using System.Collections.Frozen;
using Elternbeirat.Web.Shared;

namespace Elternbeirat.Web.Features.Home;

/// <summary>
///     Chooses the icon of a home page tile from the page's slug.
/// </summary>
/// <remarks>
///     Pure presentation, so it lives in code: the schema has no icon field, and adding
///     one needs a schema change that cannot reach production yet. A page without an
///     entry here (e.g. one an editor just created) gets <see cref="Default"/>, so a
///     new page always shows up as a complete tile.
/// </remarks>
/// <seealso cref="IconSet"/>
public static class TileIcons
{
    /// <summary>
    ///     The icon for a slug without its own entry: a generic page.
    /// </summary>
    public const string Default = "file-text";

    /// <summary>
    ///     Icon name per slug. Every value must be a name in <see cref="IconSet"/>.
    /// </summary>
    private static readonly FrozenDictionary<string, string> Icons =
        new Dictionary<string, string>
        {
            ["board"] = "users",
            ["patrons"] = "heart-handshake",
            ["faqs"] = "help-circle",
            ["downloads"] = "download",
            ["posts"] = "newspaper",
            ["events"] = "calendar",
            ["contact"] = "mail",
        }.ToFrozenDictionary(StringComparer.Ordinal);

    /// <summary>
    ///     Returns the icon name for a page.
    /// </summary>
    /// <param name="slug">The page's slug, e.g. <c>board</c>.</param>
    /// <returns>An icon name from <see cref="IconSet"/>; <see cref="Default"/> for an unknown slug.</returns>
    public static string For(string slug) =>
        Icons.GetValueOrDefault(slug, Default);
}