from PySide6.QtWidgets import (
    QMainWindow, QWidget, QVBoxLayout, QHBoxLayout,
    QScrollArea, QPushButton, QMessageBox, QLabel, QScroller
)
from PySide6.QtCore import Qt, QTimer
from ui.inspection_card import InspectionCard
from ui.incoming_inspection_page import IncomingInspectionPage
from ui.manual_inspection_page import ManualInspectionPage
from src.db_manager import DatabaseManager
from src.session_manager import SessionManager

class InspectionWindow(QMainWindow):
    def __init__(self):
        super().__init__()
        self.setWindowTitle("检验管理系统")

        # 初始化数据库管理器和分页参数
        self.db_manager = DatabaseManager()
        self.session_manager = SessionManager()
        self.current_page = 0
        self.page_size = 10
        self.is_loading = False
        self.has_more_data = True

        # Central Widget
        central_widget = QWidget()
        self.setCentralWidget(central_widget)
        
        # Main Layout
        main_layout = QVBoxLayout(central_widget)
        main_layout.setContentsMargins(0, 0, 0, 0)
        main_layout.setSpacing(0)
        
        # Scroll Area for Cards
        self.scroll_area = QScrollArea()
        self.scroll_area.setWidgetResizable(True)
        self.scroll_area.setStyleSheet("background-color: #f0f0f0; border: none;")

        self.cards_container = QWidget()
        self.cards_container.setStyleSheet("background-color: white;")
        self.cards_layout = QVBoxLayout(self.cards_container)
        self.cards_layout.setContentsMargins(10, 10, 10, 10)
        self.cards_layout.setSpacing(15)

        # 加载提示标签
        self.loading_label = QLabel("加载中...")
        self.loading_label.setAlignment(Qt.AlignCenter)
        self.loading_label.setStyleSheet("color: #666; padding: 10px;")
        self.loading_label.hide()
        self.cards_layout.addWidget(self.loading_label)

        self.cards_layout.addStretch() # Push items to top

        self.scroll_area.setWidget(self.cards_container)

        # 启用触摸滚动
        QScroller.grabGesture(self.scroll_area.viewport(), QScroller.LeftMouseButtonGesture)

        # 连接滚动条信号
        self.scroll_area.verticalScrollBar().valueChanged.connect(self.on_scroll)

        main_layout.addWidget(self.scroll_area)
        
        button_bar = QWidget()
        button_bar.setStyleSheet("background-color: #e0e0e0; border-top: 1px solid #999;")
        button_layout = QHBoxLayout(button_bar)
        button_layout.setContentsMargins(20, 15, 20, 15)
        button_layout.setSpacing(20)
        
        # 按钮样式
        btn_style = """
            QPushButton {
                background-color: #0086fa;
                color: white;
                border-radius: 5px;
                padding: 15px;
                font-family: 'Microsoft YaHei';
                font-size: 19px;
                font-weight: bold;
            }
            QPushButton:pressed {
                background-color: #006bbd;
            }
        """
        
        self.btn_incoming = QPushButton("入检")
        self.btn_incoming.setStyleSheet(btn_style)
        self.btn_incoming.clicked.connect(lambda: self.show_dialog("入检"))
        
        self.btn_manual = QPushButton("手检")
        self.btn_manual.setStyleSheet(btn_style)
        self.btn_manual.clicked.connect(lambda: self.show_dialog("手检"))
        
        button_layout.addWidget(self.btn_incoming)
        button_layout.addWidget(self.btn_manual)
        
        main_layout.addWidget(button_bar)

    def add_card(self, data):
        card = InspectionCard(data)
        count = self.cards_layout.count()
        # 插入到 loading_label 之前
        self.cards_layout.insertWidget(count - 2, card)

    def on_scroll(self, value):
        """滚动条事件处理"""
        scrollbar = self.scroll_area.verticalScrollBar()
        # 当滚动到底部附近时触发加载
        if value >= scrollbar.maximum() - 50 and not self.is_loading and self.has_more_data:
            self.load_more_data()

    def load_more_data(self):
        """加载更多数据"""
        if self.is_loading or not self.has_more_data:
            return

        self.is_loading = True
        self.loading_label.show()

        # 使用 QTimer 异步加载，避免阻塞 UI
        QTimer.singleShot(100, self._fetch_data)

    def _fetch_data(self):
        """从数据库获取数据"""
        offset = self.current_page * self.page_size
        user_id = self.session_manager.get_user_id() or ''
        rows, error = self.db_manager.get_inspection_list(self.page_size, offset, user_id=user_id)

        if error:
            self.loading_label.setText(f"加载失败: {error}")
            self.is_loading = False
            QTimer.singleShot(2000, lambda: self.loading_label.hide())
            return

        if not rows or len(rows) == 0:
            self.has_more_data = False
            self.loading_label.setText("没有更多数据")
            QTimer.singleShot(1000, lambda: self.loading_label.hide())
        else:
            for row in rows:
                self.add_card(dict(row))

            self.current_page += 1

            if len(rows) < self.page_size:
                self.has_more_data = False

            self.loading_label.hide()

        self.is_loading = False

    def load_initial_data(self):
        """加载初始数据"""
        self.current_page = 0
        self.has_more_data = True
        self.load_more_data()

    def show_dialog(self, title):
        if title == "入检":
            page = IncomingInspectionPage(self)
            page.showMaximized()
            page.exec()
        elif title == "手检":
            page = ManualInspectionPage(self)
            page.showMaximized()
            page.exec()
        else:
            msg = QMessageBox(self)
            msg.setWindowTitle(title)
            msg.setText(f"{title} - 功能开发中")
            msg.setStandardButtons(QMessageBox.Ok)
            msg.exec()