using LiteCqrs;
using Microsoft.EntityFrameworkCore;
using TeleWave.Api.Common;
using TeleWave.Application.Common.Interfaces;
using TeleWave.Application.Metadata;
using TeleWave.Application.Metadata.ApplyShowMetadata;
using TeleWave.Application.Metadata.ClearShowMetadata;
using TeleWave.Application.Metadata.GetProviders;
using TeleWave.Application.Metadata.RefreshEpisodes;
using TeleWave.Application.Metadata.SearchShows;
using TeleWave.Application.Metadata.SetShowPoster;
using TeleWave.Application.Metadata.UpdateShowMetadata;
using TeleWave.Infrastructure.Identity;

namespace TeleWave.Api.Endpoints;

public static class MetadataEndpoints
{
    private const long MaxPosterBytes = 10L * 1024 * 1024; // 10 МБ

    private static readonly IReadOnlySet<string> PosterExtensions = new HashSet<string>(
        StringComparer.OrdinalIgnoreCase
    )
    {
        ".jpg",
        ".jpeg",
        ".png",
        ".webp",
    };

    public static IEndpointRouteBuilder MapMetadataEndpoints(this IEndpointRouteBuilder app)
    {
        var admin = app.MapGroup("/api/admin/metadata")
            .WithTags("Admin.Metadata")
            .RequireAuthorization(policy => policy.RequireRole(RoleNames.Admin));

        admin.MapGet("/providers", GetProviders).Produces<IReadOnlyList<string>>();
        admin.MapGet("/search", Search).Produces<IReadOnlyList<MetadataCandidate>>();
        admin.MapPost("/shows/{showId:guid}/apply", Apply).Produces(StatusCodes.Status204NoContent);
        admin.MapPut("/shows/{showId:guid}", Update).Produces(StatusCodes.Status204NoContent);
        admin.MapDelete("/shows/{showId:guid}", Clear).Produces(StatusCodes.Status204NoContent);
        admin.MapPut("/shows/{showId:guid}/poster", UploadPoster).Produces(StatusCodes.Status204NoContent);
        admin.MapPost("/shows/{showId:guid}/refresh-episodes", RefreshEpisodes).Produces<int>();

        // Постеры/кадры отдаём публично (просто картинки, id не угадать) — чтобы работал <img src>.
        app.MapGet("/api/metadata/shows/{showId:guid}/poster", ServePoster)
            .WithTags("Metadata")
            .Produces(StatusCodes.Status200OK);
        app.MapGet("/api/metadata/episodes/{episodeId:guid}/still", ServeStill)
            .WithTags("Metadata")
            .Produces(StatusCodes.Status200OK);

        return app;
    }

    private static async Task<IResult> GetProviders(ISender sender, CancellationToken cancellationToken)
    {
        var providers = await sender.Send(new GetMetadataProvidersQuery(), cancellationToken);
        return Results.Ok(providers);
    }

    private static async Task<IResult> Search(
        string provider,
        string query,
        ISender sender,
        CancellationToken cancellationToken
    )
    {
        var result = await sender.Send(new SearchShowMetadataQuery(provider, query), cancellationToken);
        return result.ToHttpResult();
    }

    private static async Task<IResult> Apply(
        Guid showId,
        ApplyMetadataBody body,
        ISender sender,
        CancellationToken cancellationToken
    )
    {
        var result = await sender.Send(
            new ApplyShowMetadataCommand(showId, body.Provider, body.ExternalId),
            cancellationToken
        );
        return result.ToHttpResult();
    }

    private static async Task<IResult> Update(
        Guid showId,
        UpdateMetadataBody body,
        ISender sender,
        CancellationToken cancellationToken
    )
    {
        var result = await sender.Send(
            new UpdateShowMetadataCommand(showId, body.Description, body.Year),
            cancellationToken
        );
        return result.ToHttpResult();
    }

    private static async Task<IResult> Clear(
        Guid showId,
        ISender sender,
        CancellationToken cancellationToken
    )
    {
        var result = await sender.Send(new ClearShowMetadataCommand(showId), cancellationToken);
        return result.ToHttpResult();
    }

    private static async Task<IResult> UploadPoster(
        Guid showId,
        string fileName,
        HttpRequest request,
        IMetadataImageStore imageStore,
        ISender sender,
        CancellationToken cancellationToken
    )
    {
        var ext = Path.GetExtension(fileName).ToLowerInvariant();
        if (
            request.ContentLength is > MaxPosterBytes or 0 or null
            || !PosterExtensions.Contains(ext)
        )
            return MetadataErrors.InvalidPoster.ToProblem();

        var relative = await imageStore.SaveShowPosterAsync(showId, ext, request.Body, cancellationToken);
        var result = await sender.Send(new SetShowPosterCommand(showId, relative), cancellationToken);
        if (!result.IsSuccess)
            imageStore.DeleteShowImages(showId);
        return result.ToHttpResult();
    }

    private static async Task<IResult> RefreshEpisodes(
        Guid showId,
        ISender sender,
        CancellationToken cancellationToken
    )
    {
        var result = await sender.Send(
            new RefreshShowEpisodesMetadataCommand(showId),
            cancellationToken
        );
        return result.ToHttpResult();
    }

    private static async Task<IResult> ServePoster(
        Guid showId,
        IAppDbContext dbContext,
        IMetadataImageStore imageStore,
        CancellationToken cancellationToken
    )
    {
        var path = await dbContext.Shows.AsNoTracking()
            .Where(s => s.Id == showId)
            .Select(s => s.PosterPath)
            .FirstOrDefaultAsync(cancellationToken);
        return ServeImage(path, imageStore);
    }

    private static async Task<IResult> ServeStill(
        Guid episodeId,
        IAppDbContext dbContext,
        IMetadataImageStore imageStore,
        CancellationToken cancellationToken
    )
    {
        var path = await dbContext.Shows.AsNoTracking()
            .SelectMany(s => s.Episodes)
            .Where(e => e.Id == episodeId)
            .Select(e => e.StillPath)
            .FirstOrDefaultAsync(cancellationToken);
        return ServeImage(path, imageStore);
    }

    private static IResult ServeImage(string? relativePath, IMetadataImageStore imageStore)
    {
        if (string.IsNullOrEmpty(relativePath))
            return Results.NotFound();
        var abs = imageStore.ResolveAbsolutePath(relativePath);
        return abs is null ? Results.NotFound() : Results.File(abs, ContentTypeFor(Path.GetExtension(abs)));
    }

    private static string ContentTypeFor(string extension) =>
        extension.ToLowerInvariant() switch
        {
            ".png" => "image/png",
            ".webp" => "image/webp",
            _ => "image/jpeg",
        };
}

public sealed record ApplyMetadataBody(string Provider, string ExternalId);

public sealed record UpdateMetadataBody(string? Description, int? Year);