using Core.Entities;

namespace Core.Printing;

/// <summary>
/// Per-student event-rank merge tokens. <c>Rank1</c> is the official event name
/// at rank 1; <c>Rank1.ShortName</c> is the catalog short name. Every rank
/// through <see cref="StudentEventRanking.MaxRank"/> is always a map key so a
/// missing preference prints blank instead of leaving <c>{{Rank5}}</c> visible.
/// </summary>
public static class StudentRankTokens
{
    public static string NameToken(int rank) => $"Rank{rank}";

    public static string ShortNameToken(int rank) => $"Rank{rank}.ShortName";

    public static string AttributesToken(int rank) => $"Rank{rank}.Attributes";

    public static IReadOnlyList<string> AllNames { get; } =
    [
        NoteTemplateMerger.RankedEventsToken,
        .. Enumerable.Range(1, StudentEventRanking.MaxRank)
            .SelectMany(rank => (string[])
            [
                NameToken(rank),
                ShortNameToken(rank),
                AttributesToken(rank)
            ])
    ];

    public static Dictionary<string, string?> FromRankings(IEnumerable<StudentEventRanking>? rankings)
    {
        var map = new Dictionary<string, string?>(StringComparer.OrdinalIgnoreCase);
        for (var rank = 1; rank <= StudentEventRanking.MaxRank; rank++)
        {
            map[NameToken(rank)] = null;
            map[ShortNameToken(rank)] = null;
            map[AttributesToken(rank)] = null;
        }

        if (rankings is null)
            return map;

        foreach (var ranking in rankings)
        {
            if (ranking.Rank < 1 || ranking.Rank > StudentEventRanking.MaxRank)
                continue;

            var evt = ranking.EventDefinition;
            map[NameToken(ranking.Rank)] = evt?.Name;
            map[ShortNameToken(ranking.Rank)] = evt?.ShortName;
            map[AttributesToken(ranking.Rank)] = EventAttributeMarks.For(evt);
        }

        return map;
    }
}