Working on #9, completed query with search string

YahooFinanceApi.Tests/UnitTest1.cs

@@ -2,10 +2,12 @@
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Globalization;
+using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using Xunit;
-
+using YahooFinanceApi.Lookup;
+
 namespace YahooFinanceApi.Tests
 {
     public class UnitTest1
@@ -16,6 +18,14 @@ public UnitTest1()
 			CultureInfo.CurrentCulture = new CultureInfo("nl-nl");
         }
 
+        [Fact]
+        public void SymbolListTest()
+        {
+            const string Symbol = "aap";
+            var symbols = YahooLookup.GetLookupSymbolsAsync(Symbol, LookupType.Stocks, MarketType.US_Canada).Result;
+            Assert.True(symbols.Any(s => s.CompanyName == "Advance Auto Parts, Inc."));
+        }
+
         [Fact]
         public void HistoricalExceptionTest()
         {

YahooFinanceApi/Helper.cs

@@ -1,8 +1,9 @@
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using System.Runtime.Serialization;
-
+
 namespace YahooFinanceApi
 {
     static class Helper
@@ -35,5 +36,7 @@ public static string Name<T>(this T @enum)
         public static string GetRandomString(int length)
             => Guid.NewGuid().ToString().Substring(0, length);
 
+        public static IEnumerable<string> AddSuffixes(this string prefix)
+            => "abcdefghijklmnopqrstuvwxyz".Select(a => prefix + a);
     }
 }

YahooFinanceApi/Lookup/LookupSymbol.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+
+namespace YahooFinanceApi.Lookup
+{
+    public class LookupSymbol
+    {
+        public string Symbol { get; }
+        public string CompanyName { get; }
+        //public decimal LastValue { get; }
+        //public decimal Change { get; }
+        //public decimal ChangePercent { get; }
+        public string IndustryName { get; }
+        public string IndustryLink { get; }
+        public string Type { get; }
+        public string Exchange { get; }
+
+        public LookupSymbol(string symbol, string companyName, /*decimal lastValue, decimal change, decimal changePercent, */
+                      string industryName, string industryLink, string type, string exchange)
+        {
+            Exchange = exchange;
+            Type = type;
+            IndustryLink = industryLink;
+            IndustryName = industryName;
+            //ChangePercent = changePercent;
+            //Change = change;
+            //LastValue = lastValue;
+            CompanyName = companyName;
+            Symbol = symbol;
+        }
+    }
+}

YahooFinanceApi/Lookup/LookupType.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Runtime.Serialization;
+
+namespace YahooFinanceApi.Lookup
+{
+    public enum LookupType
+    {
+        [EnumMember(Value = "A")]
+        All,
+        [EnumMember(Value = "S")]
+        Stocks,
+        [EnumMember(Value = "M")]
+        MutualFunds,
+        [EnumMember(Value = "E")]
+        ETFs,
+        [EnumMember(Value = "I")]
+        Indices,
+        [EnumMember(Value = "F")]
+        Futures,
+        [EnumMember(Value = "C")]
+        Currencies
+    }
+}

YahooFinanceApi/Lookup/MarketType.cs

@@ -0,0 +1,13 @@
+using System;
+using System.Runtime.Serialization;
+
+namespace YahooFinanceApi.Lookup
+{
+    public enum MarketType
+    {
+        [EnumMember(Value = "ALL")]
+        All,
+        [EnumMember(Value = "US")]
+        US_Canada
+    }
+}

YahooFinanceApi/Lookup/YahooLookup.cs

@@ -0,0 +1,97 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Flurl.Http;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+
+namespace YahooFinanceApi.Lookup
+{
+    public static class YahooLookup
+    {
+        const string LookupUrl = "https://finance.yahoo.com/_finance_doubledown/api/resource/finance.yfinlist.symbol_lookup";
+        const string SearchTag = "s";
+        const string LookupTypeTag = "t";
+        const string MarketTag = "m";
+        const string OffsetTag = "b";
+        const string IsIncludeSimilarTag = "p";
+
+        public static async Task<IEnumerable<LookupSymbol>> GetLookupSymbolsAsync(string search, LookupType lookupType, MarketType marketType, CancellationToken token = default(CancellationToken))
+        {
+            Func<string, int, Task<Stream>> responseFunc = (s, i) => GetSymbolListResponseStreamAsync(s, lookupType, marketType, i, token);
+            var childSearches = await GetLookupSearchesAsync(search, lookupType, marketType, token);
+
+            var list = new List<LookupSymbol>();
+            foreach (var childSearch in childSearches)
+            {
+                int offset = 0;
+                while (true)
+                {
+                    using (var s = await responseFunc(childSearch, offset))
+                    using (var sr = new StreamReader(s))
+                    {
+                        var o = JObject.Parse(sr.ReadToEnd());
+                        var symbols = o["result"].ToArray();
+                        list.AddRange(symbols.Select(sym => JsonConvert.DeserializeObject<LookupSymbol>(sym.ToString())));
+
+                        var nav = o["navLink"];
+                        var navAsDict = (IDictionary<string, JToken>)nav;
+                        if (!navAsDict.ContainsKey("nextPage") || !navAsDict.ContainsKey("lastPage"))
+                            break;
+
+                        offset = nav["nextPage"]["start"].Value<int>();
+                    }
+                }
+            }
+
+            return list;
+        }
+
+        public static async Task<IEnumerable<string>> GetLookupSearchesAsync(string search, LookupType lookupType, MarketType marketType, CancellationToken token = default(CancellationToken))
+        {
+            Func<int, Task<Stream>> responseFunc = i => GetSymbolListResponseStreamAsync(search, lookupType, marketType, i, token);
+            var list = new List<string>();
+
+            if (await IsLookupSizeTooLargeAsync())
+            {
+                foreach (var subSearch in search.AddSuffixes())
+                    list.AddRange(await GetLookupSearchesAsync(subSearch, lookupType, marketType, token));
+                return list;
+            }
+
+            return new string[] { search };
+
+            async Task<bool> IsLookupSizeTooLargeAsync()
+            {
+                const int LookupSizeLimit = 2000;
+
+                using (var s = await responseFunc(0))
+                using (var sr = new StreamReader(s))
+                {
+                    var o = JObject.Parse(sr.ReadToEnd());
+                    var nav = o["navLink"];
+                    var navAsDict = (IDictionary<string, JToken>)nav;
+                    if (!navAsDict.ContainsKey("lastPage"))
+                        return false;
+
+                    return nav["lastPage"]["start"].Value<int>() >= LookupSizeLimit;
+                }
+            }
+        }
+
+        public static async Task<Stream> GetSymbolListResponseStreamAsync(string search, LookupType lookupType, MarketType marketType, int offset, CancellationToken token = default(CancellationToken))
+            => await new StringBuilder()
+                .Append(LookupUrl)
+                .Append($";{SearchTag}={search}")
+                .Append($";{LookupTypeTag}={lookupType.Name()}")
+                .Append($";{MarketTag}={marketType.Name()}")
+                .Append($";{OffsetTag}={offset}")
+                .Append($";{IsIncludeSimilarTag}=1")
+                .ToString()
+                .GetStreamAsync(token);
+    }
+}

YahooFinanceApi/YahooFinanceApi.csproj

@@ -51,4 +51,7 @@
     <PackageReference Include="Flurl" Version="2.5.0" />
     <PackageReference Include="Flurl.Http" Version="2.0.1" />
   </ItemGroup>
+  <ItemGroup>
+    <Folder Include="Lookup\" />
+  </ItemGroup>
 </Project>