jellyfin-smart-playlist/Jellyfin.Plugin.SmartPlaylist/Api/LispPlaygroundController.cs

using System.Net.Mime;
using System.Text;
using System.Web;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using System.ComponentModel.DataAnnotations;
using MediaBrowser.Common.Api;
using MediaBrowser.Controller.Library;

using YamlDotNet.Serialization;

using Jellyfin.Plugin.SmartPlaylist.Lisp;

namespace Jellyfin.Plugin.SmartPlaylist.Api {

    [Serializable]
    public class ProgramInputDto {
        public string InputLinks { get; set; }
        public string Program { get; set; }
    }

    [Serializable]
    public class ProgramOutputDto {
        public string Output { get; set; }
        public string FinalExpression { get; set; }
        public string Traceback { get; set; }
    }

    [ApiController]
    [Authorize(Policy = Policies.RequiresElevation)]
    [Route("LispPlayground")]
    [Produces(MediaTypeNames.Application.Json)]
    public class LispPlaygroundController : ControllerBase {
        private readonly ILogger _logger;
        private readonly ILibraryManager _libraryManager;

        public LispPlaygroundController(
            ILogger<LispPlaygroundController> logger,
            ILibraryManager libraryManager
        ) {
            _logger = logger;
            _libraryManager = libraryManager;
        }

        private Executor SetupExecutor(StringBuilder sb, IList<string> inputs) {
            var env = new DefaultEnvironment();
            var executor = new Executor(env);

            env["*items*"] = Lisp.Cons.FromList(inputs.Select(x => _libraryManager.GetItemById(x)).Select(x => Lisp.Object.FromBase(x)).ToList());
            executor.builtins["logd"] = (x) => {
                _logger.LogDebug(((Lisp.String)x.First()).Value(), x.Skip(1).ToArray());
                return Lisp.Boolean.TRUE;
            };
            executor.builtins["logi"] = (x) => {
                _logger.LogInformation(((Lisp.String)x.First()).Value(), x.Skip(1).ToArray());
                return Lisp.Boolean.TRUE;
            };
            executor.builtins["logw"] = (x) => {
                _logger.LogWarning(((Lisp.String)x.First()).Value(), x.Skip(1).ToArray());
                return Lisp.Boolean.TRUE;
            };
            executor.builtins["loge"] = (x) => {
                _logger.LogError(((Lisp.String)x.First()).Value(), x.Skip(1).ToArray());
                return Lisp.Boolean.TRUE;
            };
            executor.builtins["print"] = (x) => {
                sb.Append(string.Join(" ", x.Select((i) => {
                    if (i is Lisp.String i_s) {
                        return i_s.Value();
                    }
                    return i.ToString();
                })));
                return Lisp.Boolean.TRUE;
            };
                executor.builtins["print"] = (x) => {
                sb.Append(string.Join(" ", x.Select((i) => {
                    if (i is Lisp.String i_s) {
                        return i_s.Value();
                    }
                    return i.ToString();
                })));
                sb.Append("\n");
                return Lisp.Boolean.TRUE;
            };
            if (Plugin.Instance is not null) {
                executor.eval(Plugin.Instance.Configuration.InitialProgram);
            } else {
                throw new ApplicationException("Plugin Instance is not yet initialized");
            }
            return executor;
        }

        private List<string> extractItemIds(string s) {
            List<string> r = new List<string>();
            foreach (string line in s.Split("\n".ToCharArray(), StringSplitOptions.RemoveEmptyEntries)) {
                var uri = new Uri(line);
                uri = new Uri("http://some-domain.tld" + uri.Fragment.Substring(1));
                var id = HttpUtility.ParseQueryString(uri.Query).Get("id");
                if (id == null) {
                    continue;
                }
                r.Add(id);
            }
            return r;
        }

        [HttpPost]
        [ProducesResponseType(StatusCodes.Status200OK)]
        public async Task<ActionResult<ProgramOutputDto>> SetPlaylist() {
            try {
                string input;
                using (StreamReader reader = new StreamReader(Request.Body)) {
                    input = await reader.ReadToEndAsync();
                }
                var dto = new DeserializerBuilder().Build().Deserialize<ProgramInputDto>(input);
                StringBuilder output = new StringBuilder();
                var e = SetupExecutor(output, extractItemIds(dto.InputLinks));
                var r = e.eval(dto.Program).ToString();
                return Ok(new ProgramOutputDto() {
                    FinalExpression = r,
                    Output = output.ToString(),
                });
            } catch (Exception ex) {
                return Ok(new ProgramOutputDto() {
                    Traceback = ex.ToString(),
                });
            }
        }
    }
}