using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Windows.Forms;
using JD.Application.Utils;
using JD.Application.View.Misc;
using JD.Application.View.Timeline;
using JD.Audio.Annotations;
using JD.Audio.SoundPlayer;
using JD.Collections.Extensions;
using JD.Maths.Utils;
using JD.MessageService;
using JD.Timeline.Model.Clips;
using JD.Timeline.View.Actions.Refactor;
using JD.Timeline.View.ClipView;
using TeaBox;
using TeaBox.Gui;
using JD.Serialization;
using JD.WinFormExtensions;
using TeaBox.Core.Source.Gui;
using TeaBox.Core.Source.Gui.Misc;
using FrameConverter = JD.Core.FrameConverter;

namespace JD.Timeline.View.Actions
{
    /// <summary>
    /// Provides the different menu actions to create a new clip.
    /// </summary>
    public class AddNewClipActionHandler : TapeActionHandlerBase
    {
        protected virtual IEnumerable<System.Type> ClipTypes()
        {
            return Track != null ? Track.ClipTypes() : Enumerable.Empty<System.Type>();
        }

        public AddNewClipActionHandler()
        {
            ClipLimit = 500;
        }

        protected ClipViewControl CurrentControl
        {
            get
            {
                var view = CurrentView;
                return view != null ? view.ClipView : null;
            }
        }

        protected TapeTrack Track
        {
            get; set;
        }

        public override bool UpdateArray(ActionContext context, ActionArrayInfo info)
        {
            if (CurrentView == null || SelectedClips.Any())
            {
                return true;
            }

            Point currentLocation = context.Location;
            if (currentLocation == Point.Empty)
            {
                currentLocation = Control.MousePosition;
            }

            var dropLocation = CurrentControl.PointToClient(currentLocation);
            Track = CurrentControl.TrackFromPoint(dropLocation.Y);

            if (Track != null)
            {
                foreach (var clipType in ClipTypes().AsSorted((x1, x2) => System.String.Compare(x1.Name, x2.Name, System.StringComparison.Ordinal)))
                {
                    var action = new ActionInfoElement("Add " + clipType.GetStyle().DisplayName)
                                     {
                                         Icon = new ImageOrIcon(clipType.GetStyle().Icon),
                                         State = clipType
                                     };
                    info.Add(action);
                }
            }
            return true;
        }

        public override void Execute(ActionExecutionContext context)
        {
            if (CurrentTape == null)
            {
                return;
            }

            var type = (System.Type)context.State;

            // From the shortcut.
            Clip newClip;
            if (type == null)
            {
                newClip = InstantiateDefaultClip();
            }
            else
            {
                var dropLocation = CurrentControl.PointToClient(context.Location);
                newClip = Instantiate(type, dropLocation);
            }

            if (newClip != null)
            {
                CurrentTape.Clips.Add(newClip);
                var newWidget = CurrentControl.ClipWidgets.FirstOrDefault(x => x.Model == newClip);
                newWidget.OnInserted();
            }
        }

        private Clip InstantiateDefaultClip()
        {
            var trackWidget = CurrentView.ClipView.TrackView.ActiveTrack as TapeTrackWidget;
            if (trackWidget != null)
            {
                var track = trackWidget.Track;
                var clipType = track.ClipTypes().SingleOrDefault();
                var curentBeat = CurrentControl.Timeline.ConvertTo(CurrentControl.Timeline.TimeCursor.Time, TimeUnit.Beat);

                if (clipType == null)
                {
                    // When the track is not of a fixed type
                    // we assume the user might want to create the same type of clip he just created before.
                    // so we find a type that is near the actual time cursor on the same track.

                    clipType = (from clip in track.Tape.Clips
                                where clip.Track == track
                                orderby Math.Abs(clip.StartBeat - curentBeat) 
                                select clip.GetType()).FirstOrDefault();
                }

                if (clipType != null && ValidateCanAddClip(clipType))
                {
                    curentBeat = CurrentTape.TryGetWave().UnitConverter.Snap(new BeatUnit(curentBeat), EditionOptions.CurrentSnappingUnit).Value;

                    var newClip = Clip.Instantiate(clipType);
                    newClip.InitializeDefaultValues();
                    newClip.StartFrame = FindBestStartFrame(track, FrameConverter.FrameFromTimeInteger(curentBeat));
                    newClip.TrackId = track.Id;
                    return newClip;
                }
            }
            return null;
        }

        protected virtual Clip Instantiate(System.Type clipType, Point dropLocation)
        {
            var track = CurrentControl.TrackFromPoint(dropLocation.Y);

            if (track != null && ValidateCanAddClip(clipType))
            {
                var newEvent = Clip.Instantiate(clipType);
                newEvent.InitializeDefaultValues();
                newEvent.StartFrame = FindBestStartFrame(track, (int) CurrentControl.FrameFromPoint(dropLocation.X));
                newEvent.TrackId = track.Id;

                if (newEvent.DefaultDuration > 0)
                {
                    newEvent.Duration = newEvent.DefaultDuration;
                }
                else
                {
                    newEvent.Duration = (int)CurrentControl.Timeline.FrameFromPixelDuration(200);
                }
                return newEvent;
            }
            return null;
        }

        /// <summary>
        /// Sets the starting frame to make sure it does not overlap an existing clip
        /// </summary>
        private int FindBestStartFrame(TapeTrack track, int frame)
        {
            Clip collidingClip;

            while (TryGetCollidingClip(track, frame, out collidingClip))
            {
                frame = collidingClip.StopFrame;
            }

            return frame;
        }

        private bool TryGetCollidingClip(TapeTrack track, int frame, out Clip collision)
        {
            collision = track.Clips().FirstOrDefault(x => frame.IsBetween(x.StartFrame, x.StopFrame - 1));
            return collision != null;
        }

        protected int ClipLimit
        {
            get; set;
        }

        private bool ValidateCanAddClip(System.Type type)
        {
            var clipCount = CurrentControl.Tape.Clips.Count;
            if (type != typeof(TapeReferenceClip) && clipCount > ClipLimit)
            {
                var dialog = new MessageDialog
                    {
                        MainIcon = MessageDialogIcon.Warning,
                        Content =
                            $"Clip limit reached ({clipCount} clips instead of 300). Are you sure you want to continue?"
                    };

                var yes = dialog.AddButton("Add clip anyway");
                yes.Content = "We suggest you start to reduce the clip count before adding new clips.";
                var help = dialog.AddButton("Help");
                var cancel = dialog.AddButton("Cancel");
                cancel.IsDefault = true;

                var result = dialog.ShowDialog();
                if (result == help)
                {
                    ClipLimitWarning.OpenHelpFile();
                }
                return result == yes;
            }
            return true;
        }
    }
}