From 95d72cf0bd9ca9b25ac5c30b8810b3440f8fdfe6 Mon Sep 17 00:00:00 2001
From: Gervasio Marchand <github@gervas.io>
Date: Thu, 12 Jan 2023 16:11:24 -0300
Subject: [PATCH] Pull data from Grafana

---
 src/FakeRelay.Core/Config.cs                  | 13 +++-
 src/FakeRelay.Core/Helpers/GrafanaHelper.cs   | 68 +++++++++++++++++++
 .../Controllers/ApiController.cs              | 25 +++++++
 3 files changed, 104 insertions(+), 2 deletions(-)
 create mode 100644 src/FakeRelay.Core/Helpers/GrafanaHelper.cs

diff --git a/src/FakeRelay.Core/Config.cs b/src/FakeRelay.Core/Config.cs
index 8a2bb79..a889e10 100644
--- a/src/FakeRelay.Core/Config.cs
+++ b/src/FakeRelay.Core/Config.cs
@@ -13,6 +13,9 @@ public class Config
     
     public string ConfigPath { get; }
     public string? HomeRedirect { get; }
+    public string? GrafanaHost { get; }
+    public string? GrafanaKey { get; }
+    public int? GrafanaDataSourceId { get; }
 
     private Config()
     {
@@ -20,13 +23,16 @@ public class Config
         PublicKey = Host = ConfigPath = "";
     }
 
-    private Config(string publicKey, byte[] privateKey, string host, string configPath, string? homeRedirect)
+    private Config(string publicKey, byte[] privateKey, string host, string configPath, string? homeRedirect, string? grafanaHost, string? grafanaKey, int? grafanaDataSourceId)
     {
         PrivateKey = privateKey;
         PublicKey = publicKey;
         Host = host;
         ConfigPath = configPath;
         HomeRedirect = homeRedirect;
+        GrafanaHost = grafanaHost;
+        GrafanaKey = grafanaKey;
+        GrafanaDataSourceId = grafanaDataSourceId;
     }
 
     public static void Init(string path)
@@ -50,7 +56,7 @@ public class Config
         using var rsa = RSA.Create();
         rsa.ImportFromPem(data.PrivateKey.ToCharArray());
         
-        Instance = new Config(data.PublicKey, rsa.ExportRSAPrivateKey(), data.Host, path, data.HomeRedirect);
+        Instance = new Config(data.PublicKey, rsa.ExportRSAPrivateKey(), data.Host, path, data.HomeRedirect, data.GrafanaHost, data.GrafanaKey, data.GrafanaDataSourceId);
     }
 
     public static void CreateConfig(string path, string host, string publicKey, string privateKey)
@@ -70,5 +76,8 @@ public class Config
         public string? PrivateKey { get; set; }
         public string? Host { get; set; }
         public string? HomeRedirect { get; set; }
+        public string? GrafanaHost { get; set; }
+        public string? GrafanaKey { get; set; }
+        public int? GrafanaDataSourceId { get; set; }
     }
 }
diff --git a/src/FakeRelay.Core/Helpers/GrafanaHelper.cs b/src/FakeRelay.Core/Helpers/GrafanaHelper.cs
new file mode 100644
index 0000000..f9ba48d
--- /dev/null
+++ b/src/FakeRelay.Core/Helpers/GrafanaHelper.cs
@@ -0,0 +1,68 @@
+using System.Net.Http.Headers;
+using System.Runtime.Serialization;
+using Jil;
+
+namespace FakeRelay.Core.Helpers;
+
+public static class GrafanaHelper
+{
+    private static HttpClient? _httpClient;
+    private static HttpClient HttpClient => _httpClient ??= GetHttpClient();
+
+    private static HttpClient GetHttpClient()
+    {
+        var httpClient = new HttpClient { BaseAddress = new Uri("https://" + Config.Instance.GrafanaHost) };
+        httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", Config.Instance.GrafanaKey);
+
+        return httpClient;
+    }
+    
+    public static async Task<int> GetCountInPeriod(string hostname, string period)
+    {
+        if (Config.Instance.GrafanaHost.IsNullOrEmpty() || Config.Instance.GrafanaKey.IsNullOrEmpty() || !Config.Instance.GrafanaDataSourceId.HasValue)
+        {
+            return -1;
+        }
+
+        var requestContent = new StringContent($@"
+{{""queries"":[{{""datasourceId"":{Config.Instance.GrafanaDataSourceId.Value},""expr"":""increase(fr_index_requests{{exported_instance=\""{hostname}\""}}[{period}])""}}],""to"":""now"",""from"":""now""}}
+    ");
+        requestContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");
+
+        var result = await HttpClient.PostAsync("/api/ds/query", requestContent);
+        if (!result.IsSuccessStatusCode)
+        {
+            return -1;
+        }
+
+        var json = await result.Content.ReadAsStringAsync();
+        var data = JSON.Deserialize<GrafanaResponse>(json, Options.CamelCase);
+        return (int)Math.Round(data.Results.A.Frames[0].Data.Values[1][0]);
+    }
+}
+
+public class GrafanaResponse
+{
+    public ResultData Results { get; set; }
+
+    public class ResultData
+    {
+        [DataMember(Name = "A")]
+        public AData A { get; set; }
+
+        public class AData
+        {
+            public FrameData[] Frames { get; set; }
+
+            public class FrameData
+            {
+                public DataData Data { get; set; }
+
+                public class DataData
+                {
+                    public float[][] Values { get; set; }
+                }
+            }
+        }
+    }
+}
diff --git a/src/FakeRelay.Web/Controllers/ApiController.cs b/src/FakeRelay.Web/Controllers/ApiController.cs
index 1bf6844..850560c 100644
--- a/src/FakeRelay.Web/Controllers/ApiController.cs
+++ b/src/FakeRelay.Web/Controllers/ApiController.cs
@@ -1,4 +1,6 @@
 using System.Collections.Immutable;
+using System.Text.RegularExpressions;
+using FakeRelay.Core;
 using FakeRelay.Core.Helpers;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Extensions.Caching.Memory;
@@ -53,4 +55,27 @@ public class ApiController : Controller
         Response.Headers["instance"] = host;
         return Content(response, "application/activity+json");
     }
+
+    [Route("index-posts-count")]
+    public async Task<ActionResult> IndexedPostsCount(string period)
+    {
+        if (Config.Instance.GrafanaHost.IsNullOrEmpty() || Config.Instance.GrafanaKey.IsNullOrEmpty())
+        {
+            return NotFound();
+        }
+
+        if (!Regex.IsMatch(period, "^[0-9]+[mhd]$"))
+        {
+            return BadRequest();
+        }
+        
+        var host = await GetHostFromRequest();
+        if (host == null)
+        {
+            return Unauthorized();
+        }
+
+        var count = await GrafanaHelper.GetCountInPeriod(host, period);
+        return Content(count.ToString());
+    }
 }