nadekobot/NadekoBot.Core/Services/Impl/SoundCloudApiService.cs

using Newtonsoft.Json;
using System;
using System.Linq;
using System.Net.Http;
using System.Threading.Tasks;

namespace NadekoBot.Core.Services.Impl
{
    public class SoundCloudApiService : INService
    {
        private readonly IHttpClientFactory _httpFactory;

        public SoundCloudApiService(IHttpClientFactory factory)
        {
            _httpFactory = factory;
        }

        public async Task<SoundCloudVideo> ResolveVideoAsync(string url)
        {
            if (string.IsNullOrWhiteSpace(url))
                throw new ArgumentNullException(nameof(url));

            string response = "";

            using (var http = _httpFactory.CreateClient())
            {
                response = await http.GetStringAsync($"https://scapi.nadeko.bot/resolve?url={url}").ConfigureAwait(false);
            }
            
            var responseObj = JsonConvert.DeserializeObject<SoundCloudVideo>(response);
            if (responseObj?.Kind != "track")
                throw new InvalidOperationException("Url is either not a track, or it doesn't exist.");

            return responseObj;
        }

        public async Task<SoundCloudVideo> GetVideoByQueryAsync(string query)
        {
            if (string.IsNullOrWhiteSpace(query))
                throw new ArgumentNullException(nameof(query));

            var response = "";
            using (var http = _httpFactory.CreateClient())
            {
                response = await http.GetStringAsync(new Uri($"https://scapi.nadeko.bot/tracks?q={Uri.EscapeDataString(query)}")).ConfigureAwait(false);
            }

            var responseObj = JsonConvert.DeserializeObject<SoundCloudVideo[]>(response)
                .FirstOrDefault(s => s.Streamable is true);
            
            if (responseObj?.Kind != "track")
                throw new InvalidOperationException("Query yielded no results.");

            return responseObj;
        }
    }

    public class SoundCloudVideo
    {
        public string Kind { get; set; } = "";
        public long Id { get; set; } = 0;
        public SoundCloudUser User { get; set; } = new SoundCloudUser();
        public string Title { get; set; } = "";
        public string FullName => User.Name + " - " + Title;
        public bool? Streamable { get; set; } = false;
        public int Duration { get; set; }
        [JsonProperty("permalink_url")]
        public string TrackLink { get; set; } = "";
        [JsonProperty("artwork_url")]
        public string ArtworkUrl { get; set; } = "";
    }
    
    public class SoundCloudUser
    {
        [JsonProperty("username")]
        public string Name { get; set; }
    }
}