Servers/MoonlightServers.Api/Admin/Nodes/NodeService.cs

using System.Diagnostics.CodeAnalysis;
using System.Net.Http.Json;
using System.Text.Json;
using Microsoft.Extensions.Logging;
using Microsoft.Net.Http.Headers;
using MoonlightServers.Api.Infrastructure.Database.Entities;
using MoonlightServers.DaemonShared.Http;
using MoonlightServers.DaemonShared.Http.Daemon;

namespace MoonlightServers.Api.Admin.Nodes;

public class NodeService
{
    private readonly IHttpClientFactory ClientFactory;
    private readonly ILogger<NodeService> Logger;
    public NodeService(IHttpClientFactory clientFactory, ILogger<NodeService> logger)
    {
        ClientFactory = clientFactory;
        Logger = logger;
    }

    public async Task<NodeHealthStatus> GetHealthAsync(Node node)
    {
        var client = ClientFactory.CreateClient();

        var request = CreateBaseRequest(node, HttpMethod.Get, "api/health");

        try
        {
            var response = await client.SendAsync(request);

            if (!response.IsSuccessStatusCode)
                return new NodeHealthStatus((int)response.StatusCode, null);

            try
            {
                var health = await response
                    .Content
                    .ReadFromJsonAsync<HealthDto>(SerializationContext.Default.Options);

                return new NodeHealthStatus((int)response.StatusCode, health);
            }
            catch (Exception e)
            {
                Logger.LogTrace(e, "An unhandled error occured while processing health response of node {id}", node.Id);
                
                return new NodeHealthStatus((int)response.StatusCode, null);
            }
        }
        catch (Exception e)
        {
            Logger.LogTrace(e, "An error occured while fetching health status of node {id}", node.Id);
            return new NodeHealthStatus(0, null);
        }
    }

    public async Task<SystemStatisticsDto> GetStatisticsAsync(Node node)
    {
        var client = ClientFactory.CreateClient();

        var request = CreateBaseRequest(node, HttpMethod.Get, "api/system/statistics");

        var response = await client.SendAsync(request);

        await EnsureSuccessAsync(response);

        return (await response.Content.ReadFromJsonAsync<SystemStatisticsDto>(SerializationContext.Default.Options))!;
    }

    private static HttpRequestMessage CreateBaseRequest(
        Node node,
        [StringSyntax(StringSyntaxAttribute.Uri)]
        HttpMethod method,
        string endpoint
    )
    {
        var request = new HttpRequestMessage();

        request.Headers.Add(HeaderNames.Authorization, node.Token);
        request.RequestUri = new Uri(new Uri(node.HttpEndpointUrl), endpoint);
        request.Method = method;

        return request;
    }

    private async Task EnsureSuccessAsync(HttpResponseMessage message)
    {
        if (message.IsSuccessStatusCode)
            return;

        try
        {
            var problemDetails = await message.Content.ReadFromJsonAsync<ProblemDetails>(
                SerializationContext.Default.Options
            );

            if (problemDetails == null)
            {
                // If we cant handle problem details, we handle it natively
                message.EnsureSuccessStatusCode();
                return;
            }

            // Parse into exception
            throw new NodeException(
                problemDetails.Type,
                problemDetails.Title,
                problemDetails.Status,
                problemDetails.Detail,
                problemDetails.Errors
            );
        }
        catch (JsonException)
        {
            // If we cant handle problem details, we handle it natively
            message.EnsureSuccessStatusCode();
        }
    }
}

public record NodeHealthStatus(int StatusCode, HealthDto? Dto);

public class NodeException : Exception
{
    public string Type { get; }
    public string Title { get; }
    public int Status { get; }
    public string? Detail { get; }
    public Dictionary<string, string[]>? Errors { get; }

    public NodeException(
        string type,
        string title,
        int status,
        string? detail = null,
        Dictionary<string, string[]>? errors = null)
        : base(detail ?? title)
    {
        Type = type;
        Title = title;
        Status = status;
        Detail = detail;
        Errors = errors;
    }
}