#nullable disable
using NadekoBot.Modules.Searches.Common;
using Newtonsoft.Json;

namespace NadekoBot.Modules.Searches.Services;

public class CryptoService : INService
{
    private readonly IDataCache _cache;
    private readonly IHttpClientFactory _httpFactory;
    private readonly IBotCredentials _creds;

    private readonly SemaphoreSlim getCryptoLock = new(1, 1);

    public CryptoService(IDataCache cache, IHttpClientFactory httpFactory, IBotCredentials creds)
    {
        _cache = cache;
        _httpFactory = httpFactory;
        _creds = creds;
    }

    public async Task<(CryptoResponseData Data, CryptoResponseData Nearest)> GetCryptoData(string name)
    {
        if (string.IsNullOrWhiteSpace(name)) return (null, null);

        name = name.ToUpperInvariant();
        var cryptos = await CryptoData();

        if (cryptos is null)
            return (null, null);

        var crypto = cryptos?.FirstOrDefault(x
            => x.Id.ToUpperInvariant() == name
               || x.Name.ToUpperInvariant() == name
               || x.Symbol.ToUpperInvariant() == name);

        (CryptoResponseData Elem, int Distance)? nearest = null;
        if (crypto is null)
        {
            nearest = cryptos.Select(x => (x, Distance: x.Name.ToUpperInvariant().LevenshteinDistance(name)))
                             .OrderBy(x => x.Distance)
                             .Where(x => x.Distance <= 2)
                             .FirstOrDefault();

            crypto = nearest?.Elem;
        }

        if (nearest is not null) return (null, crypto);

        return (crypto, null);
    }

    public async Task<List<CryptoResponseData>> CryptoData()
    {
        await getCryptoLock.WaitAsync();
        try
        {
            var fullStrData = await _cache.GetOrAddCachedDataAsync("nadeko:crypto_data",
                async _ =>
                {
                    try
                    {
                        using var http = _httpFactory.CreateClient();
                        var strData = await http.GetStringAsync(
                            "https://pro-api.coinmarketcap.com/v1/cryptocurrency/listings/latest?"
                            + $"CMC_PRO_API_KEY={_creds.CoinmarketcapApiKey}"
                            + "&start=1"
                            + "&limit=5000"
                            + "&convert=USD");

                        JsonConvert.DeserializeObject<CryptoResponse>(strData); // just to see if its' valid

                        return strData;
                    }
                    catch (Exception ex)
                    {
                        Log.Error(ex, "Error getting crypto data: {Message}", ex.Message);
                        return default;
                    }
                },
                "",
                TimeSpan.FromHours(1));

            return JsonConvert.DeserializeObject<CryptoResponse>(fullStrData).Data;
        }
        catch (Exception ex)
        {
            Log.Error(ex, "Error retreiving crypto data: {Message}", ex.Message);
            return default;
        }
        finally
        {
            getCryptoLock.Release();
        }
    }
}