package com.moral.common.util;

import lombok.extern.log4j.Log4j;
import tk.mybatis.mapper.entity.Example;
import java.beans.PropertyDescriptor;
import java.io.UnsupportedEncodingException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URLDecoder;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Log4j
public class ExampleUtil {
    private final static String OR_SPLIT = "or\\|";
    private final static String CRITERIA_SPLIT = "\\|\\|\\|";
    private final static String CONDITION_SPLIT = "\\|\\|";
    private static Map<String, Method> criteriaMethodMap = null;

    public static Example generateExample(Class clzz, String params) {
        Example example = new Example(clzz);
        try {
            params = URLDecoder.decode(params, "UTF-8");
            if (!StringUtils.isNullOrEmpty(params) && params.startsWith("or|")) {
                String[] criteria = params.trim().split(OR_SPLIT);
                Example.Criteria criteriaOfExample = example.or();
                for (String criterion : criteria) {
                    if (!StringUtils.isNullOrEmpty(criterion)) {
                        String[] conditions = criterion.trim().split(CRITERIA_SPLIT);
                        for (String condition : conditions) {
                            if (!StringUtils.isNullOrEmpty(condition)) {
                                String[] conditionItems = condition.split(CONDITION_SPLIT);
                                if (conditionItems != null && conditionItems.length > 1) {
                                    //方法名
                                    String methodName = conditionItems[0];
                                    //属性名
                                    String propertyName = conditionItems[1];
                                    Method method = getMethod(methodName);
                                    if (method != null && isPropertyOfClass(clzz, propertyName)) {
                                        List values = new ArrayList<Object>();
                                        if (conditionItems.length > 2) {
                                            //属性到类型
                                            Class<?> valutType = new PropertyDescriptor(propertyName, clzz).getPropertyType();
                                            for (int index = 2; index < conditionItems.length; index++) {
                                                values.add(StringUtils.stringToObject4Type(valutType, conditionItems[index]));
                                            }
                                        }
                                        invokeMethod(criteriaOfExample,method,propertyName,values);
                                    }

                                }
                            }
                        }
                    }
                }
            }
        } catch (Exception ex) {
            log.error(ex.getMessage());
            ex.printStackTrace();
        }
        return example;
    }

    private static void invokeMethod(Object obj, Method method,String propertyName,List values) throws InvocationTargetException, IllegalAccessException {
        int len = values.size();
        switch (len) {
            case 0:
                if(method.getParameterCount()==1) {
                    method.invoke(obj, propertyName);
                }
                break;
            case 1:

                if(method.getParameterCount()==2){
                    method.invoke(obj,propertyName,values.get(0));
                }
                break;
            //between 查询
            case 2:
                if(method.getParameterCount()==3){
                    method.invoke(obj,propertyName,values.toArray());
                }
                break;
            //in 查询
            default:
                if(method.getParameterCount()==2){
                method.invoke(obj,propertyName,values);
                }
                break;
        }
    }

    ;

    private static boolean isPropertyOfClass(Class clzz, String propertyName) throws NoSuchFieldException {
        return clzz.getDeclaredField(propertyName) != null;
    }

    private static Method getMethod(String methodName) {
        if (criteriaMethodMap == null) {
            criteriaMethodMap = new HashMap<>();
            Method[] methods = Example.Criteria.class.getMethods();
            for (Method m : methods) {
                Method method = criteriaMethodMap.get(m.getName());
                //重载函数存储参数最长的
                if (method==null||m.getParameterTypes().length>method.getParameterTypes().length){
                    criteriaMethodMap.put(m.getName(),m);
                }
            }
        }
        return criteriaMethodMap.get(methodName);
    }
}