web/app.py

"""
Eurus Web Application
======================
FastAPI application factory and main entry point.
"""

import os
import sys
import logging
from pathlib import Path
from contextlib import asynccontextmanager

from dotenv import load_dotenv
load_dotenv()  # Load .env EARLY so /api/keys-status sees the keys

from fastapi import FastAPI
from fastapi.staticfiles import StaticFiles
from fastapi.middleware.cors import CORSMiddleware

# Add parent and src directory to path for eurus package
PROJECT_ROOT = Path(__file__).parent.parent
sys.path.insert(0, str(PROJECT_ROOT))
sys.path.insert(0, str(PROJECT_ROOT / "src"))

# IMPORT FROM EURUS PACKAGE
from eurus.config import CONFIG, PLOTS_DIR

# Configure logging
logging.basicConfig(
    level=logging.INFO,
    format='%(asctime)s | %(levelname)s | %(name)s | %(message)s',
    datefmt='%H:%M:%S'
)
logger = logging.getLogger(__name__)

# Paths
WEB_DIR = Path(__file__).parent
TEMPLATES_DIR = WEB_DIR / "templates"
STATIC_DIR = WEB_DIR / "static"


@asynccontextmanager
async def lifespan(app: FastAPI):
    """Application lifespan handler for startup/shutdown."""
    # Startup
    logger.info("Starting Eurus Web Interface...")
    logger.info(f"Templates: {TEMPLATES_DIR}")
    logger.info(f"Static files: {STATIC_DIR}")
    logger.info(f"Plots directory: {PLOTS_DIR}")

    # Sessions are created per-connection in websocket.py
    logger.info("Ready to accept connections")

    yield

    # Shutdown
    logger.info("Shutting down Eurus Web Interface...")
    from web.agent_wrapper import shutdown_agent_session
    shutdown_agent_session()


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

    app = FastAPI(
        title="Eurus Climate Agent",
        description="Interactive web interface for ERA5 climate data analysis",
        version="1.0.0",
        lifespan=lifespan,
    )

    # CORS — allow React dev server
    app.add_middleware(
        CORSMiddleware,
        allow_origins=["*"],
        allow_credentials=False,
        allow_methods=["*"],
        allow_headers=["*"],
    )

    # Mount static files
    app.mount("/static", StaticFiles(directory=str(STATIC_DIR)), name="static")

    # Mount plots directory for serving generated plots
    PLOTS_DIR.mkdir(parents=True, exist_ok=True)
    app.mount("/plots", StaticFiles(directory=str(PLOTS_DIR)), name="plots")

    # Include routers
    from web.routes import api_router, websocket_router, pages_router

    app.include_router(api_router, prefix="/api", tags=["api"])
    app.include_router(websocket_router, tags=["websocket"])
    app.include_router(pages_router, tags=["pages"])

    return app


# Create the app instance
app = create_app()


def main():
    """Main entry point for running the web server."""
    import uvicorn

    host = getattr(CONFIG, 'web_host', '127.0.0.1')
    port = getattr(CONFIG, 'web_port', 8000)

    print(f"""
╔═══════════════════════════════════════════════════════════════════════════╗
║                                                                           ║
║    ███████╗██╗   ██╗██████╗ ██╗   ██╗███████╗                              ║
║    ██╔════╝██║   ██║██╔══██╗██║   ██║██╔════╝                              ║
║    █████╗  ██║   ██║██████╔╝██║   ██║███████╗                              ║
║    ██╔══╝  ██║   ██║██╔══██╗██║   ██║╚════██║                              ║
║    ███████╗╚██████╔╝██║  ██║╚██████╔╝███████║                              ║
║    ╚══════╝ ╚═════╝ ╚═╝  ╚═╝ ╚═════╝ ╚══════╝                              ║
║                                                                           ║
║                      Eurus Web Interface v1.0                            ║
║                 ─────────────────────────────────────                     ║
║                                                                           ║
║   Starting server at: http://{host}:{port}                              ║
║                                                                           ║
╚═══════════════════════════════════════════════════════════════════════════╝
""")

    uvicorn.run(
        "web.app:app",
        host=host,
        port=port,
        reload=False,
        log_level="info",
    )


if __name__ == "__main__":
    main()