import os
import matplotlib.pyplot as plt
import pandas as pd
import logging
from typing import Optional


class FilterVisualizer:
    """过滤结果可视化器"""
    
    def __init__(self, output_dir: str):
        """
        初始化可视化器
        
        Args:
            output_dir: 输出目录路径
        """
        self.output_dir = output_dir
        self.logger = logging.getLogger('UAV_Preprocess.Visualizer')
        
    def visualize_filter_step(self, 
                            current_points: pd.DataFrame,
                            previous_points: pd.DataFrame,
                            step_name: str,
                            save_name: Optional[str] = None):
        """
        可视化单个过滤步骤的结果
        
        Args:
            current_points: 当前步骤后的点
            previous_points: 上一步骤的点
            step_name: 步骤名称
            save_name: 保存文件名，默认为step_name
        """
        self.logger.info(f"开始生成{step_name}的可视化结果")
        
        # 找出被过滤掉的点
        filtered_files = set(previous_points['file']) - set(current_points['file'])
        filtered_points = previous_points[previous_points['file'].isin(filtered_files)]
        
        # 创建图形
        plt.figure(figsize=(20, 16))
        
        # 绘制保留的点
        plt.scatter(current_points['lon'], current_points['lat'],
                   color='blue', label='Retained Points',
                   alpha=0.6, s=50)
        
        # 绘制被过滤的点
        if not filtered_points.empty:
            plt.scatter(filtered_points['lon'], filtered_points['lat'],
                       color='red', marker='x', label='Filtered Points',
                       alpha=0.6, s=100)
        
        # 设置图形属性
        plt.title(f"GPS Points After {step_name}\n"
                 f"(Filtered: {len(filtered_points)}, Retained: {len(current_points)})",
                 fontsize=14)
        plt.xlabel("Longitude", fontsize=12)
        plt.ylabel("Latitude", fontsize=12)
        plt.grid(True)
        
        # 添加统计信息
        stats_text = (
            f"Original Points: {len(previous_points)}\n"
            f"Filtered Points: {len(filtered_points)}\n"
            f"Remaining Points: {len(current_points)}\n"
            f"Filter Rate: {len(filtered_points)/len(previous_points)*100:.1f}%"
        )
        plt.figtext(0.02, 0.02, stats_text, fontsize=10,
                   bbox=dict(facecolor='white', alpha=0.8))
        
        # 添加图例
        plt.legend(loc='upper right', fontsize=10)
        
        # 调整布局
        plt.tight_layout()
        
        # 保存图形
        save_name = save_name or step_name.lower().replace(' ', '_')
        save_path = os.path.join(self.output_dir, 'filter_imgs', f'filter_{save_name}.png')
        plt.savefig(save_path, dpi=300, bbox_inches='tight')
        plt.close()
        
        self.logger.info(
            f"{step_name}过滤可视化结果已保存至 {save_path}\n"
            f"过滤掉 {len(filtered_points)} 个点，"
            f"保留 {len(current_points)} 个点，"
            f"过滤率 {len(filtered_points)/len(previous_points)*100:.1f}%"
        )


if __name__ == '__main__':
    # 测试代码
    import numpy as np
    from datetime import datetime
    
    # 创建测试数据
    np.random.seed(42)
    n_points = 1000
    
    # 生成随机点
    test_data = pd.DataFrame({
        'lon': np.random.uniform(120, 121, n_points),
        'lat': np.random.uniform(30, 31, n_points),
        'file': [f'img_{i}.jpg' for i in range(n_points)],
        'date': [datetime.now() for _ in range(n_points)]
    })
    
    # 随机选择点作为过滤后的结果
    filtered_data = test_data.sample(n=800)
    
    # 测试可视化
    visualizer = FilterVisualizer('test_output')
    os.makedirs('test_output', exist_ok=True)
    
    visualizer.visualize_filter_step(
        filtered_data,
        test_data,
        "Test Filter"
    )