package minsecurity.identity.persist.sqlite;

import org.sqlite.mc.SQLiteMCSqlCipherConfig;

import java.io.File;
import java.sql.*;

/*
 * @Author: zhengqi wu
 * @Description: Sqlite封装
 * @Version: 1.0.0
 * @Date: 22:34 2021/04/01
 * @Copyright: MIN-Group；国家重大科技基础设施——未来网络北大实验室；深圳市信息论与未来网络重点实验室
 */
// 存在配置信息，使用单例模式封装工具类
public class Sqlite {
    private static final Sqlite Instance = new Sqlite(); // sqlite 唯一object

    private String passwd = "2DD29CA851E7B56E4697B0E1F08507293D761A05CE4D1B628663F411A8086D99"; // 初始数据库密码
    private String db_file = "identity.db"; // 数据库文件名
    private String db_path = "";
    private String table_create = "CREATE TABLE IF NOT EXISTS \"identityinfo\" (\n" +
            "\t\"name\"\tvarchar(255) NOT NULL,\n" +
            "\t\"pubkey\"\tvarchar(255),\n" +
            "\t\"prikey\"\tvarchar(255),\n" +
            "\t\"pubkey_algo\"\tint,\n" +
            "\t\"signature_algo\"int,\n" +
            "\t\"pass\"\tvarchar(255),\n" +
            "\t\"cert\"\tTEXT,\n" +
            "\t\"is_default\"\tint DEFAULT 0,\n" +
            "\t\"prikey_raw_byte\" varchar(255),\n" +
            "\tPRIMARY KEY(\"name\")\n" +
            ");";

    private Sqlite(){

    }

    /**
     * 将密码转换为16进制表示
     * @return 16进制字符串 String
     */
    private String passwd2HexKey(){
        return String.format("x'%s'", passwd);
    }

    /**
     * 获取Sqlite 实例
     * @return Sqlite object
     */
    public static Sqlite getInstance() {
        return Instance;
    }

    /**
     * 设置数据库的连接密码
     * @param pass 新密码
     * @throws Exception
     */
    public void setPasswd(String pass) throws Exception {
        if (pass.length() != 64){
            throw new Exception("Invalid Length");
        }
        passwd = pass;
    }

    /**
     * 进行数据库文件的连接测试，如果表不存在则新建
     * 数据库文件默认写入地址为~/.min/identity/identity.db
     * @throws Exception
     */
    public void openDefault() throws Exception {
        Connection c = null;
        Statement stmt = null;
        try{
            String homePath = SqliteUtil.home();
            homePath += "/min/identity/";
            db_path = homePath;
            if (!SqliteUtil.pathExists(db_path)){
                new File(db_path).mkdirs();
            }
            String real_db_file = db_path + db_file;
            // 兼容sqlcipher
            c = DriverManager.getConnection("jdbc:sqlite:" + real_db_file, SQLiteMCSqlCipherConfig.getV4Defaults().withKey(passwd2HexKey()).toProperties());
            stmt = c.createStatement();
            int res = stmt.executeUpdate(table_create);
            System.out.println(res);
            stmt.close();
            c.close();
        }catch (Exception ex){
            if (c != null)
                c.close();
            throw ex;
        }
    }
    //自定义文件地址,注意要用/结尾,比如:/min/identity/

    /**
     * 打开用户指定路径的数据库文件
     * @param filePath String
     * @throws Exception
     */
    public void open(String filePath) throws Exception {
        Connection c = null;
        Statement stmt = null;
        try{
            if (filePath == null || filePath.length() == 0){
                throw new Exception("invalid db path!");
            }
            db_path = filePath;
            boolean db_exists = SqliteUtil.pathExists(db_path);
            if (!db_exists){
                new File(db_path).mkdirs();
            }
            String real_db_file = db_path + db_file;
            // 兼容sqlcipher
            c = DriverManager.getConnection("jdbc:sqlite:" + real_db_file, SQLiteMCSqlCipherConfig.getV4Defaults().withKey(passwd2HexKey()).toProperties());
            stmt = c.createStatement();
            stmt.executeUpdate(table_create);
            stmt.close();
            c.close();
        }catch (Exception ex){
            // DONE 出错时关闭数据库
            if (c != null)
                c.close();
            throw ex;
        }
    }

    /**
     * 从打开的数据库获取连接
     * @return Connection
     * @throws Exception
     */
    public Connection getConn() throws Exception {
        Connection c = null;
        try{
            String real_db_file = db_path + db_file;
            // Class.forName("org.sqlite.JDBC");
            // 兼容sqlcipher
            c = DriverManager.getConnection("jdbc:sqlite:" + real_db_file, SQLiteMCSqlCipherConfig.getV4Defaults().withKey(passwd2HexKey()).toProperties());
            // TODO 设置数据库最大连接数
            return c;
        }catch (Exception ex){
            throw ex;
        }
    }
}