package com.njcn.influx.base;


import cn.hutool.core.util.ArrayUtil;
import com.njcn.influx.ano.Delete;
import com.njcn.influx.ano.Select;
import com.njcn.influx.ano.Insert;
import com.njcn.influx.core.InfluxExecutor;
import com.njcn.influx.core.ParameterHandler;
import com.njcn.influx.core.ResultSetHandler;
import com.njcn.influx.query.InfluxQueryWrapper;

import java.lang.annotation.Annotation;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Parameter;
import java.util.List;

/**
 * @author hongawen
 */
public class ProxyMapper implements InvocationHandler {

    private ParameterHandler parameterHandler;
    private InfluxExecutor executor;
    private ResultSetHandler resultSetHandler;

    public ProxyMapper(ParameterHandler parameterHandler, InfluxExecutor executor, ResultSetHandler resultSetHandler) {
        this.parameterHandler = parameterHandler;
        this.executor = executor;
        this.resultSetHandler = resultSetHandler;
    }

    @Override
    public Object invoke(Object proxy, Method method, Object[] args) {
        Annotation[] annotations = method.getAnnotations();
        //没有注解的。查看参数是否为InfluxQueryWrapper
        if (ArrayUtil.isEmpty(annotations)) {
            Parameter[] parameters = method.getParameters();
            if (args.length == 1 && args[0] instanceof InfluxQueryWrapper) {
                InfluxQueryWrapper influxQueryWrapper = (InfluxQueryWrapper) args[0];
                Class resultType = influxQueryWrapper.getResultEntity();
                List<Object> resultList = executor.select(influxQueryWrapper.generateSql(), resultType);
                //根据返回类型返回结果
                Class<?> returnType = method.getReturnType();
                return resultSetHandler.handleResultSet(resultList, returnType);
            }
        }

        //采用注解的形式，即将sql写在注解里
        if (annotations.length == 1) {
            Annotation annotation = annotations[0];
            Class<? extends Annotation> annotationType = annotation.annotationType();
            //是查询的
            if (annotationType == Select.class) {
                Select selectAnnotation = method.getAnnotation(Select.class);
                //拼接sql
                String sql = selectAnnotation.value();
                Parameter[] parameters = method.getParameters();
                sql = parameterHandler.handleParameter(parameters, args, sql);
                //查询结果
                Class resultType = selectAnnotation.resultType();
                List<Object> list = executor.select(sql, resultType);
                //根据返回类型返回结果
                Class<?> returnType = method.getReturnType();
                return resultSetHandler.handleResultSet(list, returnType);
            }
            //是插入的
            if (annotationType == Insert.class) {
                executor.insert(args);
            }
            //是删除的
            if (annotationType == Delete.class) {
                Delete deleteAnnotation = method.getAnnotation(Delete.class);
                //拼接sql
                String sql = deleteAnnotation.value();
                Parameter[] parameters = method.getParameters();
                sql = parameterHandler.handleParameter(parameters, args, sql);
                //执行sql
                executor.delete(sql);
            }
        }
        return null;
    }
}