Theme.cs

using SkiaSharp;
using System;
using System.Collections.Generic;
using System.Text;
using Waher.Content;
using Waher.IoTGateway.Setup;
using Waher.Networking.HTTP;
using Waher.Script;
using Waher.Script.Abstraction.Elements;
using Waher.Script.Graphs;
using Waher.Script.Model;
using Waher.Script.Objects;
 
namespace Waher.IoTGateway.ScriptExtensions.Constants
{
    public class Theme : IConstant
    {
        private static readonly Dictionary<string, ThemeDefinition> definitionsPerDomain = new Dictionary<string, ThemeDefinition>(StringComparer.InvariantCultureIgnoreCase);
        private static ThemeDefinition currentDefinition = null;
 
        public Theme()
        {
        }
 
        public string ConstantName => nameof(Theme);
 
        public string[] Aliases => null;
 
        public IElement GetValueElement(Variables Variables)
        {
            ThemeDefinition Def = currentDefinition;
 
            if (Variables is SessionVariables SessionVariables &&
                SessionVariables.CurrentRequest is IHostReference HostRef)
            {
                string Host = DomainSettings.IsAlternativeDomain(HostRef.Host);
                if (!string.IsNullOrEmpty(Host))
                    Def = GetTheme(Host);
            }
 
            if (!(Variables is null))
            {
                Variables[Graph.GraphBgColorVariableName] = Def.GraphBgColor;
                Variables[Graph.GraphFgColorVariableName] = Def.GraphFgColor;
            }
 
            return new ObjectValue(Def);
        }
 
        public static ThemeDefinition GetCurrentTheme(SessionVariables Variables)
        {
            ThemeDefinition Def = currentDefinition;
 
            if (!(Variables is null) &&
                Variables.CurrentRequest is IHostReference HostRef)
            {
                string Host = DomainSettings.IsAlternativeDomain(HostRef.Host);
                if (!string.IsNullOrEmpty(Host))
                    Def = GetTheme(Host);
            }
 
            return Def;
        }
 
        public static ThemeDefinition CurrentTheme
        {
            get => currentDefinition;
            internal set => currentDefinition = value;
        }
 
        public static ThemeDefinition GetTheme(string Domain)
        {
            lock (definitionsPerDomain)
            {
                if (definitionsPerDomain.TryGetValue(Domain, out ThemeDefinition Result))
                    return Result;
            }
 
            return currentDefinition;
        }
 
        internal static void SetTheme(string Domain, ThemeDefinition Theme)
        {
            lock (definitionsPerDomain)
            {
                definitionsPerDomain[Domain] = Theme;
            }
        }
 
        private static string ColorToString(SKColor Color)
        {
            StringBuilder sb = new StringBuilder();
 
            sb.Append("#");
            sb.Append(Color.Red.ToString("X2"));
            sb.Append(Color.Green.ToString("X2"));
            sb.Append(Color.Blue.ToString("X2"));
 
            if (Color.Alpha != 255)
                sb.Append(Color.Alpha.ToString("X2"));
 
            return sb.ToString();
        }
 
    }
}