"""Dependency injection for FastAPI.

Provides singleton-like access to SSH and Jellyfin clients via FastAPI's
dependency system. Uses lru_cache so connections are reused across requests.
"""

from __future__ import annotations

from functools import lru_cache

from clients.jellyfin import JellyfinClient
from clients.ssh import RemoteSSHClient
from config import get_settings


@lru_cache
def get_jellyfin_client() -> JellyfinClient:
    """Return a cached Jellyfin client."""
    settings = get_settings()
    return JellyfinClient(settings.jellyfin.url, settings.jellyfin.api_key)


@lru_cache
def get_ssh_client() -> RemoteSSHClient:
    """Return a cached SSH client (connects on first use)."""
    settings = get_settings()
    client = RemoteSSHClient(
        host=settings.ssh.host,
        username=settings.ssh.username,
        port=settings.ssh.port,
        key_filename=settings.ssh.key_filename or None,
        password=settings.ssh.password or None,
    )
    client.connect()
    return client


def get_user_id() -> str:
    """Return the configured Jellyfin user ID, or discover the first available user."""
    settings = get_settings()
    if settings.jellyfin.user_id:
        return settings.jellyfin.user_id
    client = get_jellyfin_client()
    users = client.users()
    if not users:
        raise RuntimeError("No Jellyfin users found and JELLYFIN_USER_ID not set")
    return users[0]["Id"]