using System.Collections.Concurrent;
using Avalonia.Media.Imaging;
using Avalonia.Platform;
using IBKRTrader.Core.Modularity;

namespace IBKRTrader.App.Shell;

/// <summary>
/// Löst die toolkit-neutralen <see cref="ModuleView.IconKey"/>-Schlüssel gegen die
/// Avalonia-Bildressourcen auf. Gegenstück zum gleichnamigen Helfer der WinForms-Shell –
/// <b>dieselben Schlüssel, dieselben PNG-Dateien</b>, sodass Core und Module unverändert bleiben.
/// </summary>
public static class ViewIcons
{
    /// <summary>Symbol-Schlüssel → Dateiname unter <c>Resources/</c> (als Avalonia-Asset eingebettet).</summary>
    private static readonly Dictionary<string, string> FileByKey = new(StringComparer.OrdinalIgnoreCase)
    {
        ["dashboard"]       = "dashboard.png",
        ["workers"]         = "system_time.png",
        ["logs"]            = "error_log.png",
        ["settings"]        = "setting_tools.png",
        ["congresstrading"] = "cross_reference.png",
        ["accounting"]      = "coins_in_hand.png",
        ["supervisor"]      = "token_quantifier.png",
    };

    /// <summary>Standard-Symbolschlüssel je View-ID – identisch zur WinForms-Shell.</summary>
    private static readonly Dictionary<string, string> DefaultKeyByViewId = new(StringComparer.OrdinalIgnoreCase)
    {
        ["core.dashboard"]       = "dashboard",
        ["core.workers"]         = "workers",
        ["core.logs"]            = "logs",
        ["core.settings"]        = "settings",
        ["congresstrading.main"] = "congresstrading",
        ["accounting.main"]      = "accounting",
        ["supervisor.main"]      = "supervisor",
    };

    private static readonly ConcurrentDictionary<string, Bitmap?> Cache = new();

    /// <summary>Bild zum Schlüssel, oder <c>null</c> (kein Symbol / Datei fehlt).</summary>
    public static Bitmap? Resolve(string? iconKey)
    {
        if (iconKey is null || !FileByKey.TryGetValue(iconKey, out var file)) return null;

        return Cache.GetOrAdd(iconKey, _ =>
        {
            try
            {
                using var stream = AssetLoader.Open(
                    new Uri($"avares://IBKRTrader.App/Assets/{file}"));
                return new Bitmap(stream);
            }
            catch
            {
                // Ein fehlendes Symbol darf die Oberfläche nie aufhalten – dann eben nur Text.
                return null;
            }
        });
    }

    /// <summary>Setzt bei allen registrierten Views den Standard-Schlüssel, falls noch keiner gesetzt ist.</summary>
    public static void AssignDefaults(IModuleUiHost host)
    {
        foreach (var view in host.Views)
            if (view.IconKey is null && DefaultKeyByViewId.TryGetValue(view.Id, out var key))
                view.IconKey = key;
    }
}