admin Portal",
    description="Doctor account management system",
    version="1.0.0"
)

# CORS Configuration
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# ======================
# Security Utilities
# ======================

def verify_password(plain_password: str, hashed_password: str) -> bool:
    try:
        return pwd_context.verify(plain_password, hashed_password)
    except UnknownHashError:
        logger.error(f"Unrecognized hash format: {hashed_password[:15]}...")
        return False
    except Exception as e:
        logger.error(f"Password verification error: {str(e)}")
        return False

# ======================
# API Endpoints
# ======================

@app.get("/")
async def root():
    return {"status": "active", "service": "Medical Admin Portal"}

@app.post("/login")
async def handle_login():
    return RedirectResponse(url="/auth/login", status_code=307)

@app.get("/health")
async def health_check():
    try:
        # Verify we can get a token
        await token_manager.get_token()
        return {"status": "healthy"}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

# ======================
# Doctor Management
# ======================

async def create_doctor_api(doctor_data: DoctorCreate) -> Dict[str, Any]:
    """Core doctor creation logic"""
    token = await token_manager.get_token()
    
    headers = {
        "Authorization": f"Bearer {token}",
        "Content-Type": "application/json"
    }

    async with aiohttp.ClientSession() as session:
        async with session.post(
            f"{BACKEND_URL}/auth/admin/doctors",
            json=doctor_data.dict(),
            headers=headers,
            timeout=aiohttp.ClientTimeout(total=15)
        ) as response:
            
            if response.status == 201:
                return {"success": True, "message": "Doctor created successfully"}
            
            error_detail = await response.text()
            return {
                "success": False,
                "error": f"Error {response.status}: {error_detail}"
            }

# ======================
# Gradio Interface
# ======================

def sync_create_doctor(full_name: str, email: str, matricule: str, password: str, specialty: str) -> str:
    """Wrapper to run async code in Gradio's sync context"""
    try:
        doctor_data = DoctorCreate(
            full_name=full_name,
            email=email,
            license_number=matricule,
            password=password,
            specialty=specialty
        )
        
        # Run async code in sync context
        result = asyncio.run(create_doctor_api(doctor_data))
        
        if result["success"]:
            return "✅ " + result["message"]
        else:
            return "❌ " + result["error"]
            
    except Exception as e:
        logger.error(f"Doctor creation failed: {str(e)}")
        return f"❌ System error: {str(e)}"

with gr.Blocks(title="Doctor Management", css=".gradio-container {max-width: 800px}") as admin_ui:
    gr.Markdown("# 👨‍⚕️ Doctor Account Creator")
    
    with gr.Row():
        with gr.Column():
            full_name = gr.Textbox(label="Full Name", placeholder="Dr. First Last")
            email = gr.Textbox(label="Email", placeholder="doctor@hospital.org")
            license_num = gr.Textbox(label="License Number")
            
        with gr.Column():
            specialty = gr.Dropdown(
                label="Specialty",
                choices=[
                    "General Practice", "Cardiology", "Neurology",
                    "Pediatrics", "Orthopedics", "Dermatology"
                ]
            )
            password = gr.Textbox(
                label="Password",
                type="password",
                info="Minimum 8 characters"
            )
    
    submit_btn = gr.Button("Create Account", variant="primary")
    output = gr.Textbox(label="Status", interactive=False)
    
    submit_btn.click(
        fn=sync_create_doctor,
        inputs=[full_name, email, license_num, specialty, password],
        outputs=output
    )

# Mount Gradio interface
app = gr.mount_gradio_app(app, admin_ui, path="/admin")

# ======================
# Admin Dashboard
# ======================

@app.get("/admin-auth")
async def admin_auth(
    email: str,
    password: str,
    response: Response
):
    """Secure admin dashboard entry point"""
    if (email != ADMIN_EMAIL or 
        not verify_password(password, pwd_context.hash(ADMIN_PASSWORD))):
        response.status_code = 401
        return HTMLResponse("""
            <h1>Access Denied</h1>
            <p>Invalid admin credentials</p>
        """)
    return RedirectResponse(url="/admin")

# ======================
# Startup Event
# ======================

@app.on_event("startup")
async def startup_event():
    """Verify we can connect to the backend on startup"""
    try:
        logger.info("Testing backend connection...")
        await token_manager.get_token()
        logger.info("Backend connection successful")
    except Exception as e:
        logger.error(f"Startup connection test failed: {str(e)}")
        raise

# ======================
# Main Application
# ======================

if __name__ == "__main__":
    import uvicorn
    uvicorn.run(
        app,
        host="0.0.0.0",
        port=7860,
        log_level="info",
        timeout_keep_alive=60
    )