Merge remote-tracking branch 'origin/dev' into fix-pr-18

# Conflicts:
#	backend/API/Controllers/PrintJobsController.cs

backend/API/Controllers/PrintJobsController.cs

@@ -2,7 +2,6 @@ using Extrudex.API.DTOs;
 using Extrudex.API.DTOs.PrintJobs;
 using Extrudex.Domain.Entities;
 using Extrudex.Domain.Enums;
-using Extrudex.Domain.Interfaces;
 using Extrudex.Infrastructure.Data;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
@@ -20,22 +19,16 @@ namespace Extrudex.API.Controllers;
 public class PrintJobsController : ControllerBase
 {
     private readonly ExtrudexDbContext _dbContext;
-    private readonly ICostPerPrintService _costService;
     private readonly ILogger<PrintJobsController> _logger;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="PrintJobsController"/> class.
     /// </summary>
     /// <param name="dbContext">The database context for data access.</param>
-    /// <param name="costService">The cost-per-print calculation service.</param>
     /// <param name="logger">The logger for diagnostic output.</param>
-    public PrintJobsController(
-        ExtrudexDbContext dbContext,
-        ICostPerPrintService costService,
-        ILogger<PrintJobsController> logger)
+    public PrintJobsController(ExtrudexDbContext dbContext, ILogger<PrintJobsController> logger)
     {
         _dbContext = dbContext;
-        _costService = costService;
         _logger = logger;
     }
 
@@ -420,32 +413,90 @@ public class PrintJobsController : ControllerBase
         return NoContent();
     }
 
-    // ── POST /api/printjobs/{id}/cost ─────────────────────────────
+    // ── GET /api/printjobs/{id}/cost-summary ──────────────────────────
 
     /// <summary>
-    /// Calculates the cost of goods sold (COGS) for a specific print job.
-    /// Uses the spool’s purchase price and the print job’s derived grams consumed
-    /// to produce a cost breakdown. Returns warnings instead of errors when
-    /// cost data is missing or incomplete.
+    /// Gets the material cost summary for a specific print job.
+    /// Calculates total material cost from filament usage (grams derived)
+    /// and the spool's purchase price. Returns warnings instead of errors
+    /// when cost data is unavailable.
     /// </summary>
     /// <param name="id">The unique identifier of the print job.</param>
-    /// <returns>A cost breakdown with warnings if data is incomplete.</returns>
-    /// <response code="200">Returns the cost breakdown for the print job.</response>
+    /// <returns>A cost summary with breakdown and any warnings about missing data.</returns>
+    /// <response code="200">Returns the cost summary. Warnings field lists any missing data.</response>
     /// <response code="404">If the print job with the given ID is not found.</response>
-    [HttpPost("{id:guid}/cost")]
-    [ProducesResponseType(typeof(CostPerPrintResponse), StatusCodes.Status200OK)]
+    [HttpGet("{id:guid}/cost-summary")]
+    [ProducesResponseType(typeof(CostSummaryResponse), StatusCodes.Status200OK)]
     [ProducesResponseType(StatusCodes.Status404NotFound)]
-    public async Task<ActionResult<CostPerPrintResponse>> CalculateCost(Guid id)
+    public async Task<ActionResult<CostSummaryResponse>> GetCostSummary(Guid id)
     {
-        _logger.LogDebug("Calculating cost for print job {Id}", id);
+        _logger.LogDebug("Getting cost summary for print job {Id}", id);
 
-        var result = await _costService.CalculateAsync(id);
+        var job = await _dbContext.PrintJobs
+            .Include(j => j.Spool)
+                .ThenInclude(s => s!.MaterialBase)
+            .FirstOrDefaultAsync(j => j.Id == id);
 
-        // If the job was not found, return 404
-        if (result.Warnings.Any(w => w.Contains("not found")))
+        if (job is null)
+        {
+            _logger.LogWarning("Print job {Id} not found for cost summary", id);
             return NotFound(new { error = $"Print job with ID '{id}' not found." });
+        }
 
-        return Ok(MapCostToResponse(result));
+        var warnings = new List<string>();
+        var spool = job.Spool;
+
+        // Build response with what we have
+        var response = new CostSummaryResponse
+        {
+            PrintJobId = job.Id,
+            PrintName = job.PrintName,
+            SpoolId = job.SpoolId,
+            SpoolSerial = spool?.SpoolSerial ?? string.Empty,
+            SpoolBrand = spool?.Brand ?? string.Empty,
+            SpoolColorName = spool?.ColorName ?? string.Empty,
+            MmExtruded = job.MmExtruded,
+            GramsDerived = job.GramsDerived,
+            SpoolPurchasePrice = spool?.PurchasePrice,
+            SpoolWeightTotalGrams = spool?.WeightTotalGrams,
+            StoredCostPerPrint = job.CostPerPrint
+        };
+
+        // Validate spool data availability
+        if (spool is null)
+        {
+            warnings.Add("Spool data is not available for this print job. Cost cannot be calculated.");
+            response.Warnings = warnings;
+            return Ok(response);
+        }
+
+        // Check if we can calculate cost
+        if (!spool.PurchasePrice.HasValue)
+        {
+            warnings.Add("Spool purchase price is not set. Cost per gram and total material cost cannot be calculated.");
+        }
+
+        if (spool.WeightTotalGrams <= 0)
+        {
+            warnings.Add("Spool total weight is zero or invalid. Cost per gram and total material cost cannot be calculated.");
+        }
+
+        // If we have enough data, calculate the cost
+        if (spool.PurchasePrice.HasValue && spool.WeightTotalGrams > 0)
+        {
+            var pricePerGram = spool.PurchasePrice.Value / spool.WeightTotalGrams;
+            response.PricePerGram = Math.Round(pricePerGram, 4);
+            response.TotalMaterialCost = Math.Round(job.GramsDerived * pricePerGram, 4);
+        }
+
+        // Warn if grams derived is zero but mm extruded is non-zero
+        if (job.GramsDerived == 0 && job.MmExtruded > 0)
+        {
+            warnings.Add("GramsDerived is zero despite MmExtruded being non-zero. Cost may be inaccurate. Consider re-deriving grams from filament parameters.");
+        }
+
+        response.Warnings = warnings;
+        return Ok(response);
     }
 
     // ── Gram Derivation Formula ────────────────────────────────────
@@ -544,22 +595,4 @@ public class PrintJobsController : ControllerBase
         CreatedAt = j.CreatedAt,
         UpdatedAt = j.UpdatedAt
     };
-
-    /// <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/CostSummaryResponse.cs

@@ -0,0 +1,55 @@
+namespace Extrudex.API.DTOs.PrintJobs;
+
+/// <summary>
+/// Response DTO for the cost summary of a print job.
+/// Provides a breakdown of material cost based on filament usage
+/// and spool pricing data. If cost data is incomplete, warnings
+/// are returned instead of throwing an error.
+/// </summary>
+public class CostSummaryResponse
+{
+    /// <summary>Unique identifier of the print job.</summary>
+    public Guid PrintJobId { get; set; }
+
+    /// <summary>Human-readable name of the print job.</summary>
+    public string PrintName { get; set; } = string.Empty;
+
+    /// <summary>Foreign key to the spool used for this print job.</summary>
+    public Guid SpoolId { get; set; }
+
+    /// <summary>Serial number of the spool.</summary>
+    public string SpoolSerial { get; set; } = string.Empty;
+
+    /// <summary>Brand of the spool.</summary>
+    public string SpoolBrand { get; set; } = string.Empty;
+
+    /// <summary>Color name of the spool.</summary>
+    public string SpoolColorName { get; set; } = string.Empty;
+
+    /// <summary>Total millimeters of filament extruded during this print.</summary>
+    public decimal MmExtruded { get; set; }
+
+    /// <summary>Derived grams consumed for this print job.</summary>
+    public decimal GramsDerived { get; set; }
+
+    /// <summary>Purchase price of the full spool, if available.</summary>
+    public decimal? SpoolPurchasePrice { get; set; }
+
+    /// <summary>Total weight of the spool in grams when full.</summary>
+    public decimal? SpoolWeightTotalGrams { get; set; }
+
+    /// <summary>Calculated price per gram (purchase price / total weight), if available.</summary>
+    public decimal? PricePerGram { get; set; }
+
+    /// <summary>Calculated total material cost for this print job, if available.</summary>
+    public decimal? TotalMaterialCost { get; set; }
+
+    /// <summary>The CostPerPrint stored on the print job entity, if set.</summary>
+    public decimal? StoredCostPerPrint { get; set; }
+
+    /// <summary>
+    /// Warnings about missing data that prevent cost calculation.
+    /// Empty if all data is available and cost was calculated successfully.
+    /// </summary>
+    public List<string> Warnings { get; set; } = new();
+}