CUB-41: Add low stock indicators to filament UI

frontend/src/app/models/filament.model.ts

@@ -0,0 +1,100 @@
+/**
+ * Filament model matching the Extrudex backend FilamentResponse DTO.
+ * Used for displaying spool inventory in the filament table UI.
+ */
+export interface Filament {
+  /** Unique identifier for the filament spool. */
+  id: string;
+
+  /** Foreign key to the base material. */
+  materialBaseId: string;
+
+  /** Name of the base material (e.g., "PLA", "PETG"). */
+  materialBaseName: string;
+
+  /** Foreign key to the material finish. */
+  materialFinishId: string;
+
+  /** Name of the material finish (e.g., "Basic", "Matte"). */
+  materialFinishName: string;
+
+  /** Foreign key to the optional material modifier. */
+  materialModifierId: string | null;
+
+  /** Name of the material modifier (e.g., "Carbon Fiber"). Null if none. */
+  materialModifierName: string | null;
+
+  /** Brand name (e.g., "Bambu Lab", "Polymaker"). */
+  brand: string;
+
+  /** Human-readable color name (e.g., "Fire Engine Red"). */
+  colorName: string;
+
+  /** Hex color code (e.g., "#FF0000"). */
+  colorHex: string;
+
+  /** Total spool weight in grams when full. */
+  weightTotalGrams: number;
+
+  /** Current remaining weight in grams. */
+  weightRemainingGrams: number;
+
+  /** Filament diameter in millimeters. Typically 1.75mm. */
+  filamentDiameterMm: number;
+
+  /** Manufacturer-assigned serial number. */
+  spoolSerial: string;
+
+  /** Purchase price per spool. Null if not tracked. */
+  purchasePrice: number | null;
+
+  /** Date the spool was purchased or received. */
+  purchaseDate: string | null;
+
+  /** Whether the spool is currently active and available. */
+  isActive: boolean;
+
+  /** Timestamp when this record was created (UTC). */
+  createdAt: string;
+
+  /** Timestamp when this record was last updated (UTC). */
+  updatedAt: string;
+
+  /** URL to the QR code image for this spool. */
+  qrCodeUrl: string;
+}
+
+/**
+ * Stock level classification for low stock indicators.
+ * - critical: ≤ 10% remaining
+ * - low: ≤ 25% remaining
+ * - moderate: ≤ 50% remaining
+ * - healthy: > 50% remaining
+ */
+export type StockLevel = 'critical' | 'low' | 'moderate' | 'healthy';
+
+/**
+ * Compute the remaining weight percentage for a filament spool.
+ * Returns a value from 0 to 100.
+ */
+export function getRemainingPercent(filament: Filament): number {
+  if (filament.weightTotalGrams <= 0) return 0;
+  const pct = (filament.weightRemainingGrams / filament.weightTotalGrams) * 100;
+  return Math.min(Math.max(pct, 0), 100);
+}
+
+/**
+ * Classify the stock level based on remaining percentage.
+ * Thresholds:
+ *   critical  — ≤ 10%  (nearly empty, red alert)
+ *   low       — ≤ 25%  (getting low, amber warning)
+ *   moderate  — ≤ 50%  (half or less, yellow info)
+ *   healthy   — > 50%  (plenty left, green OK)
+ */
+export function classifyStockLevel(filament: Filament): StockLevel {
+  const pct = getRemainingPercent(filament);
+  if (pct <= 10) return 'critical';
+  if (pct <= 25) return 'low';
+  if (pct <= 50) return 'moderate';
+  return 'healthy';
+}