using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using FirebirdSql.Data.FirebirdClient;
using System.IO;
using System.Runtime.InteropServices;

namespace FireBirdUtil.SqlUtils
{
	public static class SQLExecuteUtil
	{
		/// <summary>
		/// 向指定数据库的指定表中，插入一条数据。
		/// <para>数据的Key为字段，Value为字段对应的值</para>
		/// </summary>
		/// <param name="database">数据库名（在fbembed.dll所在目录；或者是绝对路径+数据库名）</param>
		/// <param name="tableName">表名</param>
		/// <param name="fieldsValues">一条数据的信息</param>
		public static void Insert(string database, string tableName, IDictionary<string, object> fieldsValues)
		{
			var insertSql = SqlUtil.GetInsertSql(tableName, fieldsValues);
			using (FbConnection conn = new FbConnection(GetConnectionString(database))) {
				conn.Open();
				SqlExecuteBaseUtil.ExecuteNonQuery(conn, null, insertSql);
			}
		}

		/// <summary>
		/// 删除符合条件的数据
		/// </summary>
		/// <param name="database">数据库名（在fbembed.dll所在目录；或者是绝对路径+数据库名）</param>
		/// <param name="tableName">表名</param>
		/// <param name="conditions">以where打头的条件</param>
		public static void Delete(string database, string tableName, string conditions)
		{
			var deleteSql = SqlUtil.GetDeleteSql(tableName, conditions);
			using (FbConnection conn = new FbConnection(GetConnectionString(database))) {
				conn.Open();
				SqlExecuteBaseUtil.ExecuteNonQuery(conn, null, deleteSql);
			}
		}

		/// <summary>
		/// 更新符合条件的数据
		/// </summary>
		/// <param name="database">数据库名（在fbembed.dll所在目录；或者是绝对路径+数据库名）</param>
		/// <param name="tableName">表名</param>
		/// <param name="newValues">新值：Key为字段名，Value为新值</param>
		/// <param name="conditions">以where打头的条件</param>
		public static void Update(string database, string tableName, Dictionary<string, object> newValues, string conditions)
		{
			var updateSql = SqlUtil.GetUpdateSql(tableName, newValues, conditions);
			using (FbConnection conn = new FbConnection(GetConnectionString(database))) {
				conn.Open();
				SqlExecuteBaseUtil.ExecuteNonQuery(conn, null, updateSql);
			}
		}

		/// <summary>
		/// 数据库是否存在
		/// </summary>
		/// <param name="database">数据库名（在fbembed.dll所在目录；或者是绝对路径+数据库名）</param>
		public static bool IsDatabaseExist(string database)
		{
			return File.Exists(database);
		}

		/// <summary>
		/// 如果指定数据库中，不存在指定的表，则根据创建表的参数，创建之
		/// </summary>
		/// <param name="database">数据库名（在fbembed.dll所在目录；或者是绝对路径+数据库名）</param>
		/// <param name="tableName">表名</param>
		/// <param name="tableParams">创建表的字段的相关参数信息</param>
		public static void CreateTableIfNotExist(string database, string tableName, string tableParams)
		{
			if (IsTableExist(database, tableName))
				return;
			CreateTable(database, tableName, tableParams);
		}

		/// <summary>
		/// 在指定数据库中，判断表是否存在
		/// </summary>
		/// <param name="database">数据库名（在fbembed.dll所在目录；或者是绝对路径+数据库名）</param>
		/// <param name="tableName">表名</param>
    public static bool IsTableExist(string database, string tableName)
		{
			bool exist = false;
			using (FbConnection conn = new FbConnection(GetConnectionString(database))) {
				conn.Open();
				exist = SqlExecuteBaseUtil.ExecuteScalar<bool>(conn, null, SqlUtil.GetJudgeTableExistSql(tableName), obj => {
					int count = 0;
					if (obj.Equals(null) || obj.Equals(System.DBNull.Value)) {
						count = -1;
					} else {
						count = (int)obj;
					}
					return count > 0;
				});
			}
			return exist;
		}

		/// <summary>
		/// 在指定数据库中，创建数据表
		/// </summary>
		/// <param name="database">数据库名（在fbembed.dll所在目录；或者是绝对路径+数据库名）</param>
		/// <param name="tableName">表名</param>
		/// <param name="tableParams">创建表的字段的相关参数信息</param>
		public static void CreateTable(string database, string tableName, string tableParams)
		{
			FbConnection cn = new FbConnection(GetConnectionString(database));

			cn.Open();
			string strSQL = SqlUtil.GetCreateTableSql(tableName, tableParams);
			SqlExecuteBaseUtil.ExecuteNonQuery(cn, null, strSQL);
			cn.Close();
		}

		/// <summary>
		/// 如果数据库不存在，则创建数据库
		/// </summary>
		/// <param name="database">数据库名（在fbembed.dll所在目录；或者是绝对路径+数据库名）</param>
		public static void CreateDataBaseIfNotExist(string database)
		{
			if (!File.Exists(database))
				FbConnection.CreateDatabase(GetConnectionString(database));
		}

		/// <summary>
		/// 获取连接字符串
		/// </summary>
		/// <param name="database">数据库名（在fbembed.dll所在目录；或者是绝对路径+数据库名）</param>
		public static string GetConnectionString(string database)
		{
			FbConnectionStringBuilder cs = new FbConnectionStringBuilder();
			cs.Database = database;
			cs.UserID = "SYSDBA";
			cs.Password = "masterkey";
			cs.Charset = "UTF8";
			cs.ServerType = FbServerType.Embedded;
			return cs.ToString();
		}

		#region 注销的代码:插入数据。注销原因：要求数据的顺序与数据表的顺序一致
		///// <summary>
		///// 向指定数据库的指定表中，插入一条数据。
		///// <para>fields为字段，values为与字段对应的值</para>
		///// </summary>
		///// <param name="database">数据库名（在fbembed.dll所在目录；或者是绝对路径+数据库名）</param>
		///// <param name="tableName">表名</param>
		///// <param name="fields">一条数据的字段信息，与值信息一一对应</param>
		///// <param name="values">一条数据的值信息，与字段信息一一对应</param>
		//public static void Insert(string database, string tableName, IList<string> fields, IList<object> values)
		//{
		//  var preparedParams = PrepareInsertSQLParams(fields, values);
		//  InsertPrepared(database, tableName, preparedParams);
		//}

		///// <summary>
		///// 向指定数据库的指定表中，插入一条数据。
		///// <para>数据的Key为字段，Value为字段对应的值</para>
		///// </summary>
		///// <param name="database">数据库名（在fbembed.dll所在目录；或者是绝对路径+数据库名）</param>
		///// <param name="tableName">表名</param>
		///// <param name="fieldsValues">一条数据的信息</param>
		//public static void Insert(string database, string tableName, IDictionary<string, object> fieldsValues)
		//{
		//  var preparedParams = PrepareInsertSQLParams(fieldsValues);
		//  InsertPrepared(database, tableName, preparedParams);
		//}

		///// <summary>
		///// 向指定数据库的指定表中，插入一条数据。
		///// <para>数据的Key为字段对应的变量名(字段前加@)，Value为字段对应的值</para>
		///// </summary>
		///// <param name="database">数据库名（在fbembed.dll所在目录；或者是绝对路径+数据库名）</param>
		///// <param name="tableName">表名</param>
		///// <param name="fieldsValues">一条数据的信息，是经过处理的</param>
		//private static void InsertPrepared(string database, string tableName, IDictionary<string, object> fieldsValues)
		//{
		//  string insertString = "insert into {0} values ({1})";//"insert into tb_user values (@id, @word)"
		//  insertString = string.Format(insertString, tableName, string.Join(", ", fieldsValues.Keys));
		//  using (FbConnection conn = new FbConnection(GetConnectionString(database))) {
		//    conn.Open();
		//    using (FbCommand insertData = conn.CreateCommand()) {
		//      insertData.CommandText = insertString;
		//      insertData.Parameters.Clear();
		//      foreach (var item in fieldsValues) {
		//        insertData.Parameters.AddWithValue(item.Key, item.Value);
		//      }
		//      insertData.ExecuteNonQuery();
		//    }
		//  }
		//}

		//    /// <summary>
		//    /// 获取插入数据参数，key为变量名，value为值。
		//    /// <para>在字段名前加@，使其成为变量名</para>
		//    /// </summary>
		//    private static IDictionary<string, object> PrepareInsertSQLParams(IList<string> fields, IList<object> values)
		//    {
		//#if DEBUG
		//      if (fields == null || values == null)
		//        throw new ApplicationException("没有初始化参数");
		//      if (fields.Count != values.Count)
		//        throw new ApplicationException("字段与值的数量不匹配");
		//#endif
		//      Dictionary<string, object> paramS = new Dictionary<string, object>();
		//      for (int i = 0; i < fields.Count; i++)
		//        paramS.Add("@" + fields[i], values[i]);
		//      return paramS;
		//    }

		//    /// <summary>
		//    /// 获取插入数据参数，key为变量名，value为值。
		//    /// <para>在字段名前加@，使其成为变量名</para>
		//    /// </summary>
		//    private static IDictionary<string, object> PrepareInsertSQLParams(IDictionary<string, object> fieldsValues)
		//    {
		//#if DEBUG
		//      if (fieldsValues == null || fieldsValues.Count == 0)//TODO:为0时，是否要特殊处理？即不执行插入操作
		//        throw new ApplicationException("没有初始化参数");
		//#endif
		//      Dictionary<string, object> paramS = new Dictionary<string, object>();
		//      foreach (var item in fieldsValues)
		//        paramS.Add("@" + item.Key, item.Value);
		//      return paramS;
		//    }
		#endregion

	}
}