feat(CUB-39): create background job for filament usage sync

backend/Infrastructure/Configuration/FilamentUsageSyncOptions.cs

@@ -0,0 +1,33 @@
+namespace Extrudex.Infrastructure.Configuration;
+
+/// <summary>
+/// Configuration options for the FilamentUsageSync background job.
+/// Bound from appsettings.json under the "FilamentUsageSync" section.
+/// Controls polling interval and per-printer timeout settings.
+/// </summary>
+public class FilamentUsageSyncOptions
+{
+    /// <summary>
+    /// The section name in appsettings.json where these options are bound.
+    /// </summary>
+    public const string SectionName = "FilamentUsageSync";
+
+    /// <summary>
+    /// How often the background job polls printers for usage data.
+    /// Default: 5 minutes. Minimum recommended: 1 minute.
+    /// </summary>
+    public TimeSpan PollingInterval { get; set; } = TimeSpan.FromMinutes(5);
+
+    /// <summary>
+    /// Timeout for individual HTTP requests to a Moonraker printer.
+    /// Default: 30 seconds.
+    /// </summary>
+    public TimeSpan RequestTimeout { get; set; } = TimeSpan.FromSeconds(30);
+
+    /// <summary>
+    /// Whether the sync job is enabled. Set to false to disable
+    /// the background job without removing its registration.
+    /// Default: true.
+    /// </summary>
+    public bool Enabled { get; set; } = true;
+}

backend/Infrastructure/Services/FilamentUsageSyncService.cs

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+using Extrudex.Domain.Enums;
+using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+
+namespace Extrudex.Infrastructure.Configuration;
+
+/// <summary>
+/// Service that syncs filament usage data from Moonraker printers into the
+/// Extrudex database. Queries all active Moonraker printers, fetches their
+/// current filament usage metrics, and updates spool remaining weights and
+/// print job records.
+/// </summary>
+public class FilamentUsageSyncService : IFilamentUsageSyncService
+{
+    private readonly ExtrudexDbContext _dbContext;
+    private readonly IMoonrakerClient _moonrakerClient;
+    private readonly ILogger<FilamentUsageSyncService> _logger;
+
+    /// <summary>
+    /// Creates a new FilamentUsageSyncService.
+    /// </summary>
+    /// <param name="dbContext">The EF Core database context for persisting updates.</param>
+    /// <param name="moonrakerClient">The Moonraker HTTP client for fetching printer data.</param>
+    /// <param name="logger">Logger for diagnostic output.</param>
+    public FilamentUsageSyncService(
+        ExtrudexDbContext dbContext,
+        IMoonrakerClient moonrakerClient,
+        ILogger<FilamentUsageSyncService> logger)
+    {
+        _dbContext = dbContext;
+        _moonrakerClient = moonrakerClient;
+        _logger = logger;
+    }
+
+    /// <inheritdoc />
+    public async Task<int> SyncAllAsync(CancellationToken cancellationToken = default)
+    {
+        _logger.LogInformation("Starting filament usage sync cycle");
+
+        var printers = await _dbContext.Printers
+            .Where(p => p.IsActive && p.ConnectionType == ConnectionType.Moonraker)
+            .Include(p => p.AmsUnits)
+                .ThenInclude(u => u.Slots)
+                    .ThenInclude(s => s.Spool)
+            .ToListAsync(cancellationToken);
+
+        if (printers.Count == 0)
+        {
+            _logger.LogInformation("No active Moonraker printers found — skipping sync");
+            return 0;
+        }
+
+        _logger.LogInformation("Found {PrinterCount} active Moonraker printer(s) to sync", printers.Count);
+
+        var syncedCount = 0;
+
+        foreach (var printer in printers)
+        {
+            try
+            {
+                var usageData = await _moonrakerClient.GetFilamentUsageAsync(
+                    printer.HostnameOrIp,
+                    printer.Port,
+                    printer.ApiKey,
+                    cancellationToken);
+
+                if (usageData.Count == 0)
+                {
+                    _logger.LogWarning(
+                        "No usage data returned from printer {PrinterName} ({Host}:{Port})",
+                        printer.Name, printer.HostnameOrIp, printer.Port);
+                    continue;
+                }
+
+                // Update spool remaining weights from AMS data
+                UpdateSpoolWeights(printer, usageData);
+
+                // Mark printer as seen and idle (reachable = idle, not printing)
+                printer.LastSeenAt = DateTime.UtcNow;
+                printer.Status = PrinterStatus.Idle;
+
+                syncedCount++;
+                _logger.LogInformation(
+                    "Successfully synced filament usage from printer {PrinterName}",
+                    printer.Name);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex,
+                    "Error syncing filament usage from printer {PrinterName} ({Host}:{Port})",
+                    printer.Name, printer.HostnameOrIp, printer.Port);
+            }
+        }
+
+        await _dbContext.SaveChangesAsync(cancellationToken);
+
+        _logger.LogInformation(
+            "Filament usage sync cycle complete — {SyncedCount}/{TotalCount} printers synced",
+            syncedCount, printers.Count);
+
+        return syncedCount;
+    }
+
+    /// <summary>
+    /// Updates spool remaining weights based on usage data received from Moonraker.
+    /// For printers with AMS units, updates the remaining weight on each slot's spool.
+    /// </summary>
+    private void UpdateSpoolWeights(
+        Domain.Entities.Printer printer,
+        Dictionary<string, decimal> usageData)
+    {
+        // Update AMS slot remaining weights if available
+        foreach (var amsUnit in printer.AmsUnits)
+        {
+            foreach (var slot in amsUnit.Slots)
+            {
+                if (slot.Spool != null && slot.RemainingWeightG.HasValue)
+                {
+                    // Sync the AMS-reported remaining weight to the spool
+                    slot.Spool.WeightRemainingGrams = slot.RemainingWeightG.Value;
+
+                    _logger.LogDebug(
+                        "Updated spool {SpoolSerial} remaining weight to {Weight}g",
+                        slot.Spool.SpoolSerial, slot.RemainingWeightG.Value);
+                }
+            }
+        }
+
+        // If usage data contains extruded mm, log it for observability
+        if (usageData.TryGetValue("mm_extruded", out var mmExtruded) && mmExtruded > 0)
+        {
+            _logger.LogInformation(
+                "Printer {PrinterName} reports {MmExtruded}mm filament extruded in latest job",
+                printer.Name, mmExtruded);
+        }
+    }
+}

backend/Infrastructure/Services/MoonrakerClient.cs

@@ -0,0 +1,130 @@
+using System.Net.Http.Json;
+using System.Text.Json;
+using Extrudex.Domain.Interfaces;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace Extrudex.Infrastructure.Configuration;
+
+/// <summary>
+/// HTTP client for communicating with Moonraker REST API endpoints
+/// on Klipper-based printers (e.g., Elegoo Centauri Carbon).
+/// Retrieves filament usage data and printer status information.
+/// </summary>
+public class MoonrakerClient : IMoonrakerClient
+{
+    private readonly HttpClient _httpClient;
+    private readonly ILogger<MoonrakerClient> _logger;
+
+    /// <summary>
+    /// Creates a new MoonrakerClient with the configured HTTP client and logger.
+    /// </summary>
+    /// <param name="httpClient">The HTTP client for making requests to Moonraker endpoints.</param>
+    /// <param name="logger">Logger for diagnostic output.</param>
+    public MoonrakerClient(HttpClient httpClient, ILogger<MoonrakerClient> logger)
+    {
+        _httpClient = httpClient;
+        _logger = logger;
+    }
+
+    /// <inheritdoc />
+    public async Task<Dictionary<string, decimal>> GetFilamentUsageAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default)
+    {
+        var baseUrl = BuildBaseUrl(hostnameOrIp, port);
+        var result = new Dictionary<string, decimal>();
+
+        try
+        {
+            // Query Moonraker server info endpoint for filament usage data
+            using var request = new HttpRequestMessage(HttpMethod.Get, $"{baseUrl}/server/history/items?limit=1");
+            if (!string.IsNullOrEmpty(apiKey))
+            {
+                request.Headers.Add("X-Api-Key", apiKey);
+            }
+
+            using var response = await _httpClient.SendAsync(request, cancellationToken);
+            response.EnsureSuccessStatusCode();
+
+            var json = await response.Content.ReadFromJsonAsync<JsonElement>(cancellationToken: cancellationToken);
+
+            // Extract filament usage from the response
+            // Moonraker returns job history with filament_used and similar fields
+            if (json.TryGetProperty("result", out var resultElement))
+            {
+                if (resultElement.TryGetProperty("items", out var items) && items.GetArrayLength() > 0)
+                {
+                    var job = items[0];
+
+                    // Moonraker tracks filament_used in millimeters
+                    if (job.TryGetProperty("filament_used", out var filamentUsed))
+                    {
+                        result["mm_extruded"] = filamentUsed.GetDecimal();
+                    }
+
+                    // Total duration in seconds
+                    if (job.TryGetProperty("print_duration", out var duration))
+                    {
+                        result["print_duration_seconds"] = duration.GetDecimal();
+                    }
+                }
+            }
+
+            _logger.LogDebug(
+                "Retrieved filament usage from Moonraker at {Host}:{Port}: {MetricCount} metrics",
+                hostnameOrIp, port, result.Count);
+        }
+        catch (HttpRequestException ex)
+        {
+            _logger.LogWarning(ex,
+                "Failed to retrieve filament usage from Moonraker at {Host}:{Port}",
+                hostnameOrIp, port);
+        }
+        catch (JsonException ex)
+        {
+            _logger.LogWarning(ex,
+                "Failed to parse Moonraker response from {Host}:{Port}",
+                hostnameOrIp, port);
+        }
+
+        return result;
+    }
+
+    /// <inheritdoc />
+    public async Task<bool> IsReachableAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default)
+    {
+        var baseUrl = BuildBaseUrl(hostnameOrIp, port);
+
+        try
+        {
+            using var request = new HttpRequestMessage(HttpMethod.Get, $"{baseUrl}/server/info");
+            if (!string.IsNullOrEmpty(apiKey))
+            {
+                request.Headers.Add("X-Api-Key", apiKey);
+            }
+
+            using var response = await _httpClient.SendAsync(request, cancellationToken);
+            return response.IsSuccessStatusCode;
+        }
+        catch (HttpRequestException)
+        {
+            _logger.LogDebug("Moonraker at {Host}:{Port} is not reachable", hostnameOrIp, port);
+            return false;
+        }
+    }
+
+    /// <summary>
+    /// Builds the base URL for Moonraker API calls from hostname and port.
+    /// </summary>
+    private static string BuildBaseUrl(string hostnameOrIp, int port)
+    {
+        return $"http://{hostnameOrIp}:{port}";
+    }
+}