from fastapi import FastAPI, Request
from fastapi.exceptions import RequestValidationError
from fastapi.responses import JSONResponse
from starlette.exceptions import HTTPException as StarletteHTTPException

from app.config import get_settings
from app.routers import api_router


def create_app() -> FastAPI:
    settings = get_settings()
    app = FastAPI(
        title=settings.app_name,
        version="0.1.0",
        description="HTTP API for RF visibility, terrain profiles, coverage, and link budget.",
    )

    @app.get("/health", tags=["health"])
    def health() -> dict[str, str]:
        return {"status": "ok"}

    @app.exception_handler(StarletteHTTPException)
    def http_exception_handler(_request: Request, exc: StarletteHTTPException) -> JSONResponse:
        detail = exc.detail
        if not (isinstance(detail, dict) and "code" in detail and "detail" in detail):
            detail = {"code": "HTTP_ERROR", "detail": detail}
        return JSONResponse(status_code=exc.status_code, content={"detail": detail})

    @app.exception_handler(RequestValidationError)
    def validation_exception_handler(
        _request: Request,
        exc: RequestValidationError,
    ) -> JSONResponse:
        return JSONResponse(
            status_code=422,
            content={
                "detail": {
                    "code": "VALIDATION_ERROR",
                    "detail": "Request validation failed",
                    "errors": exc.errors(),
                }
            },
        )

    app.include_router(api_router, prefix=settings.api_v1_prefix)
    return app


app = create_app()