// Copyright (c) Microsoft Corporation
// The Microsoft Corporation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Media.Imaging;
using ProjectsEditor.Models;

namespace ProjectsEditor.Utils
{
    public class DrawHelper
    {
        public static BitmapImage DrawPreview(Project project, Rectangle bounds)
        {
            double scale = 0.1;
            int Scaled(double value)
            {
                return (int)(value * scale);
            }

            Dictionary<string, int> repeatCounter = new Dictionary<string, int>();

            var selectedApps = project.Applications.Where(x => x.IsSelected);
            foreach (Application app in selectedApps)
            {
                if (repeatCounter.TryGetValue(app.AppPath, out int value))
                {
                    repeatCounter[app.AppPath] = ++value;
                }
                else
                {
                    repeatCounter.Add(app.AppPath, 1);
                }

                app.RepeatIndex = repeatCounter[app.AppPath];
            }

            // remove those repeatIndexes, which are single 1-es (no repetitions) by setting them to 0
            foreach (Application app in selectedApps.Where(x => repeatCounter[x.AppPath] == 1))
            {
                app.RepeatIndex = 0;
            }

            foreach (Application app in project.Applications.Where(x => !x.IsSelected))
            {
                app.RepeatIndex = 0;
            }

            // now that all repeat index values are set, update the repeat index strings on UI
            foreach (Application app in project.Applications)
            {
                app.OnPropertyChanged(new PropertyChangedEventArgs("RepeatIndexString"));
            }

            Bitmap previewBitmap = new Bitmap(Scaled(bounds.Width), Scaled(bounds.Height * 1.2));
            using (Graphics g = Graphics.FromImage(previewBitmap))
            {
                g.SmoothingMode = SmoothingMode.AntiAlias;
                g.InterpolationMode = InterpolationMode.HighQualityBicubic;
                g.PixelOffsetMode = PixelOffsetMode.HighQuality;

                g.Clear(Color.FromArgb(0, 0, 0, 0));
                Brush brush = new SolidBrush(Color.FromArgb(10, 255, 255, 255)); // TODO: set theme-related colors
                foreach (Application app in project.Applications.Where(x => x.IsSelected && !x.Minimized))
                {
                    Rectangle rect = new Rectangle(Scaled(app.ScaledPosition.X - bounds.Left), Scaled(app.ScaledPosition.Y - bounds.Top), Scaled(app.ScaledPosition.Width), Scaled(app.ScaledPosition.Height));
                    DrawWindow(g, brush, rect, app);
                }

                Rectangle rectMinimized = new Rectangle(0, Scaled(bounds.Height), Scaled(bounds.Width), Scaled(bounds.Height * 0.2));
                DrawWindow(g, brush, rectMinimized, project.Applications.Where(x => x.IsSelected && x.Minimized));
            }

            using (var memory = new MemoryStream())
            {
                previewBitmap.Save(memory, ImageFormat.Png);
                memory.Position = 0;

                var bitmapImage = new BitmapImage();
                bitmapImage.BeginInit();
                bitmapImage.StreamSource = memory;
                bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
                bitmapImage.EndInit();
                bitmapImage.Freeze();

                return bitmapImage;
            }
        }

        public static void DrawWindow(Graphics graphics, Brush brush, Rectangle bounds, Application app)
        {
            if (graphics == null)
            {
                return;
            }

            if (brush == null)
            {
                return;
            }

            using (GraphicsPath path = RoundedRect(bounds))
            {
                if (app.IsHighlighted)
                {
                    graphics.DrawPath(new Pen(Color.White, graphics.VisibleClipBounds.Height / 25), path); // TODO: set theme-related colors
                }
                else
                {
                    graphics.DrawPath(new Pen(Color.FromArgb(128, 82, 82, 82), graphics.VisibleClipBounds.Height / 100), path); // TODO: set theme-related colors
                }

                graphics.FillPath(brush, path);
            }

            double iconSize = Math.Min(bounds.Width, bounds.Height) * 0.3;
            Rectangle iconBounds = new Rectangle((int)(bounds.Left + (bounds.Width / 2) - (iconSize / 2)), (int)(bounds.Top + (bounds.Height / 2) - (iconSize / 2)), (int)iconSize, (int)iconSize);

            try
            {
                graphics.DrawIcon(app.Icon, iconBounds);
                if (app.RepeatIndex > 0)
                {
                    string indexString = app.RepeatIndex.ToString(CultureInfo.InvariantCulture);
                    System.Drawing.Font font = new System.Drawing.Font("Tahoma", 8);
                    int indexSize = (int)(iconBounds.Width * 0.5);
                    Rectangle indexBounds = new Rectangle(iconBounds.Right - indexSize, iconBounds.Bottom - indexSize, indexSize, indexSize);

                    var textSize = graphics.MeasureString(indexString, font);
                    var state = graphics.Save();
                    graphics.TranslateTransform(indexBounds.Left, indexBounds.Top);
                    graphics.ScaleTransform(indexBounds.Width / textSize.Width, indexBounds.Height / textSize.Height);
                    graphics.DrawString(indexString, font, Brushes.Black, PointF.Empty);
                    graphics.Restore(state);
                }
            }
            catch (Exception)
            {
                // sometimes drawing an icon throws an exception despite that the icon seems to be ok
            }
        }

        public static void DrawWindow(Graphics graphics, Brush brush, Rectangle bounds, IEnumerable<Application> apps)
        {
            int appsCount = apps.Count();
            if (appsCount == 0)
            {
                return;
            }

            if (graphics == null)
            {
                return;
            }

            if (brush == null)
            {
                return;
            }

            using (GraphicsPath path = RoundedRect(bounds))
            {
                if (apps.Where(x => x.IsHighlighted).Any())
                {
                    graphics.DrawPath(new Pen(Color.White, graphics.VisibleClipBounds.Height / 25), path);
                }
                else
                {
                    graphics.DrawPath(new Pen(Color.FromArgb(128, 82, 82, 82), graphics.VisibleClipBounds.Height / 100), path);
                }

                graphics.FillPath(brush, path);
            }

            double iconSize = Math.Min(bounds.Width, bounds.Height) * 0.5;
            for (int iconCounter = 0; iconCounter < appsCount; iconCounter++)
            {
                Application app = apps.ElementAt(iconCounter);
                Rectangle iconBounds = new Rectangle((int)(bounds.Left + (bounds.Width / 2) - (iconSize * ((appsCount / 2) - iconCounter))), (int)(bounds.Top + (bounds.Height / 2) - (iconSize / 2)), (int)iconSize, (int)iconSize);

                try
                {
                    graphics.DrawIcon(app.Icon, iconBounds);
                    if (app.RepeatIndex > 0)
                    {
                        string indexString = app.RepeatIndex.ToString(CultureInfo.InvariantCulture);
                        System.Drawing.Font font = new System.Drawing.Font("Tahoma", 8);
                        int indexSize = (int)(iconBounds.Width * 0.5);
                        Rectangle indexBounds = new Rectangle(iconBounds.Right - indexSize, iconBounds.Bottom - indexSize, indexSize, indexSize);

                        var textSize = graphics.MeasureString(indexString, font);
                        var state = graphics.Save();
                        graphics.TranslateTransform(indexBounds.Left, indexBounds.Top);
                        graphics.ScaleTransform(indexBounds.Width / textSize.Width, indexBounds.Height / textSize.Height);
                        graphics.DrawString(indexString, font, Brushes.Black, PointF.Empty);
                        graphics.Restore(state);
                    }
                }
                catch (Exception)
                {
                    // sometimes drawing an icon throws an exception despite that the icon seems to be ok
                }
            }
        }

        public static GraphicsPath RoundedRect(Rectangle bounds)
        {
            int minorSize = Math.Min(bounds.Width, bounds.Height);
            int radius = (int)(minorSize / 8);

            int diameter = radius * 2;
            Size size = new Size(diameter, diameter);
            Rectangle arc = new Rectangle(bounds.Location, size);
            GraphicsPath path = new GraphicsPath();

            if (radius == 0)
            {
                path.AddRectangle(bounds);
                return path;
            }

            // top left arc
            path.AddArc(arc, 180, 90);

            // top right arc
            arc.X = bounds.Right - diameter;
            path.AddArc(arc, 270, 90);

            // bottom right arc
            arc.Y = bounds.Bottom - diameter;
            path.AddArc(arc, 0, 90);

            // bottom left arc
            arc.X = bounds.Left;
            path.AddArc(arc, 90, 90);

            path.CloseFigure();
            return path;
        }
    }
}