package com.vci.server.base.utility;

import java.beans.PropertyDescriptor;
import java.lang.reflect.Field;

import com.vci.common.annotaion.CustomAnnotaion;

public class LogHelper {
	
	public LogHelper() {
	}
	
	public static String toNewLogString(Object obj) {
		if (obj == null)
			return "";
		
		Class<?> objClass = obj.getClass();
		
		Field[] fields = objClass.getDeclaredFields();
		
		StringBuffer sbLog = new StringBuffer();
		for(Field f : fields){
			if(!f.isAnnotationPresent(CustomAnnotaion.class)){
				continue;
			}
			
			CustomAnnotaion caField = f.getAnnotation(CustomAnnotaion.class);
			if(caField.InToString()){
				String fieldDes = caField.CustomDescription();
				Object value = getTargetObjectValue(f, obj);

				if (sbLog.length() > 0)
					sbLog.append(", ");
				
				sbLog.append(String.format("%s=%s", fieldDes, value));
			}
		}

		return sbLog.toString();
	}
	
	public static String toUpdataLogString(Object oldObj, Object newObj) {
		if (oldObj == null || newObj == null) {
			//System.out.println("================================\n oldObj == null || newObj == null");
			return "";
		}
		
		Class<?> objClass = newObj.getClass();
		
		Field[] fields = objClass.getDeclaredFields();
		
		StringBuffer sbBefor = new StringBuffer();
		StringBuffer sbAfter = new StringBuffer();
		for(Field f : fields){
			if(!f.isAnnotationPresent(CustomAnnotaion.class)){
				continue;
			}
			
			CustomAnnotaion caField = f.getAnnotation(CustomAnnotaion.class);
			if(caField.InToString()){
				String fieldDes = caField.CustomDescription();
				String oldValue = getTargetObjectValue(f, oldObj);
				String newValue = getTargetObjectValue(f, newObj);
				//System.out.println(String.format("============== %s =======================\noldValue = %s;   newValue = %s", fieldDes, oldValue, newValue));

				if (oldValue.equals(newValue))
					continue;

				if (sbBefor.length() > 0)
					sbBefor.append(", ");
				sbBefor.append(String.format("%s=%s", fieldDes, oldValue));
				
				if (sbAfter.length() > 0)
					sbAfter.append(", ");
				sbAfter.append(String.format("%s=%s", fieldDes, newValue));
			}
		}
		
		if (sbAfter.length() == 0 || sbBefor.length() == 0) {
			//System.out.println(String.format("=====================================\noldObj = %s;   newObj = %s", sbBefor, sbAfter));
			return "";
		}
		
		return String.format("更改前[%s]；更改后[%s]", sbBefor.toString(), sbAfter.toString());
	}
	
	

    /**
     * 通过内省机制获取字段值
     * @param declaredField 字段
     * @param t 对象
     * @return 值
     */
    private static String getTargetObjectValue(Field field, Object t) {
        Object value;
        try {
            PropertyDescriptor propDesc = new PropertyDescriptor(field.getName(), t.getClass());
            value = propDesc.getReadMethod().invoke(t);
            
            if (value == null)
            	value = "";
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException("获取对应数据失败");
        }
        return value.toString();
    }

}