Merge branch 'dev' into agent/dex/CUB-64-docker-runtime-setup

Reviewed-on: #16

backend/API/Controllers/CostAnalysisController.cs

@@ -0,0 +1,108 @@
+using Extrudex.API.DTOs.PrintJobs;
+using Extrudex.Domain.Interfaces;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Extrudex.API.Controllers;
+
+/// <summary>
+/// Controller for cost analysis endpoints. Provides spool-level
+/// cost breakdowns and aggregated COGS reporting.
+/// </summary>
+[ApiController]
+[Route("api/cost-analysis")]
+public class CostAnalysisController : ControllerBase
+{
+    private readonly ICostPerPrintService _costService;
+    private readonly ILogger<CostAnalysisController> _logger;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="CostAnalysisController"/> class.
+    /// </summary>
+    /// <param name="costService">The cost-per-print calculation service.</param>
+    /// <param name="logger">The logger for diagnostic output.</param>
+    public CostAnalysisController(
+        ICostPerPrintService costService,
+        ILogger<CostAnalysisController> logger)
+    {
+        _costService = costService;
+        _logger = logger;
+    }
+
+    // ── POST /api/cost-analysis/spool ────────────────────────────
+
+    /// <summary>
+    /// Calculates cost breakdowns for all print jobs associated with a specific spool.
+    /// Returns per-job costs plus an aggregated total. Jobs with missing cost data
+    /// include warnings and null cost fields — the endpoint never throws for missing data.
+    /// </summary>
+    /// <param name="request">The request containing the spool identifier.</param>
+    /// <returns>A spool-level cost summary with per-job breakdowns.</returns>
+    /// <response code="200">Returns the spool cost breakdown with per-job details.</response>
+    /// <response code="404">If the spool has no print jobs.</response>
+    [HttpPost("spool")]
+    [ProducesResponseType(typeof(SpoolCostResponse), StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public async Task<ActionResult<SpoolCostResponse>> CalculateSpoolCost([FromBody] SpoolCostRequest request)
+    {
+        _logger.LogDebug("Calculating cost breakdown for spool {SpoolId}", request.SpoolId);
+
+        var results = await _costService.CalculateBySpoolAsync(request.SpoolId);
+
+        if (results.Count == 0)
+        {
+            return NotFound(new { error = $"No print jobs found for spool with ID '{request.SpoolId}'." });
+        }
+
+        // Build the spool-level summary
+        var firstResult = results[0];
+        var jobResponses = results.Select(MapCostToResponse).ToList();
+
+        // Aggregate total cost and grams — only include jobs that have a valid cost
+        var calculableJobs = results.Where(r => r.CostPerPrint.HasValue).ToList();
+        var totalCost = calculableJobs.Count == results.Count
+            ? Math.Round(calculableJobs.Sum(r => r.CostPerPrint!.Value), 4)
+            : (decimal?)null;
+
+        var aggregateWarnings = new List<string>();
+        if (calculableJobs.Count < results.Count)
+        {
+            aggregateWarnings.Add(
+                $"{results.Count - calculableJobs.Count} of {results.Count} print jobs have missing cost data. " +
+                "Total cost reflects only jobs with complete data.");
+        }
+
+        var response = new SpoolCostResponse
+        {
+            SpoolId = request.SpoolId,
+            SpoolSerial = firstResult.SpoolSerial,
+            PurchasePrice = firstResult.PurchasePrice,
+            WeightTotalGrams = firstResult.WeightTotalGrams,
+            CostPerGram = firstResult.CostPerGram,
+            TotalGramsConsumed = results.Sum(r => r.GramsDerived),
+            TotalCost = totalCost,
+            JobCount = results.Count,
+            Jobs = jobResponses,
+            Warnings = aggregateWarnings
+        };
+
+        return Ok(response);
+    }
+
+    /// <summary>
+    /// Maps a domain CostPerPrintResult to an API CostPerPrintResponse DTO.
+    /// </summary>
+    private static CostPerPrintResponse MapCostToResponse(CostPerPrintResult r) => new()
+    {
+        PrintJobId = r.PrintJobId,
+        PrintName = r.PrintName,
+        SpoolId = r.SpoolId,
+        SpoolSerial = r.SpoolSerial,
+        MmExtruded = r.MmExtruded,
+        GramsDerived = r.GramsDerived,
+        PurchasePrice = r.PurchasePrice,
+        WeightTotalGrams = r.WeightTotalGrams,
+        CostPerGram = r.CostPerGram,
+        CostPerPrint = r.CostPerPrint,
+        Warnings = r.Warnings
+    };
+}

backend/API/DTOs/PrintJobs/CostPerPrintDtos.cs

@@ -0,0 +1,99 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace Extrudex.API.DTOs.PrintJobs;
+
+/// <summary>
+/// Response DTO for cost-per-print calculation. Contains the full cost
+/// breakdown and any warnings about missing or incomplete data.
+/// </summary>
+public class CostPerPrintResponse
+{
+    /// <summary>The print job identifier this result belongs to.</summary>
+    public Guid PrintJobId { get; set; }
+
+    /// <summary>Human-readable name of the print job.</summary>
+    public string PrintName { get; set; } = string.Empty;
+
+    /// <summary>The spool identifier that provided filament.</summary>
+    public Guid SpoolId { get; set; }
+
+    /// <summary>Serial number of the spool.</summary>
+    public string SpoolSerial { get; set; } = string.Empty;
+
+    /// <summary>Total millimeters of filament extruded.</summary>
+    public decimal MmExtruded { get; set; }
+
+    /// <summary>Derived grams consumed for this print.</summary>
+    public decimal GramsDerived { get; set; }
+
+    /// <summary>The spool's purchase price. Null if not recorded.</summary>
+    public decimal? PurchasePrice { get; set; }
+
+    /// <summary>The spool's total weight in grams when full.</summary>
+    public decimal? WeightTotalGrams { get; set; }
+
+    /// <summary>Cost per gram of filament. Null if purchase price or total weight is missing.</summary>
+    public decimal? CostPerGram { get; set; }
+
+    /// <summary>Calculated cost of this print job. Null if cost data is incomplete.</summary>
+    public decimal? CostPerPrint { get; set; }
+
+    /// <summary>
+    /// Warnings about missing or incomplete data. Empty when all data is available
+    /// and the calculation succeeded.
+    /// </summary>
+    public List<string> Warnings { get; set; } = new();
+}
+
+/// <summary>
+/// Request DTO for batch cost calculation by spool. Returns cost breakdowns
+/// for all print jobs associated with the specified spool.
+/// </summary>
+public class SpoolCostRequest
+{
+    /// <summary>The unique identifier of the spool to calculate costs for.</summary>
+    [Required(ErrorMessage = "SpoolId is required.")]
+    public Guid SpoolId { get; set; }
+}
+
+/// <summary>
+/// Response DTO for spool-level cost calculation. Contains cost breakdowns
+/// for all print jobs on the spool, plus a total cost summary.
+/// </summary>
+public class SpoolCostResponse
+{
+    /// <summary>The spool identifier.</summary>
+    public Guid SpoolId { get; set; }
+
+    /// <summary>Serial number of the spool.</summary>
+    public string SpoolSerial { get; set; } = string.Empty;
+
+    /// <summary>The spool's purchase price. Null if not recorded.</summary>
+    public decimal? PurchasePrice { get; set; }
+
+    /// <summary>The spool's total weight in grams when full.</summary>
+    public decimal? WeightTotalGrams { get; set; }
+
+    /// <summary>Cost per gram of filament. Null if cost data is incomplete.</summary>
+    public decimal? CostPerGram { get; set; }
+
+    /// <summary>Total grams consumed across all print jobs on this spool.</summary>
+    public decimal TotalGramsConsumed { get; set; }
+
+    /// <summary>Total calculated cost across all print jobs. Null if any job has missing data.</summary>
+    public decimal? TotalCost { get; set; }
+
+    /// <summary>Number of print jobs included in this calculation.</summary>
+    public int JobCount { get; set; }
+
+    /// <summary>
+    /// Individual cost breakdowns per print job. Jobs with missing data
+    /// will have null cost fields and populated warnings.
+    /// </summary>
+    public List<CostPerPrintResponse> Jobs { get; set; } = new();
+
+    /// <summary>
+    /// Aggregate warnings about missing data across all jobs.
+    /// </summary>
+    public List<string> Warnings { get; set; } = new();
+}

backend/API/Jobs/FilamentUsageSyncJob.cs

@@ -0,0 +1,79 @@
+using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Configuration;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace Extrudex.API.Jobs;
+
+/// <summary>
+/// Background job that periodically syncs filament usage data from
+/// Moonraker printers. Runs as a hosted service and polls all active
+/// Moonraker printers on a configurable interval to persist usage
+/// data to the Extrudex database.
+/// 
+/// Configuration is bound from the "FilamentUsageSync" section in
+/// appsettings.json. Set Enabled=false to disable without removing
+/// the service registration.
+/// </summary>
+public class FilamentUsageSyncJob : BackgroundService
+{
+    private readonly IFilamentUsageSyncService _syncService;
+    private readonly FilamentUsageSyncOptions _options;
+    private readonly ILogger<FilamentUsageSyncJob> _logger;
+
+    /// <summary>
+    /// Creates a new FilamentUsageSyncJob.
+    /// </summary>
+    /// <param name="syncService">The service that performs the actual sync logic.</param>
+    /// <param name="options">Configuration options for polling interval and timeouts.</param>
+    /// <param name="logger">Logger for diagnostic output.</param>
+    public FilamentUsageSyncJob(
+        IFilamentUsageSyncService syncService,
+        IOptions<FilamentUsageSyncOptions> options,
+        ILogger<FilamentUsageSyncJob> logger)
+    {
+        _syncService = syncService;
+        _options = options.Value;
+        _logger = logger;
+    }
+
+    /// <inheritdoc />
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        if (!_options.Enabled)
+        {
+            _logger.LogInformation("Filament usage sync job is disabled via configuration — exiting");
+            return;
+        }
+
+        _logger.LogInformation(
+            "Filament usage sync job starting — polling every {Interval}",
+            _options.PollingInterval);
+
+        // Delay briefly on startup to allow the web host to fully initialize
+        await Task.Delay(TimeSpan.FromSeconds(10), stoppingToken);
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            try
+            {
+                var syncedCount = await _syncService.SyncAllAsync(stoppingToken);
+
+                _logger.LogInformation(
+                    "Filament usage sync completed — {SyncedCount} printer(s) synced. Next sync in {Interval}",
+                    syncedCount, _options.PollingInterval);
+            }
+            catch (Exception ex) when (ex is not OperationCanceledException)
+            {
+                _logger.LogError(ex,
+                    "Error during filament usage sync cycle — will retry in {Interval}",
+                    _options.PollingInterval);
+            }
+
+            await Task.Delay(_options.PollingInterval, stoppingToken);
+        }
+
+        _logger.LogInformation("Filament usage sync job shutting down");
+    }
+}

backend/Domain/Interfaces/ICostPerPrintService.cs

@@ -0,0 +1,76 @@
+namespace Extrudex.Domain.Interfaces;
+
+/// <summary>
+/// Service interface for calculating the cost of goods sold (COGS) per print job.
+/// Uses the spool's purchase price and the print job's derived grams consumed
+/// to produce a cost breakdown. Handles missing cost data gracefully by returning
+/// warnings rather than throwing exceptions.
+/// </summary>
+public interface ICostPerPrintService
+{
+    /// <summary>
+    /// Calculates the cost per print for a specific print job.
+    /// </summary>
+    /// <param name="printJobId">The unique identifier of the print job.</param>
+    /// <param name="cancellationToken">Optional cancellation token.</param>
+    /// <returns>
+    /// A <see cref="CostPerPrintResult"/> containing the cost breakdown,
+    /// or warnings if cost data is missing or incomplete.
+    /// </returns>
+    Task<CostPerPrintResult> CalculateAsync(Guid printJobId, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Calculates cost breakdowns for all print jobs associated with a specific spool.
+    /// Useful for spool-level COGS reporting.
+    /// </summary>
+    /// <param name="spoolId">The unique identifier of the spool.</param>
+    /// <param name="cancellationToken">Optional cancellation token.</param>
+    /// <returns>
+    /// A list of <see cref="CostPerPrintResult"/> for each print job on the spool.
+    /// Jobs with missing cost data will include warnings.
+    /// </returns>
+    Task<IReadOnlyList<CostPerPrintResult>> CalculateBySpoolAsync(Guid spoolId, CancellationToken cancellationToken = default);
+}
+
+/// <summary>
+/// Result of a cost-per-print calculation. Contains the cost breakdown
+/// and any warnings about missing or incomplete cost data.
+/// </summary>
+public class CostPerPrintResult
+{
+    /// <summary>The print job identifier this result belongs to.</summary>
+    public Guid PrintJobId { get; set; }
+
+    /// <summary>Human-readable name of the print job.</summary>
+    public string PrintName { get; set; } = string.Empty;
+
+    /// <summary>The spool identifier that provided filament.</summary>
+    public Guid SpoolId { get; set; }
+
+    /// <summary>Serial number of the spool.</summary>
+    public string SpoolSerial { get; set; } = string.Empty;
+
+    /// <summary>Total millimeters of filament extruded.</summary>
+    public decimal MmExtruded { get; set; }
+
+    /// <summary>Derived grams consumed for this print.</summary>
+    public decimal GramsDerived { get; set; }
+
+    /// <summary>The spool's purchase price. Null if not recorded.</summary>
+    public decimal? PurchasePrice { get; set; }
+
+    /// <summary>The spool's total weight in grams when full.</summary>
+    public decimal? WeightTotalGrams { get; set; }
+
+    /// <summary>Cost per gram of filament. Null if purchase price or total weight is missing.</summary>
+    public decimal? CostPerGram { get; set; }
+
+    /// <summary>Calculated cost of this print job. Null if cost data is incomplete.</summary>
+    public decimal? CostPerPrint { get; set; }
+
+    /// <summary>
+    /// Warnings about missing or incomplete data that prevented a full calculation.
+    /// Empty when all data is available and the calculation succeeded.
+    /// </summary>
+    public List<string> Warnings { get; set; } = new();
+}

backend/Domain/Interfaces/IFilamentUsageSyncService.cs

@@ -0,0 +1,19 @@
+namespace Extrudex.Domain.Interfaces;
+
+/// <summary>
+/// Service interface for syncing filament usage data from printers
+/// into the Extrudex database. Handles querying Moonraker printers,
+/// computing derived usage metrics, and persisting updates to spools
+/// and print job records.
+/// </summary>
+public interface IFilamentUsageSyncService
+{
+    /// <summary>
+    /// Performs a single sync cycle: queries all active Moonraker printers,
+    /// fetches their current filament usage data, and persists updates to
+    /// the database.
+    /// </summary>
+    /// <param name="cancellationToken">Cancellation token for graceful shutdown.</param>
+    /// <returns>The number of printers successfully synced.</returns>
+    Task<int> SyncAllAsync(CancellationToken cancellationToken = default);
+}

backend/Domain/Interfaces/IMoonrakerClient.cs

@@ -0,0 +1,39 @@
+namespace Extrudex.Domain.Interfaces;
+
+/// <summary>
+/// Client interface for communicating with Moonraker REST API endpoints
+/// on Klipper-based printers (e.g., Elegoo Centauri Carbon).
+/// Used to retrieve filament usage data, print job status, and
+/// remaining spool weight from the printer.
+/// </summary>
+public interface IMoonrakerClient
+{
+    /// <summary>
+    /// Fetches the current filament usage data from the Moonraker server.
+    /// Returns a dictionary of usage metrics reported by the printer.
+    /// </summary>
+    /// <param name="hostnameOrIp">The printer's hostname or IP address.</param>
+    /// <param name="port">The Moonraker API port (default: 7125).</param>
+    /// <param name="apiKey">Optional API key for authentication.</param>
+    /// <param name="cancellationToken">Cancellation token for the HTTP request.</param>
+    /// <returns>A dictionary of usage metric names to their decimal values.</returns>
+    Task<Dictionary<string, decimal>> GetFilamentUsageAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Checks whether the Moonraker server is reachable and responding.
+    /// </summary>
+    /// <param name="hostnameOrIp">The printer's hostname or IP address.</param>
+    /// <param name="port">The Moonraker API port (default: 7125).</param>
+    /// <param name="apiKey">Optional API key for authentication.</param>
+    /// <param name="cancellationToken">Cancellation token for the HTTP request.</param>
+    /// <returns><c>true</c> if the server responded successfully; otherwise <c>false</c>.</returns>
+    Task<bool> IsReachableAsync(
+        string hostnameOrIp,
+        int port,
+        string? apiKey,
+        CancellationToken cancellationToken = default);
+}

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/CostPerPrintService.cs

@@ -0,0 +1,158 @@
+using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+
+namespace Extrudex.Infrastructure.Services;
+
+/// <summary>
+/// Calculates the cost of goods sold (COGS) per print job using the spool's
+/// purchase price and the print job's derived grams consumed.
+///
+/// Formula:
+///   cost_per_gram = purchase_price / weight_total_grams
+///   cost_per_print = grams_derived × cost_per_gram
+///
+/// Handles missing data gracefully — if the spool has no purchase price or
+/// weight recorded, the result includes warnings and null cost fields
+/// instead of throwing exceptions.
+/// </summary>
+public class CostPerPrintService : ICostPerPrintService
+{
+    private readonly ExtrudexDbContext _dbContext;
+    private readonly ILogger<CostPerPrintService> _logger;
+
+    /// <summary>
+    /// Initializes a new instance of the <see cref="CostPerPrintService"/> class.
+    /// </summary>
+    /// <param name="dbContext">The database context for data access.</param>
+    /// <param name="logger">The logger for diagnostic output.</param>
+    public CostPerPrintService(ExtrudexDbContext dbContext, ILogger<CostPerPrintService> logger)
+    {
+        _dbContext = dbContext;
+        _logger = logger;
+    }
+
+    /// <inheritdoc />
+    public async Task<CostPerPrintResult> CalculateAsync(Guid printJobId, CancellationToken cancellationToken = default)
+    {
+        _logger.LogDebug("Calculating cost per print for job {PrintJobId}", printJobId);
+
+        var job = await _dbContext.PrintJobs
+            .Include(j => j.Spool)
+            .ThenInclude(s => s!.MaterialBase)
+            .FirstOrDefaultAsync(j => j.Id == printJobId, cancellationToken);
+
+        if (job is null)
+        {
+            _logger.LogWarning("Print job {PrintJobId} not found for cost calculation", printJobId);
+            return new CostPerPrintResult
+            {
+                PrintJobId = printJobId,
+                Warnings = new List<string> { $"Print job with ID '{printJobId}' not found." }
+            };
+        }
+
+        return BuildResult(job);
+    }
+
+    /// <inheritdoc />
+    public async Task<IReadOnlyList<CostPerPrintResult>> CalculateBySpoolAsync(
+        Guid spoolId, CancellationToken cancellationToken = default)
+    {
+        _logger.LogDebug("Calculating cost per print for all jobs on spool {SpoolId}", spoolId);
+
+        var jobs = await _dbContext.PrintJobs
+            .Include(j => j.Spool)
+            .ThenInclude(s => s!.MaterialBase)
+            .Where(j => j.SpoolId == spoolId)
+            .OrderByDescending(j => j.CreatedAt)
+            .ToListAsync(cancellationToken);
+
+        if (jobs.Count == 0)
+        {
+            _logger.LogDebug("No print jobs found for spool {SpoolId}", spoolId);
+            return Array.Empty<CostPerPrintResult>();
+        }
+
+        return jobs.Select(BuildResult).ToList();
+    }
+
+    /// <summary>
+    /// Builds a <see cref="CostPerPrintResult"/> from a print job entity.
+    /// Computes cost_per_gram and cost_per_print when all required data is available.
+    /// Populates warnings when data is missing or incomplete.
+    /// </summary>
+    /// <param name="job">The print job entity with Spool navigation loaded.</param>
+    /// <returns>A cost calculation result with breakdown and any warnings.</returns>
+    private CostPerPrintResult BuildResult(Domain.Entities.PrintJob job)
+    {
+        var warnings = new List<string>();
+        var spool = job.Spool;
+
+        // Map what we always have
+        var result = new CostPerPrintResult
+        {
+            PrintJobId = job.Id,
+            PrintName = job.PrintName,
+            SpoolId = job.SpoolId,
+            SpoolSerial = spool?.SpoolSerial ?? string.Empty,
+            MmExtruded = job.MmExtruded,
+            GramsDerived = job.GramsDerived,
+        };
+
+        // Guard: spool must be loaded
+        if (spool is null)
+        {
+            warnings.Add("Spool data is not available for this print job.");
+            result.Warnings = warnings;
+            return result;
+        }
+
+        // Capture purchase price
+        result.PurchasePrice = spool.PurchasePrice;
+        result.WeightTotalGrams = spool.WeightTotalGrams;
+
+        // Check for missing purchase price
+        if (!spool.PurchasePrice.HasValue)
+        {
+            warnings.Add(
+                "Spool purchase price is not recorded. Cost calculation requires a purchase price on the spool.");
+        }
+
+        // Check for zero or negative weight — prevents division by zero
+        if (spool.WeightTotalGrams <= 0)
+        {
+            warnings.Add(
+                "Spool total weight is zero or not recorded. Cost calculation requires a positive weight_total_grams on the spool.");
+        }
+
+        // Check for zero grams derived
+        if (job.GramsDerived <= 0)
+        {
+            warnings.Add(
+                "Derived grams consumed is zero. Ensure mm_extruded, filament diameter, and material density are recorded for this print job.");
+        }
+
+        // If all data is present and valid, compute the cost
+        if (spool.PurchasePrice.HasValue && spool.WeightTotalGrams > 0 && job.GramsDerived > 0)
+        {
+            var costPerGram = spool.PurchasePrice.Value / spool.WeightTotalGrams;
+            result.CostPerGram = Math.Round(costPerGram, 6);
+            result.CostPerPrint = Math.Round(job.GramsDerived * costPerGram, 4);
+
+            _logger.LogDebug(
+                "Cost calculated for job {PrintJobId}: {GramsDerived}g × {CostPerGram:C}/g = {CostPerPrint:C}",
+                job.Id, job.GramsDerived, result.CostPerGram, result.CostPerPrint);
+        }
+        else
+        {
+            _logger.LogDebug(
+                "Cost calculation incomplete for job {PrintJobId}: missing data (warnings: {WarningCount})",
+                job.Id, warnings.Count);
+        }
+
+        result.Warnings = warnings;
+        return result;
+    }
+}

backend/Infrastructure/Services/FilamentUsageSyncService.cs

@@ -0,0 +1,139 @@
+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}";
+    }
+}

backend/Program.cs

@@ -1,7 +1,9 @@
 using System.Reflection;
 using Extrudex.API.Filters;
 using Extrudex.API.Hubs;
+using Extrudex.API.Jobs;
 using Extrudex.Domain.Interfaces;
+using Extrudex.Infrastructure.Configuration;
 using Extrudex.Infrastructure.Data;
 using Extrudex.Infrastructure.Services;
 using FluentValidation;
@@ -50,6 +52,9 @@ builder.Services.AddSwaggerGen(c =>
 // ── QR Code Generation ──────────────────────────────────────
 builder.Services.AddSingleton<IQrCodeService, QrCodeService>();
 
+// ── Cost Per Print Calculation ─────────────────────────────
+builder.Services.AddScoped<ICostPerPrintService, CostPerPrintService>();
+
 // ── FluentValidation ──────────────────────────────────────
 // Registers all validators from the API assembly into DI.
 builder.Services.AddValidatorsFromAssembly(Assembly.GetExecutingAssembly());
@@ -77,6 +82,16 @@ builder.Services.AddCors(options =>
 // ── SignalR (real-time printer updates) ────────────────────
 builder.Services.AddSignalR();
 
+// ── Filament Usage Sync (Background Job) ──────────────────
+builder.Services.Configure<FilamentUsageSyncOptions>(
+    builder.Configuration.GetSection(FilamentUsageSyncOptions.SectionName));
+builder.Services.AddHttpClient<IMoonrakerClient, MoonrakerClient>(client =>
+{
+    client.DefaultRequestHeaders.Add("User-Agent", "Extrudex/1.0");
+});
+builder.Services.AddScoped<IFilamentUsageSyncService, FilamentUsageSyncService>();
+builder.Services.AddHostedService<FilamentUsageSyncJob>();
+
 // ── Health Checks ───────────────────────────────────────────
 builder.Services.AddHealthChecks()
     .AddNpgSql(connectionString);

backend/appsettings.Development.json

@@ -8,5 +8,10 @@
   },
   "ConnectionStrings": {
     "ExtrudexDb": "Host=localhost;Port=5432;Database=extrudex_dev;Username=extrudex;Password=changeme"
+  },
+  "FilamentUsageSync": {
+    "PollingInterval": "00:01:00",
+    "RequestTimeout": "00:00:30",
+    "Enabled": true
   }
 }

backend/appsettings.json

@@ -9,5 +9,10 @@
   "AllowedHosts": "*",
   "ConnectionStrings": {
     "ExtrudexDb": "Host=localhost;Port=5432;Database=extrudex;Username=extrudex;Password=changeme"
+  },
+  "FilamentUsageSync": {
+    "PollingInterval": "00:05:00",
+    "RequestTimeout": "00:00:30",
+    "Enabled": true
   }
 }

frontend/src/app/components/filament-filter/filament-filter.component.html

@@ -0,0 +1,76 @@
+<!-- Filament Filter Bar — material type, color search, low stock, active-only -->
+<div class="filament-filter-bar" role="search" aria-label="Filter filament inventory">
+
+  <!-- Material Type Multi-Select -->
+  <mat-form-field appearance="outline" class="filter-field material-filter">
+    <mat-label>Material</mat-label>
+    <mat-select multiple
+                [value]="selectedMaterials()"
+                (selectionChange)="onMaterialChange($event.value)"
+                aria-label="Filter by material type">
+      @for (material of materialOptions(); track material) {
+        <mat-option [value]="material">{{ material }}</mat-option>
+      }
+    </mat-select>
+    @if (selectedMaterials().length > 0) {
+      <mat-chip-set class="selected-chips" matSuffix>
+        @for (mat of selectedMaterials(); track mat) {
+          <mat-chip (removed)="removeMaterial(mat)"
+                    class="filter-chip">
+            <span>{{ mat }}</span>
+            <mat-icon matChipRemove>cancel</mat-icon>
+          </mat-chip>
+        }
+      </mat-chip-set>
+    }
+  </mat-form-field>
+
+  <!-- Color Search -->
+  <mat-form-field appearance="outline" class="filter-field color-filter">
+    <mat-label>Color</mat-label>
+    <input matInput
+           type="text"
+           [value]="colorSearch()"
+           (input)="onColorSearchChange($any($event.target).value)"
+           placeholder="Search color..."
+           aria-label="Filter by color name" />
+    @if (colorSearch().trim()) {
+      <mat-icon matSuffix class="filter-active-icon">filter_list</mat-icon>
+    }
+  </mat-form-field>
+
+  <!-- Low Stock Toggle -->
+  <mat-checkbox [checked]="lowStockOnly()"
+                (change)="onLowStockToggle($event.checked)"
+                class="filter-checkbox"
+                aria-label="Show low stock only"
+                matTooltip="Show only spools at 25% or less remaining"
+                matTooltipPosition="below">
+    <mat-icon class="checkbox-icon" [class.active]="lowStockOnly()">warning</mat-icon>
+    Low Stock
+  </mat-checkbox>
+
+  <!-- Active Only Toggle -->
+  <mat-checkbox [checked]="activeOnly()"
+                (change)="onActiveOnlyToggle($event.checked)"
+                class="filter-checkbox"
+                aria-label="Show active spools only"
+                matTooltip="Show only spools currently in use"
+                matTooltipPosition="below">
+    <mat-icon class="checkbox-icon" [class.active]="activeOnly()">check_circle</mat-icon>
+    Active Only
+  </mat-checkbox>
+
+  <!-- Clear All Filters -->
+  @if (hasActiveFilters()) {
+    <button mat-button
+            class="clear-filters-btn"
+            (click)="clearAll()"
+            aria-label="Clear all filters"
+            matTooltip="Remove all filters"
+            matTooltipPosition="below">
+      <mat-icon>filter_alt_off</mat-icon>
+      Clear
+    </button>
+  }
+</div>

frontend/src/app/components/filament-filter/filament-filter.component.scss

@@ -0,0 +1,134 @@
+/**
+ * Filament Filter Bar Styles
+ * Responsive filter layout for kiosk and mobile
+ */
+
+$spacing-unit: 8px;
+
+.filament-filter-bar {
+  display: flex;
+  align-items: center;
+  gap: $spacing-unit * 2;
+  flex-wrap: wrap;
+  padding: $spacing-unit * 2 0;
+  margin-bottom: $spacing-unit * 2;
+}
+
+// Form field sizing
+.filter-field {
+  flex: 0 1 auto;
+  min-width: 160px;
+
+  &.material-filter {
+    min-width: 200px;
+  }
+
+  &.color-filter {
+    min-width: 180px;
+  }
+
+  // Reduce vertical spacing inside filter fields
+  .mat-mdc-form-field-subscript-wrapper {
+    display: none; // No hint/error text needed for filters
+  }
+}
+
+// Selected material chips
+.selected-chips {
+  flex-wrap: wrap;
+  gap: 4px;
+}
+
+.filter-chip {
+  font-size: 12px !important;
+  min-height: 24px !important;
+
+  mat-icon {
+    font-size: 14px !important;
+    width: 14px !important;
+    height: 14px !important;
+  }
+}
+
+// Active filter icon
+.filter-active-icon {
+  color: var(--mat-sys-primary);
+  font-size: 18px !important;
+  width: 18px !important;
+  height: 18px !important;
+}
+
+// Checkbox styling
+.filter-checkbox {
+  display: flex;
+  align-items: center;
+  gap: 4px;
+  white-space: nowrap;
+  user-select: none;
+  touch-action: manipulation; // Prevent zoom on double-tap
+
+  .checkbox-icon {
+    font-size: 18px !important;
+    width: 18px !important;
+    height: 18px !important;
+    color: var(--mat-sys-on-surface-variant);
+    transition: color 0.2s ease;
+
+    &.active {
+      color: var(--mat-sys-primary);
+    }
+  }
+}
+
+// Clear filters button
+.clear-filters-btn {
+  display: flex;
+  align-items: center;
+  gap: 4px;
+  font-size: 13px;
+
+  mat-icon {
+    font-size: 18px !important;
+    width: 18px !important;
+    height: 18px !important;
+  }
+}
+
+// Responsive: stack filters vertically on small screens
+@media (max-width: 768px) {
+  .filament-filter-bar {
+    flex-direction: column;
+    align-items: stretch;
+    gap: $spacing-unit;
+  }
+
+  .filter-field {
+    width: 100%;
+    min-width: unset;
+
+    &.material-filter,
+    &.color-filter {
+      min-width: unset;
+    }
+  }
+
+  .filter-checkbox {
+    padding: $spacing-unit 0;
+  }
+
+  .clear-filters-btn {
+    align-self: flex-start;
+  }
+}
+
+// Extra-small screens (phone portrait)
+@media (max-width: 480px) {
+  .filament-filter-bar {
+    padding: $spacing-unit 0;
+    margin-bottom: $spacing-unit;
+  }
+
+  .filter-checkbox {
+    font-size: 13px;
+  }
+}

frontend/src/app/components/filament-filter/filament-filter.component.ts

@@ -0,0 +1,158 @@
+import {
+  ChangeDetectionStrategy,
+  Component,
+  EventEmitter,
+  Input,
+  Output,
+  computed,
+  signal,
+} from '@angular/core';
+import { CommonModule } from '@angular/common';
+import { FormsModule } from '@angular/forms';
+import { MatFormFieldModule } from '@angular/material/form-field';
+import { MatSelectModule } from '@angular/material/select';
+import { MatInputModule } from '@angular/material/input';
+import { MatCheckboxModule } from '@angular/material/checkbox';
+import { MatIconModule } from '@angular/material/icon';
+import { MatChipsModule } from '@angular/material/chips';
+import { MatButtonModule } from '@angular/material/button';
+import { MatTooltipModule } from '@angular/material/tooltip';
+import {
+  Filament,
+  StockLevel,
+  classifyStockLevel,
+} from '../../models/filament.model';
+
+/** Filter state emitted by the filament filter component */
+export interface FilamentFilterState {
+  /** Selected material base names — empty means all */
+  materialBaseNames: string[];
+
+  /** Color search text — empty string means all */
+  colorSearch: string;
+
+  /** Whether to show only low/critical stock */
+  lowStockOnly: boolean;
+
+  /** Whether to show only active spools */
+  activeOnly: boolean;
+}
+
+/**
+ * FilamentFilterComponent — Filter bar for the filament inventory list.
+ *
+ * Provides:
+ * - Material type multi-select filter
+ * - Color name text search
+ * - Low stock toggle (shows only critical/low spools)
+ * - Active-only toggle
+ * - Clear all filters action
+ */
+@Component({
+  selector: 'app-filament-filter',
+  standalone: true,
+  imports: [
+    CommonModule,
+    FormsModule,
+    MatFormFieldModule,
+    MatSelectModule,
+    MatInputModule,
+    MatCheckboxModule,
+    MatIconModule,
+    MatChipsModule,
+    MatButtonModule,
+    MatTooltipModule,
+  ],
+  templateUrl: './filament-filter.component.html',
+  styleUrl: './filament-filter.component.scss',
+  changeDetection: ChangeDetectionStrategy.OnPush,
+})
+export class FilamentFilterComponent {
+  /** Filament data input — used to derive material options */
+  @Input() set filaments(value: Filament[]) {
+    this._filaments.set(value);
+    const materials = [...new Set(value.map((f) => f.materialBaseName))].sort();
+    this.materialOptions.set(materials);
+  }
+  get filaments(): Filament[] {
+    return this._filaments();
+  }
+  private readonly _filaments = signal<Filament[]>([]);
+
+  /** Available material base names derived from filament data */
+  readonly materialOptions = signal<string[]>([]);
+
+  /** Selected material base names */
+  readonly selectedMaterials = signal<string[]>([]);
+
+  /** Color search text */
+  readonly colorSearch = signal('');
+
+  /** Low stock only toggle */
+  readonly lowStockOnly = signal(false);
+
+  /** Active only toggle */
+  readonly activeOnly = signal(false);
+
+  /** Computed: whether any filters are active */
+  readonly hasActiveFilters = computed(
+    () =>
+      this.selectedMaterials().length > 0 ||
+      this.colorSearch().trim().length > 0 ||
+      this.lowStockOnly() ||
+      this.activeOnly()
+  );
+
+  /** Emits the current filter state whenever filters change */
+  @Output() readonly filterChange = new EventEmitter<FilamentFilterState>();
+
+  /** Handle material selection change */
+  onMaterialChange(selected: string[]): void {
+    this.selectedMaterials.set(selected);
+    this.emitFilterState();
+  }
+
+  /** Handle color search input */
+  onColorSearchChange(value: string): void {
+    this.colorSearch.set(value);
+    this.emitFilterState();
+  }
+
+  /** Handle low stock toggle */
+  onLowStockToggle(checked: boolean): void {
+    this.lowStockOnly.set(checked);
+    this.emitFilterState();
+  }
+
+  /** Handle active-only toggle */
+  onActiveOnlyToggle(checked: boolean): void {
+    this.activeOnly.set(checked);
+    this.emitFilterState();
+  }
+
+  /** Remove a single material chip */
+  removeMaterial(material: string): void {
+    const updated = this.selectedMaterials().filter((m) => m !== material);
+    this.selectedMaterials.set(updated);
+    this.emitFilterState();
+  }
+
+  /** Clear all filters */
+  clearAll(): void {
+    this.selectedMaterials.set([]);
+    this.colorSearch.set('');
+    this.lowStockOnly.set(false);
+    this.activeOnly.set(false);
+    this.emitFilterState();
+  }
+
+  /** Emit the current filter state */
+  private emitFilterState(): void {
+    this.filterChange.emit({
+      materialBaseNames: this.selectedMaterials(),
+      colorSearch: this.colorSearch().trim().toLowerCase(),
+      lowStockOnly: this.lowStockOnly(),
+      activeOnly: this.activeOnly(),
+    });
+  }
+}

frontend/src/app/components/filament-table/filament-table.component.html

@@ -1,6 +1,12 @@
-<!-- Filament Inventory Table — with low stock indicators -->
+<!-- Filament Inventory Table — with filters and low stock indicators -->
 <div class="filament-table-container" role="region" aria-label="Filament inventory">
 
+  <!-- Filter Bar -->
+  <app-filament-filter
+    [filaments]="allFilaments()"
+    (filterChange)="onFilterChange($event)"
+    aria-label="Filter filament inventory" />
+
   <!-- Low Stock Alert Banner — shown when critical or low stock spools exist -->
   @if (criticalCount() > 0) {
     <div class="alert-banner critical" role="alert">
@@ -16,7 +22,7 @@
 
   <!-- Filament Table -->
   <table mat-table
-         [dataSource]="sortedFilaments()"
+         [dataSource]="filteredFilaments()"
          matSort
          (matSortChange)="sortData($event)"
          class="filament-table"
@@ -113,7 +119,15 @@
     </tr>
   </table>
 
-  <!-- Empty state -->
+  <!-- Filtered empty state -->
+  @if (filteredFilaments().length === 0 && filaments().length > 0) {
+    <div class="empty-state" role="status">
+      <mat-icon aria-hidden="true">filter_alt_off</mat-icon>
+      <p>No filaments match the current filters</p>
+    </div>
+  }
+
+  <!-- No data empty state -->
   @if (filaments().length === 0) {
     <div class="empty-state" role="status">
       <mat-icon aria-hidden="true">inventory_2</mat-icon>

frontend/src/app/components/filament-table/filament-table.component.ts

@@ -12,6 +12,7 @@ import { MatIconModule } from '@angular/material/icon';
 import { MatProgressBarModule } from '@angular/material/progress-bar';
 import { MatTooltipModule } from '@angular/material/tooltip';
 import { MatSortModule, Sort } from '@angular/material/sort';
+import { FilamentFilterComponent, FilamentFilterState } from '../filament-filter/filament-filter.component';
 import {
   Filament,
   StockLevel,
@@ -40,6 +41,7 @@ export type FilamentColumn =
     MatProgressBarModule,
     MatTooltipModule,
     MatSortModule,
+    FilamentFilterComponent,
   ],
   templateUrl: './filament-table.component.html',
   styleUrl: './filament-table.component.scss',
@@ -70,9 +72,24 @@ export class FilamentTableComponent {
   /** Default columns for template binding */
   readonly columns = this._displayedColumns;
 
+  /** Current filter state */
+  readonly filterState = signal<FilamentFilterState>({
+    materialBaseNames: [],
+    colorSearch: '',
+    lowStockOnly: false,
+    activeOnly: false,
+  });
+
   /** Sorted filament data */
   readonly sortedFilaments = signal<Filament[]>([]);
 
+  /** Computed: filtered + sorted filament data for display */
+  readonly filteredFilaments = computed(() => {
+    const data = this.sortedFilaments();
+    const filters = this.filterState();
+    return data.filter((f) => this.matchesFilter(f, filters));
+  });
+
   /** Computed: count of low/critical spools */
   readonly lowStockCount = computed(() =>
     this.filaments().filter(
@@ -211,6 +228,9 @@ export class FilamentTableComponent {
     this.sortedFilaments.set([...data]);
   }
 
+  /** All filament data — for the filter component to derive material options */
+  readonly allFilaments = this.filaments;
+
   /** Handle sort changes from MatSort */
   sortData(sort: Sort): void {
     const data = [...this.filaments()];
@@ -252,6 +272,46 @@ export class FilamentTableComponent {
     this.sortedFilaments.set(sorted);
   }
 
+  /** Handle filter changes from FilamentFilterComponent */
+  onFilterChange(state: FilamentFilterState): void {
+    this.filterState.set(state);
+  }
+
+  /** Check if a filament matches the current filter state */
+  private matchesFilter(filament: Filament, filters: FilamentFilterState): boolean {
+    // Material filter — empty means all
+    if (
+      filters.materialBaseNames.length > 0 &&
+      !filters.materialBaseNames.includes(filament.materialBaseName)
+    ) {
+      return false;
+    }
+
+    // Color search — empty means all
+    if (
+      filters.colorSearch &&
+      !filament.colorName.toLowerCase().includes(filters.colorSearch) &&
+      !filament.colorHex.toLowerCase().includes(filters.colorSearch)
+    ) {
+      return false;
+    }
+
+    // Low stock filter — show only critical/low
+    if (filters.lowStockOnly) {
+      const level = classifyStockLevel(filament);
+      if (level !== 'critical' && level !== 'low') {
+        return false;
+      }
+    }
+
+    // Active only filter
+    if (filters.activeOnly && !filament.isActive) {
+      return false;
+    }
+
+    return true;
+  }
+
   /** Template helper: get remaining percent */
   getRemainingPercent = getRemainingPercent;