Optional MAX_COUNT.

Dockerfile

@@ -19,5 +19,6 @@ ENV ASPNETCORE_URLS=http://+:2022
 ENV NODE=http://node:7076
 ENV DISABLE_CORS=true
 ENV EXCLUDED_CALLS=delegators;delegators_count;representatives
+ENV MAX_COUNT=500
 
 CMD [ "dotnet", "NanoPublicApi.dll" ]

NanoPublicApi/Config/Options.cs

@@ -3,4 +3,5 @@ namespace NanoPublicApi.Config;
 public class Options
 {
     public IEnumerable<string> ExcludedCalls { get; set; }
+    public int MaxCount { get; set; }
 }

NanoPublicApi/Controllers/ApiController.cs

@@ -1,7 +1,9 @@
 using System.Net;
 using System.Reflection;
+using System.Text.Json.Serialization;
 using Microsoft.AspNetCore.Mvc;
 using NanoPublicApi.Config;
+using Newtonsoft.Json;
 
 namespace NanoPublicApi.Controllers;
 
@@ -37,6 +39,18 @@ public ApiController(Options options)
 
     #endregion
 
+    [HttpGet("api_info")]
+    [ProducesResponseType(typeof(AggregatedApiInfo), (int)HttpStatusCode.OK)]
+    public IActionResult ApiInfo()
+    {
+        return Json(new AggregatedApiInfo
+        {
+            ExcludedCalls = AllCalls.Intersect(Options.ExcludedCalls),
+            SupportedCalls = AllCalls.Except(Options.ExcludedCalls),
+            MaxCount = Options.MaxCount
+        });
+    }
+
     [HttpGet("excluded_calls")]
     [ProducesResponseType(typeof(IEnumerable<string>), (int)HttpStatusCode.OK)]
     public IActionResult ExcludedCalls()
@@ -50,5 +64,28 @@ public IActionResult SupportedCalls()
     {
         return Json(AllCalls.Except(Options.ExcludedCalls));
     }
+
+    [HttpGet("max_count")]
+    [ProducesResponseType(typeof(int), (int)HttpStatusCode.OK)]
+    public IActionResult MaxCount()
+    {
+        return Json(Options.MaxCount);
+    }
+
+    #region " AggregatedApiInfo "
+
+    public class AggregatedApiInfo
+    {
+        [JsonPropertyName("excluded_calls")]
+        public IEnumerable<string> ExcludedCalls { get; set; }
+
+        [JsonPropertyName("supported_calls")]
+        public IEnumerable<string> SupportedCalls { get; set; }
+
+        [JsonPropertyName("max_count")]
+        public int MaxCount { get; set; }
+    }
+
+    #endregion
 
 }

NanoPublicApi/Controllers/NodeController.cs

@@ -301,6 +301,14 @@ private async Task<IActionResult> Call<T>(string name, T request)
         where T : Request
     {
         if (Options.ExcludedCalls.Contains(name)) { return Error($"{name} not supported"); }
+        if (Options.MaxCount > 0 && request is ICountRequest countable)
+        {
+            if (!int.TryParse(countable.Count, out int count) || count < 0 || count > Options.MaxCount)
+            {
+                return Error($"{count} greater than max count {Options.MaxCount}");
+            }
+        }
+
         request.Action = name;
         return await Node.Proxy(request);
     }

NanoPublicApi/Entities/ICountRequest.cs

@@ -0,0 +1,6 @@
+namespace NanoPublicApi.Entities;
+
+public interface ICountRequest
+{
+    public string Count { get; set; }
+}

NanoPublicApi/Entities/Input/AccountHistoryRequest.cs

@@ -4,7 +4,7 @@
 
 namespace NanoPublicApi.Entities.Input;
 
-public class AccountHistoryRequest : AccountRequest
+public class AccountHistoryRequest : AccountRequest, ICountRequest
 {
 
     [DefaultValue("account_history")]

NanoPublicApi/Entities/Input/AccountsPendingRequest.cs

@@ -4,7 +4,7 @@
 
 namespace NanoPublicApi.Entities.Input;
 
-public class AccountsPendingRequest : AccountsRequest
+public class AccountsPendingRequest : AccountsRequest, ICountRequest
 {
 
     [DefaultValue("accounts_pending_request")]

NanoPublicApi/Entities/Input/ChainRequest.cs

@@ -3,7 +3,7 @@
 
 namespace NanoPublicApi.Entities.Input;
 
-public class ChainRequest : Request
+public class ChainRequest : Request, ICountRequest
 {
 
     [DefaultValue("chain")]

NanoPublicApi/Entities/Input/DelegatorsRequest.cs

@@ -3,7 +3,7 @@
 
 namespace NanoPublicApi.Entities.Input;
 
-public class DelegatorsRequest : AccountRequest
+public class DelegatorsRequest : AccountRequest, ICountRequest
 {
 
     [DefaultValue("delegators")]

NanoPublicApi/Entities/Input/FrontiersRequest.cs

@@ -3,7 +3,7 @@
 
 namespace NanoPublicApi.Entities.Input;
 
-public class FrontiersRequest : AccountRequest
+public class FrontiersRequest : AccountRequest, ICountRequest
 {
 
     [DefaultValue("frontiers")]

NanoPublicApi/Entities/Input/ReceivableRequest.cs

@@ -4,7 +4,7 @@
 
 namespace NanoPublicApi.Entities.Input;
 
-public class ReceivableRequest : AccountRequest
+public class ReceivableRequest : AccountRequest, ICountRequest
 {
 
     [DefaultValue("receivable")]

NanoPublicApi/Entities/Input/RepresentativesRequest.cs

@@ -3,7 +3,7 @@
 
 namespace NanoPublicApi.Entities.Input;
 
-public class RepresentativesRequest : Request
+public class RepresentativesRequest : Request, ICountRequest
 {
 
     [DefaultValue("representatives")]

NanoPublicApi/Entities/Input/SuccessorsRequest.cs

@@ -3,7 +3,7 @@
 
 namespace NanoPublicApi.Entities.Input;
 
-public class SuccessorsRequest : Request
+public class SuccessorsRequest : Request, ICountRequest
 {
 
     [DefaultValue("successors")]

NanoPublicApi/Program.cs

@@ -2,13 +2,15 @@
 using NanoPublicApi.Config;
 using NanoPublicApi.Connectors;
 
-var env = Environment.GetEnvironmentVariables();
-var node = env["NODE"] as string;
-var disableCors = bool.Parse(env["DISABLE_CORS"] as string);
-var excludedCalls = (env["EXCLUDED_CALLS"] as string)?.Split(
-        ';',
-        StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries
-    ) ?? Enumerable.Empty<string>();
+var env = GetEnvironmentVariables();
+var node = env["NODE"];
+var disableCors = bool.Parse(env["DISABLE_CORS"]);
+var excludedCalls = env["EXCLUDED_CALLS"]?.Split(
+    ';',
+    StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries
+) ?? Enumerable.Empty<string>();
+var maxCount = int.Parse(env["MAX_COUNT"]);
+if (maxCount == 0) { maxCount = -1; }
 
 var builder = WebApplication.CreateBuilder(args);
 
@@ -17,23 +19,28 @@
     builder.Services.AddCors(options =>
         options.AddDefaultPolicy(policy =>
             policy.AllowAnyOrigin()
-                  .AllowAnyHeader()
-                  .WithMethods("get", "post"))
+                .AllowAnyHeader()
+                .WithMethods("get", "post"))
     );
 }
 
 builder.Services.AddControllers()
-                .AddJsonOptions(options =>
-                {
-                    options.JsonSerializerOptions.Converters.Add(new JsonStringEnumConverter());
-                    options.JsonSerializerOptions.DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull;
-                });
+    .AddJsonOptions(options =>
+    {
+        options.JsonSerializerOptions.Converters.Add(new JsonStringEnumConverter());
+        options.JsonSerializerOptions.DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull;
+    });
 
 builder.Services.AddEndpointsApiExplorer();
 builder.Services.AddSwaggerGen();
 
 builder.Services.AddSingleton(_ => new NodeConnector(new Uri(node)));
-builder.Services.AddSingleton(_ => new Options { ExcludedCalls = excludedCalls });
+builder.Services.AddSingleton(_ =>
+    new Options
+    {
+        ExcludedCalls = excludedCalls,
+        MaxCount = maxCount
+    });
 
 var app = builder.Build();
 
@@ -51,3 +58,16 @@
 app.MapControllers();
 
 app.Run();
+
+
+static IDictionary<string, string> GetEnvironmentVariables()
+{
+    var env = Environment.GetEnvironmentVariables();
+    var dic = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+    foreach (string key in env.Keys)
+    {
+        dic.Add(key, (string)env[key]);
+    }
+
+    return dic;
+}

README.md

@@ -75,6 +75,8 @@ services:
       - 'DISABLE_CORS=true'
       # optional; specifies which calls to remove from support; default value provided
       - 'EXCLUDED_CALLS=delegators;delegators_count;representatives'
+      # optional; specifices a maximum value for count; -1 for no limit; default value provided
+      - 'MAX_COUNT=500'
     networks:
       - traefik
       - nano