"""
tests/unit/test_device_management_panel.py

Unit tests for DeviceManagementPanel QWidget.

TDD: Red phase — tests written before implementation.
Uses conftest.py Stubs for PyQt5 so no display hardware is needed.
"""
from unittest.mock import MagicMock, patch
import pytest

from core.device.device_manager import DeviceInfo, DeviceManager
from ui.components.device_management_panel import DeviceManagementPanel


# ---------------------------------------------------------------------------
# Helpers
# ---------------------------------------------------------------------------

def _make_device_manager(devices=None):
    """Return a DeviceManager-like mock with controllable scan_devices()."""
    mgr = MagicMock(spec=DeviceManager)
    if devices is None:
        devices = [
            DeviceInfo(
                device_id="usb-1",
                series="KL520",
                product_id=0x100,
                status="online",
                gops=2,
                assigned_stage=None,
                current_fps=15.0,
                utilization_pct=50.0,
            )
        ]
    mgr.scan_devices.return_value = devices
    mgr.get_device_statistics.return_value = {d.device_id: d for d in devices}
    mgr.get_load_balance_recommendation.return_value = {}
    return mgr


# ---------------------------------------------------------------------------
# Panel instantiation
# ---------------------------------------------------------------------------

class TestDeviceManagementPanelInit:
    def test_panel_creates_without_error(self):
        mgr = _make_device_manager()
        panel = DeviceManagementPanel(device_manager=mgr)
        assert panel is not None

    def test_panel_has_auto_balance_button(self):
        mgr = _make_device_manager()
        panel = DeviceManagementPanel(device_manager=mgr)
        # auto_balance_button must exist
        assert hasattr(panel, "auto_balance_button")

    def test_auto_balance_button_text(self):
        mgr = _make_device_manager()
        panel = DeviceManagementPanel(device_manager=mgr)
        assert panel.auto_balance_button._text == "Auto Balance"


# ---------------------------------------------------------------------------
# refresh()
# ---------------------------------------------------------------------------

class TestDeviceManagementPanelRefresh:
    def test_refresh_calls_scan_devices(self):
        mgr = _make_device_manager()
        panel = DeviceManagementPanel(device_manager=mgr)
        mgr.scan_devices.reset_mock()
        panel.refresh()
        mgr.scan_devices.assert_called_once()

    def test_refresh_updates_known_devices(self):
        mgr = _make_device_manager()
        panel = DeviceManagementPanel(device_manager=mgr)
        panel.refresh()
        # After refresh, panel should have device data accessible
        assert len(panel._devices) == 1
        assert panel._devices[0].device_id == "usb-1"

    def test_refresh_with_no_devices_sets_empty_list(self):
        mgr = _make_device_manager(devices=[])
        panel = DeviceManagementPanel(device_manager=mgr)
        panel.refresh()
        assert panel._devices == []


# ---------------------------------------------------------------------------
# set_auto_refresh()
# ---------------------------------------------------------------------------

class TestSetAutoRefresh:
    def test_set_auto_refresh_stores_interval(self):
        mgr = _make_device_manager()
        panel = DeviceManagementPanel(device_manager=mgr)
        panel.set_auto_refresh(interval_ms=3000)
        assert panel._auto_refresh_interval_ms == 3000

    def test_set_auto_refresh_default_interval(self):
        mgr = _make_device_manager()
        panel = DeviceManagementPanel(device_manager=mgr)
        panel.set_auto_refresh()
        assert panel._auto_refresh_interval_ms == 2000