package com.welampiot.configuration;


import org.apache.commons.collections4.CollectionUtils;
import org.apache.ibatis.executor.statement.StatementHandler;
import org.apache.ibatis.mapping.BoundSql;
import org.apache.ibatis.mapping.MappedStatement;
import org.apache.ibatis.mapping.ParameterMapping;
import org.apache.ibatis.plugin.*;
import org.apache.ibatis.reflection.MetaObject;
import org.apache.ibatis.reflection.SystemMetaObject;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.ResultHandler;
import org.apache.ibatis.type.TypeHandlerRegistry;
import org.springframework.stereotype.Component;

import java.sql.Statement;
import java.text.DateFormat;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.util.Properties;
import java.util.regex.Matcher;


@Intercepts({
        @Signature(type = StatementHandler.class, method = "query", args = {Statement.class, ResultHandler.class}),
        @Signature(type = StatementHandler.class, method = "update", args = {Statement.class}),
        @Signature(type = StatementHandler.class, method = "batch", args = {Statement.class})
})
@Component
public class LastSqlInterceptor implements Interceptor {
    public String sqlContent;

    //获取sql语句
    @Override
    public Object intercept(Invocation invocation) throws Throwable {
        // 耗时开始时间
        long startTime = System.currentTimeMillis();
        // 获取 StatementHandler ，默认是 RoutingStatementHandler
        StatementHandler statementHandler = (StatementHandler) invocation.getTarget();
        // 获取 StatementHandler 包装类
        MetaObject metaObjectHandler = SystemMetaObject.forObject(statementHandler);
        // 获取查询接口映射的相关信息
        MappedStatement mappedStatement = (MappedStatement) metaObjectHandler.getValue("delegate.mappedStatement");
        // 获取请求时的参数
        Object parameterObject = statementHandler.getParameterHandler().getParameterObject();
        // 获取sql
        String sql = showSql(mappedStatement.getConfiguration(),  mappedStatement.getBoundSql(parameterObject));
        // 获取执行sql方法
        String sqlId = mappedStatement.getId();
        // 执行sql
        Object result = invocation.proceed();
        // 计算总耗时
        long cost = System.currentTimeMillis() - startTime;
        System.out.println(" ======> SQL方法 : {} , 总耗时 : {}毫秒,  SQL语句 : {} "+ sqlId+"----"+cost+"----"+sql);
        this.sqlContent = sql;
        return result;
    }


    /**
     * 拦截器对应的封装原始对象的方法，获取代理对象
     */
    @Override
    public Object plugin(Object target) {
        return (target instanceof StatementHandler) ? Plugin.wrap(target, this) : target;
    }


    /**
     * 设置注册拦截器时设定的属性，设置代理对象的参数
     */
    @Override
    public void setProperties(Properties properties) {
    }


    private static String showSql(Configuration configuration, BoundSql boundSql) {
        // 获取参数
        Object parameterObject = boundSql.getParameterObject();
        List<ParameterMapping> parameterMappings = boundSql.getParameterMappings();
        // sql语句中多个空格都用一个空格代替
        String sql = boundSql.getSql().replaceAll("[\\s]+", " ");
        if (CollectionUtils.isNotEmpty(parameterMappings) && parameterObject != null) {
            // 获取类型处理器注册器，类型处理器的功能是进行java类型和数据库类型的转换
            TypeHandlerRegistry typeHandlerRegistry = configuration.getTypeHandlerRegistry();
            // 如果根据parameterObject.getClass(）可以找到对应的类型，则替换
            if (typeHandlerRegistry.hasTypeHandler(parameterObject.getClass())) {
                sql = sql.replaceFirst("\\?", Matcher.quoteReplacement(getParameterValue(parameterObject)));
            } else {
                // MetaObject主要是封装了originalObject对象，提供了get和set的方法用于获取和设置originalObject的属性值,主要支持对JavaBean、Collection、Map三种类型对象的操作
                MetaObject metaObject = configuration.newMetaObject(parameterObject);
                for (ParameterMapping parameterMapping : parameterMappings) {
                    String propertyName = parameterMapping.getProperty();
                    if (metaObject.hasGetter(propertyName)) {
                        Object obj = metaObject.getValue(propertyName);
                        sql = sql.replaceFirst("\\?", Matcher.quoteReplacement(getParameterValue(obj)));
                    } else if (boundSql.hasAdditionalParameter(propertyName)) {
                        // 该分支是动态sql
                        Object obj = boundSql.getAdditionalParameter(propertyName);
                        sql = sql.replaceFirst("\\?", Matcher.quoteReplacement(getParameterValue(obj)));
                    } else {
                        // 打印出缺失，提醒该参数缺失并防止错位
                        sql = sql.replaceFirst("\\?", "缺失");
                    }
                }
            }
        }

        return sql;
    }


    private static String getParameterValue(Object obj) {
        String value;

        if (obj instanceof String) {
            value = "'" + obj.toString() + "'";
        }
        else if (obj instanceof Date) {
            DateFormat formatter = DateFormat.getDateTimeInstance(DateFormat.DEFAULT, DateFormat.DEFAULT, Locale.CHINA);
            value = "'" + formatter.format(new Date()) + "'";
        }
        else {
            if (obj != null) {
                value = obj.toString();
            } else {
                value = "";
            }
        }

        return value;
    }

}