using System.ComponentModel;
using ErsatzTV.Application.Artworks;
using ErsatzTV.Core;
using ErsatzTV.Core.Api.Artwork;
using ErsatzTV.Core.Domain;
using ErsatzTV.Extensions;
using MediatR;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace ErsatzTV.Controllers.Api;

[ApiController]
public class ArtworkUploadController(IMediator mediator) : ControllerBase
{
    [HttpPost("/api/artwork/uploads", Name = "UploadArtwork")]
    [Consumes("multipart/form-data")]
    [Tags("Artwork")]
    [EndpointSummary("Upload channel logo or watermark artwork")]
    [EndpointGroupName("general")]
    [ProducesResponseType(typeof(ArtworkUploadResponseModel), StatusCodes.Status201Created)]
    [ProducesResponseType(typeof(ProblemDetails), StatusCodes.Status422UnprocessableEntity)]
    public async Task<IActionResult> Upload(
        IFormFile file,
        [FromForm] [Description("Artwork target: 'logo' (default) or 'watermark'")] string target,
        CancellationToken cancellationToken)
    {
        if (file is null || file.Length == 0)
        {
            return BaseError.New("A non-empty image file is required").ToErrorResult();
        }

        long maxBytes = (long)SystemEnvironment.MaximumUploadMb * 1024 * 1024;
        if (file.Length > maxBytes)
        {
            return BaseError.New($"Image exceeds the maximum allowed size of {SystemEnvironment.MaximumUploadMb} MB")
                .ToErrorResult();
        }

        if (!TryParseTarget(target, out ArtworkKind artworkKind))
        {
            return BaseError.New($"Unknown upload target '{target}'; expected 'logo' or 'watermark'").ToErrorResult();
        }

        await using Stream stream = file.OpenReadStream();
        Either<BaseError, ArtworkUploadResponseModel> result = await mediator.Send(
            new UploadArtwork(stream, file.ContentType, artworkKind),
            cancellationToken);

        return result.ToCreatedResult(
            value => LocationFor(artworkKind, value.Path, value.ContentType),
            value => value);
    }

    // "logo" (default) and "watermark" are the two channel-artwork surfaces the API exposes today.
    private static bool TryParseTarget(string target, out ArtworkKind artworkKind)
    {
        switch ((target ?? string.Empty).Trim().ToLowerInvariant())
        {
            case "":
            case "logo":
                artworkKind = ArtworkKind.Logo;
                return true;
            case "watermark":
                artworkKind = ArtworkKind.Watermark;
                return true;
            default:
                artworkKind = ArtworkKind.Logo;
                return false;
        }
    }

    // Both GetImage (IptvController) and GetWatermark (ArtworkController) require a contentType
    // query param to serve the cached file, so the Location header must carry it too.
    private static string LocationFor(ArtworkKind artworkKind, string path, string contentType)
    {
        string encodedContentType = Uri.EscapeDataString(contentType);
        return artworkKind switch
        {
            // logo paths already carry the servable prefix ("iptv/logos/{file}")
            ArtworkKind.Logo => $"/{path}?contentType={encodedContentType}",
            _ => $"/artwork/watermarks/{path}?contentType={encodedContentType}"
        };
    }
}