"""
Tenant Middleware - ServiceManagerWeb

Middleware para manejo de multi-tenancy
"""

from fastapi import Request, HTTPException, status
from starlette.middleware.base import BaseHTTPMiddleware
from starlette.responses import Response
import structlog
from contextlib import asynccontextmanager
from sqlalchemy.sql import text

logger = structlog.get_logger(__name__)


# Correct the usage of async for by wrapping it in an async function
@asynccontextmanager
async def get_db_context():
    from app.core.database import get_db
    async for db in get_db():
        yield db


class TenantMiddleware(BaseHTTPMiddleware):
    """
    Middleware para extraer y validar información del tenant.
    
    Extrae el tenant_id del header X-Tenant-ID y lo almacena 
    en el estado de la request para uso posterior.
    """
    
    # Rutas que no requieren tenant
    EXCLUDED_PATHS = {
        "/health",
        "/",
        "/v1/auth/login",
        "/docs",
        "/openapi.json",
        "/redoc"
    }
    
    async def dispatch(self, request: Request, call_next) -> Response:
        """Process request and add tenant information."""
        
        # Skip tenant validation for excluded paths
        if request.url.path in self.EXCLUDED_PATHS or any(request.url.path.startswith(path) for path in self.EXCLUDED_PATHS):
            return await call_next(request)
        
        # Extract tenant from header
        tenant_id = request.headers.get("X-Tenant-ID")
        tenant_slug = request.headers.get("X-Tenant-Slug")
        
        # Revertir cambios para requerir encabezados de tenant
        if not tenant_id and not tenant_slug:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail="Tenant information required (X-Tenant-ID or X-Tenant-Slug header)"
            )
        
        # Store tenant info in request state
        request.state.tenant_id = tenant_id
        request.state.tenant_slug = tenant_slug
        
        # Validate tenant exists and is active
        if tenant_id or tenant_slug:
            from app.core.database import get_db
            from app.models.tenant import Tenant

            # Update the middleware to use the new context manager
            async with get_db_context() as db:
                tenant = await db.execute(
                    text(
                        """
                        SELECT * FROM tenants
                        WHERE id = :tenant_id OR slug = :tenant_slug AND status = 'active'
                        """
                    ),
                    {"tenant_id": tenant_id, "tenant_slug": tenant_slug}
                )
                tenant = tenant.fetchone()

                if not tenant:
                    raise HTTPException(
                        status_code=status.HTTP_404_NOT_FOUND,
                        detail="Tenant not found or inactive"
                    )

                # Store validated tenant info
                request.state.tenant = tenant

        else:
            raise HTTPException(
                status_code=status.HTTP_400_BAD_REQUEST,
                detail="Tenant information required (X-Tenant-ID or X-Tenant-Slug header)"
            )
        
        logger.debug(
            "Tenant middleware processed",
            tenant_id=tenant_id,
            tenant_slug=tenant_slug,
            path=request.url.path
        )
        
        return await call_next(request)