import sys
import time
import tkinter as tk
from unittest.mock import MagicMock

import pytest

from knoe.ui.screens.cfg import ConfigMixin


class _DummyNamespaceApp(ConfigMixin):
    """Minimal surface to exercise `ConfigMixin._propagate_namespace_change`."""

    def __init__(self, root: tk.Tk):
        self.root = root
        # Keep the test fast and deterministic.
        # Use a debounce long enough that the scheduled `after()` callback will not
        # run between the simulated keystrokes (which call `root.update()`).
        self._namespace_debounce_ms = 100

        self.db_namespace = tk.StringVar(master=root, value="old-db")
        self.service_namespace = tk.StringVar(master=root, value="knoe-system")

        # Independent namespaces that must not be rewritten.
        self.gitops_namespace = tk.StringVar(master=root, value="gitea")
        self.argocd_namespace = tk.StringVar(master=root, value="argocd")

        self._last_synced_ns = self.db_namespace.get()

        # Inputs dict is used by the sweep logic; include a service namespace entry
        # to ensure it is not touched.
        self.inputs = {
            "init_cluster.service_namespace": self.service_namespace.get(),
        }

        self.save_calls = 0
        self.updated_namespace = None

    def _update_env_namespace(self, namespace: str):
        self.updated_namespace = namespace

    def _save_prole_cfg(self):
        self.save_calls += 1


def _drain_tk_events(root: tk.Tk, timeout_s: float = 0.2) -> None:
    end = time.monotonic() + timeout_s
    while time.monotonic() < end:
        root.update()
        time.sleep(0.001)


def test_namespace_typing_does_not_corrupt_service_namespace():
    # Some test modules replace tkinter with MagicMocks at import-time.
    if isinstance(sys.modules.get("tkinter"), MagicMock):
        pytest.skip("tkinter is mocked in this test run")

    root = tk.Tk()
    root.withdraw()
    try:
        app = _DummyNamespaceApp(root)
        app.db_namespace.trace_add("write", app._propagate_namespace_change)

        # Simulate typing a new namespace in the UI entry box.
        for partial in [
            "k",
            "kn",
            "kno",
            "knoe",
            "knoe-",
            "knoe-d",
            "knoe-db",
        ]:
            app.db_namespace.set(partial)
            root.update()

        _drain_tk_events(root, timeout_s=0.3)

        # Regression: SERVICE_NAMESPACE must remain unchanged.
        assert app.service_namespace.get() == "knoe-system"

        # Debounced propagation should result in a single save.
        assert app.save_calls == 1
    finally:
        try:
            root.destroy()
        except Exception:
            pass