"""
Middleware personalizado para Anexo76
- Validación de licencias
- Gestión de multi-tenancy
- Logging de requests
"""
from fastapi import Request, HTTPException
from starlette.middleware.base import BaseHTTPMiddleware
from typing import Callable
import logging
import time
from datetime import datetime
from sqlalchemy.orm import Session
from .database import CoreSessionLocal
from .security import verify_token, get_tenant_from_token
from .config import settings

logger = logging.getLogger(__name__)


class TenantMiddleware(BaseHTTPMiddleware):
    """
    Middleware para identificar y validar el tenant en cada request
    """
    
    async def dispatch(self, request: Request, call_next: Callable):
        # Rutas públicas que no requieren tenant
        # Permitir acceso sin autenticación a rutas de documentación y salud
        doc_prefixes = [
            "/api/redoc",
            "/api/openapi.json"
        ]
        public_prefixes = [
            "/api/v1/auth",
            "/api/v1/status",
            "/api/health",
            "/api/"
        ]

        path = request.url.path
        # Permitir cualquier subruta de docs/redoc/openapi.json (por ejemplo, /api/docs, /api/docs/, /api/docs/oauth2-redirect)
        if any(path == prefix or path.startswith(prefix + "/") for prefix in doc_prefixes):
            return await call_next(request)
        # Permitir rutas públicas exactas o con prefijo
        if any(path == prefix or (prefix != "/" and path.startswith(prefix)) for prefix in public_prefixes):
            return await call_next(request)
        
        # Extraer token y obtener tenant
        auth_header = request.headers.get("Authorization")
        
        if not auth_header or not auth_header.startswith("Bearer "):
            raise HTTPException(status_code=401, detail="Missing or invalid authorization header")
        
        token = auth_header.split(" ")[1]
        
        try:
            user_info = verify_token(token)
            tenant_id = get_tenant_from_token(user_info)
            
            # ⚠️ NOTA: tenant_id puede ser None para usuarios SSO que aún no tienen tenant asignado
            # En ese caso, el endpoint específico deberá manejarlo
            if not tenant_id:
                logger.warning(f"⚠️ Token sin tenant_id para usuario: {user_info.get('sub', 'unknown')}")
                # No lanzamos error aquí, dejamos que el endpoint decida qué hacer
            
            # Agregar tenant_id al state del request (puede ser None)
            request.state.tenant_id = tenant_id
            request.state.user_info = user_info
            
        except HTTPException:
            # Re-lanzar HTTPException directamente
            raise
        except Exception as e:
            logger.error(f"❌ Tenant validation error: {str(e)}")
            raise HTTPException(status_code=401, detail="Invalid authentication")
        
        response = await call_next(request)
        return response


class LicenseValidationMiddleware(BaseHTTPMiddleware):
    """
    Middleware para validar la licencia del tenant antes de procesar requests
    """
    
    async def dispatch(self, request: Request, call_next: Callable):
        if not settings.LICENSE_CHECK_ENABLED:
            return await call_next(request)
        
        # Rutas que no requieren validación de licencia
        exempt_paths = [
            "/api/docs", 
            "/api/redoc",
            "/openapi.json", 
            "/api/v1/auth", 
            "/api/v1/auth", 
            "/api/v1/status",
            "/api/v1/status",
            "/api/health",
            "/api/"
        ]
        
        # Verificar si la ruta está exenta (comparación exacta o prefijo)
        is_exempt = False
        for path in exempt_paths:
            if request.url.path == path or (path != "/" and request.url.path.startswith(path)):
                is_exempt = True
                break
        
        if is_exempt:
            return await call_next(request)
        
        # Obtener tenant_id del request state (debe ser seteado por TenantMiddleware)
        tenant_id = getattr(request.state, "tenant_id", None)
        
        if not tenant_id:
            return await call_next(request)  # Dejamos que TenantMiddleware maneje esto
        
        # Validar licencia
        db = CoreSessionLocal()
        try:
            # Importar aquí para evitar imports circulares
            from api.v1.modules.a76.licenses.service import LicenseService
            
            license_service = LicenseService(db)
            license_info = license_service.validate_license(tenant_id)
            
            if not license_info["is_valid"]:
                raise HTTPException(
                    status_code=402,
                    detail=f"License validation failed: {license_info['reason']}"
                )
            
            # Agregar info de licencia al request state
            request.state.license_info = license_info
            
        except HTTPException:
            raise
        except Exception as e:
            logger.error(f"License validation error: {str(e)}")
            raise HTTPException(status_code=500, detail="License validation error")
        finally:
            db.close()
        
        response = await call_next(request)
        return response


class RequestLoggingMiddleware(BaseHTTPMiddleware):
    """
    Middleware para logging de requests
    """
    
    async def dispatch(self, request: Request, call_next: Callable):
        start_time = time.time()
        
        # Log request
        logger.info(f"Request: {request.method} {request.url.path}")
        
        response = await call_next(request)
        
        # Log response
        process_time = time.time() - start_time
        logger.info(
            f"Response: {request.method} {request.url.path} "
            f"Status: {response.status_code} "
            f"Duration: {process_time:.3f}s"
        )
        
        # Agregar header con tiempo de procesamiento
        response.headers["X-Process-Time"] = str(process_time)
        
        return response