fix: ispravi prikaz računa u admin/frontendu i smanji PDF slike

- admin.py: thumbnail_preview u WorkOrderInvoiceInline i WorkOrderInvoiceAdmin
  prikazuje slike/PDF veze putem optimiziranog image endpointa
- serializers.py: image_url sada uključuje ?w=1280&q=80&fmt=jpeg za ne-PDF slike
- views.py: doda _compress_image_for_pdf() helper, zamijeni ImageReader(photo.image)
  s kompresiranom JPEG verzijom na oba mjesta u PDF generiranju
- tasks.py: kompresija invoice slike u JPEG u memoriji prije ImageReader poziva
- WorkOrderInvoicesPdfPage.jsx:
  * InvoiceImagePreview prikazuje 'Učitavanje...' dok se blob dohvaća (ne 401 fallback)
  * uklonjen resolveMediaUrl fallback koji uzrokuje 401 greške
  * svaka invoice kartica je klikabilna i otvara InvoiceDetailModal
  * InvoiceDetailModal prikazuje detalje i uvećanu sliku/PDF vezu

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/modules/fleet/admin.py

@@ -1,3 +1,4 @@
+from pathlib import Path
 from django.contrib import admin
 from django.contrib.admin import ModelAdmin
 from django.utils.html import format_html
@@ -61,8 +62,27 @@ class ServiceRecordInline(admin.TabularInline):
 class WorkOrderInvoiceInline(admin.TabularInline):
     model = WorkOrderInvoice
     extra = 0
-    fields = ('naziv_racuna', 'lokacija', 'datum', 'opis', 'image', 'created_by', 'created_at', 'is_active')
-    readonly_fields = ('created_at',)
+    fields = ('thumbnail_preview', 'naziv_racuna', 'lokacija', 'datum', 'opis', 'image', 'created_by', 'created_at', 'is_active')
+    readonly_fields = ('thumbnail_preview', 'created_at')
+
+    @admin.display(description="Pregled")
+    def thumbnail_preview(self, obj):
+        if not obj.pk or not obj.image:
+            return "—"
+        suffix = Path(obj.image.name or '').suffix.lower()
+        if suffix == '.pdf':
+            return format_html(
+                '<a href="/api/fleet/work-order-invoices/{}/image/" target="_blank">📄 PDF</a>',
+                obj.pk,
+            )
+        return format_html(
+            '<a href="/api/fleet/work-order-invoices/{}/image/?w=1600&q=90&fmt=jpeg" target="_blank">'
+            '<img src="/api/fleet/work-order-invoices/{}/image/?w=200&q=75&fmt=jpeg" '
+            'style="height:64px;width:auto;border-radius:4px;object-fit:cover;" />'
+            '</a>',
+            obj.pk,
+            obj.pk,
+        )
 
 
 class WorkOrderPhotoInline(admin.TabularInline):
@@ -193,10 +213,30 @@ class WorkOrderAdmin(admin.ModelAdmin):
 
 @admin.register(WorkOrderInvoice)
 class WorkOrderInvoiceAdmin(admin.ModelAdmin):
-    list_display = ('id', 'work_order', 'naziv_racuna', 'lokacija', 'datum', 'created_by', 'is_active')
+    list_display = ('id', 'image_preview', 'work_order', 'naziv_racuna', 'lokacija', 'datum', 'created_by', 'is_active')
     list_filter = ('datum', 'is_active', 'work_order')
     search_fields = ('naziv_racuna', 'lokacija', 'opis', 'work_order__id')
     ordering = ('-datum', '-created_at')
+    readonly_fields = ('image_preview', 'created_at')
+
+    @admin.display(description="Slika")
+    def image_preview(self, obj):
+        if not obj.pk or not obj.image:
+            return "—"
+        suffix = Path(obj.image.name or '').suffix.lower()
+        if suffix == '.pdf':
+            return format_html(
+                '<a href="/api/fleet/work-order-invoices/{}/image/" target="_blank">📄 PDF</a>',
+                obj.pk,
+            )
+        return format_html(
+            '<a href="/api/fleet/work-order-invoices/{}/image/?w=1600&q=90&fmt=jpeg" target="_blank">'
+            '<img src="/api/fleet/work-order-invoices/{}/image/?w=200&q=75&fmt=jpeg" '
+            'style="height:80px;width:auto;border-radius:4px;object-fit:cover;" />'
+            '</a>',
+            obj.pk,
+            obj.pk,
+        )
 
 
 @admin.register(WorkOrderAdditionalCostsTable)

backend/modules/fleet/serializers.py

@@ -373,9 +373,13 @@ class WorkOrderInvoiceSerializer(serializers.ModelSerializer):
             return None
         if request is None:
             return None
-        return request.build_absolute_uri(
+        base = request.build_absolute_uri(
             reverse('work-order-invoice-image', kwargs={'pk': obj.pk})
         )
+        suffix = Path(obj.image.name or '').suffix.lower()
+        if suffix == '.pdf':
+            return base
+        return f"{base}?w=1280&q=80&fmt=jpeg"
 
     def get_image_content_type(self, obj):
         if not obj.image:

backend/modules/fleet/tasks.py

@@ -645,10 +645,19 @@ def _build_work_order_invoices_pdf(work_order):
                     y = content_top
                     max_height = y - content_bottom
 
+                # Kompresiraj u JPEG u memoriji radi manje veličine PDF-a
+                compress_w = min(image.width, 1280)
+                if image.width > compress_w:
+                    ratio_c = compress_w / float(image.width)
+                    image = image.resize((compress_w, max(1, int(image.height * ratio_c))), Image.LANCZOS)
+                buf = BytesIO()
+                image.save(buf, format='JPEG', quality=75, optimize=True)
+                buf.seek(0)
+
                 ratio = min(max_width / float(image.width), max_height / float(image.height), 1.0)
                 draw_width = max(1, int(image.width * ratio))
                 draw_height = max(1, int(image.height * ratio))
-                image_reader = ImageReader(image)
+                image_reader = ImageReader(buf)
                 pdf.drawImage(
                     image_reader,
                     margin,

backend/modules/fleet/views.py

@@ -208,6 +208,32 @@ def _docx_filename(work_order, doc_type):
     return f"{display_code}.work-order.docx"
 
 
+def _compress_image_for_pdf(image_field, max_width=1280, quality=75):
+    """
+    Otvori image_field (Django FileField), kompresiraj na max_width JPEG u memoriji,
+    vrati ImageReader spreman za reportlab. Vraća None ako slika nije dostupna.
+    """
+    try:
+        image_field.open('rb')
+        with Image.open(image_field) as src:
+            img = src.convert('RGB')
+            if img.width > max_width:
+                ratio = max_width / float(img.width)
+                new_h = max(1, int(img.height * ratio))
+                img = img.resize((max_width, new_h), Image.LANCZOS)
+            buf = BytesIO()
+            img.save(buf, format='JPEG', quality=quality, optimize=True)
+            buf.seek(0)
+        return ImageReader(buf)
+    except Exception:
+        return None
+    finally:
+        try:
+            image_field.close()
+        except Exception:
+            pass
+
+
 def _get_cached_pdf(work_order, pdf_type):
     now = timezone.now()
     expected_filename = _pdf_filename(work_order, pdf_type)
@@ -1166,7 +1192,9 @@ def _build_work_order_service_records_pdf(work_order):
                     prepared = []
                     for photo in row_photos:
                         try:
-                            image_reader = ImageReader(photo.image)
+                            image_reader = _compress_image_for_pdf(photo.image)
+                            if image_reader is None:
+                                continue
                             source_w, source_h = image_reader.getSize()
                             if not source_w or not source_h:
                                 continue
@@ -1390,7 +1418,9 @@ def _build_service_record_pdf(service_record):
             prepared = []
             for photo in row_photos:
                 try:
-                    image_reader = ImageReader(photo.image)
+                    image_reader = _compress_image_for_pdf(photo.image)
+                    if image_reader is None:
+                        continue
                     source_w, source_h = image_reader.getSize()
                     if not source_w or not source_h:
                         continue

frontend/src/components/dashboard/WorkOrderInvoicesPdfPage.jsx

@@ -19,7 +19,7 @@ import { $accessToken, $authReady, hydrateAuthFromStorage } from '../../stores/a
 import { fetchNotifications, connectNotifications } from '../../stores/notificationStore';
 import { formatWorkOrderDisplayCode } from '../../lib/displayIds';
 import { showToast } from '../../stores/toastStore';
-import { resolveMediaUrl, useAuthenticatedMediaSources } from './WorkOrderImageCarousel';
+import { useAuthenticatedMediaSources } from './WorkOrderImageCarousel';
 import TaskWorkHoursTableModal from './TaskWorkHoursTableModal';
 import WorkOrderAdditionalCostsModal from './WorkOrderAdditionalCostsModal';
 import WorkOrderServiceNotesModal from './WorkOrderServiceNotesModal';
@@ -32,9 +32,11 @@ function readWorkOrderIdFromQuery() {
     return params.get('workOrderId') || '';
 }
 
-function InvoiceImagePreview({ imageUrl, alt, contentType }) {
+function InvoiceImagePreview({ imageUrl, rawUrl, alt, contentType, onClick }) {
     const [broken, setBroken] = useState(false);
     const isPdf = String(contentType || '').toLowerCase() === 'application/pdf';
+    const isProtected = typeof rawUrl === 'string' && /\/api\/fleet\//i.test(rawUrl);
+    const isLoading = isProtected && !imageUrl && !broken;
 
     if (isPdf && imageUrl) {
         return (
@@ -49,6 +51,14 @@ function InvoiceImagePreview({ imageUrl, alt, contentType }) {
         );
     }
 
+    if (isLoading) {
+        return (
+            <div className="flex h-28 w-28 items-center justify-center rounded-lg border border-border-hairline bg-canvas-deep text-center text-[11px] text-text-muted">
+                <span className="animate-pulse">Učitavanje…</span>
+            </div>
+        );
+    }
+
     if (!imageUrl || broken) {
         return (
             <div className="flex h-28 w-28 items-center justify-center rounded-lg border border-border-hairline bg-canvas-deep text-center text-[11px] text-text-muted">
@@ -58,14 +68,76 @@ function InvoiceImagePreview({ imageUrl, alt, contentType }) {
     }
 
     return (
-        <a href={imageUrl} target="_blank" rel="noopener noreferrer" className="inline-flex">
+        <button
+            type="button"
+            onClick={onClick}
+            className="inline-flex cursor-pointer focus:outline-none"
+            aria-label={`Otvori pregled: ${alt}`}
+        >
             <img
                 src={imageUrl}
                 alt={alt}
                 onError={() => setBroken(true)}
-                className="h-28 w-28 rounded-lg border border-border-hairline object-cover"
+                className="h-28 w-28 rounded-lg border border-border-hairline object-cover hover:opacity-90 transition-opacity"
             />
+        </button>
+    );
+}
+
+function InvoiceDetailModal({ invoice, imageUrl, contentType, onClose }) {
+    const isPdf = String(contentType || '').toLowerCase() === 'application/pdf';
+
+    useEffect(() => {
+        const handleKey = (e) => { if (e.key === 'Escape') onClose(); };
+        window.addEventListener('keydown', handleKey);
+        return () => window.removeEventListener('keydown', handleKey);
+    }, [onClose]);
+
+    return (
+        <div
+            className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 p-4"
+            onClick={(e) => { if (e.target === e.currentTarget) onClose(); }}
+        >
+            <div className="relative flex max-h-[95vh] w-full max-w-3xl flex-col overflow-auto rounded-xl bg-canvas-base shadow-2xl">
+                <div className="flex items-center justify-between border-b border-border-hairline px-5 py-3">
+                    <h2 className="text-base font-semibold text-text-main">{invoice.naziv_racuna || 'Račun'}</h2>
+                    <button
+                        type="button"
+                        onClick={onClose}
+                        className="rounded p-1 text-text-muted hover:text-text-main focus:outline-none"
+                        aria-label="Zatvori"
+                    >
+                        ✕
+                    </button>
+                </div>
+                <div className="space-y-1 px-5 py-3 text-sm text-text-main border-b border-border-hairline">
+                    <div><span className="font-semibold">Naziv:</span> {invoice.naziv_racuna || '-'}</div>
+                    <div><span className="font-semibold">Lokacija:</span> {invoice.lokacija || '-'}</div>
+                    <div><span className="font-semibold">Datum:</span> {invoice.datum || '-'}</div>
+                    <div><span className="font-semibold">Opis:</span> {invoice.opis || '-'}</div>
+                </div>
+                <div className="flex flex-1 items-center justify-center p-5">
+                    {isPdf && imageUrl ? (
+                        <a
+                            href={imageUrl}
+                            target="_blank"
+                            rel="noopener noreferrer"
+                            className="rounded-lg bg-indigo-600 px-4 py-2 text-sm font-semibold text-white hover:bg-indigo-700"
+                        >
+                            Otvori PDF u novom tabu
                         </a>
+                    ) : imageUrl ? (
+                        <img
+                            src={imageUrl}
+                            alt={invoice.naziv_racuna}
+                            className="max-h-[60vh] max-w-full rounded-lg object-contain shadow"
+                        />
+                    ) : (
+                        <p className="text-sm text-text-muted">Slika nije dostupna.</p>
+                    )}
+                </div>
+            </div>
+        </div>
     );
 }
 
@@ -86,6 +158,7 @@ export default function WorkOrderInvoicesPdfPage() {
     const [editingServiceReportNote, setEditingServiceReportNote] = useState(false);
     const [savingServiceReportNote, setSavingServiceReportNote] = useState(false);
     const [serviceReportNoteError, setServiceReportNoteError] = useState('');
+    const [invoiceDetailModal, setInvoiceDetailModal] = useState(null);
 
     useEffect(() => {
         hydrateAuthFromStorage();
@@ -408,8 +481,18 @@ export default function WorkOrderInvoicesPdfPage() {
                 )}
                 {!loading && !error && invoices.length > 0 && (
                     <div className="space-y-3">
-                        {invoices.map((invoice) => (
-                            <article key={invoice.id} className="rounded-lg border border-border-hairline bg-canvas-base p-3">
+                                        {invoices.map((invoice) => {
+                                            const rawUrl = invoice.image_url || invoice.image || '';
+                                            const blobUrl = getAuthenticatedMediaSrc(rawUrl);
+                                            return (
+                                                <article
+                                                    key={invoice.id}
+                                                    className="cursor-pointer rounded-lg border border-border-hairline bg-canvas-base p-3 hover:bg-canvas-deep transition-colors"
+                                                    onClick={() => setInvoiceDetailModal(invoice)}
+                                                    role="button"
+                                                    tabIndex={0}
+                                                    onKeyDown={(e) => { if (e.key === 'Enter' || e.key === ' ') setInvoiceDetailModal(invoice); }}
+                                                >
                                                     <div className="grid gap-3 sm:grid-cols-[1fr_auto] sm:items-start">
                                                         <div className="space-y-1 text-sm text-text-main">
                                                             <div><span className="font-semibold">naziv_računa:</span> {invoice.naziv_racuna}</div>
@@ -418,13 +501,16 @@ export default function WorkOrderInvoicesPdfPage() {
                                                             <div><span className="font-semibold">opis:</span> {invoice.opis || '-'}</div>
                                                         </div>
                                                         <InvoiceImagePreview
-                                        imageUrl={getAuthenticatedMediaSrc(invoice.image_url || invoice.image) || resolveMediaUrl(invoice.image_url || invoice.image)}
+                                                            imageUrl={blobUrl}
+                                                            rawUrl={rawUrl}
                                                             alt={`Račun ${invoice.naziv_racuna}`}
                                                             contentType={invoice.image_content_type}
+                                                            onClick={(e) => { e.stopPropagation(); setInvoiceDetailModal(invoice); }}
                                                         />
                                                     </div>
                                                 </article>
-                        ))}
+                                            );
+                                        })}
                                     </div>
                                 )}
             </div>
@@ -455,6 +541,14 @@ export default function WorkOrderInvoicesPdfPage() {
                 }}
                 onSave={handleSaveServiceReportNote}
             />
+            {invoiceDetailModal && (
+                <InvoiceDetailModal
+                    invoice={invoiceDetailModal}
+                    imageUrl={getAuthenticatedMediaSrc(invoiceDetailModal.image_url || invoiceDetailModal.image || '')}
+                    contentType={invoiceDetailModal.image_content_type}
+                    onClose={() => setInvoiceDetailModal(null)}
+                />
+            )}
         </section>
     );
 }