using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Data.SQLite;
using System.Reflection;
/// <summary>
/// SQLite数据库帮助类
/// </summary>
public class SQLiteHelper
{
    /// <summary>
    /// 数据库路径
    /// </summary>
    private static readonly string m_DataSource = ConfigurationManager.AppSettings["Test"];

    /// <summary>
    /// ConnectionString样例：Data Source=Test.db;Pooling=true;FailIfMissing=false
    /// </summary>
    private static readonly string m_ConnectionString;

    /// <summary>
    /// 静态构造函数，初始化连接字符串，检查数据库连接
    /// </summary>
    static SQLiteHelper()
    {
        try
        {
            SQLiteConnectionStringBuilder connectionStringBuilder = new SQLiteConnectionStringBuilder
            {
                Version = 0,
                Pooling = true,
                FailIfMissing = false,
                DataSource = m_DataSource
            };
            m_ConnectionString = connectionStringBuilder.ConnectionString;
            using (SQLiteConnection conn = new SQLiteConnection(m_ConnectionString))
            {
                conn.Open();
            }
        }
        catch { }
    }
    /// <summary>
    /// 获得连接对象
    /// </summary>
    /// <returns></returns>
    private static SQLiteConnection GetSQLiteConnection()
    {
        return new SQLiteConnection(m_ConnectionString);
    }

    /// <summary>
    /// 预备命令
    /// </summary>
    /// <param name="cmd"></param>
    /// <param name="conn"></param>
    /// <param name="cmdText"></param>
    /// <param name="commandParameters"></param>
    private static void PrepareCommand(SQLiteCommand cmd, SQLiteConnection conn, string cmdText, params object[] commandParameters)
    {
        if (conn.State != ConnectionState.Open)
            conn.Open();
        cmd.Parameters.Clear();
        cmd.Connection = conn;
        cmd.CommandText = cmdText;
        cmd.CommandType = CommandType.Text;
        cmd.CommandTimeout = 0;
        if (commandParameters != null)
        {
            foreach (object parm in commandParameters)
                cmd.Parameters.AddWithValue(string.Empty, parm);

            //for (int i = 0; i < p.Length; i++)
            //    cmd.Parameters[i].Value = p[i];
        }
    }


    /// <summary>
    /// 返回受影响的行数
    /// </summary>
    /// <param name="cmdText">执行语句</param>
    /// <param name="commandParameters">传入的参数</param>
    /// <returns>返回受影响行数</returns>
    public static int ExecuteNonQuery(string cmdText, params object[] commandParameters)
    {
        SQLiteCommand command = new SQLiteCommand();
        using (SQLiteConnection connection = GetSQLiteConnection())
        {
            PrepareCommand(command, connection, cmdText, commandParameters);
            return command.ExecuteNonQuery();
        }
    }

    /// <summary>
    /// 返回表集合
    /// </summary>
    /// <param name="cmdText">执行语句</param>
    /// <param name="commandParameters">传入的参数</param>
    /// <returns>返回DataSet</returns>
    public static DataSet ExecuteDataset(string cmdText, params object[] commandParameters)
    {
        DataSet ds = new DataSet();
        SQLiteCommand command = new SQLiteCommand();
        using (SQLiteConnection connection = GetSQLiteConnection())
        {
            PrepareCommand(command, connection, cmdText, commandParameters);
            SQLiteDataAdapter da = new SQLiteDataAdapter(command);
            da.Fill(ds);
        }
        return ds;
    }

    /// <summary>
    /// 返回SqlDataReader对象
    /// </summary>
    /// <param name="cmdText">执行语句</param>
    /// <param name="commandParameters">传入的参数</param>
    /// <returns>返回SQLiteDataReader</returns>
    public static SQLiteDataReader ExecuteReader(string cmdText, params object[] commandParameters)
    {
        SQLiteCommand command = new SQLiteCommand();
        SQLiteConnection connection = GetSQLiteConnection();
        try
        {
            PrepareCommand(command, connection, cmdText, commandParameters);
            SQLiteDataReader reader = command.ExecuteReader(CommandBehavior.CloseConnection);
            return reader;
        }
        catch
        {
            connection.Close();
            throw;
        }
    }


    /// <summary>
    /// 返回表第一行
    /// </summary>
    /// <param name="cmdText">执行语句</param>
    /// <param name="commandParameters">传入的参数</param>
    /// <returns>返回：第一行</returns>
    public static DataRow ExecuteDataRow(string cmdText, params object[] commandParameters)
    {
        DataSet ds = ExecuteDataset(cmdText, commandParameters);
        if (ds != null && ds.Tables.Count > 0 && ds.Tables[0].Rows.Count > 0)
            return ds.Tables[0].Rows[0];
        return null;
    }

    /// <summary>
    /// 返回结果集中的第一行第一列，忽略其他行或列
    /// </summary>
    /// <param name="cmdText">执行语句</param>
    /// <param name="commandParameters">传入的参数</param>
    /// <returns>返回：第一行第一列</returns>
    public static object ExecuteScalar(string cmdText, params object[] commandParameters)
    {
        SQLiteCommand cmd = new SQLiteCommand();
        using (SQLiteConnection connection = GetSQLiteConnection())
        {
            PrepareCommand(cmd, connection, cmdText, commandParameters);
            return cmd.ExecuteScalar();
        }
    }


    ///// <summary>
    ///// 获取表所有数据
    ///// </summary>
    ///// <typeparam name="T">实体类型</typeparam>
    ///// <param name="tableName">表名</param>
    ///// <returns>表所有数据</returns>
    //public static List<T> GetTableData<T>(string tableName) where T : class
    //{
    //    List<T> dataList = new List<T>();
    //    try
    //    {
    //        using (SQLiteConnection  context = new SQLiteConnection (new SQLiteConnection(m_ConnectionString)))
    //        {
    //            string sql = "select * from " + tableName;
    //            dataList = context.ExecuteQuery<T>(sql).ToList();
    //            context.SubmitChanges();
    //        }
    //    }
    //    catch { }
    //    return dataList;
    //}

    ///// <summary>
    ///// 获取表数据
    ///// </summary>
    ///// <typeparam name="T">实体类型</typeparam>
    ///// <param name="cmdText">sql语句</param>
    ///// <param name="parameter">参数</param>
    ///// <returns>表所有数据</returns>
    //public static List<T> GetTableData<T>(string cmdText, params object[] parameter) where T : class
    //{
    //    List<T> dataList = new List<T>();
    //    try
    //    {
    //        using (SqliteDataContext context = new SqliteDataContext(new SQLiteConnection(m_ConnectionString)))
    //        {
    //            dataList = context.ExecuteQuery<T>(cmdText, parameter).ToList();
    //        }
    //    }
    //    catch { }
    //    return dataList;
    //}

    /// <summary>
    /// 插入表数据
    /// </summary>
    /// <typeparam name="T">数据类型</typeparam>
    /// <param name="tableName">表名</param>
    /// <param name="dataList">数据集合</param>
    /// <returns>true或false</returns>
    public static bool BatchInsert<T>(string tableName, List<T> dataList)
    {
        try
        {
            if (dataList != null && dataList.Count > 0)
            {
                var temp = dataList[0];
                PropertyInfo[] propertyInfos = temp.GetType().GetProperties();
                List<string> propertyStrs = new List<string>();
                string propertyStr = "";
                foreach (var propertyInfo in propertyInfos)
                {
                    propertyStrs.Add(propertyInfo.Name);
                    propertyStr = propertyStr + "@" + propertyInfo.Name + ",";
                }
                propertyStr = propertyStr.Remove(propertyStr.Length - 1);

                using (SQLiteConnection conn = new SQLiteConnection(m_ConnectionString))
                {
                    using (SQLiteCommand command = new SQLiteCommand(conn))
                    {
                        command.Connection.Open();
                        using (SQLiteTransaction transaction = conn.BeginTransaction())
                        {
                            command.Transaction = transaction;
                            command.CommandText = "insert into " + tableName + " values(" + propertyStr + ")";
                            foreach (var needInsertData in dataList)
                            {
                                command.Parameters.Clear();
                                for (int i = 0; i < propertyStrs.Count; i++)
                                {
                                    command.Parameters.AddWithValue("@" + propertyStrs[i], propertyInfos[i].GetValue(needInsertData, null));
                                }
                                command.ExecuteNonQuery();
                            }
                            transaction.Commit();
                        }
                    }
                }
            }
        }
        catch (Exception ex)
        {
            return false;
        }
        return true;
    }

    /// <summary>
    /// 删除表数据
    /// </summary>
    /// <param name="tableName">表名</param>
    /// <returns>true或false</returns>
    public static bool DeleteTableData(string tableName)
    {
        try
        {
            using (SQLiteConnection conn = new SQLiteConnection(m_ConnectionString))
            {
                using (SQLiteCommand command = new SQLiteCommand(conn))
                {
                    command.Connection.Open();
                    command.CommandText = "delete from " + tableName;
                    command.ExecuteNonQuery();
                }
            }
        }
        catch (Exception ex)
        {
            return false;
        }
        return true;
    }
}