# -*- coding: utf-8 -*-
"""
ArrowComboBox - 带动态箭头的下拉框组件
展开时箭头向上，收起时箭头向下
"""
import os
import re
import tempfile

from PySide6.QtWidgets import QComboBox
from PySide6.QtGui import QPixmap, QPainter, QTransform, QPolygonF
from PySide6.QtCore import Qt, Signal, QTimer, QPointF

from utils.image_paths import ImagePaths


class ArrowComboBox(QComboBox):
    """带动态箭头的下拉框，展开时箭头向上，收起时箭头向下
    
    Signals:
        popupShown: 下拉列表展开时发出
        popupHidden: 下拉列表收起时发出
        arrowDirectionChanged: 箭头方向改变时发出 (is_up: bool)
    """
    
    # 信号定义
    popupShown = Signal()              # 下拉列表展开
    popupHidden = Signal()             # 下拉列表收起
    arrowDirectionChanged = Signal(bool)  # 箭头方向改变 (True=向上, False=向下)
    
    # 类缓存
    _arrow_down_path = None  # 向下箭头图片路径
    _arrow_up_path = None    # 向上箭头图片路径
    _initialized = False     # 是否已初始化
    
    @classmethod
    def init_arrow_resources(cls, arrow_image_path: str = None, arrow_size: tuple = (14, 8)):
        """初始化箭头资源（类方法，只需调用一次）
        
        Args:
            arrow_image_path: 自定义箭头图片路径，默认使用 ImagePaths.SYSTEM_DIAGNOSTICS_DROPDOWN_ARROW
            arrow_size: 箭头尺寸 (width, height)，默认 (14, 8)
        """
        if cls._initialized:
            return
        
        arrow_width, arrow_height = arrow_size
        
        # 加载原始箭头图片
        if arrow_image_path is None:
            arrow_image_path = ImagePaths.SYSTEM_DIAGNOSTICS_DROPDOWN_ARROW
        
        original = QPixmap(arrow_image_path)
        if original.isNull():
            # 如果加载失败，创建默认箭头
            original = QPixmap(arrow_width, arrow_height)
            original.fill(Qt.transparent)
            painter = QPainter(original)
            painter.setRenderHint(QPainter.Antialiasing)
            painter.setPen(Qt.NoPen)
            painter.setBrush(Qt.white)
            points = [
                QPointF(1, 1), 
                QPointF(arrow_width - 1, 1), 
                QPointF(arrow_width / 2, arrow_height - 1)
            ]
            painter.drawPolygon(QPolygonF(points))
            painter.end()
        
        down_pixmap = original.scaled(arrow_width, arrow_height, Qt.KeepAspectRatio, Qt.SmoothTransformation)
        
        # 垂直翻转得到向上箭头
        transform = QTransform()
        transform.scale(1, -1)
        up_pixmap = down_pixmap.transformed(transform)
        
        # 保存到临时文件
        temp_dir = tempfile.gettempdir()
        cls._arrow_down_path = os.path.join(temp_dir, "arrow_down.png").replace("\\", "/")
        cls._arrow_up_path = os.path.join(temp_dir, "arrow_up.png").replace("\\", "/")
        down_pixmap.save(cls._arrow_down_path, "PNG")
        up_pixmap.save(cls._arrow_up_path, "PNG")
        cls._initialized = True
    
    @classmethod
    def get_arrow_paths(cls):
        """获取箭头图片路径
        
        Returns:
            tuple: (向下箭头路径, 向上箭头路径)
        """
        return cls._arrow_down_path, cls._arrow_up_path
    
    def __init__(self, parent=None):
        super().__init__(parent)
        ArrowComboBox.init_arrow_resources()
        self._is_open = False
        self._updating_style = False
        self._arrow_size = (14, 8)  # 默认箭头尺寸
        
        # 延迟初始化箭头（等待样式设置后）
        QTimer.singleShot(0, self._update_arrow_style)
    
    @property
    def isPopupOpen(self) -> bool:
        """返回下拉列表是否打开"""
        return self._is_open
    
    @property
    def arrowDirection(self) -> str:
        """返回当前箭头方向 ('up' 或 'down')"""
        return 'up' if self._is_open else 'down'
    
    def setArrowSize(self, width: int, height: int):
        """设置箭头尺寸
        
        Args:
            width: 箭头宽度
            height: 箭头高度
        """
        self._arrow_size = (width, height)
        self._update_arrow_style()
    
    def setArrowDirection(self, is_up: bool):
        """手动设置箭头方向
        
        Args:
            is_up: True 为向上，False 为向下
        """
        if self._is_open != is_up:
            self._is_open = is_up
            self._update_arrow_style()
            self.arrowDirectionChanged.emit(is_up)
    
    def showPopup(self):
        """展开下拉列表时切换为向上箭头"""
        super().showPopup()
        self._is_open = True
        self._update_arrow_style()
        self.popupShown.emit()
        self.arrowDirectionChanged.emit(True)
    
    def hidePopup(self):
        """收起下拉列表时切换为向下箭头"""
        super().hidePopup()
        self._is_open = False
        self._update_arrow_style()
        self.popupHidden.emit()
        self.arrowDirectionChanged.emit(False)
    
    def togglePopup(self):
        """切换下拉列表的展开/收起状态"""
        if self._is_open:
            self.hidePopup()
        else:
            self.showPopup()
    
    def refreshArrowStyle(self):
        """刷新箭头样式（外部调用）"""
        self._update_arrow_style()
    
    def _update_arrow_style(self):
        """更新箭头样式（内部方法）"""
        if self._updating_style:
            return
        self._updating_style = True
        try:
            arrow_path = self._arrow_up_path if self._is_open else self._arrow_down_path
            arrow_width, arrow_height = self._arrow_size
            style = self.styleSheet()
            # 移除旧的箭头样式
            style = re.sub(r'QComboBox::down-arrow\s*\{[^}]*\}', '', style)
            style += f"""QComboBox::down-arrow {{ image: url({arrow_path}); width: {arrow_width}px; height: {arrow_height}px; }}"""
            super().setStyleSheet(style)
        finally:
            self._updating_style = False