package com.util;

import java.io.IOException;

import java.lang.reflect.Field;

/**

 * Created by Jeff on 2018/12/5.

 */

public class GenerateSqlMapperUtil {

    /**

     * @param args

     * @throws IOException

     */

    public static void main(String[] args) throws IOException {

        generateSqlMapper(com.entity.Test.class, null);

    }

    public static void generateSqlMapper(Class obj,String tableName) throws IOException{

        Field[] fields = obj.getDeclaredFields();

        String param = null;

        String cameCaseColumn = null;

        String underScoreCaseColumn = null;

        StringBuilder sql = new StringBuilder();

        if(tableName==null||tableName.equals("")){

            // 未传表明默认用类名

            tableName = obj.getName().substring(obj.getName().lastIndexOf(".")+1);

        }

        /**

         * 以下部分生成建表Sql

         */

        sql.append("drop table if exists ").append(tableName).append(";\r\n");

        sql.append("create table ").append(tableName).append("( \r\n");

        boolean firstId = true;

        for(Field f : fields){

            cameCaseColumn = f.getName();

            underScoreCaseColumn = cameCaseColumn;

            for(int i = 0; i < cameCaseColumn.length(); i++)

                if(Character.isUpperCase(cameCaseColumn.charAt(i)))

                    // 将javabean中小驼峰命名变量的“大写字母”转换为“_小写字母”

                    underScoreCaseColumn = cameCaseColumn.substring(0, i) + '_' + cameCaseColumn.substring(i, i+1).toLowerCase() + cameCaseColumn.substring(i+1, cameCaseColumn.length());

            sql.append(underScoreCaseColumn).append(" ");

            param = f.getType().getTypeName();

            if(param.equals("java.lang.Integer")){

                sql.append("INTEGER");

            }else{

                // 根据需要自行修改

                sql.append("VARCHAR(20)");

            }

            if(firstId){

                // 默认第一个字段为ID主键

                sql.append(" PRIMARY KEY AUTO_INCREMENT");

                firstId = false;

            }

            sql.append(",\n");

        }

        sql.delete(sql.lastIndexOf(","), sql.length()).append("\n)ENGINE=INNODB DEFAULT CHARSET=UTF8 AUTO_INCREMENT=1;\r\n");

        System.out.println(sql);

        /**

         * 以下部分生成Mapper

         */

        firstId = true;

        StringBuilder mapper = new StringBuilder();

        StringBuilder resultMap = new StringBuilder();

        StringBuilder insert = new StringBuilder();

        StringBuilder insertValues = new StringBuilder();

        StringBuilder update = new StringBuilder();

        StringBuilder updateWhere = new StringBuilder();

        StringBuilder delete = new StringBuilder();

        StringBuilder deleteWhere = new StringBuilder();

        mapper.append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n");

        mapper.append("<!DOCTYPE mapper PUBLIC \"-//mybatis.org//DTD Mapper 3.0//EN\" \"http://mybatis.org/dtd/mybatis-3-mapper.dtd\">\r\n");

        mapper.append("<mapper namespace=\"com..mapper.").append(tableName).append("Mapper\">\r\n");

        resultMap.append("    <resultMap id=\"Base").append(tableName).append("\" type=\"").append(obj.getName()).append("\">\r\n");

        insert.append("    <insert id=\"save").append(tableName).append("\" parameterType=\"").append(obj.getName()).append("\">\r\n");

        insert.append("        INSERT INTO ").append(tableName.toLowerCase()).append(" (");

        update.append("    <update id=\"update").append(tableName).append("\" parameterType=\"").append(obj.getName()).append("\">\r\n");

        update.append("        UPDATE ").append(tableName.toLowerCase()).append(" SET ");

        delete.append("    <delete id=\"delete").append(tableName).append("\" parameterType=\"int\">\r\n");

        delete.append("        DELETE FROM ").append(tableName.toLowerCase());

        for(Field f : fields){

            cameCaseColumn = f.getName();

            underScoreCaseColumn = cameCaseColumn;

            for(int i = 0; i < cameCaseColumn.length(); i++)

                if(Character.isUpperCase(cameCaseColumn.charAt(i)))

                    // 将javabean中小驼峰命名变量的“大写字母”转换为“_小写字母”

                    underScoreCaseColumn = cameCaseColumn.substring(0, i) + '_' + cameCaseColumn.substring(i, i+1).toLowerCase() + cameCaseColumn.substring(i+1, cameCaseColumn.length());

            resultMap.append("         ");

            if(firstId){

                resultMap.append("<id column=\"").append(underScoreCaseColumn).append("\" property=\"").append(cameCaseColumn).append("\" jdbcType=\"");

                updateWhere.append("         WHERE ").append(underScoreCaseColumn).append(" = #{").append(cameCaseColumn).append("}\r\n");

                deleteWhere.append(" WHERE ").append(underScoreCaseColumn).append(" = #{").append(cameCaseColumn).append("}\r\n");

                firstId = false;

            } else {

                resultMap.append("<result column=\"").append(underScoreCaseColumn).append("\" property=\"").append(cameCaseColumn).append("\" jdbcType=\"");

                insert.append(underScoreCaseColumn).append(", ");

                insertValues.append("#{").append(cameCaseColumn).append("},");

                update.append(underScoreCaseColumn).append(" = #{").append(cameCaseColumn).append("}, ");

            }

            param = f.getType().getTypeName();

            if(param.equals("java.lang.Integer")){

                resultMap.append("INTEGER\" />\r\n");

            }else{

                // 根据需要自行修改

                resultMap.append("VARCHAR\" />\r\n");

            }

        }

        resultMap.append("    </resultMap>\r\n");

        insert.delete(insert.lastIndexOf(","), insert.length()).append(")\r\n");

        insertValues.delete(insertValues.lastIndexOf(","), insertValues.length());

        insert.append("              VALUES (");

        insert.append(insertValues).append(")\r\n");

        insert.append("    </insert>\r\n");

        update.delete(update.lastIndexOf(","), update.length()).append("\r\n");

        update.append(updateWhere);

        update.append("    </update>\r\n");

        delete.append(deleteWhere);

        delete.append("    </delete>\r\n");

        mapper.append(resultMap).append(insert).append(update).append(delete);

        mapper.append("</mapper>");

        System.out.println(mapper);

    }

}