btcpayserver/BTCPayServer/Controllers/RateController.cs

using BTCPayServer.Models;
using Microsoft.AspNetCore.Mvc;
using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;
using System.Threading.Tasks;
using BTCPayServer.Filters;
using BTCPayServer.Services.Rates;
using BTCPayServer.Services.Stores;
using BTCPayServer.Rating;
using Newtonsoft.Json;

namespace BTCPayServer.Controllers
{
    public class RateController : Controller
    {
        BTCPayRateProviderFactory _RateProviderFactory;
        BTCPayNetworkProvider _NetworkProvider;
        CurrencyNameTable _CurrencyNameTable;
        StoreRepository _StoreRepo;
        public RateController(
            BTCPayRateProviderFactory rateProviderFactory,
            BTCPayNetworkProvider networkProvider,
            StoreRepository storeRepo,
            CurrencyNameTable currencyNameTable)
        {
            _RateProviderFactory = rateProviderFactory ?? throw new ArgumentNullException(nameof(rateProviderFactory));
            _NetworkProvider = networkProvider;
            _StoreRepo = storeRepo;
            _CurrencyNameTable = currencyNameTable ?? throw new ArgumentNullException(nameof(currencyNameTable));
        }

        [Route("rates")]
        [HttpGet]
        [BitpayAPIConstraint]
        public async Task<IActionResult> GetRates(string currencyPairs, string storeId)
        {
            storeId = storeId ?? this.HttpContext.GetStoreData()?.Id;
            var result = await GetRates2(currencyPairs, storeId);
            var rates = (result as JsonResult)?.Value as Rate[];
            if (rates == null)
                return result;
            return Json(new DataWrapper<Rate[]>(rates));
        }

        [Route("api/rates")]
        [HttpGet]
        public async Task<IActionResult> GetRates2(string currencyPairs, string storeId)
        {
            if(storeId == null || currencyPairs == null)
            {
                var result = Json(new BitpayErrorsModel() { Error = "You need to specify storeId (in your store settings) and currencyPairs (eg. BTC_USD,LTC_CAD)" });
                result.StatusCode = 400;
                return result;
            }

            var store = this.HttpContext.GetStoreData();
            if(store == null || store.Id != storeId)
                store = await _StoreRepo.FindStore(storeId);
            if (store == null)
            {
                var result = Json(new BitpayErrorsModel() { Error = "Store not found" });
                result.StatusCode = 404;
                return result;
            }
            var rules = store.GetStoreBlob().GetRateRules(_NetworkProvider);

            HashSet<CurrencyPair> pairs = new HashSet<CurrencyPair>();
            foreach(var currency in currencyPairs.Split(','))
            {
                if(!CurrencyPair.TryParse(currency, out var pair))
                {
                    var result = Json(new BitpayErrorsModel() { Error = $"Currency pair {currency} uncorrectly formatted" });
                    result.StatusCode = 400;
                    return result;
                }
                pairs.Add(pair);
            }

            var fetching = _RateProviderFactory.FetchRates(pairs, rules);
            await Task.WhenAll(fetching.Select(f => f.Value).ToArray());
            return Json(pairs
                            .Select(r => (Pair: r, Value: fetching[r].GetAwaiter().GetResult().Value))
                            .Where(r => r.Value.HasValue)
                            .Select(r =>
                            new Rate()
                            {
                                CryptoCode = r.Pair.Left,
                                Code = r.Pair.Right,
                                CurrencyPair = r.Pair.ToString(),
                                Name = _CurrencyNameTable.GetCurrencyData(r.Pair.Right, true).Name,
                                Value = r.Value.Value
                            }).Where(n => n.Name != null).ToArray());
        }

        public class Rate
        {

            [JsonProperty(PropertyName = "name")]
            public string Name
            {
                get;
                set;
            }
            [JsonProperty(PropertyName = "cryptoCode")]
            public string CryptoCode
            {
                get;
                set;
            }

            [JsonProperty(PropertyName = "currencyPair")]
            public string CurrencyPair
            {
                get;
                set;
            }

            [JsonProperty(PropertyName = "code")]
            public string Code
            {
                get;
                set;
            }
            [JsonProperty(PropertyName = "rate")]
            public decimal Value
            {
                get;
                set;
            }
        }
    }
}