FluentTerminal/FluentTerminal.App.Services/Implementation/ITermThemeParser.cs

using FluentTerminal.App.Services.Exceptions;
using FluentTerminal.Models;
using PListNet;
using PListNet.Nodes;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Threading.Tasks;

namespace FluentTerminal.App.Services.Implementation
{
    public class ITermThemeParser : IThemeParser
    {
        private const byte Opacity30Percent = 77;

        public IEnumerable<string> SupportedFileTypes { get; } = new string[] { ".itermcolors" };

        private static class ITermThemeKeys
        {
            public const string Ansi0Color = "Ansi 0 Color";
            public const string Ansi1Color = "Ansi 1 Color";
            public const string Ansi2Color = "Ansi 2 Color";
            public const string Ansi3Color = "Ansi 3 Color";
            public const string Ansi4Color = "Ansi 4 Color";
            public const string Ansi5Color = "Ansi 5 Color";
            public const string Ansi6Color = "Ansi 6 Color";
            public const string Ansi7Color = "Ansi 7 Color";
            public const string Ansi8Color = "Ansi 8 Color";
            public const string Ansi9Color = "Ansi 9 Color";
            public const string Ansi10Color = "Ansi 10 Color";
            public const string Ansi11Color = "Ansi 11 Color";
            public const string Ansi12Color = "Ansi 12 Color";
            public const string Ansi13Color = "Ansi 13 Color";
            public const string Ansi14Color = "Ansi 14 Color";
            public const string Ansi15Color = "Ansi 15 Color";

            public const string BackgroundColor = "Background Color";
            public const string BoldColor = "Bold Color";
            public const string CursorColor = "Cursor Color";
            public const string CursorTextColor = "Cursor Text Color";
            public const string ForegroundColor = "Foreground Color";
            public const string SelectedTextColor = "Selected Text Color";
            public const string SelectionColor = "Selection Color";
        }

        private static class ITermThemeColorKeys
        {
            public const string BlueComponent = "Blue Component";
            public const string GreenComponent = "Green Component";
            public const string RedComponent = "Red Component";
        }

        public Task<TerminalTheme> Parse(string fileName, Stream fileContent)
        {
            if (string.IsNullOrWhiteSpace(fileName))
            {
                throw new ArgumentNullException(nameof(fileName));
            }

            if (fileContent == null)
            {
                throw new ArgumentNullException(nameof(fileContent));
            }

            var node = PList.Load(fileContent) as DictionaryNode ?? throw new ParseThemeException("Root node was not a dictionary.");

            return Task.FromResult(new TerminalTheme
            {
                Name = Path.GetFileNameWithoutExtension(fileName),
                Colors = GetColors(node),
                Id = Guid.NewGuid(),
                PreInstalled = false
            });
        }

        private TerminalColors GetColors(DictionaryNode themeDictionary)
        {
            return new TerminalColors
            {
                Background = GetColorString(themeDictionary[ITermThemeKeys.BackgroundColor]),
                Foreground = GetColorString(themeDictionary[ITermThemeKeys.ForegroundColor]),
                Cursor = GetColorString(themeDictionary[ITermThemeKeys.CursorColor]),
                CursorAccent = GetColorString(themeDictionary[ITermThemeKeys.CursorTextColor]),
                Selection = GetColorString(themeDictionary[ITermThemeKeys.SelectionColor], Opacity30Percent),
                SelectionForeground = GetColorString(themeDictionary[ITermThemeKeys.SelectedTextColor]),
                SelectionBackground = GetColorString(themeDictionary[ITermThemeKeys.SelectionColor]),
                Black = GetColorString(themeDictionary[ITermThemeKeys.Ansi0Color]),
                Red = GetColorString(themeDictionary[ITermThemeKeys.Ansi1Color]),
                Green = GetColorString(themeDictionary[ITermThemeKeys.Ansi2Color]),
                Yellow = GetColorString(themeDictionary[ITermThemeKeys.Ansi3Color]),
                Blue = GetColorString(themeDictionary[ITermThemeKeys.Ansi4Color]),
                Magenta = GetColorString(themeDictionary[ITermThemeKeys.Ansi5Color]),
                Cyan = GetColorString(themeDictionary[ITermThemeKeys.Ansi6Color]),
                White = GetColorString(themeDictionary[ITermThemeKeys.Ansi7Color]),
                BrightBlack = GetColorString(themeDictionary[ITermThemeKeys.Ansi8Color]),
                BrightRed = GetColorString(themeDictionary[ITermThemeKeys.Ansi9Color]),
                BrightGreen = GetColorString(themeDictionary[ITermThemeKeys.Ansi10Color]),
                BrightYellow = GetColorString(themeDictionary[ITermThemeKeys.Ansi11Color]),
                BrightBlue = GetColorString(themeDictionary[ITermThemeKeys.Ansi12Color]),
                BrightMagenta = GetColorString(themeDictionary[ITermThemeKeys.Ansi13Color]),
                BrightCyan = GetColorString(themeDictionary[ITermThemeKeys.Ansi14Color]),
                BrightWhite = GetColorString(themeDictionary[ITermThemeKeys.Ansi15Color]),
            };
        }

        private string GetColorString(PNode colorNode, byte alpha = Byte.MaxValue)
        {
            var dictionaryNode = colorNode as DictionaryNode ?? throw new ParseThemeException("Color node was not a dictionary");

            var red = dictionaryNode[ITermThemeColorKeys.RedComponent] as RealNode ?? throw new ParseThemeException("Red node value was not a real number");
            var green = dictionaryNode[ITermThemeColorKeys.GreenComponent] as RealNode ?? throw new ParseThemeException("Green node value was not a real number");
            var blue = dictionaryNode[ITermThemeColorKeys.BlueComponent] as RealNode ?? throw new ParseThemeException("Blue node value was not a real number");

            if (alpha == byte.MaxValue)
            {
                return $"#{GetByteValue(red):X2}{GetByteValue(green):X2}{GetByteValue(blue):X2}";
            }
            else
            {
                return $"rgba({GetByteValue(red):G}, {GetByteValue(green):G}, {GetByteValue(blue):G}, {ToDoubleString(alpha)})";
            }
        }

        private byte GetByteValue(RealNode node)
        {
            var doubleValue = node.Value * Byte.MaxValue;

            return Convert.ToByte(doubleValue);
        }

        private static string ToDoubleString(byte alpha)
        {
            return (alpha / 256.0).ToString(CultureInfo.InvariantCulture);
        }

        public async Task<ExportedTerminalTheme> Import(string fileName, Stream fileContent)
        {
            if (string.IsNullOrWhiteSpace(fileName))
            {
                throw new ArgumentNullException(nameof(fileName));
            }

            if (fileContent == null)
            {
                throw new ArgumentNullException(nameof(fileContent));
            }

            var node = PList.Load(fileContent) as DictionaryNode ?? throw new ParseThemeException("Root node was not a dictionary.");

            var terminalTheme = new TerminalTheme
            {
                Name = Path.GetFileNameWithoutExtension(fileName),
                Colors = GetColors(node),
                Id = Guid.NewGuid(),
                PreInstalled = false
            };

            return new ExportedTerminalTheme(terminalTheme, string.Empty);
        }
    }
}