import numpy as np
import json

class BackData:
    def __init__(self, json_data):
        """
        初始化背部数据处理器
        
        Args:
            json_data: 包含背部标注信息的JSON数据字典
        """
        self.json_data = json_data
        self.vertices = []          # 背部区域四个顶点
        self.back_center_point = None  # 背部中心点坐标
        self.length = 0             # 背部区域长度
        self.width = 0             # 背部区域宽度
        
        # 处理数据
        self._process_data()
    
    def _calculate_distance(self, point1, point2):
        """计算两点之间的欧几里得距离"""
        return np.sqrt((point2[0] - point1[0])**2 + (point2[1] - point1[1])**2)
    
    def _process_data(self):
        """处理JSON数据，提取背部相关信息"""
        for shape in self.json_data.get('shapes', []):
            label = shape['label']
            points = shape['points']
            
            if shape['shape_type'] == 'polygon' and label == 'back':
                # 存储四个顶点坐标
                self.vertices = [tuple(map(float, point)) for point in points]
                
                # 计算背部长和宽
                self.length = self._calculate_distance(points[0], points[1])  # 第1点和第2点之间的距离
                self.width = self._calculate_distance(points[1], points[2])    # 第2点和第3点之间的距离
                
            elif shape['shape_type'] == 'point' and label == 'back_center':
                # 存储背部中心点坐标
                self.back_center_point = tuple(map(float, points[0]))
    
    def get_all_data(self):
        """获取所有处理后的背部数据"""
        return {
            'vertices': self.vertices,
            'back_center_point': self.back_center_point,
            'dimensions': {
                'length': self.length,
                'width': self.width
            }
        }
    
    def get_vertices(self):
        """获取背部区域四个顶点坐标"""
        return self.vertices
    
    def get_back_center_point(self):
        """获取背部中心点坐标"""
        return self.back_center_point
    
    def get_dimensions(self):
        """获取背部区域长度和宽度"""
        return {
            'length': self.length,
            'width': self.width
        }

# 使用示例
if __name__ == "__main__":
    # 示例JSON数据
    sample_json = {
        "version": "5.6.0",
        "flags": {},
        "shapes": [
            {
                "label": "back",
                "points": [
                    [263.12977099236645, 119.96183206106873],
                    [451.2977099236641, 140.19083969465652],
                    [439.0839694656489, 243.24427480916032],
                    [250.53435114503822, 218.4351145038168]
                ],
                "shape_type": "polygon"
            },
            {
                "label": "back_center",
                "points": [[358.5496183206107, 184.84732824427482]],
                "shape_type": "point"
            }
        ]
    }
    # 从文件读取JSON数据
    with open('/home/kira/codes/jsfb-back-manal/rotjsons1/color_65.json', 'r') as f:
        sample_json = json.load(f)
    
    # 创建背部数据处理器实例
    processor = BackData(sample_json)
    
    # 获取所有数据
    all_data = processor.get_all_data()
    
    # 打印结果
    print("背部区域四个顶点坐标：")
    for i, vertex in enumerate(processor.get_vertices(), 1):
        print(f"顶点{i}: {vertex}")
    
    print(f"\n背部中心点坐标: {processor.get_back_center_point()}")
    
    dimensions = processor.get_dimensions()
    print(f"\n背部长度: {dimensions['length']:.2f}")
    print(f"背部宽度: {dimensions['width']:.2f}")