package com.cm.utils.db;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;

import com.j256.ormlite.android.apptools.OrmLiteSqliteOpenHelper;
import com.j256.ormlite.dao.Dao;
import com.j256.ormlite.support.ConnectionSource;
import com.j256.ormlite.table.TableUtils;

import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;

/**
 * Created by Xuer on 2017/3/9.
 */
public class DBHelper extends OrmLiteSqliteOpenHelper {
    Context context;
    private static DBHelper instance;
    private Map<String, Dao> daos = new HashMap<String, Dao>();

    /**
     * @param context
     * @param dbName  数据库名称
     */
    private DBHelper(Context context, String dbName) {
        super(context, dbName, null, 1);
        this.context = context;
    }


    @Override
    public void onCreate(SQLiteDatabase database, ConnectionSource connectionSource) {

        try {
            for (String table : getTableList())
                TableUtils.createTable(connectionSource, Class.forName(table));
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onUpgrade(SQLiteDatabase database, ConnectionSource connectionSource, int oldVersion, int newVersion) {

    }

    /**
     * 单例获取该Helper
     *
     * @param dbName  数据库名称
     * @param context
     * @return
     */
    public static synchronized DBHelper getHelper(Context context, String dbName) {
        context = context.getApplicationContext();
        if (instance == null) {
            synchronized (DBHelper.class) {
                if (instance == null)
                    instance = new DBHelper(context, dbName);
            }
        }

        return instance;
    }

    /**
     * getDao为一个泛型方法，
     * 会根据传入Class对象进行创建Dao，
     * 并且使用一个Map来保持所有的Dao对象，
     * 只有第一次调用时才会去调用底层的getDao()。
     * @param clazz
     * @return
     * @throws SQLException
     */
    public synchronized Dao getDao(Class clazz) throws SQLException {
        Dao dao = null;
        String className = clazz.getSimpleName();

        if (daos.containsKey(className)) {
            dao = daos.get(className);
        }
        if (dao == null) {
            dao = super.getDao(clazz);
            daos.put(className, dao);
        }
        return dao;
    }

    /**
     * 释放资源
     */
    @Override
    public void close() {
        super.close();

        for (String key : daos.keySet()) {
            Dao dao = daos.get(key);
            dao = null;
        }
    }
    //读取配置文件,获取所需要建的表
    public String[] getTableList() {
        String[] tables = null;
        Properties properties = new Properties();
        try {
            properties.load(context.getAssets().open("dbtable.prop"));
            String tablelist = properties.getProperty("tablelist");
            tables = tablelist.split(",");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return tables;
    }
}