"""
ui/dialogs/benchmark_dialog.py

BenchmarkDialog — 一鍵啟動 Benchmark 的 QDialog。

顯示三階段進度條（熱機/循序/平行）、即時 FPS、完成後加速倍數大字體
以及循序 vs 平行的 FPS 與延遲對比表。

Benchmark 執行透過 QThread 進行，避免 UI 凍結。
若 pipeline_config 為空，顯示提示訊息並禁用開始按鈕。
"""
from typing import Any, List, Optional

from PyQt5.QtCore import QThread, pyqtSignal
from PyQt5.QtWidgets import (
    QDialog,
    QHBoxLayout,
    QLabel,
    QProgressBar,
    QPushButton,
    QTableWidget,
    QTableWidgetItem,
    QVBoxLayout,
    QWidget,
)


class _BenchmarkWorker(QThread):
    """在背景執行緒執行 benchmark，避免 UI 凍結。"""

    progress_updated = pyqtSignal(str, int)
    result_ready = pyqtSignal(object, object, float)
    error_occurred = pyqtSignal(str)

    def __init__(self, benchmarker: Any) -> None:
        super().__init__()
        self._benchmarker = benchmarker

    def run(self) -> None:
        try:
            seq_result, par_result, speedup = self._benchmarker.run_full_benchmark(
                progress_callback=self._on_progress
            )
            self.result_ready.emit(seq_result, par_result, speedup)
        except Exception as exc:
            self.error_occurred.emit(str(exc))

    def _on_progress(self, phase: str, value: int) -> None:
        self.progress_updated.emit(phase, value)


class BenchmarkDialog(QDialog):
    """Benchmark 觸發與結果顯示對話框。

    Args:
        parent: 父視窗。
        pipeline_config: 目前的 pipeline Stage 設定列表。若為空，禁用開始按鈕。
    """

    def __init__(
        self,
        parent: Optional[QWidget],
        pipeline_config: List[Any],
    ) -> None:
        super().__init__(parent)

        self._pipeline_config = pipeline_config
        self.seq_result: Optional[Any] = None
        self.par_result: Optional[Any] = None
        self.current_phase: str = ""
        self._worker: Optional[_BenchmarkWorker] = None

        self.setWindowTitle("Performance Benchmark")

        # UI 元件
        self.info_label = QLabel("")
        self.progress_bar = QProgressBar()
        self.progress_bar.setMinimum(0)
        self.progress_bar.setMaximum(100)

        self.fps_label = QLabel("FPS: —")
        self.phase_label = QLabel("")
        self.speedup_label = QLabel("")

        self.result_table = QTableWidget(2, 3)
        self.result_table.setHorizontalHeaderLabels(["模式", "FPS", "Avg Latency (ms)"])

        self.start_button = QPushButton("開始 Benchmark")
        self.close_button = QPushButton("關閉")

        self._setup_ui()
        self._apply_initial_state()

    def _setup_ui(self) -> None:
        layout = QVBoxLayout()

        layout.addWidget(self.info_label)

        progress_row = QHBoxLayout()
        progress_row.addWidget(self.progress_bar)
        progress_row.addWidget(self.phase_label)
        layout.addLayout(progress_row)

        fps_row = QHBoxLayout()
        fps_row.addWidget(QLabel("即時 FPS："))
        fps_row.addWidget(self.fps_label)
        layout.addLayout(fps_row)

        layout.addWidget(self.speedup_label)
        layout.addWidget(self.result_table)

        btn_row = QHBoxLayout()
        btn_row.addWidget(self.start_button)
        btn_row.addWidget(self.close_button)
        layout.addLayout(btn_row)

        self.setLayout(layout)

    def _apply_initial_state(self) -> None:
        if not self._pipeline_config:
            self.info_label.setText("尚未設定 Pipeline，請先在 Pipeline Editor 中建立 Stage。")
            self.start_button.setEnabled(False)
        else:
            self.info_label.setText(f"已載入 {len(self._pipeline_config)} 個 Stage，可開始 Benchmark。")
            self.start_button.setEnabled(True)

    def start_benchmark(self, benchmarker: Any) -> None:
        """在 QThread 中執行 benchmark，避免 UI 凍結。

        Args:
            benchmarker: PerformanceBenchmarker 實例。
        """
        self._worker = _BenchmarkWorker(benchmarker)
        self._worker.progress_updated.connect(self.update_progress)
        self._worker.result_ready.connect(self._on_result_ready)
        self._worker.error_occurred.connect(self._on_error)
        self._worker.finished.connect(self._worker.deleteLater)
        self.start_button.setEnabled(False)
        self._worker.start()

    def update_progress(self, phase: str, value: int) -> None:
        """更新進度條與當前階段。

        Args:
            phase: 當前階段名稱（"warmup" / "sequential" / "parallel"）。
            value: 進度值（0–100）。
        """
        _PHASE_LABELS = {
            "warmup": "熱機中...",
            "sequential": "循序測試...",
            "parallel": "平行測試...",
        }
        self.current_phase = phase
        self.progress_bar.setValue(value)
        self.phase_label.setText(_PHASE_LABELS.get(phase, phase))

    def show_result(
        self,
        seq_result: Any,
        par_result: Any,
        speedup: float,
    ) -> None:
        """顯示 benchmark 結果。

        Args:
            seq_result: 循序模式的 BenchmarkResult。
            par_result: 平行模式的 BenchmarkResult。
            speedup: 加速倍數（par.fps / seq.fps）。
        """
        self.seq_result = seq_result
        self.par_result = par_result

        font = self.speedup_label.font()
        font.setPointSize(20)
        font.setBold(True)
        self.speedup_label.setFont(font)
        self.speedup_label.setText(f"{speedup:.1f}x FASTER")
        self._populate_table(seq_result, par_result)

    def _populate_table(self, seq_result: Any, par_result: Any) -> None:
        rows = [
            ("循序", seq_result),
            ("平行", par_result),
        ]
        for row_idx, (mode_label, result) in enumerate(rows):
            self.result_table.setItem(row_idx, 0, QTableWidgetItem(mode_label))
            try:
                self.result_table.setItem(row_idx, 1, QTableWidgetItem(f"{result.fps:.1f}"))
                self.result_table.setItem(
                    row_idx, 2, QTableWidgetItem(f"{result.avg_latency_ms:.1f}")
                )
            except (AttributeError, TypeError):
                pass

    def _on_result_ready(
        self,
        seq_result: Any,
        par_result: Any,
        speedup: float,
    ) -> None:
        self.show_result(seq_result, par_result, speedup)

    def _on_error(self, message: str) -> None:
        self.info_label.setText(f"Benchmark 失敗：{message}")
        self.progress_bar.setValue(0)
        self._worker = None
        self.start_button.setEnabled(True)