/* 
 * Copyright (c) 2009 Craig Sutherland
 * 
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

using System.Data;
using System.Data.Common;
using System;

namespace FastForward.Cache
{
    /// <summary>
    /// An abstraction of the database connection.
    /// </summary>
    /// <remarks>
    /// This allows the cache to be independent of any particular database implementation.
    /// </remarks>
    public abstract class DatabaseConnection
    {
        #region Public properties
        #region ConnectionString
        /// <summary>
        /// Gets or sets the connection string.
        /// </summary>
        public string ConnectionString { get; set; }
        #endregion
        #endregion

        #region Public methods
        #region Initialise()
        /// <summary>
        /// Initialise a new database connection.
        /// </summary>
        /// <param name="type"></param>
        /// <param name="connectionString"></param>
        /// <returns></returns>
        public static DatabaseConnection Initialise(string type, string connectionString)
        {
            var actualType = Type.GetType(type);
            var connection = Activator.CreateInstance(actualType) as DatabaseConnection;
            connection.ConnectionString = connectionString;
            connection.OnInitialiseSchema();
            return connection;
        }
        #endregion

        #region RetrieveData()
        /// <summary>
        /// Retrieve some data from the database.
        /// </summary>
        /// <returns>a <see cref="IDataReader"/> containing the data.</returns>
        public abstract DbDataReader RetrieveData(string dataSource, DatabaseCondition condition);
        #endregion

        #region Insert()
        /// <summary>
        /// Inserts a row into the database.
        /// </summary>
        /// <param name="dataSource">The data store (e.g table).</param>
        /// <param name="values">The values to insert.</param>
        public abstract void Insert(string dataSource, params DatabaseValue[] values);
        #endregion
        #endregion

        #region Protected methods
        #region OnInitialise()
        /// <summary>
        /// Initialise the database schema if necessary.
        /// </summary>
        protected virtual void OnInitialiseSchema()
        {
        }
        #endregion
        #endregion
    }
}