#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.Drawing;
using System.Windows.Forms;

namespace MiniSqlQuery.Core.Commands
{
    /// <summary>
    /// 	<para>A basic implementation of the <see cref="ICommand"/> interface.</para>
    /// 	<para>Represents a "command", typically a user action such as saving a file or executing a query.</para>
    /// 	<para>Inheritors must implement the abstract method <see cref="Execute"/>.</para>
    /// </summary>
    public abstract class CommandBase : ICommand
    {
        /// <summary>
        /// 	The host window.
        /// </summary>
        private IHostWindow _hostWindow;

        /// <summary>
        /// 	The command name.
        /// </summary>
        private string _name;

        /// <summary>
        /// 	Initializes a new instance of the <see cref="CommandBase"/> class.
        /// 	The default value for <see cref="Enabled"/> is true, and <see cref="ShortcutKeys"/> is Keys.None.
        /// </summary>
        /// <param name="name">
        /// 	The name of the command.
        /// </param>
        protected CommandBase(string name)
        {
            _name = name;
            ShortcutKeys = Keys.None;
        }

        /// <summary>
        /// 	Gets a value indicating whether this <see cref = "ICommand" /> is enabled.
        /// </summary>
        /// <value><c>true</c> if enabled; otherwise, <c>false</c> (the default is true).</value>
        public virtual bool Enabled
        {
            get { return true; }
        }

        public object Host { get; set; }

        /// <summary>
        /// 	The name of the command, used in menus and buttons.
        /// </summary>
        /// <value>The name of the command.</value>
        public virtual string Name
        {
            get { return _name; }
            protected set
            {
                if (_name == value)
                {
                    return;
                }

                _name = value;

                // if the "host" of this command is a toolstring item, update its Text property.
                var item = Host as ToolStripItem;
                if (item != null)
                {
                    item.Text = _name;
                }
            }
        }

        /// <summary>
        /// 	A reference to the application services to allow access to the other components.
        /// </summary>
        /// <value>A reference to the <see cref = "IApplicationServices" /> instance.</value>
        public IApplicationServices Services { get; set; }

        /// <summary>
        /// 	Gets a reference to the application settings.
        /// </summary>
        /// <value>The application settings.</value>
        public IApplicationSettings Settings { get; set; }

        /// <summary>
        /// 	Gets the menu shortcut keys for this command (e.g. Keys.F5).
        /// </summary>
        /// <value>The shortcut keys for this command (the default is Keys.None).</value>
        public virtual Keys ShortcutKeys { get; protected set; }

        /// <summary>
        /// 	Gets the shortcut key text to be displayed as help.
        /// </summary>
        /// <value>The shortcut keys text.</value>
        public string ShortcutKeysText { get; protected set; }

        /// <summary>
        /// 	Gets the "small image" associated with this control (for use on buttons or menu items).
        /// 	Use null (or Nothing in Visual Basic) if there is no image.
        /// </summary>
        /// <value>The small image representing this command (the default is null).</value>
        public virtual Image SmallImage { get; protected set; }

        /// <summary>
        /// 	Attempts to convert the current host windows active form to <see cref = "IEditor" />.
        /// </summary>
        /// <value>A reference to the active base editor window, otherwise null.</value>
        protected IEditor ActiveFormAsEditor
        {
            get { return Services.HostWindow.ActiveChildForm as IEditor; }
        }

        /// <summary>
        /// 	Attempts to convert the current host windows active form to <see cref = "IQueryEditor" />.
        /// </summary>
        /// <value>A reference to the active query editor window, otherwise null.</value>
        protected IQueryEditor ActiveFormAsSqlQueryEditor
        {
            get { return Services.HostWindow.ActiveChildForm as IQueryEditor; }
        }

        /// <summary>
        /// 	Gets a reference to the host window.
        /// </summary>
        /// <value>The host window.</value>
        protected IHostWindow HostWindow
        {
            get { return _hostWindow ?? (_hostWindow = Services.HostWindow); }
        }

        /// <summary>
        /// 	Executes the command based on the current settings (abstract).
        /// </summary>
        /// <remarks>
        /// 	If a commands <see cref="Enabled"/> value is false, a call to <see cref="Execute"/> should have no effect
        /// 	(and not throw an exception).
        /// </remarks>
        public abstract void Execute();
    }
}