from __future__ import annotations

import os
import socket

import uvicorn

def find_free_port(host: str = "127.0.0.1") -> int:
    """Ask the OS for a currently available local TCP port."""
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as server_socket:
        server_socket.bind((host, 0))
        server_socket.listen(1)
        return int(server_socket.getsockname()[1])


def is_huggingface_space() -> bool:
    """Return True when running inside a Hugging Face Space runtime."""
    return bool(os.getenv("SPACE_ID") or os.getenv("SPACE_HOST"))


def bootstrap_runtime_port() -> None:
    """Seed PORT early so backend imports cannot override the Hugging Face runtime port."""
    if is_huggingface_space() and not os.getenv("PORT", "").strip():
        os.environ["PORT"] = "7860"


bootstrap_runtime_port()

from backend.main import app


def resolve_server_port() -> int:
    """Use the runtime PORT when defined, keep Hugging Face on 7860, else pick a free local port."""
    raw_port = os.getenv("PORT", "").strip()
    if raw_port:
        return int(raw_port)
    if is_huggingface_space():
        os.environ["PORT"] = "7860"
        return 7860

    port = find_free_port()
    os.environ["PORT"] = str(port)
    return port


if __name__ == "__main__":
    uvicorn.run(app, host="0.0.0.0", port=resolve_server_port())