import logging
from collections.abc import AsyncGenerator
from contextlib import asynccontextmanager

from fastapi import FastAPI

from src.gateway.config import get_gateway_config
from src.gateway.routers import artifacts, models

# Configure logging
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s",
    datefmt="%Y-%m-%d %H:%M:%S",
)

logger = logging.getLogger(__name__)


@asynccontextmanager
async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
    """Application lifespan handler."""
    config = get_gateway_config()
    logger.info(f"Starting API Gateway on {config.host}:{config.port}")

    # Initialize MCP tools at startup
    try:
        from src.mcp import initialize_mcp_tools

        await initialize_mcp_tools()
    except Exception as e:
        logger.warning(f"Failed to initialize MCP tools: {e}")

    yield
    logger.info("Shutting down API Gateway")


def create_app() -> FastAPI:
    """Create and configure the FastAPI application.

    Returns:
        Configured FastAPI application instance.
    """

    app = FastAPI(
        title="DeerFlow API Gateway",
        description="API Gateway for DeerFlow - provides custom endpoints (models, artifacts). LangGraph requests are handled by nginx.",
        version="0.1.0",
        lifespan=lifespan,
    )

    # CORS is handled by nginx - no need for FastAPI middleware

    # Include routers
    # Models API is mounted at /api/models
    app.include_router(models.router)

    # Artifacts API is mounted at /api/threads/{thread_id}/artifacts
    app.include_router(artifacts.router)

    @app.get("/health")
    async def health_check() -> dict:
        """Health check endpoint."""
        return {"status": "healthy", "service": "deer-flow-gateway"}

    return app


# Create app instance for uvicorn
app = create_app()