package com.moral.common.util;

import com.moral.common.bean.PageBean;
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;
    private static void setOrderByClause(Example example,String orderByClause) throws UnsupportedEncodingException, NoSuchFieldException {
           orderByClause = URLDecoder.decode(orderByClause,"UTF-8");
           String[] orderBys = orderByClause.split(CRITERIA_SPLIT);
           for(String orderBy : orderBys){
               String[] items = orderBy.split(CONDITION_SPLIT);
               if(items.length == 2){
                   String property = items[0];
                   String sort = items[1];
                   if(isPropertyOfClass(example.getEntityClass(),property)){

                       if("asc".equals(sort)){
                           example.orderBy(property).asc();
                       }else{
                           example.orderBy(property).desc();
                       }
                   }
               }
           }
    }
    public static Example generateExample(Class clzz, PageBean page) {
        Example example = null;
        try {
            String params = page.getQueryParams();
            String orderByClause = page.getOrderByClause();
            example = new Example(clzz);
            if(!StringUtils.isNullOrEmpty(orderByClause)){
                setOrderByClause(example,orderByClause);
            }
            if(StringUtils.isNullOrEmpty(params)){ return example;}
            params = URLDecoder.decode(params, "UTF-8");
            if (!StringUtils.isNullOrEmpty(params) && params.startsWith("or|")) {
                String[] criteria = params.trim().split(OR_SPLIT);
                for (String criterion : criteria) {
                    // criterion为null或""跳过
                    if(StringUtils.isNullOrEmpty(criterion)) { continue;};
                    Example.Criteria criteriaOfExample = example.or();
                    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) {
                                            for (int index = 2; index < conditionItems.length; index++) {
                                                values.add(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);
    }
}