using LiteCqrs;
using Microsoft.EntityFrameworkCore;
using TeleWave.Application.Common.Interfaces;
using TeleWave.Application.Common.Models;

namespace TeleWave.Application.Library.GetShow;

public sealed class GetShowQueryHandler(IAppDbContext dbContext)
    : IQueryHandler<GetShowQuery, Result<ShowDto>>
{
    public async Task<Result<ShowDto>> Handle(GetShowQuery query, CancellationToken cancellationToken)
    {
        var show = await dbContext.Shows.AsNoTracking()
            .Include(s => s.Episodes)
            .FirstOrDefaultAsync(s => s.Id == query.Id, cancellationToken);
        if (show is null)
            return Result.Failure<ShowDto>(ShowErrors.NotFound);

        var episodes = show.Episodes.OrderBy(e => e.Position).ToList();
        var assetIds = episodes.Select(e => e.MediaAssetId).ToList();
        var assets = await dbContext.MediaAssets.AsNoTracking()
            .Where(a => assetIds.Contains(a.Id))
            .Select(a => new
            {
                a.Id,
                a.OriginalFileName,
                a.Status,
                a.Duration,
            })
            .ToDictionaryAsync(a => a.Id, cancellationToken);

        var episodeDtos = episodes
            .Select(e =>
            {
                assets.TryGetValue(e.MediaAssetId, out var asset);
                return new EpisodeDto(
                    e.Id,
                    e.MediaAssetId,
                    e.Position,
                    asset?.OriginalFileName,
                    asset?.Status,
                    asset?.Duration?.TotalSeconds,
                    e.Season,
                    e.Episode,
                    e.Title,
                    e.Overview,
                    e.StillImageId,
                    e.AirDate
                );
            })
            .ToList();

        return Result.Success(
            new ShowDto(
                show.Id,
                show.Name,
                show.OriginalName,
                show.Kind,
                show.Description,
                show.MetadataProvider,
                show.MetadataExternalId,
                show.Year,
                show.PosterImageId,
                episodeDtos
            )
        );
    }
}