using System;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Media;
using Flow.Launcher.Infrastructure.Image;
using Flow.Launcher.Infrastructure.Logger;
using Flow.Launcher.Infrastructure.UserSettings;
using Flow.Launcher.Plugin;
using System.IO;
using System.Drawing.Text;
using System.Collections.Generic;

namespace Flow.Launcher.ViewModel
{
    public class ResultViewModel : BaseModel
    {
        private static PrivateFontCollection fontCollection = new();
        private static Dictionary<string, string> fonts = new();

        public ResultViewModel(Result result, Settings settings)
        {
            Settings = settings;

            if (result == null)
            {
                return;
            }
            Result = result;

            if (Result.Glyph is { FontFamily: not null } glyph)
            {
                // Checks if it's a system installed font, which does not require path to be provided. 
                if (glyph.FontFamily.EndsWith(".ttf") || glyph.FontFamily.EndsWith(".otf"))
                {
                    string fontFamilyPath = glyph.FontFamily;

                    if (!Path.IsPathRooted(fontFamilyPath))
                    {
                        fontFamilyPath = Path.Combine(Result.PluginDirectory, fontFamilyPath);
                    }

                    if (fonts.ContainsKey(fontFamilyPath))
                    {
                        Glyph = glyph with
                        {
                            FontFamily = fonts[fontFamilyPath]
                        };
                    }
                    else
                    {
                        fontCollection.AddFontFile(fontFamilyPath);
                        fonts[fontFamilyPath] = $"{Path.GetDirectoryName(fontFamilyPath)}/#{fontCollection.Families[^1].Name}";
                        Glyph = glyph with
                        {
                            FontFamily = fonts[fontFamilyPath]
                        };
                    }
                }
                else
                {
                    Glyph = glyph;
                }
            }

        }

        private Settings Settings { get; }

        public Visibility ShowOpenResultHotkey =>
            Settings.ShowOpenResultHotkey ? Visibility.Visible : Visibility.Collapsed;

        public Visibility ShowDefaultPreview => Result.PreviewPanel == null ? Visibility.Visible : Visibility.Collapsed;

        public Visibility ShowCustomizedPreview => Result.PreviewPanel == null ? Visibility.Collapsed : Visibility.Visible;

        public Visibility ShowIcon
        {
            get
            {
                // If both glyph and image icons are not available, it will then be the default icon
                if (!ImgIconAvailable && !GlyphAvailable)
                    return Visibility.Visible;

                // Although user can choose to use glyph icons, plugins may choose to supply only image icons.
                // In this case we ignore the setting because otherwise icons will not display as intended
                if (Settings.UseGlyphIcons && !GlyphAvailable && ImgIconAvailable)
                    return Visibility.Visible;

                return !Settings.UseGlyphIcons && ImgIconAvailable ? Visibility.Visible : Visibility.Hidden;
            }
        }

        public bool ShowPreviewImage
        {
            get
            {
                if (!string.IsNullOrEmpty(Result.Preview.PreviewImagePath) || Result.Preview.PreviewDelegate != null)
                {
                    return true;
                }
                else
                {
                    // Fall back to Icon
                    if (!ImgIconAvailable && !GlyphAvailable)
                        return true;

                    // Although user can choose to use glyph icons, plugins may choose to supply only image icons.
                    // In this case we ignore the setting because otherwise icons will not display as intended
                    if (Settings.UseGlyphIcons && !GlyphAvailable && ImgIconAvailable)
                        return true;

                    return !Settings.UseGlyphIcons && ImgIconAvailable;
                }
            }
        }

        public double IconRadius
        {
            get
            {
                if (Result.RoundedIcon)
                {
                    return IconXY / 2;
                }
                return IconXY;
            }

        }

        public Visibility ShowGlyph
        {
            get
            {
                // Although user can choose to not use glyph icons, plugins may choose to supply only glyph icons.
                // In this case we ignore the setting because otherwise icons will not display as intended
                if (!Settings.UseGlyphIcons && !ImgIconAvailable && GlyphAvailable)
                    return Visibility.Visible;

                return Settings.UseGlyphIcons && GlyphAvailable ? Visibility.Visible : Visibility.Collapsed;
            }
        }

        private bool GlyphAvailable => Glyph is not null;

        private bool ImgIconAvailable => !string.IsNullOrEmpty(Result.IcoPath) || Result.Icon is not null;

        private bool PreviewImageAvailable => !string.IsNullOrEmpty(Result.Preview.PreviewImagePath) || Result.Preview.PreviewDelegate != null;

        public string OpenResultModifiers => Settings.OpenResultModifiers;

        public string ShowTitleToolTip => string.IsNullOrEmpty(Result.TitleToolTip)
            ? Result.Title
            : Result.TitleToolTip;

        public string ShowSubTitleToolTip => string.IsNullOrEmpty(Result.SubTitleToolTip)
            ? Result.SubTitle
            : Result.SubTitleToolTip;

        private volatile bool ImageLoaded;
        private volatile bool PreviewImageLoaded;

        private ImageSource image = ImageLoader.LoadingImage;
        private ImageSource previewImage = ImageLoader.LoadingImage;

        public ImageSource Image
        {
            get
            {
                if (!ImageLoaded)
                {
                    ImageLoaded = true;
                    _ = LoadImageAsync();
                }

                return image;
            }
            private set => image = value;
        }

        public ImageSource PreviewImage
        {
            get => previewImage;
            private set => previewImage = value;
        }

        /// <summary>
        /// Determines if to use the full width of the preview panel
        /// </summary>
        public bool UseBigThumbnail => Result.Preview.IsMedia;

        public GlyphInfo Glyph { get; set; }

        private async Task<ImageSource> LoadImageInternalAsync(string imagePath, Result.IconDelegate icon, bool loadFullImage)
        {
            if (string.IsNullOrEmpty(imagePath) && icon != null)
            {
                try
                {
                    var image = await Task.Run(() => icon()).ConfigureAwait(false);
                    return image;
                }
                catch (Exception e)
                {
                    Log.Exception(
                        $"|ResultViewModel.LoadImageInternalAsync|IcoPath is empty and exception when calling IconDelegate for result <{Result.Title}> of plugin <{Result.PluginDirectory}>",
                        e);
                }
            }

            return await ImageLoader.LoadAsync(imagePath, loadFullImage).ConfigureAwait(false);
        }

        private async Task LoadImageAsync()
        {
            var imagePath = Result.IcoPath;
            var iconDelegate = Result.Icon;
            if (ImageLoader.TryGetValue(imagePath, false, out ImageSource img))
            {
                image = img;
            }
            else
            {
                // We need to modify the property not field here to trigger the OnPropertyChanged event
                Image = await LoadImageInternalAsync(imagePath, iconDelegate, false).ConfigureAwait(false);
            }
        }

        private async Task LoadPreviewImageAsync()
        {
            var imagePath = Result.Preview.PreviewImagePath ?? Result.IcoPath;
            var iconDelegate = Result.Preview.PreviewDelegate ?? Result.Icon;
            if (ImageLoader.TryGetValue(imagePath, true, out ImageSource img))
            {
                previewImage = img;
            }
            else
            {
                // We need to modify the property not field here to trigger the OnPropertyChanged event
                PreviewImage = await LoadImageInternalAsync(imagePath, iconDelegate, true).ConfigureAwait(false);
            }
        }

        public void LoadPreviewImage()
        {
            if (ShowDefaultPreview == Visibility.Visible)
            {
                if (!PreviewImageLoaded && ShowPreviewImage)
                {
                    PreviewImageLoaded = true;
                    _ = LoadPreviewImageAsync();
                }
            }
        }

        public Result Result { get; }
        public int ResultProgress
        {
            get
            {
                if (Result.ProgressBar == null)
                    return 0;

                return Result.ProgressBar.Value;
            }
        }

        public string QuerySuggestionText { get; set; }

        public double IconXY { get; set; } = 32;

        public override bool Equals(object obj)
        {
            return obj is ResultViewModel r && Result.Equals(r.Result);
        }

        public override int GetHashCode()
        {
            return Result.GetHashCode();
        }

        public override string ToString()
        {
            return Result.ToString();
        }
    }
}