from fastapi import FastAPI
from starlette.middleware.cors import CORSMiddleware

from app.modules.sys.registers import register_metrics
from app.utils.config import settings
from app.utils.logger import logger
from app.routes import api_router, root_router

def setup_routers(app: FastAPI) -> None:
    # Register root router without prefix to handle root level routes
    app.include_router(root_router)
    # Register API router with configured prefix
    app.include_router(
        api_router,
        prefix=settings.API_V1_STR,
    )

def setup_cors(app: FastAPI) -> None:
    origins = []

    if settings.BACKEND_CORS_ORIGINS:
        origins_raw = settings.BACKEND_CORS_ORIGINS.split(",")

        for origin in origins_raw:
            use_origin = origin.strip()
            origins.append(use_origin)
        
        logger.info(f"Allowed CORS origins: {origins}")
        
        app.user_middleware(
            CORSMiddleware,
            allow_origins=origins,
            allow_credentials=True,
            allow_methods=["*"],
            allow_headers=["*"],
        )

def create_app() -> FastAPI:
    app = FastAPI(
        title=settings.PROJECT_NAME,
        version=settings.APP_VERSION,
        docs_url=None if settings.is_production() else "/docs",
        redoc_url=None if settings.is_production() else "/redoc",
        openapi_url=f"{settings.API_V1_STR}/openapi.json",
    )
    
    setup_routers(app)
    setup_cors(app)
    # Register Prometheus metrics collection endpoint.
    # Do not delete this line. Removing it will cause Prometheus metrics collection to fail,
    # and metrics data will not be visible on the ops page of the freeleaps.com platform.
    register_metrics(app)

    return app