"""
tests/unit/test_export_report_dialog.py — ExportReportDialog 單元測試。

在無 PyQt5 環境下，使用 conftest.py 中的 Stub 進行測試。
"""
from unittest.mock import MagicMock, patch
import pytest

from core.performance.benchmarker import BenchmarkResult
from core.performance.report_exporter import DeviceSummary, ReportData
from ui.dialogs.export_report_dialog import ExportReportDialog


# ---------------------------------------------------------------------------
# Fixtures
# ---------------------------------------------------------------------------

def _make_benchmark_result(mode: str = "sequential", fps: float = 14.2) -> BenchmarkResult:
    return BenchmarkResult(
        mode=mode,
        fps=fps,
        avg_latency_ms=70.4,
        p95_latency_ms=95.0,
        total_frames=426,
        timestamp=1743856222.0,
        device_config={"KL720": 1},
        id=f"benchmark_20260405_143022_{mode}",
    )


def _make_dialog(
    benchmarker=None,
    history=None,
    device_manager=None,
    dashboard=None,
) -> ExportReportDialog:
    """建立 ExportReportDialog，所有依賴預設為 MagicMock。"""
    if benchmarker is None:
        benchmarker = MagicMock()
        benchmarker.history = []
    if history is None:
        history = MagicMock()
        history.get_history.return_value = []
    if device_manager is None:
        device_manager = MagicMock()
        device_manager.scan_devices.return_value = []
    if dashboard is None:
        dashboard = MagicMock()

    return ExportReportDialog(
        parent=None,
        benchmarker=benchmarker,
        history=history,
        device_manager=device_manager,
        dashboard=dashboard,
    )


# ---------------------------------------------------------------------------
# 基本建立
# ---------------------------------------------------------------------------

class TestExportReportDialogCreation:
    def test_dialog_can_be_created(self):
        """ExportReportDialog 應可正常建立"""
        dialog = _make_dialog()
        assert dialog is not None

    def test_dialog_is_instance_of_qdialog(self):
        """ExportReportDialog 應繼承自 QDialog（或其 Stub）"""
        from PyQt5.QtWidgets import QDialog
        dialog = _make_dialog()
        assert isinstance(dialog, QDialog)

    def test_dialog_default_format_is_pdf(self):
        """格式選擇預設應為 PDF"""
        dialog = _make_dialog()
        assert dialog._selected_format == "pdf"


# ---------------------------------------------------------------------------
# _collect_report_data
# ---------------------------------------------------------------------------

class TestCollectReportData:
    def test_returns_report_data_instance(self):
        """_collect_report_data() 應回傳 ReportData 型別"""
        dialog = _make_dialog()
        result = dialog._collect_report_data()
        assert isinstance(result, ReportData)

    def test_uses_history_records(self):
        """_collect_report_data() 應使用 history.get_history() 的結果"""
        history = MagicMock()
        records = [_make_benchmark_result("parallel")]
        history.get_history.return_value = records

        dialog = _make_dialog(history=history)
        result = dialog._collect_report_data()

        history.get_history.assert_called_once()
        assert result.history_records == records

    def test_uses_device_manager_scan(self):
        """_collect_report_data() 應呼叫 device_manager.scan_devices()"""
        device_manager = MagicMock()
        device_manager.scan_devices.return_value = []

        dialog = _make_dialog(device_manager=device_manager)
        dialog._collect_report_data()

        device_manager.scan_devices.assert_called_once()

    def test_handles_history_failure_gracefully(self):
        """history.get_history() 拋出例外時，應回傳空的 history_records"""
        history = MagicMock()
        history.get_history.side_effect = Exception("history error")

        dialog = _make_dialog(history=history)
        result = dialog._collect_report_data()

        assert result.history_records == []

    def test_handles_device_manager_failure_gracefully(self):
        """device_manager.scan_devices() 拋出例外時，devices 應為空列表"""
        device_manager = MagicMock()
        device_manager.scan_devices.side_effect = Exception("device error")

        dialog = _make_dialog(device_manager=device_manager)
        result = dialog._collect_report_data()

        assert result.devices == []

    def test_uses_latest_benchmark_from_history_as_parallel_result(self):
        """benchmarker.history 有記錄時，應使用最新一筆作為 parallel_result"""
        benchmarker = MagicMock()
        latest = _make_benchmark_result("parallel", fps=45.6)
        benchmarker.history = [_make_benchmark_result("sequential"), latest]

        dialog = _make_dialog(benchmarker=benchmarker)
        result = dialog._collect_report_data()

        # parallel_result 應為最新一筆（index -1）
        assert result.parallel_result == latest

    def test_parallel_result_is_none_when_history_empty(self):
        """benchmarker.history 為空時，parallel_result 應為 None"""
        benchmarker = MagicMock()
        benchmarker.history = []

        dialog = _make_dialog(benchmarker=benchmarker)
        result = dialog._collect_report_data()

        assert result.parallel_result is None

    def test_chart_image_bytes_is_none(self):
        """chart_image_bytes 應為 None（截圖整合留未來）"""
        dialog = _make_dialog()
        result = dialog._collect_report_data()
        assert result.chart_image_bytes is None


# ---------------------------------------------------------------------------
# 格式選擇
# ---------------------------------------------------------------------------

class TestFormatSelection:
    def test_set_format_to_csv(self):
        """可將格式設為 CSV"""
        dialog = _make_dialog()
        dialog._set_format("csv")
        assert dialog._selected_format == "csv"

    def test_set_format_to_pdf(self):
        """可將格式設回 PDF"""
        dialog = _make_dialog()
        dialog._set_format("csv")
        dialog._set_format("pdf")
        assert dialog._selected_format == "pdf"