from fastapi import FastAPI, HTTPException, Request, Response, Depends, status
from fastapi.middleware.cors import CORSMiddleware
from fastapi.security import OAuth2PasswordRequestForm
import uvicorn
from datetime import datetime, timedelta
import httpx
import os
import asyncio
import logging
from typing import Any
from contextlib import asynccontextmanager
from auth import (
    Token, UserLogin, UserInDB,
    verify_password, get_password_hash,
    create_access_token, get_current_user,
    ACCESS_TOKEN_EXPIRE_MINUTES
)

# Import event consumer
from event_consumer import AdvancedEventConsumer

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

# Global event consumer instance
event_consumer = None

@asynccontextmanager
async def lifespan(app: FastAPI):
    # Startup
    global event_consumer
    
    try:
        # Initialize and start event consumer
        event_consumer = AdvancedEventConsumer(
            topics=["user-events", "oauth-events"],
            group_id="console-consumer-group",
            redis_url=os.getenv("REDIS_URL", "redis://redis:6379"),
            bootstrap_servers=os.getenv("KAFKA_BOOTSTRAP_SERVERS", "kafka:9092"),
            enable_dlq=True,
            dlq_topic="dead-letter-queue"
        )
        
        await event_consumer.start()
        logger.info("Event consumer started successfully")
        
    except Exception as e:
        logger.error(f"Failed to start event consumer: {e}")
        # Continue without event consumer (degraded mode)
        event_consumer = None
    
    yield
    
    # Shutdown
    if event_consumer:
        await event_consumer.stop()
        logger.info("Event consumer stopped")

app = FastAPI(
    title="Console API Gateway",
    description="Central orchestrator for microservices",
    version="0.1.0",
    lifespan=lifespan
)

# Service URLs from environment
USERS_SERVICE_URL = os.getenv("USERS_SERVICE_URL", "http://users-backend:8000")
IMAGES_SERVICE_URL = os.getenv("IMAGES_SERVICE_URL", "http://images-backend:8000")

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

@app.get("/")
async def root():
    return {
        "message": "Console API Gateway",
        "status": "running",
        "timestamp": datetime.now().isoformat()
    }

@app.get("/health")
async def health_check():
    return {
        "status": "healthy",
        "service": "console",
        "timestamp": datetime.now().isoformat(),
        "event_consumer": "running" if event_consumer else "not running"
    }

# Event Management Endpoints
@app.get("/api/events/stats")
async def get_event_stats(current_user = Depends(get_current_user)):
    """Get event consumer statistics"""
    if not event_consumer:
        raise HTTPException(status_code=503, detail="Event consumer not available")
    
    return {
        "stats": event_consumer.stats,
        "timestamp": datetime.now().isoformat()
    }

@app.get("/api/events/dlq")
async def get_dlq_messages(
    limit: int = 10,
    current_user = Depends(get_current_user)
):
    """Get messages from Dead Letter Queue"""
    if not event_consumer:
        raise HTTPException(status_code=503, detail="Event consumer not available")
    
    messages = await event_consumer.get_dlq_messages(limit=limit)
    return {
        "messages": messages,
        "count": len(messages),
        "timestamp": datetime.now().isoformat()
    }

@app.post("/api/events/dlq/{event_id}/retry")
async def retry_dlq_message(
    event_id: str,
    current_user = Depends(get_current_user)
):
    """Manually retry a message from DLQ"""
    if not event_consumer:
        raise HTTPException(status_code=503, detail="Event consumer not available")
    
    success = await event_consumer.retry_dlq_message(event_id)
    if not success:
        raise HTTPException(status_code=404, detail="Event not found in DLQ")
    
    return {
        "status": "retry_initiated",
        "event_id": event_id,
        "timestamp": datetime.now().isoformat()
    }

@app.get("/api/events/schemas")
async def get_event_schemas():
    """Get all event schemas documentation"""
    from shared.kafka.schema_registry import SchemaRegistry
    
    schemas = SchemaRegistry.get_all_schemas()
    return {
        "schemas": schemas,
        "version": "1.0.0",
        "timestamp": datetime.now().isoformat()
    }

# Authentication endpoints
@app.post("/api/auth/login", response_model=Token)
async def login(form_data: OAuth2PasswordRequestForm = Depends()):
    """Login endpoint for authentication"""
    # For demo purposes - in production, check against database
    # This is temporary until we integrate with Users service
    demo_users = {
        "admin": {
            "username": "admin",
            "hashed_password": get_password_hash("admin123"),
            "email": "admin@site11.com",
            "full_name": "Administrator",
            "is_active": True
        },
        "user": {
            "username": "user",
            "hashed_password": get_password_hash("user123"),
            "email": "user@site11.com",
            "full_name": "Test User",
            "is_active": True
        }
    }
    
    user = demo_users.get(form_data.username)
    if not user or not verify_password(form_data.password, user["hashed_password"]):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Incorrect username or password",
            headers={"WWW-Authenticate": "Bearer"},
        )
    
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user["username"]}, expires_delta=access_token_expires
    )
    return {"access_token": access_token, "token_type": "bearer"}

@app.get("/api/auth/me")
async def get_me(current_user = Depends(get_current_user)):
    """Get current user information"""
    return {
        "username": current_user.username,
        "email": f"{current_user.username}@site11.com",
        "is_active": True
    }

@app.post("/api/auth/logout")
async def logout(current_user = Depends(get_current_user)):
    """Logout endpoint"""
    # In a real application, you might want to blacklist the token
    return {"message": "Successfully logged out"}

@app.get("/api/status")
async def system_status():
    services_status = {}
    
    # Check Users service
    try:
        async with httpx.AsyncClient() as client:
            response = await client.get(f"{USERS_SERVICE_URL}/health", timeout=2.0)
            services_status["users"] = "online" if response.status_code == 200 else "error"
    except:
        services_status["users"] = "offline"
    
    # Check Images service
    try:
        async with httpx.AsyncClient() as client:
            response = await client.get(f"{IMAGES_SERVICE_URL}/health", timeout=2.0)
            services_status["images"] = "online" if response.status_code == 200 else "error"
    except:
        services_status["images"] = "offline"
    
    # Other services (not yet implemented)
    services_status["oauth"] = "pending"
    services_status["applications"] = "pending"
    services_status["data"] = "pending"
    services_status["statistics"] = "pending"
    
    return {
        "console": "online",
        "services": services_status,
        "timestamp": datetime.now().isoformat()
    }

# Protected endpoint example
@app.get("/api/protected")
async def protected_route(current_user = Depends(get_current_user)):
    """Example of a protected route"""
    return {
        "message": "This is a protected route",
        "user": current_user.username
    }

# API Gateway - Route to Images service  
@app.api_route("/api/images/{path:path}", methods=["GET", "POST", "PUT", "DELETE", "PATCH"])
async def proxy_to_images(path: str, request: Request):
    """Proxy requests to Images service (public for image proxy)"""
    try:
        async with httpx.AsyncClient() as client:
            # Build the target URL
            url = f"{IMAGES_SERVICE_URL}/api/v1/{path}"
            
            # Get request body if exists
            body = None
            if request.method in ["POST", "PUT", "PATCH"]:
                body = await request.body()
            
            # Forward the request
            response = await client.request(
                method=request.method,
                url=url,
                headers={
                    key: value for key, value in request.headers.items()
                    if key.lower() not in ["host", "content-length"]
                },
                content=body,
                params=request.query_params
            )
            
            # Return the response
            return Response(
                content=response.content,
                status_code=response.status_code,
                headers=dict(response.headers)
            )
    except httpx.ConnectError:
        raise HTTPException(status_code=503, detail="Images service unavailable")
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

# API Gateway - Route to Users service
@app.api_route("/api/users/{path:path}", methods=["GET", "POST", "PUT", "DELETE", "PATCH"])
async def proxy_to_users(path: str, request: Request, current_user = Depends(get_current_user)):
    """Proxy requests to Users service (protected)"""
    try:
        async with httpx.AsyncClient() as client:
            # Build the target URL
            url = f"{USERS_SERVICE_URL}/{path}"
            
            # Get request body if exists
            body = None
            if request.method in ["POST", "PUT", "PATCH"]:
                body = await request.body()
            
            # Forward the request
            response = await client.request(
                method=request.method,
                url=url,
                headers={
                    key: value for key, value in request.headers.items()
                    if key.lower() not in ["host", "content-length"]
                },
                content=body,
                params=request.query_params
            )
            
            # Return the response
            return Response(
                content=response.content,
                status_code=response.status_code,
                headers=dict(response.headers)
            )
    except httpx.ConnectError:
        raise HTTPException(status_code=503, detail="Users service unavailable")
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

if __name__ == "__main__":
    uvicorn.run(
        "main:app",
        host="0.0.0.0",
        port=8000,
        reload=True
    )