#region License

// Copyright 2005-2019 Paul Kohler (https://github.com/paulkohler/minisqlquery). All rights reserved.
// This source code is made available under the terms of the GNU Lesser General Public License v3.0
// https://github.com/paulkohler/minisqlquery/blob/master/LICENSE

#endregion

using System;
using System.Collections.Generic;

namespace MiniSqlQuery.Core
{
    /// <summary>
    /// 	Stores instances of commands by type.
    /// </summary>
    public class CommandManager
    {
        /// <summary>
        /// 	The command cache.
        /// </summary>
        private static readonly Dictionary<Type, ICommand> CommandCache = new Dictionary<Type, ICommand>();

        /// <summary>
        /// 	Gets the command instance by <paramref name = "commandTypeName" />.
        /// </summary>
        /// <param name = "commandTypeName">Name of the command, e.g. "OpenFileCommand".</param>
        /// <returns>The first command by that name or null if not found.</returns>
        public static ICommand GetCommandInstance(string commandTypeName)
        {
            foreach (Type cmdType in CommandCache.Keys)
            {
                if (cmdType.Name == commandTypeName)
                {
                    return CommandCache[cmdType];
                }
            }

            return null;
        }

        /// <summary>
        /// 	Gets or creates an instance of a command by type.
        /// </summary>
        /// <typeparam name = "TCommand">The type of command to get or create.</typeparam>
        /// <returns>An instance of <typeparamref name = "TCommand" />.</returns>
        public static ICommand GetCommandInstance<TCommand>() where TCommand : ICommand, new()
        {
            ICommand cmd;

            if (CommandCache.ContainsKey(typeof(TCommand)))
            {
                cmd = CommandCache[typeof(TCommand)];
            }
            else
            {
                cmd = new TCommand();
                cmd.Services = ApplicationServices.Instance;
                cmd.Settings = ApplicationServices.Instance.Settings;
                CommandCache[typeof(TCommand)] = cmd;
            }

            return cmd;
        }

        /// <summary>
        /// 	Gets command instance by it's partial name, e.g. "OpenFile".
        /// </summary>
        /// <param name = "commandName">Name partial of the command.</param>
        /// <returns>The first command by that name or null if not found.</returns>
        public static ICommand GetCommandInstanceByPartialName(string commandName)
        {
            string cmdName = commandName + "Command";

            foreach (Type cmdType in CommandCache.Keys)
            {
                if (cmdType.Name.EndsWith(commandName) || cmdType.Name.EndsWith(cmdName))
                {
                    return CommandCache[cmdType];
                }
            }

            return null;
        }
    }
}