using System;
using System.Collections.Generic;
using System.Windows.Forms;
using JD.Kernel.StaticHelpers;
using JD.Sequencers.Controls;

namespace JD.Sequencers.Tools
{
    /// <summary>
    /// Manages the tools for a <see cref="WindowlessContainer"/>
    /// </summary>
    public class ToolManager
    {
        #region Variables

        private readonly WindowlessContainer m_container;
        private Tool m_currentTool;

        private readonly List<Tool> m_mouseDownTools = new List<Tool>();
        private readonly List<Tool> m_mouseMoveTools = new List<Tool>();
        private readonly List<Tool> m_mouseUpTools = new List<Tool>();
        private readonly List<Tool> m_mouseWheelTools = new List<Tool>();

        #endregion

        #region Constructor

        /// <summary>
        /// Constructor.
        /// </summary>
        public ToolManager(WindowlessContainer container)
        {
            Throw.IfNull(container, "container");
            m_container = container;
        }

        #endregion

        #region Properties

        public WindowlessContainer Container
        {
            get { return m_container; }
        }

        /// <summary>
        /// The current tool.
        /// </summary>
        public Tool CurrentTool
        {
            get { return m_currentTool; }
            set
            {
                if (m_currentTool != value)
                {
                    if (m_currentTool != null)
                    {
                        m_currentTool.End();
                    }

                    m_currentTool = value;

                    if (m_currentTool != null)
                    {
                        m_currentTool.Start();
                    }

                    OnCurrentToolChanged(EventArgs.Empty);
                }
            }
        }

        #region Mouse Tools

        /// <summary>
        /// Mouse Down Tools
        /// </summary>
        public IList<Tool> MouseDownTools
        {
            get
            {
                return m_mouseDownTools;
            }
        }

        /// <summary>
        /// Mouse Move Tools
        /// </summary>
        public IList<Tool> MouseMoveTools
        {
            get
            {
                return m_mouseMoveTools;
            }
        }

        /// <summary>
        /// Mouse Up Tools
        /// </summary>
        public IList<Tool> MouseUpTools
        {
            get
            {
                return m_mouseUpTools;
            }
        }

        /// <summary>
        /// Mouse Wheel Tools
        /// </summary>
        public IList<Tool> MouseWheelTools
        {
            get
            {
                return m_mouseWheelTools;
            }
        }

        #endregion

        #endregion

        #region Methods

        public void OnMouseDown(MouseEventArgs e)
        {
            StartToolIfPossible(MouseDownTools, e);
            if (CurrentTool != null)
            {
                CurrentTool.OnMouseDown(e);
            }
        }

        public void OnMouseUp(MouseEventArgs e)
        {
            StartToolIfPossible(MouseUpTools, e);
            if (CurrentTool != null)
            {
                CurrentTool.OnMouseUp(e);
            }
        }

        public void OnMouseMove(MouseEventArgs e)
        {
            if (CurrentTool != null)
            {
                CurrentTool.OnMouseMove(e);
            }
            else
            {
                StartToolIfPossible(MouseMoveTools, e);
            }
        }

        public void OnMouseWheel(MouseEventArgs e)
        {
            StartToolIfPossible(MouseWheelTools, e);
            if (CurrentTool != null)
            {
                CurrentTool.OnMouseWheel(e);
            }
        }

        private void StartToolIfPossible(IEnumerable<Tool> tools, MouseEventArgs e)
        {
            foreach (Tool tool in tools)
            {
                var eventArgs = new ToolStartingEventArgs(e);

                bool canStart = tool.CanStart(eventArgs);

                if (eventArgs.CancelEntireEvent)
                {
                    return;
                }

                if (canStart)
                {
                    CurrentTool = tool;
                    return;
                }
            }
        }

        #endregion

        #region Events

        /// <summary>
        /// Triggered when the <see cref="CurrentTool"/> changes.
        /// </summary>
        public event EventHandler CurrentToolChanged;

        /// <summary>
        /// Triggers the <see cref="CurrentToolChanged"/> event.
        /// </summary>
        /// <param name="e">Event Args.</param>
        protected void OnCurrentToolChanged(EventArgs e)
        {
            CurrentToolChanged?.Invoke(Container, e);
        }

        #endregion
    }
}