"""
PerformanceDashboard 的單元測試。

測試策略：
- PyQt5 在 CI 環境中不可用，透過 conftest.py 的 Mock 注入繞過 import。
- 測試驗證 PerformanceDashboard 的行為邏輯：
  update_stats 是否更新顯示值、reset 是否歸零、set_display_window 是否儲存設定。
- 使用 MagicMock 取代真實 QLabel，透過記錄 setText 呼叫來驗證。
"""
import sys
import pytest
from unittest.mock import MagicMock, patch, call


# ---------------------------------------------------------------------------
# 測試：PerformanceDashboard 可以建立
# ---------------------------------------------------------------------------

class TestPerformanceDashboardInit:
    def should_be_importable(self):
        """PerformanceDashboard 模組應可匯入（即使 PyQt5 被 Mock）。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        assert PerformanceDashboard is not None

    def should_instantiate_without_error(self):
        """PerformanceDashboard() 應可無錯誤地建立實例。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        dashboard = PerformanceDashboard()
        assert dashboard is not None


# ---------------------------------------------------------------------------
# 測試：update_stats 更新顯示值
# ---------------------------------------------------------------------------

class TestUpdateStats:
    def should_store_fps_after_update(self):
        """update_stats 後，current_fps 屬性應更新為傳入的值。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        dashboard = PerformanceDashboard()
        dashboard.update_stats({"fps": 30.5, "avg_latency_ms": 10.0, "p95_latency_ms": 15.0})
        assert dashboard.current_fps == pytest.approx(30.5)

    def should_store_avg_latency_after_update(self):
        """update_stats 後，current_avg_latency_ms 屬性應更新。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        dashboard = PerformanceDashboard()
        dashboard.update_stats({"fps": 30.0, "avg_latency_ms": 12.3, "p95_latency_ms": 20.0})
        assert dashboard.current_avg_latency_ms == pytest.approx(12.3)

    def should_store_p95_latency_after_update(self):
        """update_stats 後，current_p95_latency_ms 屬性應更新。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        dashboard = PerformanceDashboard()
        dashboard.update_stats({"fps": 30.0, "avg_latency_ms": 12.0, "p95_latency_ms": 25.7})
        assert dashboard.current_p95_latency_ms == pytest.approx(25.7)

    def should_call_fps_label_setText(self):
        """update_stats 應對 fps_label 呼叫 setText，包含 fps 數值。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        dashboard = PerformanceDashboard()
        dashboard.fps_label.setText.reset_mock()
        dashboard.update_stats({"fps": 45.0, "avg_latency_ms": 10.0, "p95_latency_ms": 15.0})
        dashboard.fps_label.setText.assert_called_once()
        call_arg = dashboard.fps_label.setText.call_args[0][0]
        assert "45" in call_arg

    def should_call_avg_latency_label_setText(self):
        """update_stats 應對 avg_latency_label 呼叫 setText，包含延遲數值。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        dashboard = PerformanceDashboard()
        dashboard.avg_latency_label.setText.reset_mock()
        dashboard.update_stats({"fps": 30.0, "avg_latency_ms": 8.5, "p95_latency_ms": 12.0})
        dashboard.avg_latency_label.setText.assert_called_once()
        call_arg = dashboard.avg_latency_label.setText.call_args[0][0]
        assert "8.5" in call_arg or "8" in call_arg

    def should_call_p95_latency_label_setText(self):
        """update_stats 應對 p95_latency_label 呼叫 setText，包含 p95 數值。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        dashboard = PerformanceDashboard()
        dashboard.p95_latency_label.setText.reset_mock()
        dashboard.update_stats({"fps": 30.0, "avg_latency_ms": 8.0, "p95_latency_ms": 19.2})
        dashboard.p95_latency_label.setText.assert_called_once()
        call_arg = dashboard.p95_latency_label.setText.call_args[0][0]
        assert "19" in call_arg


# ---------------------------------------------------------------------------
# 測試：reset 歸零
# ---------------------------------------------------------------------------

class TestReset:
    def should_reset_fps_to_zero(self):
        """reset() 後 current_fps 應歸零。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        dashboard = PerformanceDashboard()
        dashboard.update_stats({"fps": 55.0, "avg_latency_ms": 5.0, "p95_latency_ms": 8.0})
        dashboard.reset()
        assert dashboard.current_fps == 0.0

    def should_reset_avg_latency_to_zero(self):
        """reset() 後 current_avg_latency_ms 應歸零。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        dashboard = PerformanceDashboard()
        dashboard.update_stats({"fps": 30.0, "avg_latency_ms": 12.0, "p95_latency_ms": 18.0})
        dashboard.reset()
        assert dashboard.current_avg_latency_ms == 0.0

    def should_reset_p95_latency_to_zero(self):
        """reset() 後 current_p95_latency_ms 應歸零。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        dashboard = PerformanceDashboard()
        dashboard.update_stats({"fps": 30.0, "avg_latency_ms": 12.0, "p95_latency_ms": 18.0})
        dashboard.reset()
        assert dashboard.current_p95_latency_ms == 0.0

    def should_call_label_setText_with_zero_on_reset(self):
        """reset() 應對 fps_label 呼叫 setText，更新為 0 值。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        dashboard = PerformanceDashboard()
        dashboard.fps_label.setText.reset_mock()
        dashboard.reset()
        dashboard.fps_label.setText.assert_called_once()


# ---------------------------------------------------------------------------
# 測試：set_display_window 儲存設定
# ---------------------------------------------------------------------------

class TestSetDisplayWindow:
    def should_store_display_window_seconds(self):
        """set_display_window(120) 後，display_window_seconds 應為 120。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        dashboard = PerformanceDashboard()
        dashboard.set_display_window(120)
        assert dashboard.display_window_seconds == 120

    def should_default_to_60_seconds(self):
        """不傳參數時 display_window_seconds 預設應為 60。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        dashboard = PerformanceDashboard()
        dashboard.set_display_window()
        assert dashboard.display_window_seconds == 60

    def should_update_display_window_on_second_call(self):
        """連續呼叫 set_display_window 應覆蓋舊值。"""
        from ui.components.performance_dashboard import PerformanceDashboard
        dashboard = PerformanceDashboard()
        dashboard.set_display_window(30)
        dashboard.set_display_window(90)
        assert dashboard.display_window_seconds == 90