import csv
import os

from qgis import processing
from qgis.PyQt import uic
from qgis.PyQt.QtCore import QVariant, QThread, pyqtSignal
from qgis.PyQt.QtWidgets import QFileDialog
from qgis.core import QgsUnitTypes, QgsDistanceArea, QgsMapLayer, QgsWkbTypes
from qgis.utils import iface

from qgis.PyQt import QtCore,  QtWidgets

FORM_CLASS, _ = uic.loadUiType(os.path.join(
    os.path.dirname(__file__), 'cyanlove_calc_area_base.ui'))


class cyanlove_calc_area(QtWidgets.QDockWidget, FORM_CLASS):
    closingPlugin = pyqtSignal()

    def __init__(self, parent=None):
        super(cyanlove_calc_area, self).__init__(parent)

        self.export_thread = None
        self.iface = iface
        self.canvas = iface.mapCanvas()
        self.setupUi(self)
        self.setFloating(True)
        self.property_dict = None  # 存储搜索出来的名称，图元中心经纬度
        self.is_running = False  # 线程状态标志
        self.setWindowFlags(QtCore.Qt.Dialog)  # 使对话框始终在前
        # 设置为模态窗口
        # self.setWindowModality(QtCore.Qt.ApplicationModal)  # 或者使用 Qt.WindowModal
        self.btn_calc_area.clicked.connect(self.calc_area)

    # 调用内置算法，计算面积和周长
    def calc_area2(self):
        current_layer = self.mMapLayerComboBox.currentLayer()
        if current_layer is None or current_layer.type() != QgsMapLayer.VectorLayer:
            self.label_show.setText("选择的图层不是矢量图层！")
            return
        # 定义算法参数
        params = {
            'INPUT': current_layer,
            'uniqueGeometryType': 'yes',
            'CALC_METHOD': 2,  # 椭球体
            'OUTPUT': 'D:/方法2.csv'
        }
        # 运行算法
        result = processing.run("qgis:exportaddgeometrycolumns", params)

        # 输出结果信息
        print("Algorithm executed successfully!")
        print("Output file saved at:", result['OUTPUT'])

    def calc_area(self):
        options = QFileDialog.Options()  # 创建文件对话框选项
        options |= QFileDialog.ReadOnly  # 可以设置一些选项，例如只读
        csv_file_path, _ = QFileDialog.getSaveFileName(self,
                                                       "选择文件",
                                                       "",
                                                       "CSV文件 (*.csv);;所有文件 (*)",  # 可以添加其他过滤器
                                                       options=options)  # 传递 options 参数
        # 检查用户是否选择了文件
        if csv_file_path:
            current_layer = self.mMapLayerComboBox.currentLayer()
            if current_layer is None or current_layer.type() != QgsMapLayer.VectorLayer:
                self.label_show.setText("选择的图层不是矢量图层！")
                return
            # 确保使用现有的进度条
            self.progressBar.setRange(0, 100)  # 设置进度条范围
            self.progressBar.setValue(0)  # 初始化进度条值
            self.progressBar.show()  # 显示进度条 (如果之前是隐藏状态)
            geom_type = current_layer.wkbType()
            if geom_type in [QgsWkbTypes.Polygon, QgsWkbTypes.MultiPolygon]:
                # 启动导出线程
                self.export_thread = ExportThread(current_layer, csv_file_path)
                self.export_thread.progress.connect(self.update_progress)  # 连接信号到槽
                self.export_thread.finished.connect(self.export_finished)  # 导出完成后连接到槽
                self.export_thread.start()  # 启动线程
            else:
                self.label_show.setText("不是Polygon图层！")

    def update_progress(self, value):
        self.progressBar.setValue(value)  # 更新进度条的值

    def export_finished(self):
        print("导出完成！")
        self.label_show.setText('导出完毕')
        self.progressBar.setValue(100)


class ExportThread(QThread):
    progress = pyqtSignal(int)  # 声明一个信号

    def __init__(self, selected_layer, csv_file_path):
        super().__init__()
        self.selected_layer = selected_layer
        self.csv_file_path = csv_file_path

    def run(self):
        context = QgsDistanceArea()
        # 创建处理上下文
        field_names = [f"{field.name()}" for field in self.selected_layer.fields()] + ['Area平方米']
        context.setEllipsoid('WGS84')
        total_features = self.selected_layer.featureCount()
        with open(self.csv_file_path, mode='w', newline='', encoding='gbk') as csv_file:
            writer = csv.writer(csv_file)
            writer.writerow(field_names)
            for index, feature in enumerate(self.selected_layer.getFeatures()):
                try:
                    row = []
                    for field_name in field_names[:-1]:  # 不包括 WKT_BJ
                        value = feature[field_name]  # 获取每个字段的值
                        row.append(f'{value}')  # 在每个值两边添加双引号
                    geometry = feature.geometry()
                    if geometry:
                        areauint = context.convertAreaMeasurement(context.measureArea(geometry),
                                                                  QgsUnitTypes.AreaSquareMeters)
                        row.append(f'{areauint}')  # 添加面积
                    # 发送进度更新
                    writer.writerow(row)

                    progress_value = int((index + 1) / total_features * 100)
                    self.progress.emit(progress_value)

                except Exception as e:
                    pass


        # 输出结果信息
        print("计算完毕!")
