Fixed .crypto sparklines

src/NadekoBot/Modules/Searches/Crypto/CryptoCommands.cs

@@ -157,18 +157,21 @@ public partial class Searches
             var marketCap = usd.MarketCap.ToString("C0", localCulture);
             var dominance = (usd.MarketCapDominance / 100).ToString("P2", localCulture);
 
+            await using var sparkline = await _service.GetSparklineAsync(crypto.Id, usd.PercentChange7d >= 0);
+            var fileName = $"{crypto.Slug}_7d.png";
+            
             var toSend = _eb.Create()
                             .WithOkColor()
                             .WithAuthor($"#{crypto.CmcRank}")
                             .WithTitle($"{crypto.Name} ({crypto.Symbol})")
                             .WithUrl($"https://coinmarketcap.com/currencies/{crypto.Slug}/")
-                            .WithThumbnailUrl( $"https://s3.coinmarketcap.com/static/img/coins/128x128/{crypto.Id}.png")
+                            .WithThumbnailUrl($"https://s3.coinmarketcap.com/static/img/coins/128x128/{crypto.Id}.png")
                             .AddField(GetText(strs.market_cap), marketCap, true)
                             .AddField(GetText(strs.price), price, true)
                             .AddField(GetText(strs.volume_24h), volume, true)
                             .AddField(GetText(strs.change_7d_24h), $"{sevenDay} / {lastDay}", true)
                             .AddField(GetText(strs.market_cap_dominance), dominance, true)
-                            .WithImageUrl($"https://s3.coinmarketcap.com/generated/sparklines/web/7d/usd/{crypto.Id}.png");
+                            .WithImageUrl($"attachment://{fileName}");
 
             if (crypto.CirculatingSupply is double cs)
             {
@@ -185,9 +188,9 @@ public partial class Searches
                     toSend.AddField(GetText(strs.circulating_supply), csStr, true);
                 }
             }
-            
-            
-            await ctx.Channel.EmbedAsync(toSend);
+
+
+            await ctx.Channel.SendFileAsync(sparkline, fileName, embed: toSend.Build());
         }
     }
 }

src/NadekoBot/Modules/Searches/Crypto/CryptoService.cs

@@ -1,6 +1,13 @@
-#nullable disable
+#nullable enable
 using NadekoBot.Modules.Searches.Common;
+using SixLabors.ImageSharp;
+using SixLabors.ImageSharp.Drawing.Processing;
+using SixLabors.ImageSharp.PixelFormats;
+using SixLabors.ImageSharp.Processing;
+using System.Globalization;
 using System.Net.Http.Json;
+using System.Xml;
+using Color = SixLabors.ImageSharp.Color;
 using JsonSerializer = System.Text.Json.JsonSerializer;
 using StringExtensions = NadekoBot.Extensions.StringExtensions;
 
@@ -21,7 +28,75 @@ public class CryptoService : INService
         _creds = creds;
     }
 
-    public async Task<(CmcResponseData Data, CmcResponseData Nearest)> GetCryptoData(string name)
+    private PointF[] GetSparklinePointsFromSvgText(string svgText)
+    {
+        var xml = new XmlDocument();
+        xml.LoadXml(svgText);
+
+        var gElement = xml["svg"]?["g"];
+        if (gElement is null)
+            return Array.Empty<PointF>();
+
+        Span<PointF> points = new PointF[gElement.ChildNodes.Count];
+        var cnt = 0;
+
+        bool GetValuesFromAttributes(XmlAttributeCollection attrs,
+            out float x1,
+            out float y1,
+            out float x2,
+            out float y2)
+        {
+            (x1, y1, x2, y2) = (0, 0, 0, 0);
+            return attrs["x1"]?.Value is string x1Str
+                   && float.TryParse(x1Str, NumberStyles.Any, CultureInfo.InvariantCulture, out x1)
+                   && attrs["y1"]?.Value is string y1Str
+                   && float.TryParse(y1Str, NumberStyles.Any, CultureInfo.InvariantCulture, out y1)
+                   && attrs["x2"]?.Value is string x2Str
+                   && float.TryParse(x2Str, NumberStyles.Any, CultureInfo.InvariantCulture, out x2)
+                   && attrs["y2"]?.Value is string y2Str
+                   && float.TryParse(y2Str, NumberStyles.Any, CultureInfo.InvariantCulture, out y2);
+        }
+        
+        foreach (XmlElement x in gElement.ChildNodes)
+        {
+            if (x.Name != "line")
+                continue;
+
+            if (GetValuesFromAttributes(x.Attributes, out var x1, out var y1, out var x2, out var y2))
+            {
+                points[cnt++] = new(x1, y1);
+                // this point will be set twice to the same value
+                // on all points except the last one
+                if(cnt + 1 < points.Length)
+                    points[cnt + 1] = new(x2, y2);
+            }
+        }
+
+        if (cnt == 0)
+            return Array.Empty<PointF>();
+        
+        return points.Slice(0, cnt).ToArray();
+    }
+    
+    private SixLabors.ImageSharp.Image<Rgba32> GenerateSparklineChart(PointF[] points, bool up)
+    {
+        const int width = 164;
+        const int height = 48;
+        
+        var img = new Image<Rgba32>(width, height, Color.Transparent);
+        var color = up
+            ? Color.Green
+            : Color.FromRgb(220, 0, 0);
+
+        img.Mutate(x =>
+        {
+            x.DrawLines(color, 2, points);
+        });
+        
+        return img;
+    }
+    
+    public async Task<(CmcResponseData? Data, CmcResponseData? Nearest)> GetCryptoData(string name)
     {
         if (string.IsNullOrWhiteSpace(name))
             return (null, null);
@@ -29,10 +104,10 @@ public class CryptoService : INService
         name = name.ToUpperInvariant();
         var cryptos = await GetCryptoDataInternal();
 
-        if (cryptos is null)
+        if (cryptos is null or { Count: 0 })
             return (null, null);
 
-        var crypto = cryptos?.FirstOrDefault(x
+        var crypto = cryptos.FirstOrDefault(x
             => x.Slug.ToUpperInvariant() == name
                || x.Name.ToUpperInvariant() == name
                || x.Symbol.ToUpperInvariant() == name);
@@ -50,7 +125,7 @@ public class CryptoService : INService
         return (null, nearest.Elem);
     }
 
-    public async Task<List<CmcResponseData>> GetCryptoDataInternal()
+    public async Task<List<CmcResponseData>?> GetCryptoDataInternal()
     {
         await _getCryptoLock.WaitAsync();
         try
@@ -79,6 +154,9 @@ public class CryptoService : INService
                 "",
                 TimeSpan.FromHours(2));
 
+            if (fullStrData is null)
+                return default;
+            
             return JsonSerializer.Deserialize<CryptoResponse>(fullStrData)?.Data ?? new();
         }
         catch (Exception ex)
@@ -91,4 +169,50 @@ public class CryptoService : INService
             _getCryptoLock.Release();
         }
     }
+
+    public async Task<Stream?> GetSparklineAsync(int id, bool up)
+    {
+        var key = $"crypto:sparkline:{id}";
+        
+        // attempt to get from cache
+        var db = _cache.Redis.GetDatabase();
+        byte[] bytes = await db.StringGetAsync(key);
+        // if it succeeds, return it
+        if (bytes is { Length: > 0 })
+        {
+            return bytes.ToStream();
+        }
+        
+        // if it fails, generate a new one
+        var points = await DownloadSparklinePointsAsync(id);
+        if (points is null)
+            return default;
+        
+        var sparkline = GenerateSparklineChart(points, up);
+
+        // add to cache for 1h and return it
+        
+        var stream = sparkline.ToStream();
+        await db.StringSetAsync(key, stream.ToArray(), expiry: TimeSpan.FromHours(1));
+        return stream;
+    }
+
+    private async Task<PointF[]?> DownloadSparklinePointsAsync(int id)
+    {
+        try
+        {
+            using var http = _httpFactory.CreateClient();
+            var str = await http.GetStringAsync(
+                $"https://s3.coinmarketcap.com/generated/sparklines/web/7d/usd/{id}.svg");
+            var points = GetSparklinePointsFromSvgText(str);
+            return points;
+        }
+        catch(Exception ex)
+        {
+            Log.Warning(ex,
+                "Exception occurred while downloading sparkline points: {ErrorMessage}",
+                ex.Message);
+            return default;
+        }
+    }
 }