package com.zy.common.service.erp;

import com.core.common.Cools;
import com.zy.common.properties.ErpDbProperties;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.sql.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * 简单持久层框架
 * Created by vincent on 2020/11/26
 */
@Service
public class ErpSqlServer {

    // 数据库连接
    private Connection conn;
    // 创建预编译语句对象，一般都是用这个而不用Statement
    private PreparedStatement pstm = null;
    // 创建一个结果集对象
    private ResultSet rs = null;

    @Autowired
    private ErpDbProperties erpDbProperties;

    /*****************************************************************************/
    /**********************************   封装   **********************************/
    /*****************************************************************************/

    /**
     * 查询
     */
    public <T> List<T> select(String sql, Class<T> cls) {
        List<Map<String, Object>> result = executeQuery(sql);
        List<T> list = new ArrayList<>();
        if (null != result) {
            for (Map<String, Object> entity : result) {
                list.add(Cools.conver(entity, cls));
            }
        }
        return list;
    }

    public List<Map<String, Object>> select(String sql) {
        return executeQuery(sql);
    }

    /**
     * 修改
     */
    public int update(String sql) {
        return executeUpdate(sql);
    }

    /*****************************************************************************/
    /*********************************   核心层   *********************************/
    /*****************************************************************************/

    private List<Map<String, Object>> executeQuery(String sql) {
        try {
            Connection conn = getConn();
            pstm = conn.prepareStatement(sql);
            rs = pstm.executeQuery();
            return convertList(rs);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        } finally {
            release();
        }
    }

    private int executeUpdate(String sql) {
        try {
            Connection conn = getConn();
            pstm = conn.prepareStatement(sql);
            return pstm.executeUpdate();
        } catch (Exception e) {
            e.printStackTrace();
            return 0;
        } finally {
            release();
        }
    }

    private static List<Map<String, Object>> convertList(ResultSet rs) throws SQLException {
        List<Map<String, Object>> list = new ArrayList<>();
        ResultSetMetaData md = rs.getMetaData();
        int columnCount = md.getColumnCount();
        while (rs.next()) {
            Map<String, Object> rowData = new HashMap<>();
            for (int i = 1; i <= columnCount; i++) {
                rowData.put(md.getColumnName(i), rs.getObject(i));
            }
            list.add(rowData);
        }
        return list;
    }

    private Connection getConn() {
        if (null == this.conn) {
            try {
                Class.forName(erpDbProperties.getDriver_class_name()).newInstance();
                this.conn = DriverManager.getConnection(erpDbProperties.getUr(), erpDbProperties.getUsername(), erpDbProperties.getPassword());
            } catch (Exception e) {
                e.printStackTrace();
                throw new RuntimeException("获取ERP数据库连接失败");
            }
        }
        return this.conn;
    }

    private void release() {
        if (rs != null) {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
        if (pstm != null) {
            try {
                pstm.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
//        if (conn != null) {
//            try {
//                conn.close();
//            } catch (SQLException e) {
//                e.printStackTrace();
//            }
//        }
    }

}