using MangaReader.Core.Search;
using MangaReader.Core.Sources.MangaDex.Api;
using System.Text.RegularExpressions;

namespace MangaReader.Core.Sources.MangaDex.Search;

public partial class MangaDexSearchProvider(IMangaDexClient mangaDexClient) : IMangaSearchProvider, IMangaSourceComponent
{
    [GeneratedRegex(@"[^a-z0-9\s-]")]
    private static partial Regex InvalidSlugCharactersRegex();

    [GeneratedRegex(@"\s+")]
    private static partial Regex WhitespaceRegex();

    public string SourceId => "MangaDex";

    public async Task<MangaSearchResult[]> SearchAsync(string keyword, CancellationToken cancellationToken)
    {
        MangaDexResponse? response = await mangaDexClient.SearchMangaByTitleAsync(keyword, cancellationToken);

        if (response == null || (response is not MangaDexCollectionResponse collectionResponse))
            return [];

        List<MangaSearchResult> mangaSearchResults = [];

        foreach (MangaDexEntity entity in collectionResponse.Data)
        {
            MangaSearchResult? mangaSearchResult = GetMangaSearchResult(entity);

            if (mangaSearchResult == null)
                continue;

            mangaSearchResults.Add(mangaSearchResult);

        }

        return [.. mangaSearchResults];
    }

    private static MangaSearchResult? GetMangaSearchResult(MangaDexEntity entity)
    {
        if (entity is not MangaEntity mangaEntity)
            return null;

        if (mangaEntity.Attributes == null)
            return null;

        string title = mangaEntity.Attributes.Title.FirstOrDefault().Value;
        string slug = GenerateSlug(title);

        MangaSearchResult mangaSearchResult = new()
        {
            Title = title,
            Url = $"https://mangadex.org/title/{mangaEntity.Id}/{slug}",
            Thumbnail = GetThumbnail(mangaEntity)
        };

        return mangaSearchResult;
    }

    public static string GenerateSlug(string title)
    {
        // title.ToLowerInvariant().Normalize(NormalizationForm.FormD);

        title = title.ToLowerInvariant();
        //title = InvalidSlugCharactersRegex().Replace(title, ""); // remove invalid chars
        title = InvalidSlugCharactersRegex().Replace(title, "-"); // replace invalid chars with dash
        title = WhitespaceRegex().Replace(title, "-");         // replace spaces with dash

        return title.Trim('-');
    }

    private static string? GetThumbnail(MangaDexEntity mangaDexEntity)
    {
        CoverArtEntity? coverArtEntity = (CoverArtEntity?)mangaDexEntity.Relationships.FirstOrDefault(entity =>
            entity is CoverArtEntity);

        if (coverArtEntity == null || string.IsNullOrWhiteSpace(coverArtEntity.Attributes?.FileName))
            return null;

        string? fileName = coverArtEntity.Attributes?.FileName;

        if (string.IsNullOrWhiteSpace(coverArtEntity.Attributes?.FileName))
            return null;

        return $"https://mangadex.org/covers/{mangaDexEntity.Id}/{fileName}";
    }
}