using System.Text.RegularExpressions;
using Chrono.Model;
using Microsoft.AspNetCore.Components;

namespace Shared.Services;

public class CardRenderingService
{
    private readonly Dictionary<string, CardData> _cardLookup;
    private readonly List<string> _cardNames;
    private readonly Regex _nameRegex;

    public CardRenderingService()
    {
        var allCards = CardDatabase.Cards
            .Where(c => !string.IsNullOrWhiteSpace(c.Name))
            .ToList();

        _cardLookup = allCards
            .GroupBy(c => c.Name, StringComparer.OrdinalIgnoreCase)
            .ToDictionary(g => g.Key, g => g.First(), StringComparer.OrdinalIgnoreCase);

        _cardNames = allCards
            .Select(c => c.Name)
            .OrderByDescending(n => n.Length)
            .ToList();

        var pattern = string.Join("|", _cardNames.Select(n => $@"\b{Regex.Escape(n)}\b"));
        _nameRegex = new Regex(pattern, RegexOptions.IgnoreCase | RegexOptions.Compiled);
    }

    public RenderFragment RenderDescription(string description, Action<CardData?> onCardClick)
    {
        return builder =>
        {
            var sequence = 0;
            var paragraphs = description.Split('\n', StringSplitOptions.RemoveEmptyEntries);

            foreach (var paragraph in paragraphs)
            {
                builder.OpenElement(sequence++, "p");

                var matches = _nameRegex.Matches(paragraph);
                var lastIndex = 0;

                foreach (Match match in matches)
                {
                    if (match.Index > lastIndex)
                        builder.AddContent(sequence++, paragraph.Substring(lastIndex, match.Index - lastIndex));

                    var cardName = match.Value;
                    var card = LookupCard(cardName);

                    builder.OpenElement(sequence++, "button");
                    builder.AddAttribute(sequence++, "class", "inline-card-btn");
                    builder.AddAttribute(sequence++, "onclick",
                        EventCallback.Factory.Create(this, () => onCardClick(card)));
                    builder.AddContent(sequence++, cardName);
                    builder.CloseElement();

                    lastIndex = match.Index + match.Length;
                }

                if (lastIndex < paragraph.Length) builder.AddContent(sequence++, paragraph.Substring(lastIndex));

                builder.CloseElement();
            }
        };
    }

    private CardData? LookupCard(string cardName)
    {
        return _cardLookup.GetValueOrDefault(cardName);
    }
}