CUB-131: Build Filament Detail page with usage history

Reviewed-on: https://code.cubecraftcreations.com/CubeCraft-Creations/Extrudex/pulls/45

frontend/package-lock.json

@@ -25,6 +25,7 @@
         "eslint": "^9.15.0",
         "eslint-plugin-react-hooks": "^5.0.0",
         "eslint-plugin-react-refresh": "^0.4.14",
+        "globals": "^17.6.0",
         "postcss": "^8.4.49",
         "tailwindcss": "^4.0.0",
         "typescript": "~5.6.0",
@@ -823,6 +824,18 @@
         "url": "https://opencollective.com/eslint"
       }
     },
+    "node_modules/@eslint/eslintrc/node_modules/globals": {
+      "version": "14.0.0",
+      "resolved": "https://registry.npmjs.org/globals/-/globals-14.0.0.tgz",
+      "integrity": "sha512-oahGvuMGQlPw/ivIYBjVSrWAfWLBeku5tpPE2fOPLi+WHffIWbuh2tCjhyQhTBPMf5E9jDEH4FOmTYgYwbKwtQ==",
+      "dev": true,
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/@eslint/js": {
       "version": "9.39.4",
       "resolved": "https://registry.npmjs.org/@eslint/js/-/js-9.39.4.tgz",
@@ -2808,9 +2821,9 @@
       }
     },
     "node_modules/globals": {
-      "version": "14.0.0",
+      "version": "17.6.0",
-      "resolved": "https://registry.npmjs.org/globals/-/globals-14.0.0.tgz",
+      "resolved": "https://registry.npmjs.org/globals/-/globals-17.6.0.tgz",
-      "integrity": "sha512-oahGvuMGQlPw/ivIYBjVSrWAfWLBeku5tpPE2fOPLi+WHffIWbuh2tCjhyQhTBPMf5E9jDEH4FOmTYgYwbKwtQ==",
+      "integrity": "sha512-sepffkT8stwnIYbsMBpoCHJuJM5l98FUF2AnE07hfvE0m/qp3R586hw4jF4uadbhvg1ooIdzuu7CsfD2jzCaNA==",
       "dev": true,
       "engines": {
         "node": ">=18"

frontend/package.json

@@ -27,6 +27,7 @@
     "eslint": "^9.15.0",
     "eslint-plugin-react-hooks": "^5.0.0",
     "eslint-plugin-react-refresh": "^0.4.14",
+    "globals": "^17.6.0",
     "postcss": "^8.4.49",
     "tailwindcss": "^4.0.0",
     "typescript": "~5.6.0",

frontend/src/App.tsx

@@ -1,51 +1,38 @@
 import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
-import { BrowserRouter, Routes, Route, NavLink } from 'react-router-dom'
+import { BrowserRouter, Routes, Route } from 'react-router-dom'
-import { Box, Printer } from 'lucide-react'
 import Dashboard from './pages/Dashboard'
 import InventoryPage from './pages/InventoryPage'
-import PrintJobsPage from './pages/PrintJobsPage'
+import FilamentDetailPage from './pages/FilamentDetailPage'
+import ToastContainer from './components/ToastContainer'
+import { useSSE } from './hooks/useSSE'
 
 const queryClient = new QueryClient()
 
-function NavItem({ to, icon: Icon, label }: { to: string; icon: React.ComponentType<{ size?: number }>; label: string }) {
+function SSEProvider({ children }: { children: React.ReactNode }) {
-  return (
+  useSSE()
-    <NavLink
+  return <>{children}</>
-      to={to}
-      className={({ isActive }) =>
-        `inline-flex items-center gap-2 rounded-lg px-3 py-2 text-sm font-medium transition-colors ${
-          isActive
-            ? 'bg-emerald-600/20 text-emerald-300 border border-emerald-700'
-            : 'text-slate-400 hover:text-slate-200 hover:bg-slate-700/50'
-        }`
-      }
-    >
-      <Icon size={16} /> {label}
-    </NavLink>
-  )
 }
 
 export default function App() {
   return (
     <QueryClientProvider client={queryClient}>
       <BrowserRouter>
-        <div className="min-h-screen bg-slate-900 text-slate-50">
+        <SSEProvider>
-          <header className="bg-slate-800 border-b border-slate-700 px-4 py-3 flex items-center gap-3 sticky top-0 z-20">
+          <div className="min-h-screen bg-slate-900 text-slate-50">
-            <div className="w-8 h-8 rounded bg-emerald-500 flex items-center justify-center text-slate-900 font-bold text-lg">E</div>
+            <header className="bg-slate-800 border-b border-slate-700 px-4 py-3 flex items-center gap-3 sticky top-0 z-20">
-            <h1 className="text-lg font-semibold">Extrudex</h1>
+              <div className="w-8 h-8 rounded bg-emerald-500 flex items-center justify-center text-slate-900 font-bold text-lg">E</div>
-            <nav className="ml-6 flex items-center gap-1">
+              <h1 className="text-lg font-semibold">Extrudex</h1>
-              <NavItem to="/" icon={Box} label="Dashboard" />
+            </header>
-              <NavItem to="/inventory" icon={Box} label="Inventory" />
+            <main className="p-4">
-              <NavItem to="/print-jobs" icon={Printer} label="Print Jobs" />
+              <Routes>
-            </nav>
+                <Route path="/" element={<Dashboard />} />
-          </header>
+                <Route path="/inventory" element={<InventoryPage />} />
-          <main className="p-4">
+                <Route path="/filament/:id" element={<FilamentDetailPage />} />
-            <Routes>
+              </Routes>
-              <Route path="/" element={<Dashboard />} />
+            </main>
-              <Route path="/inventory" element={<InventoryPage />} />
+          </div>
-              <Route path="/print-jobs" element={<PrintJobsPage />} />
+          <ToastContainer />
-            </Routes>
+        </SSEProvider>
-          </main>
-        </div>
       </BrowserRouter>
     </QueryClientProvider>
   )

frontend/src/components/PrinterStatusBadge.tsx

@@ -0,0 +1,17 @@
+import { Printer } from 'lucide-react'
+
+const STYLES = {
+  online: 'bg-emerald-600 text-white',
+  offline: 'bg-slate-600 text-slate-200',
+  printing: 'bg-blue-600 text-white animate-pulse',
+}
+
+export default function PrinterStatusBadge({ status, name }: { status: string; name?: string }) {
+  const style = STYLES[status as keyof typeof STYLES] ?? STYLES.offline
+  return (
+    <span className={`inline-flex items-center gap-1.5 rounded-full px-2.5 py-1 text-xs font-medium ${style}`}>
+      <Printer size={12} />
+      {name ? `${name} · ${status}` : status}
+    </span>
+  )
+}

frontend/src/components/ToastContainer.tsx

@@ -0,0 +1,70 @@
+import { useEffect, useState, useCallback } from 'react'
+import { X, CheckCircle, AlertTriangle, Info } from 'lucide-react'
+import { addToastListener, type ToastMessage } from '../hooks/useSSE'
+
+const ICONS = {
+  info: Info,
+  success: CheckCircle,
+  warning: AlertTriangle,
+}
+
+const STYLES = {
+  info: 'border-blue-600 bg-blue-900/40 text-blue-100',
+  success: 'border-emerald-600 bg-emerald-900/40 text-emerald-100',
+  warning: 'border-amber-600 bg-amber-900/40 text-amber-100',
+}
+
+export default function ToastContainer() {
+  const [toasts, setToasts] = useState<ToastMessage[]>([])
+
+  const remove = useCallback((id: string) => {
+    setToasts(prev => prev.filter(t => t.id !== id))
+  }, [])
+
+  useEffect(() => {
+    return addToastListener((toast) => {
+      setToasts(prev => {
+        // Prevent duplicate identical toasts within 3 seconds
+        const now = Date.now()
+        const recent = prev.filter(
+          t => t.title === toast.title && now - parseInt(t.id.split('-').pop() || '0', 10) < 3000
+        )
+        if (recent.length > 0) return prev
+        return [...prev.slice(-4), toast]
+      })
+      // Auto-dismiss after 5 seconds
+      setTimeout(() => remove(toast.id), 5000)
+    })
+  }, [remove])
+
+  return (
+    <div className="fixed bottom-4 right-4 z-50 flex flex-col gap-2 max-w-sm w-full pointer-events-none">
+      {toasts.map((toast) => {
+        const Icon = ICONS[toast.type]
+        return (
+          <div
+            key={toast.id}
+            className={`pointer-events-auto rounded-lg border px-4 py-3 shadow-lg backdrop-blur-sm transition-all ${STYLES[toast.type]}`}
+          >
+            <div className="flex items-start gap-3">
+              <Icon size={18} className="mt-0.5 shrink-0" />
+              <div className="flex-1 min-w-0">
+                <p className="text-sm font-semibold leading-snug">{toast.title}</p>
+                {toast.body && (
+                  <p className="text-xs opacity-80 mt-0.5">{toast.body}</p>
+                )}
+              </div>
+              <button
+                onClick={() => remove(toast.id)}
+                className="shrink-0 -mr-1 -mt-1 p-1 rounded hover:bg-white/10 text-current opacity-70 hover:opacity-100 transition-opacity"
+                aria-label="Dismiss"
+              >
+                <X size={14} />
+              </button>
+            </div>
+          </div>
+        )
+      })}
+    </div>
+  )
+}

frontend/src/hooks/useSSE.ts

@@ -0,0 +1,193 @@
+import { useEffect, useRef, useCallback } from 'react'
+import { useQueryClient } from '@tanstack/react-query'
+
+export type SSEEventType =
+  | 'printer.status'
+  | 'job.started'
+  | 'job.completed'
+  | 'filament.low'
+
+export interface SSEEvent {
+  type: SSEEventType
+  payload: unknown
+  timestamp: string
+}
+
+export interface ToastMessage {
+  id: string
+  type: 'info' | 'success' | 'warning'
+  title: string
+  body?: string
+}
+
+let toastListeners: Array<(toast: ToastMessage) => void> = []
+
+export function addToastListener(cb: (toast: ToastMessage) => void) {
+  toastListeners.push(cb)
+  return () => {
+    toastListeners = toastListeners.filter(l => l !== cb)
+  }
+}
+
+function emitToast(toast: ToastMessage) {
+  toastListeners.forEach(cb => cb(toast))
+}
+
+const RECONNECT_BASE_MS = 1000
+const RECONNECT_MAX_MS = 30000
+
+export function useSSE(enabled = true) {
+  const queryClient = useQueryClient()
+  const esRef = useRef<EventSource | null>(null)
+  const reconnectTimerRef = useRef<ReturnType<typeof setTimeout> | null>(null)
+  const attemptRef = useRef(0)
+
+  const connect = useCallback(() => {
+    if (!enabled) return
+    if (esRef.current) {
+      esRef.current.close()
+    }
+
+    const es = new EventSource('/api/events')
+    esRef.current = es
+
+    es.onopen = () => {
+      attemptRef.current = 0
+    }
+
+    es.addEventListener('printer.status', (e) => {
+      try {
+        const data = JSON.parse(e.data) as SSEEvent
+        const payload = data.payload as {
+          printer_id: number
+          printer_name: string
+          status: string
+        }
+        // Update printer list cache if it exists
+        queryClient.setQueryData(['printers'], (old: unknown) => {
+          if (!Array.isArray(old)) return old
+          return old.map((p: Record<string, unknown>) =>
+            p.id === payload.printer_id
+              ? { ...p, status: payload.status, name: payload.printer_name }
+              : p
+          )
+        })
+      } catch {
+        // ignore malformed event
+      }
+    })
+
+    es.addEventListener('job.started', (e) => {
+      try {
+        const data = JSON.parse(e.data) as SSEEvent
+        const payload = data.payload as {
+          job_id: number
+          job_name: string
+          printer_id: number
+          spool_id?: number
+        }
+        emitToast({
+          id: `job-started-${payload.job_id}-${Date.now()}`,
+          type: 'info',
+          title: `Job started: ${payload.job_name}`,
+          body: `Printer #${payload.printer_id}`,
+        })
+        // Invalidate print jobs list
+        queryClient.invalidateQueries({ queryKey: ['print-jobs'] })
+      } catch {
+        // ignore malformed event
+      }
+    })
+
+    es.addEventListener('job.completed', (e) => {
+      try {
+        const data = JSON.parse(e.data) as SSEEvent
+        const payload = data.payload as {
+          job_id: number
+          job_name: string
+          printer_id: number
+          duration_seconds?: number
+          total_grams_used?: number
+          total_cost_usd?: number
+        }
+        const parts: string[] = []
+        if (payload.duration_seconds != null) {
+          const mins = Math.round(payload.duration_seconds / 60)
+          parts.push(`${mins} min`)
+        }
+        if (payload.total_grams_used != null) {
+          parts.push(`${payload.total_grams_used.toFixed(1)} g used`)
+        }
+        emitToast({
+          id: `job-completed-${payload.job_id}-${Date.now()}`,
+          type: 'success',
+          title: `Job completed: ${payload.job_name}`,
+          body: parts.join(' · ') || `Printer #${payload.printer_id}`,
+        })
+        queryClient.invalidateQueries({ queryKey: ['print-jobs'] })
+        queryClient.invalidateQueries({ queryKey: ['filaments'] })
+      } catch {
+        // ignore malformed event
+      }
+    })
+
+    es.addEventListener('filament.low', (e) => {
+      try {
+        const data = JSON.parse(e.data) as SSEEvent
+        const payload = data.payload as {
+          spool_id: number
+          spool_name: string
+          remaining_grams: number
+          threshold_grams: number
+        }
+        emitToast({
+          id: `filament-low-${payload.spool_id}-${Date.now()}`,
+          type: 'warning',
+          title: `Low filament: ${payload.spool_name}`,
+          body: `${payload.remaining_grams} g remaining (threshold ${payload.threshold_grams} g)`,
+        })
+        // Update filament inventory cache in place for instant UI feedback
+        queryClient.setQueryData(['filaments'], (old: unknown) => {
+          if (!old || typeof old !== 'object') return old
+          const o = old as { data?: Array<Record<string, unknown>>; total?: number }
+          if (!Array.isArray(o.data)) return old
+          return {
+            ...o,
+            data: o.data.map((f) =>
+              (f.id as number) === payload.spool_id
+                ? { ...f, remaining_grams: payload.remaining_grams }
+                : f
+            ),
+          }
+        })
+      } catch {
+        // ignore malformed event
+      }
+    })
+
+    es.onerror = () => {
+      es.close()
+      // Exponential backoff with jitter
+      const base = Math.min(RECONNECT_MAX_MS, RECONNECT_BASE_MS * 2 ** attemptRef.current)
+      const jitter = Math.random() * 1000
+      const delay = base + jitter
+      attemptRef.current += 1
+      reconnectTimerRef.current = setTimeout(() => {
+        connect()
+      }, delay)
+    }
+  }, [enabled, queryClient])
+
+  useEffect(() => {
+    connect()
+    return () => {
+      if (reconnectTimerRef.current) {
+        clearTimeout(reconnectTimerRef.current)
+      }
+      if (esRef.current) {
+        esRef.current.close()
+        esRef.current = null
+      }
+    }
+  }, [connect])
+}

frontend/src/pages/FilamentDetailPage.tsx

@@ -0,0 +1,391 @@
+import { useState } from 'react'
+import { useParams, useNavigate } from 'react-router-dom'
+import { useQuery, useQueryClient } from '@tanstack/react-query'
+import { ArrowLeft, Pencil, Trash2, AlertTriangle, Loader2, Archive } from 'lucide-react'
+import ColorSwatch from '../components/ColorSwatch'
+import { fetchFilamentById, fetchUsageLogs, deleteFilament } from '../services/filamentService'
+import type { UsageLog } from '../types/filament'
+
+export default function FilamentDetailPage() {
+  const { id } = useParams<{ id: string }>()
+  const spoolId = Number(id)
+  const navigate = useNavigate()
+  const queryClient = useQueryClient()
+  const [deleteConfirm, setDeleteConfirm] = useState(false)
+  const [deleting, setDeleting] = useState(false)
+
+  const {
+    data: spool,
+    isLoading: spoolLoading,
+    error: spoolError,
+    refetch: refetchSpool,
+  } = useQuery({
+    queryKey: ['filament', spoolId],
+    queryFn: () => fetchFilamentById(spoolId),
+    enabled: !isNaN(spoolId),
+  })
+
+  const {
+    data: usageLogs,
+    isLoading: usageLoading,
+    error: usageError,
+    refetch: refetchUsage,
+  } = useQuery({
+    queryKey: ['usage-logs', spoolId],
+    queryFn: () => fetchUsageLogs(spoolId),
+    enabled: !isNaN(spoolId),
+  })
+
+  const handleDelete = async () => {
+    setDeleting(true)
+    try {
+      await deleteFilament(spoolId)
+      queryClient.invalidateQueries({ queryKey: ['filaments'] })
+      navigate('/')
+    } catch {
+      setDeleting(false)
+      setDeleteConfirm(false)
+    }
+  }
+
+  // ── Loading state ──
+  if (spoolLoading) {
+    return (
+      <div className="flex flex-col items-center justify-center py-24 gap-3 text-slate-400">
+        <Loader2 size={32} className="animate-spin text-emerald-400" />
+        <span>Loading spool details…</span>
+      </div>
+    )
+  }
+
+  // ── Error state ──
+  if (spoolError || !spool) {
+    return (
+      <div className="flex flex-col items-center justify-center py-24 gap-4">
+        <div className="flex h-14 w-14 items-center justify-center rounded-full bg-red-900/30">
+          <AlertTriangle size={28} className="text-red-400" />
+        </div>
+        <p className="text-red-400 font-medium">Failed to load spool details.</p>
+        <div className="flex gap-3">
+          <button
+            onClick={() => refetchSpool()}
+            className="rounded-lg bg-slate-700 px-4 py-2 text-sm font-medium text-slate-200 hover:bg-slate-600 transition-colors"
+          >
+            Retry
+          </button>
+          <button
+            onClick={() => navigate('/')}
+            className="rounded-lg bg-slate-800 border border-slate-700 px-4 py-2 text-sm font-medium text-slate-300 hover:bg-slate-700 transition-colors"
+          >
+            Back to Inventory
+          </button>
+        </div>
+      </div>
+    )
+  }
+
+  const pctRemaining = spool.initial_grams > 0
+    ? (spool.remaining_grams / spool.initial_grams) * 100
+    : 0
+  const isLow = spool.remaining_grams <= (spool.low_stock_threshold_grams || 0)
+
+  return (
+    <div className="space-y-6">
+      {/* ── Header Bar ── */}
+      <div className="flex flex-col sm:flex-row sm:items-center sm:justify-between gap-3">
+        <button
+          onClick={() => navigate('/')}
+          className="inline-flex items-center gap-2 rounded-lg bg-slate-800 border border-slate-700 px-3 py-2 text-sm font-medium text-slate-200 hover:bg-slate-700 active:bg-slate-600 transition-colors w-fit"
+        >
+          <ArrowLeft size={16} />
+          Back to Inventory
+        </button>
+
+        <div className="flex items-center gap-2">
+          <button className="inline-flex items-center gap-2 rounded-lg bg-slate-700 px-4 py-2 text-sm font-semibold text-slate-200 hover:bg-slate-600 active:bg-slate-500 transition-colors">
+            <Pencil size={16} />
+            Edit
+          </button>
+          <button
+            onClick={() => setDeleteConfirm(true)}
+            className="inline-flex items-center gap-2 rounded-lg bg-red-900/30 border border-red-700 px-4 py-2 text-sm font-semibold text-red-300 hover:bg-red-900/50 active:bg-red-900/70 transition-colors"
+          >
+            <Trash2 size={16} />
+            Delete
+          </button>
+        </div>
+      </div>
+
+      {/* ── Spool Info Card ── */}
+      <div className="rounded-xl border border-slate-700 bg-slate-800 overflow-hidden">
+        {/* Card header */}
+        <div className="px-6 py-5 border-b border-slate-700 flex flex-col sm:flex-row sm:items-center sm:justify-between gap-3">
+          <div className="flex items-center gap-3">
+            <ColorSwatch colorHex={spool.color_hex} size={36} />
+            <div>
+              <h1 className="text-xl font-bold text-slate-100">{spool.name}</h1>
+              <p className="text-sm text-slate-400">
+                {spool.brand && <span>{spool.brand} · </span>}
+                {spool.diameter_mm}mm
+              </p>
+            </div>
+          </div>
+          <div>
+            {isLow ? (
+              <span className="inline-flex items-center gap-1.5 rounded-full bg-red-900/40 border border-red-700 px-3 py-1 text-sm font-medium text-red-300">
+                <AlertTriangle size={14} /> Low Stock
+              </span>
+            ) : (
+              <span className="inline-flex items-center gap-1.5 rounded-full bg-emerald-900/30 border border-emerald-700 px-3 py-1 text-sm font-medium text-emerald-300">
+                In Stock
+              </span>
+            )}
+          </div>
+        </div>
+
+        {/* Card body — 2-column grid */}
+        <div className="px-6 py-5 grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-x-8 gap-y-4">
+          <DetailItem label="Material" value={spool.material_base?.name ?? '—'} />
+          <DetailItem label="Finish" value={spool.material_finish?.name ?? '—'} />
+          <DetailItem
+            label="Modifier"
+            value={spool.material_modifier?.name ?? 'None'}
+          />
+          <DetailItem label="Color" value={spool.color_hex.toUpperCase()} />
+          <DetailItem label="Brand" value={spool.brand || '—'} />
+          <DetailItem label="Diameter" value={`${spool.diameter_mm}mm`} />
+          <DetailItem
+            label="Remaining"
+            value={
+              <span className="font-semibold tabular-nums">
+                {spool.remaining_grams.toLocaleString()} g
+              </span>
+            }
+          />
+          <DetailItem
+            label="Initial"
+            value={`${spool.initial_grams.toLocaleString()} g`}
+          />
+          <DetailItem
+            label="Cost"
+            value={
+              spool.cost_usd != null
+                ? `$${spool.cost_usd.toFixed(2)}`
+                : '—'
+            }
+          />
+        </div>
+
+        {/* Progress Bar */}
+        <div className="px-6 pb-5 pt-1">
+          <div className="flex items-center justify-between text-sm mb-1.5">
+            <span className="text-slate-400">
+              <span className="text-slate-200 font-semibold tabular-nums">
+                {spool.remaining_grams.toLocaleString()}g
+              </span>{' '}
+              of {spool.initial_grams.toLocaleString()}g
+            </span>
+            <span className="text-slate-400 font-medium tabular-nums">
+              {pctRemaining.toFixed(1)}%
+            </span>
+          </div>
+          <div className="w-full h-3 rounded-full bg-slate-700 overflow-hidden">
+            <div
+              className={`h-full rounded-full transition-all duration-500 ${
+                pctRemaining <= 10
+                  ? 'bg-red-500'
+                  : pctRemaining <= 25
+                    ? 'bg-amber-500'
+                    : 'bg-emerald-500'
+              }`}
+              style={{ width: `${Math.min(100, pctRemaining)}%` }}
+            />
+          </div>
+        </div>
+      </div>
+
+      {/* ── Usage History ── */}
+      <div className="rounded-xl border border-slate-700 bg-slate-800 overflow-hidden">
+        <div className="px-6 py-4 border-b border-slate-700">
+          <h2 className="text-lg font-semibold text-slate-100">Usage History</h2>
+        </div>
+
+        {/* Loading sub-state */}
+        {usageLoading && (
+          <div className="px-6 py-8 text-center text-slate-400">
+            <Loader2 size={20} className="animate-spin inline mr-2" />
+            Loading usage history…
+          </div>
+        )}
+
+        {/* Usage error sub-state */}
+        {usageError && !usageLoading && (
+          <div className="px-6 py-8 text-center">
+            <p className="text-red-400 text-sm">
+              Failed to load usage history.
+            </p>
+            <button
+              onClick={() => refetchUsage()}
+              className="mt-2 text-sm text-emerald-400 hover:text-emerald-300 underline"
+            >
+              Retry
+            </button>
+          </div>
+        )}
+
+        {/* Empty state */}
+        {!usageLoading && !usageError && usageLogs && usageLogs.length === 0 && (
+          <div className="px-6 py-10 text-center">
+            <Archive size={32} className="mx-auto text-slate-600 mb-2" />
+            <p className="text-slate-400 text-sm">No usage recorded yet.</p>
+            <p className="text-slate-500 text-xs mt-1">
+              Usage data will appear here when this spool is used in print jobs.
+            </p>
+          </div>
+        )}
+
+        {/* Table — desktop */}
+        {!usageLoading && !usageError && usageLogs && usageLogs.length > 0 && (
+          <>
+            <div className="hidden md:block overflow-x-auto">
+              <table className="w-full text-sm">
+                <thead className="bg-slate-800/50 text-slate-300">
+                  <tr>
+                    <th className="px-6 py-3 text-left font-semibold">Date</th>
+                    <th className="px-6 py-3 text-left font-semibold">Print Job</th>
+                    <th className="px-6 py-3 text-right font-semibold">mm Extruded</th>
+                    <th className="px-6 py-3 text-right font-semibold">Grams Used</th>
+                    <th className="px-6 py-3 text-right font-semibold">Cost</th>
+                  </tr>
+                </thead>
+                <tbody className="divide-y divide-slate-700">
+                  {usageLogs.map((log: UsageLog) => (
+                    <tr
+                      key={log.id}
+                      className="hover:bg-slate-700/30 transition-colors"
+                    >
+                      <td className="px-6 py-3 text-slate-200 tabular-nums">
+                        {new Date(log.logged_at).toLocaleDateString('en-US', {
+                          year: 'numeric',
+                          month: 'short',
+                          day: 'numeric',
+                        })}
+                      </td>
+                      <td className="px-6 py-3 text-slate-300">
+                        {log.print_job_name || `Job #${log.print_job_id ?? log.id}`}
+                      </td>
+                      <td className="px-6 py-3 text-right text-slate-200 tabular-nums">
+                        {log.mm_extruded.toLocaleString()}
+                      </td>
+                      <td className="px-6 py-3 text-right text-slate-200 tabular-nums">
+                        {log.grams_used.toFixed(2)} g
+                      </td>
+                      <td className="px-6 py-3 text-right text-slate-200 tabular-nums">
+                        {log.cost_usd != null ? `$${log.cost_usd.toFixed(3)}` : '—'}
+                      </td>
+                    </tr>
+                  ))}
+                </tbody>
+              </table>
+            </div>
+
+            {/* Mobile cards */}
+            <div className="md:hidden divide-y divide-slate-700">
+              {usageLogs.map((log: UsageLog) => (
+                <div key={log.id} className="px-4 py-4 space-y-2">
+                  <div className="flex items-center justify-between">
+                    <span className="text-sm font-medium text-slate-200">
+                      {log.print_job_name || `Job #${log.print_job_id ?? log.id}`}
+                    </span>
+                    <span className="text-xs text-slate-400 tabular-nums">
+                      {new Date(log.logged_at).toLocaleDateString('en-US', {
+                        month: 'short',
+                        day: 'numeric',
+                      })}
+                    </span>
+                  </div>
+                  <div className="flex items-center justify-between text-sm">
+                    <span className="text-slate-400">
+                      Extruded:{' '}
+                      <span className="text-slate-300 tabular-nums">
+                        {log.mm_extruded.toLocaleString()} mm
+                      </span>
+                    </span>
+                    <span className="text-slate-400">
+                      Used:{' '}
+                      <span className="text-slate-300 tabular-nums">
+                        {log.grams_used.toFixed(2)} g
+                      </span>
+                    </span>
+                    <span className="text-slate-400">
+                      {log.cost_usd != null ? (
+                        <>
+                          Cost:{' '}
+                          <span className="text-slate-300 tabular-nums">
+                            ${log.cost_usd.toFixed(3)}
+                          </span>
+                        </>
+                      ) : (
+                        '—'
+                      )}
+                    </span>
+                  </div>
+                </div>
+              ))}
+            </div>
+          </>
+        )}
+      </div>
+
+      {/* ── Delete Confirmation Modal ── */}
+      {deleteConfirm && (
+        <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 backdrop-blur-sm p-4">
+          <div className="w-full max-w-sm rounded-xl bg-slate-800 border border-slate-700 p-6 shadow-2xl space-y-4">
+            <div className="flex items-center gap-3">
+              <div className="flex h-10 w-10 items-center justify-center rounded-full bg-red-900/30 flex-shrink-0">
+                <AlertTriangle size={20} className="text-red-400" />
+              </div>
+              <div>
+                <h3 className="text-lg font-semibold text-slate-100">
+                  Delete &ldquo;{spool.name}&rdquo;?
+                </h3>
+                <p className="text-sm text-slate-400">
+                  This permanently removes the spool and all usage history. This cannot be undone.
+                </p>
+              </div>
+            </div>
+            <div className="flex justify-end gap-3">
+              <button
+                onClick={() => setDeleteConfirm(false)}
+                disabled={deleting}
+                className="rounded-lg bg-slate-700 px-4 py-2 text-sm font-medium text-slate-200 hover:bg-slate-600 transition-colors disabled:opacity-50"
+              >
+                Cancel
+              </button>
+              <button
+                onClick={handleDelete}
+                disabled={deleting}
+                className="inline-flex items-center gap-2 rounded-lg bg-red-600 px-4 py-2 text-sm font-medium text-white hover:bg-red-500 transition-colors disabled:opacity-50"
+              >
+                {deleting && <Loader2 size={16} className="animate-spin" />}
+                {deleting ? 'Deleting…' : 'Delete'}
+              </button>
+            </div>
+          </div>
+        </div>
+      )}
+    </div>
+  )
+}
+
+/** Small detail row for the info card grid */
+function DetailItem({ label, value }: { label: string; value: React.ReactNode }) {
+  return (
+    <div>
+      <dt className="text-xs font-medium uppercase tracking-wider text-slate-500 mb-0.5">
+        {label}
+      </dt>
+      <dd className="text-sm text-slate-200">{value}</dd>
+    </div>
+  )
+}

frontend/src/pages/InventoryPage.tsx

@@ -35,7 +35,7 @@ export default function InventoryPage() {
     queryFn: () => fetchFilaments(filter),
   })
 
-  const filaments = data?.data ?? []
+  const filaments = useMemo(() => data?.data ?? [], [data?.data])
   const total = data?.total ?? 0
   const totalPages = Math.max(1, Math.ceil(total / PAGE_SIZE))
 

frontend/src/pages/PrintJobsPage.tsx

@@ -1,283 +0,0 @@
-import { useState, useMemo } from 'react'
-import { useQuery } from '@tanstack/react-query'
-import { Search, Filter, ChevronLeft, ChevronRight, Loader2 } from 'lucide-react'
-import { fetchPrintJobs } from '../services/printJobService'
-import type { PrintJob, PrintJobFilter, PrintJobStatus } from '../types/printJob'
-
-const PAGE_SIZE = 20
-
-type SortField = 'name' | 'started_at' | 'duration_seconds' | 'filament_grams_used' | 'cost_usd'
-type SortDir = 'asc' | 'desc'
-
-// ── Status helpers ────────────────────────────────────────────────────────────
-
-const STATUS_CONFIG: Record<PrintJobStatus, { label: string; badge: string; icon: string }> = {
-  pending:   { label: 'Pending',   badge: 'bg-slate-700 text-slate-300 border-slate-600',       icon: '⏳' },
-  printing:  { label: 'Printing',  badge: 'bg-blue-900/40 text-blue-300 border-blue-700',       icon: '🖨️' },
-  completed: { label: 'Completed', badge: 'bg-emerald-900/30 text-emerald-300 border-emerald-700', icon: '✅' },
-  failed:    { label: 'Failed',    badge: 'bg-red-900/40 text-red-300 border-red-700',          icon: '❌' },
-}
-
-function StatusBadge({ status }: { status: PrintJobStatus }) {
-  const cfg = STATUS_CONFIG[status] ?? STATUS_CONFIG.pending
-  return (
-    <span className={`inline-flex items-center gap-1 rounded-full border px-2 py-0.5 text-xs font-medium ${cfg.badge}`}>
-      <span className="text-xs">{cfg.icon}</span> {cfg.label}
-    </span>
-  )
-}
-
-// ── Duration formatter ────────────────────────────────────────────────────────
-
-function formatDuration(totalSeconds?: number): string {
-  if (totalSeconds == null || totalSeconds <= 0) return '—'
-  const h = Math.floor(totalSeconds / 3600)
-  const m = Math.floor((totalSeconds % 3600) / 60)
-  const s = totalSeconds % 60
-  if (h > 0) return `${h}h ${m}m`
-  if (m > 0) return `${m}m ${s}s`
-  return `${s}s`
-}
-
-function formatDateTime(iso: string): string {
-  const d = new Date(iso)
-  return d.toLocaleString(undefined, {
-    month: 'short', day: 'numeric',
-    hour: 'numeric', minute: '2-digit',
-  })
-}
-
-// ── Component ─────────────────────────────────────────────────────────────────
-
-export default function PrintJobsPage() {
-  const [search, setSearch] = useState('')
-  const [statusFilter, setStatusFilter] = useState<PrintJobStatus | ''>('')
-  const [printerFilter, setPrinterFilter] = useState('')
-  const [sortBy, setSortBy] = useState<SortField>('started_at')
-  const [sortDir, setSortDir] = useState<SortDir>('desc')
-  const [page, setPage] = useState(0)
-
-  const filter: PrintJobFilter = useMemo(() => ({
-    status: statusFilter || undefined,
-    printer: printerFilter || undefined,
-    sort_by: sortBy,
-    sort_dir: sortDir,
-    limit: PAGE_SIZE,
-    offset: page * PAGE_SIZE,
-  }), [statusFilter, printerFilter, sortBy, sortDir, page])
-
-  const { data, isLoading, error, refetch } = useQuery({
-    queryKey: ['printJobs', filter],
-    queryFn: () => fetchPrintJobs(filter),
-  })
-
-  const total = data?.total ?? 0
-  const totalPages = Math.max(1, Math.ceil(total / PAGE_SIZE))
-
-  // Client-side search (name + printer name)
-  const filtered = useMemo(() => {
-    const jobList = data?.data ?? []
-    if (!search.trim()) return jobList
-    const q = search.toLowerCase()
-    return jobList.filter(
-      (j: PrintJob) =>
-        j.name.toLowerCase().includes(q) ||
-        j.printer_name.toLowerCase().includes(q)
-    )
-  }, [data?.data, search])
-
-  const handleSort = (field: SortField) => {
-    if (sortBy === field) {
-      setSortDir(prev => (prev === 'asc' ? 'desc' : 'asc'))
-    } else {
-      setSortBy(field)
-      setSortDir('asc')
-    }
-    setPage(0)
-  }
-
-  const SortIndicator = ({ field }: { field: SortField }) => {
-    if (sortBy !== field) return <span className="text-slate-600 ml-1">↕</span>
-    return <span className="text-emerald-400 ml-1">{sortDir === 'asc' ? '↑' : '↓'}</span>
-  }
-
-  return (
-    <div className="space-y-4">
-      {/* Header */}
-      <div className="flex flex-col sm:flex-row sm:items-center sm:justify-between gap-3">
-        <div>
-          <h2 className="text-xl font-bold text-slate-100">Print Jobs</h2>
-          <p className="text-sm text-slate-400">{total} job(s) total</p>
-        </div>
-      </div>
-
-      {/* Filters */}
-      <div className="flex flex-col lg:flex-row gap-3">
-        {/* Search */}
-        <div className="relative flex-1">
-          <Search size={16} className="absolute left-3 top-1/2 -translate-y-1/2 text-slate-400" />
-          <input
-            type="text"
-            placeholder="Search by job or printer name…"
-            value={search}
-            onChange={e => { setSearch(e.target.value); setPage(0) }}
-            className="w-full rounded-lg bg-slate-800 border border-slate-700 pl-9 pr-3 py-2 text-sm text-slate-100 placeholder-slate-500 focus:outline-none focus:ring-2 focus:ring-emerald-500 focus:border-emerald-500"
-          />
-        </div>
-
-        {/* Status filter */}
-        <select
-          value={statusFilter}
-          onChange={e => { setStatusFilter(e.target.value as PrintJobStatus | ''); setPage(0) }}
-          className="rounded-lg bg-slate-800 border border-slate-700 px-3 py-2 text-sm text-slate-100 focus:outline-none focus:ring-2 focus:ring-emerald-500"
-        >
-          <option value="">All Statuses</option>
-          <option value="pending">Pending</option>
-          <option value="printing">Printing</option>
-          <option value="completed">Completed</option>
-          <option value="failed">Failed</option>
-        </select>
-
-        {/* Printer filter */}
-        <input
-          type="text"
-          placeholder="Filter by printer…"
-          value={printerFilter}
-          onChange={e => { setPrinterFilter(e.target.value); setPage(0) }}
-          className="rounded-lg bg-slate-800 border border-slate-700 px-3 py-2 text-sm text-slate-100 placeholder-slate-500 focus:outline-none focus:ring-2 focus:ring-emerald-500 focus:border-emerald-500 min-w-[160px]"
-        />
-
-        {/* Filter indicator */}
-        {(statusFilter || printerFilter) && (
-          <span className="inline-flex items-center gap-1 rounded-lg bg-emerald-900/30 border border-emerald-700 px-3 py-2 text-xs text-emerald-300">
-            <Filter size={14} />
-            {[statusFilter && `Status: ${statusFilter}`, printerFilter && `Printer: ${printerFilter}`].filter(Boolean).join(' · ')}
-          </span>
-        )}
-      </div>
-
-      {/* Loading / Error */}
-      {isLoading && (
-        <div className="flex items-center justify-center py-12 gap-2 text-slate-400">
-          <Loader2 size={18} className="animate-spin" /> Loading print jobs…
-        </div>
-      )}
-      {error && (
-        <div className="text-center py-12 text-red-400">
-          Failed to load print jobs.
-          <button onClick={() => refetch()} className="ml-2 underline hover:text-red-300">Retry</button>
-        </div>
-      )}
-
-      {/* Desktop Table */}
-      {!isLoading && !error && (
-        <>
-          <div className="hidden md:block overflow-x-auto rounded-lg border border-slate-700">
-            <table className="w-full text-sm">
-              <thead className="bg-slate-800 text-slate-300">
-                <tr>
-                  <th className="px-4 py-3 text-left font-semibold cursor-pointer select-none hover:text-slate-100" onClick={() => handleSort('name')}>
-                    Job <SortIndicator field="name" />
-                  </th>
-                  <th className="px-4 py-3 text-left font-semibold">Printer</th>
-                  <th className="px-4 py-3 text-left font-semibold">Status</th>
-                  <th className="px-4 py-3 text-left font-semibold cursor-pointer select-none hover:text-slate-100" onClick={() => handleSort('started_at')}>
-                    Started <SortIndicator field="started_at" />
-                  </th>
-                  <th className="px-4 py-3 text-right font-semibold cursor-pointer select-none hover:text-slate-100" onClick={() => handleSort('duration_seconds')}>
-                    Duration <SortIndicator field="duration_seconds" />
-                  </th>
-                  <th className="px-4 py-3 text-right font-semibold cursor-pointer select-none hover:text-slate-100" onClick={() => handleSort('filament_grams_used')}>
-                    Filament <SortIndicator field="filament_grams_used" />
-                  </th>
-                  <th className="px-4 py-3 text-right font-semibold cursor-pointer select-none hover:text-slate-100" onClick={() => handleSort('cost_usd')}>
-                    Cost <SortIndicator field="cost_usd" />
-                  </th>
-                </tr>
-              </thead>
-              <tbody className="divide-y divide-slate-700">
-                {filtered.length === 0 && (
-                  <tr>
-                    <td colSpan={7} className="px-4 py-8 text-center text-slate-500">No print jobs found.</td>
-                  </tr>
-                )}
-                {filtered.map((job: PrintJob) => (
-                  <tr key={job.id} className="bg-slate-800/50 hover:bg-slate-700/50 transition-colors">
-                    <td className="px-4 py-3 font-medium text-slate-100">{job.name}</td>
-                    <td className="px-4 py-3 text-slate-300">{job.printer_name}</td>
-                    <td className="px-4 py-3"><StatusBadge status={job.status} /></td>
-                    <td className="px-4 py-3 text-slate-300">{formatDateTime(job.started_at)}</td>
-                    <td className="px-4 py-3 text-right tabular-nums text-slate-300">{formatDuration(job.duration_seconds)}</td>
-                    <td className="px-4 py-3 text-right tabular-nums text-slate-300">{job.filament_grams_used != null ? `${job.filament_grams_used.toLocaleString()} g` : '—'}</td>
-                    <td className="px-4 py-3 text-right tabular-nums text-slate-300">{job.cost_usd != null ? `$${job.cost_usd.toFixed(2)}` : '—'}</td>
-                  </tr>
-                ))}
-              </tbody>
-            </table>
-          </div>
-
-          {/* Mobile Cards */}
-          <div className="md:hidden space-y-3">
-            {filtered.length === 0 && (
-              <div className="text-center py-12 text-slate-500">No print jobs found.</div>
-            )}
-            {filtered.map((job: PrintJob) => (
-              <div key={job.id} className="rounded-lg border border-slate-700 bg-slate-800 p-4 space-y-3">
-                <div className="flex items-start justify-between">
-                  <div>
-                    <div className="font-semibold text-slate-100">{job.name}</div>
-                    <div className="text-xs text-slate-400 mt-0.5">{job.printer_name}</div>
-                  </div>
-                  <StatusBadge status={job.status} />
-                </div>
-
-                <div className="grid grid-cols-2 gap-2 text-sm">
-                  <div>
-                    <span className="text-slate-500 text-xs">Started</span>
-                    <div className="text-slate-300">{formatDateTime(job.started_at)}</div>
-                  </div>
-                  <div>
-                    <span className="text-slate-500 text-xs">Duration</span>
-                    <div className="text-slate-300 tabular-nums">{formatDuration(job.duration_seconds)}</div>
-                  </div>
-                  <div>
-                    <span className="text-slate-500 text-xs">Filament</span>
-                    <div className="text-slate-300 tabular-nums">{job.filament_grams_used != null ? `${job.filament_grams_used.toLocaleString()} g` : '—'}</div>
-                  </div>
-                  <div>
-                    <span className="text-slate-500 text-xs">Cost</span>
-                    <div className="text-slate-300 tabular-nums">{job.cost_usd != null ? `$${job.cost_usd.toFixed(2)}` : '—'}</div>
-                  </div>
-                </div>
-              </div>
-            ))}
-          </div>
-
-          {/* Pagination */}
-          <div className="flex items-center justify-between pt-2">
-            <span className="text-sm text-slate-400">
-              Showing {total === 0 ? 0 : page * PAGE_SIZE + 1}–{Math.min((page + 1) * PAGE_SIZE, total)} of {total}
-            </span>
-            <div className="flex items-center gap-2">
-              <button
-                onClick={() => setPage(p => Math.max(0, p - 1))}
-                disabled={page === 0}
-                className="p-2 rounded-lg bg-slate-800 border border-slate-700 text-slate-300 hover:bg-slate-700 disabled:opacity-40 disabled:cursor-not-allowed transition-colors"
-              >
-                <ChevronLeft size={16} />
-              </button>
-              <span className="text-sm text-slate-300 tabular-nums">{page + 1} / {totalPages}</span>
-              <button
-                onClick={() => setPage(p => Math.min(totalPages - 1, p + 1))}
-                disabled={page >= totalPages - 1}
-                className="p-2 rounded-lg bg-slate-800 border border-slate-700 text-slate-300 hover:bg-slate-700 disabled:opacity-40 disabled:cursor-not-allowed transition-colors"
-              >
-                <ChevronRight size={16} />
-              </button>
-            </div>
-          </div>
-        </>
-      )}
-    </div>
-  )
-}

frontend/src/services/filamentService.ts

@@ -1,5 +1,5 @@
 import axios from 'axios'
-import type { FilamentSpool, ListResponse, FilamentFilter } from '../types/filament'
+import type { FilamentSpool, ListResponse, UsageLog, FilamentFilter } from '../types/filament'
 
 const API_BASE = '/api'
 
@@ -19,6 +19,16 @@ export async function fetchFilaments(filter: FilamentFilter): Promise<ListRespon
   return res.data
 }
 
+export async function fetchFilamentById(id: number): Promise<FilamentSpool> {
+  const res = await axios.get<FilamentSpool>(`${API_BASE}/filaments/${id}`)
+  return res.data
+}
+
+export async function fetchUsageLogs(spoolId: number): Promise<UsageLog[]> {
+  const res = await axios.get<UsageLog[]>(`${API_BASE}/usage-logs?spool_id=${spoolId}`)
+  return res.data
+}
+
 export async function deleteFilament(id: number): Promise<void> {
   await axios.delete(`${API_BASE}/filaments/${id}`)
 }

frontend/src/services/printJobService.ts

@@ -1,17 +0,0 @@
-import axios from 'axios'
-import type { PrintJob, ListResponse, PrintJobFilter } from '../types/printJob'
-
-const API_BASE = '/api'
-
-export async function fetchPrintJobs(filter: PrintJobFilter): Promise<ListResponse<PrintJob>> {
-  const params = new URLSearchParams()
-  if (filter.status) params.set('status', filter.status)
-  if (filter.printer) params.set('printer', filter.printer)
-  if (filter.sort_by) params.set('sort_by', filter.sort_by)
-  if (filter.sort_dir) params.set('sort_dir', filter.sort_dir)
-  if (filter.limit !== undefined) params.set('limit', String(filter.limit))
-  if (filter.offset !== undefined) params.set('offset', String(filter.offset))
-
-  const res = await axios.get<ListResponse<PrintJob>>(`${API_BASE}/print-jobs?${params.toString()}`)
-  return res.data
-}

frontend/src/types/filament.ts

@@ -59,6 +59,19 @@ export interface ListResponse<T> {
   offset: number
 }
 
+export interface UsageLog {
+  id: number
+  spool_id: number
+  print_job_id?: number
+  print_job_name?: string
+  mm_extruded: number
+  grams_used: number
+  cost_usd?: number
+  logged_at: string
+  notes?: string
+  created_at: string
+}
+
 export interface FilamentFilter {
   material?: string
   finish?: string

frontend/src/types/printJob.ts

@@ -1,32 +0,0 @@
-// Print Job domain types
-
-export type PrintJobStatus = 'pending' | 'printing' | 'completed' | 'failed'
-
-export interface PrintJob {
-  id: number
-  name: string
-  printer_name: string
-  status: PrintJobStatus
-  started_at: string
-  duration_seconds?: number
-  filament_grams_used?: number
-  cost_usd?: number
-  created_at: string
-  updated_at: string
-}
-
-export interface ListResponse<T> {
-  data: T[]
-  total: number
-  limit: number
-  offset: number
-}
-
-export interface PrintJobFilter {
-  status?: PrintJobStatus
-  printer?: string
-  sort_by?: string
-  sort_dir?: 'asc' | 'desc'
-  limit?: number
-  offset?: number
-}