using Elternbeirat.Contracts;
using Elternbeirat.Web.Features.Layout;
using Elternbeirat.Web.Shared;

namespace Elternbeirat.Web.Features.Home;

/// <summary>
///     One tile on the home page, leading to a section of the site.
/// </summary>
/// <param name="Href">Target URL of the page.</param>
/// <param name="Title">The page's title.</param>
/// <param name="Description">
///     The first sentence of the page's body, or an empty string, in which case the
///     tile shows only the title.
/// </param>
/// <param name="Icon">The icon name, see <see cref="TileIcons"/>.</param>
public sealed record HomeTile(string Href, string Title, string Description, string Icon)
{
    /// <summary>
    ///     Builds one tile per header page except the home page itself.
    /// </summary>
    /// <param name="pages">All public pages.</param>
    /// <returns>The tiles, in menu order.</returns>
    /// <remarks>
    ///     The tiles mirror the header menu (<see cref="NavBuilder.HeaderPages"/>), so a
    ///     page an editor puts into the header appears here too, without any code. The
    ///     home page is left out: a tile leading to the page it sits on would be useless.
    /// </remarks>
    public static IReadOnlyList<HomeTile> From(IReadOnlyList<Page> pages) =>
    [
        .. NavBuilder.HeaderPages(pages)
            .Where(page => !Page.IsHomeSlug(page.Slug))
            .Select(page => new HomeTile(
                NavBuilder.HrefFor(page.Slug),
                page.Title,
                Markdown.FirstSentence(page.Body),
                TileIcons.For(page.Slug))),
    ];
}