roadie/Roadie.Api/ModelBinding/SubsonicRequestBinder.cs

using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.AspNetCore.WebUtilities;
using Roadie.Library.Models.ThirdPartyApi.Subsonic;
using Roadie.Library.Utility;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace Roadie.Api.ModelBinding
{
    /// <summary>
    ///     This is needed as some clienst post some get, some query string some body post.
    /// </summary>
    public class SubsonicRequestBinder : IModelBinder
    {
        public Task BindModelAsync(ModelBindingContext bindingContext)
        {
            if (bindingContext == null) throw new ArgumentNullException(nameof(bindingContext));
            var queryDictionary = QueryHelpers.ParseQuery(bindingContext.HttpContext.Request.QueryString.ToString());

            // Create a dictionary of all the properties to populate on the result model
            var modelDictionary = new Dictionary<string, object>(StringComparer.InvariantCultureIgnoreCase)
            {
                {"albumCount", null},
                {"albumOffset", null},
                {"artist", null},
                {"artistCount", null},
                {"artistOffset", null},
                {"c", null},
                {"callback", null},
                {"f", null},
                {"fromYear", null},
                {"genre", null},
                {"id", null},
                {"musicFolderId", null},
                {"offset", null},
                {"p", null},
                {"message", null},
                {"query", null},
                {"s", null},
                {"size", null},
                {"songCount", null},
                {"songOffset", null},
                {"t", null},
                {"toYear", null},
                {"type", null},
                {"u", null},
                {"v", null}
            };

            // Setup model dictionary from Query Parameters
            modelDictionary["albumCount"] = queryDictionary.ContainsKey("albumCount")
                ? SafeParser.ToNumber<int?>(queryDictionary["albumCount"].First())
                : null;
            modelDictionary["albumOffset"] = queryDictionary.ContainsKey("albumOffset")
                ? SafeParser.ToNumber<int?>(queryDictionary["albumOffset"].First())
                : null;
            modelDictionary["artist"] =
                queryDictionary.ContainsKey("artist") ? queryDictionary["artist"].First() : null;
            modelDictionary["artistCount"] = queryDictionary.ContainsKey("artistCount")
                ? SafeParser.ToNumber<int?>(queryDictionary["artistCount"].First())
                : null;
            modelDictionary["artistOffset"] = queryDictionary.ContainsKey("artistOffset")
                ? SafeParser.ToNumber<int?>(queryDictionary["artistOffset"].First())
                : null;
            modelDictionary["c"] = queryDictionary.ContainsKey("c") ? queryDictionary["c"].First() : null;
            modelDictionary["callback"] =
                queryDictionary.ContainsKey("callback") ? queryDictionary["callback"].First() : null;
            modelDictionary["f"] = queryDictionary.ContainsKey("f") ? queryDictionary["f"].First() : null;
            modelDictionary["fromYear"] = queryDictionary.ContainsKey("fromYear")
                ? SafeParser.ToNumber<int?>(queryDictionary["fromYear"].First())
                : null;
            modelDictionary["genre"] = queryDictionary.ContainsKey("genre") ? queryDictionary["genre"].First() : null;
            modelDictionary["id"] = queryDictionary.ContainsKey("id") ? queryDictionary["id"].First() : null;
            modelDictionary["musicFolderId"] = queryDictionary.ContainsKey("musicFolderId")
                ? SafeParser.ToNumber<int?>(queryDictionary["musicFolderId"].First())
                : null;
            modelDictionary["offset"] = queryDictionary.ContainsKey("offset")
                ? SafeParser.ToNumber<int?>(queryDictionary["offset"].First())
                : null;
            modelDictionary["p"] = queryDictionary.ContainsKey("p") ? queryDictionary["p"].First() : null;
            modelDictionary["query"] = queryDictionary.ContainsKey("query") ? queryDictionary["query"].First() : null;
            modelDictionary["s"] = queryDictionary.ContainsKey("s") ? queryDictionary["s"].First() : null;
            var size = queryDictionary.ContainsKey("size")
                ? SafeParser.ToNumber<int?>(queryDictionary["size"].First())
                : null;
            var count = queryDictionary.ContainsKey("count")
                ? SafeParser.ToNumber<int?>(queryDictionary["count"].First())
                : null;
            modelDictionary["size"] = size ?? count ?? 20;
            modelDictionary["songCount"] = queryDictionary.ContainsKey("songCount")
                ? SafeParser.ToNumber<int?>(queryDictionary["songCount"].First())
                : null;
            modelDictionary["songOffset"] = queryDictionary.ContainsKey("songOffset")
                ? SafeParser.ToNumber<int?>(queryDictionary["songOffset"].First())
                : null;
            modelDictionary["t"] = queryDictionary.ContainsKey("t") ? queryDictionary["t"].First() : null;
            modelDictionary["toYear"] = queryDictionary.ContainsKey("toYear")
                ? SafeParser.ToNumber<int?>(queryDictionary["toYear"].First())
                : null;
            modelDictionary["type"] = queryDictionary.ContainsKey("type")
                ? SafeParser.ToEnum<ListType>(queryDictionary["type"].First())
                : ListType.AlphabeticalByName;
            modelDictionary["u"] = queryDictionary.ContainsKey("u") ? queryDictionary["u"].First() : null;
            modelDictionary["v"] = queryDictionary.ContainsKey("v") ? queryDictionary["v"].First() : null;
            modelDictionary["message"] =
                queryDictionary.ContainsKey("message") ? queryDictionary["message"].First() : null;

            // Setup model dictionary from Posted Body values
            var postedIds = new List<string>();
            if (!bindingContext.HttpContext.Request.Method.Equals("GET", StringComparison.OrdinalIgnoreCase) &&
                !string.IsNullOrEmpty(bindingContext.HttpContext.Request.ContentType))
            {
                var formCollection = bindingContext.HttpContext.Request.Form;
                if (formCollection != null && formCollection.Any())
                    foreach (var form in formCollection)
                    {
                        if (modelDictionary.ContainsKey(form.Key))
                            modelDictionary[form.Key] = form.Value.FirstOrDefault();
                        else
                            modelDictionary.Add(form.Key, form.Value.FirstOrDefault());
                        if (form.Key == "id") postedIds.AddRange(form.Value.ToArray());
                    }
            }

            var model = new SubsonicRequest
            {
                AlbumCount = SafeParser.ToNumber<short?>(modelDictionary["albumCount"]) ?? 20,
                AlbumOffset = SafeParser.ToNumber<int?>(modelDictionary["albumOffset"]),
                ArtistCount = SafeParser.ToNumber<short?>(modelDictionary["artistCount"]) ?? 20,
                ArtistName = SafeParser.ToString(modelDictionary["artist"]),
                ArtistOffset = SafeParser.ToNumber<int?>(modelDictionary["artistOffset"]),
                c = SafeParser.ToString(modelDictionary["c"]),
                callback = SafeParser.ToString(modelDictionary["callback"]),
                f = SafeParser.ToString(modelDictionary["f"]),
                FromYear = SafeParser.ToNumber<int?>(modelDictionary["fromYear"]),
                Genre = SafeParser.ToString(modelDictionary["genre"]),
                id = SafeParser.ToString(modelDictionary["id"]),
                ids = postedIds?.ToArray(),
                MusicFolderId = SafeParser.ToNumber<int?>(modelDictionary["musicFolderId"]),
                Message = SafeParser.ToString(modelDictionary["message"]),
                Offset = SafeParser.ToNumber<int?>(modelDictionary["offset"]),
                p = SafeParser.ToString(modelDictionary["p"]),
                Query = SafeParser.ToString(modelDictionary["query"]),
                s = SafeParser.ToString(modelDictionary["s"]),
                Size = SafeParser.ToNumber<short?>(modelDictionary["size"]),
                SongCount = SafeParser.ToNumber<short?>(modelDictionary["songCount"]) ?? 20,
                SongOffset = SafeParser.ToNumber<int?>(modelDictionary["songOffset"]),
                t = SafeParser.ToString(modelDictionary["t"]),
                ToYear = SafeParser.ToNumber<int?>(modelDictionary["toYear"]),
                Type = SafeParser.ToEnum<ListType>(modelDictionary["type"]),
                u = SafeParser.ToString(modelDictionary["u"]),
                v = SafeParser.ToString(modelDictionary["v"])
            };

            bindingContext.Result = ModelBindingResult.Success(model);

            return Task.CompletedTask;
        }
    }
}