feat: add StatusBadge, ConfirmationModal, LoadingSkeleton, and FilePreviewPanel

frontend/module/components/confirmation-modal/ConfirmationModal.tsx

@@ -0,0 +1,115 @@
+"use client";
+
+import { useEffect, useRef } from "react";
+
+interface ConfirmationModalProps {
+  isOpen: boolean;
+  title: string;
+  message: string;
+  confirmLabel?: string;
+  cancelLabel?: string;
+  isLoading?: boolean;
+  onConfirm: () => void;
+  onCancel: () => void;
+}
+
+export default function ConfirmationModal({
+  isOpen,
+  title,
+  message,
+  confirmLabel = "Delete",
+  cancelLabel = "Cancel",
+  isLoading = false,
+  onConfirm,
+  onCancel,
+}: ConfirmationModalProps) {
+  const cancelRef = useRef<HTMLButtonElement>(null);
+  const confirmRef = useRef<HTMLButtonElement>(null);
+  const prevFocusRef = useRef<Element | null>(null);
+
+  useEffect(() => {
+    if (isOpen) {
+      prevFocusRef.current = document.activeElement;
+      cancelRef.current?.focus();
+    } else {
+      (prevFocusRef.current as HTMLElement | null)?.focus();
+    }
+  }, [isOpen]);
+
+  useEffect(() => {
+    if (!isOpen) return;
+    function handleKeyDown(e: KeyboardEvent) {
+      if (e.key === "Escape") onCancel();
+      if (e.key === "Tab") {
+        const focusable = [cancelRef.current, confirmRef.current].filter(Boolean);
+        const first = focusable[0];
+        const last = focusable[focusable.length - 1];
+        if (e.shiftKey) {
+          if (document.activeElement === first) {
+            e.preventDefault();
+            last?.focus();
+          }
+        } else {
+          if (document.activeElement === last) {
+            e.preventDefault();
+            first?.focus();
+          }
+        }
+      }
+    }
+    document.addEventListener("keydown", handleKeyDown);
+    return () => document.removeEventListener("keydown", handleKeyDown);
+  }, [isOpen, onCancel]);
+
+  if (!isOpen) return null;
+
+  return (
+    <div
+      className="fixed inset-0 z-50 flex items-center justify-center"
+      role="dialog"
+      aria-modal="true"
+      aria-labelledby="confirm-title"
+      aria-describedby="confirm-message"
+    >
+      <div
+        className="absolute inset-0 bg-black/50"
+        onClick={onCancel}
+        aria-hidden="true"
+      />
+
+      <div className="relative z-10 mx-4 w-full max-w-md rounded-xl bg-white p-6 shadow-xl">
+        <h2
+          id="confirm-title"
+          className="text-lg font-semibold text-gray-900"
+        >
+          {title}
+        </h2>
+        <p id="confirm-message" className="mt-2 text-sm text-gray-600">
+          {message}
+        </p>
+
+        <div className="mt-6 flex justify-end gap-3">
+          <button
+            ref={cancelRef}
+            onClick={onCancel}
+            disabled={isLoading}
+            className="rounded-lg border border-gray-300 px-4 py-2 text-sm font-medium text-gray-700 hover:bg-gray-50 disabled:opacity-50"
+          >
+            {cancelLabel}
+          </button>
+          <button
+            ref={confirmRef}
+            onClick={onConfirm}
+            disabled={isLoading}
+            className="flex items-center gap-2 rounded-lg bg-red-600 px-4 py-2 text-sm font-medium text-white hover:bg-red-700 disabled:opacity-50"
+          >
+            {isLoading && (
+              <div className="h-3.5 w-3.5 animate-spin rounded-full border-2 border-white border-t-transparent" />
+            )}
+            {confirmLabel}
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}

frontend/module/components/file-preview/FilePreviewPanel.tsx

@@ -0,0 +1,107 @@
+"use client";
+
+import { useEffect, useState } from "react";
+
+interface FilePreviewPanelProps {
+  documentId: string;
+  mimeType: string;
+}
+
+const SUPPORTED_IMAGE_TYPES = ["image/png", "image/jpeg"];
+const SUPPORTED_TYPES = [...SUPPORTED_IMAGE_TYPES, "application/pdf"];
+
+export default function FilePreviewPanel({
+  documentId,
+  mimeType,
+}: FilePreviewPanelProps) {
+  const [fileUrl, setFileUrl] = useState<string | null>(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState<string | null>(null);
+
+  const isSupported = SUPPORTED_TYPES.includes(mimeType);
+  const isImage = SUPPORTED_IMAGE_TYPES.includes(mimeType);
+  const isPdf = mimeType === "application/pdf";
+
+  const downloadUrl = `${process.env.NEXT_PUBLIC_API_URL}/api/module/documents/${documentId}/download`;
+
+  useEffect(() => {
+    if (!isSupported) {
+      setLoading(false);
+      return;
+    }
+
+    (async () => {
+      try {
+        const res = await fetch(downloadUrl, {
+          headers: {
+            Authorization: `Bearer ${localStorage.getItem("access_token") ?? ""}`,
+          },
+        });
+        if (!res.ok) throw new Error("Failed to fetch file.");
+        const blob = await res.blob();
+        setFileUrl(URL.createObjectURL(blob));
+      } catch (err) {
+        setError(err instanceof Error ? err.message : "Failed to load file.");
+      } finally {
+        setLoading(false);
+      }
+    })();
+
+    return () => {
+      if (fileUrl) URL.revokeObjectURL(fileUrl);
+    };
+  }, [documentId, downloadUrl, isSupported]);
+
+  function handleDownload() {
+    const a = document.createElement("a");
+    a.href = fileUrl ?? downloadUrl;
+    a.download = `document-${documentId}`;
+    a.click();
+  }
+
+  return (
+    <div className="rounded-xl border border-gray-200 bg-white">
+      <div className="max-h-[600px] overflow-auto">
+        {loading ? (
+          <div className="flex h-48 items-center justify-center">
+            <div className="h-8 w-8 animate-spin rounded-full border-4 border-blue-600 border-t-transparent" />
+          </div>
+        ) : error ? (
+          <div className="flex h-48 flex-col items-center justify-center gap-3 text-center">
+            <p className="text-sm text-red-600">{error}</p>
+          </div>
+        ) : !isSupported ? (
+          <div className="flex h-48 flex-col items-center justify-center gap-3 text-center p-6">
+            <p className="text-sm text-gray-600">
+              This file type cannot be previewed.
+            </p>
+          </div>
+        ) : isImage && fileUrl ? (
+          <img
+            src={fileUrl}
+            alt="Document preview"
+            className="mx-auto max-w-full object-contain"
+          />
+        ) : isPdf && fileUrl ? (
+          <iframe
+            src={fileUrl}
+            title="Document preview"
+            className="h-[600px] w-full border-0"
+          />
+        ) : null}
+      </div>
+
+      <div className="flex justify-end border-t border-gray-200 p-3">
+        <button
+          onClick={handleDownload}
+          className="flex items-center gap-2 rounded-lg border border-gray-300 px-4 py-2 text-sm font-medium text-gray-700 hover:bg-gray-50"
+        >
+          <svg className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
+            <path strokeLinecap="round" strokeLinejoin="round" d="M4 16v1a3 3 0 003 3h10a3 3 0 003-3v-1m-4-4l-4 4m0 0l-4-4m4 4V4" />
+          </svg>
+          Download
+        </button>
+      </div>
+    </div>
+  );
+}

frontend/module/components/loading-skeleton/LoadingSkeleton.tsx

@@ -0,0 +1,81 @@
+"use client";
+
+interface SkeletonProps {
+  width?: string;
+  height?: string;
+  borderRadius?: string;
+  className?: string;
+}
+
+export function Skeleton({
+  width = "100%",
+  height = "1rem",
+  borderRadius = "0.375rem",
+  className = "",
+}: SkeletonProps) {
+  return (
+    <div
+      aria-hidden="true"
+      style={{ width, height, borderRadius }}
+      className={`skeleton-shimmer bg-gray-200 ${className}`}
+    >
+      <style jsx>{`
+        @media (prefers-reduced-motion: no-preference) {
+          .skeleton-shimmer {
+            background: linear-gradient(
+              90deg,
+              #e5e7eb 25%,
+              #f3f4f6 50%,
+              #e5e7eb 75%
+            );
+            background-size: 200% 100%;
+            animation: shimmer 1.4s infinite;
+          }
+        }
+        @keyframes shimmer {
+          0% { background-position: 200% 0; }
+          100% { background-position: -200% 0; }
+        }
+      `}</style>
+    </div>
+  );
+}
+
+export function DocumentCardSkeleton() {
+  return (
+    <div className="flex items-center justify-between rounded-lg border border-gray-200 bg-white p-4">
+      <div className="flex-1 space-y-2">
+        <Skeleton width="60%" height="1rem" />
+        <Skeleton width="40%" height="0.75rem" />
+      </div>
+      <Skeleton width="4rem" height="1.5rem" borderRadius="9999px" />
+    </div>
+  );
+}
+
+export function StatCardSkeleton() {
+  return (
+    <div className="rounded-xl border border-gray-200 bg-white p-5">
+      <Skeleton width="6rem" height="0.875rem" />
+      <Skeleton width="4rem" height="2rem" className="mt-2" />
+    </div>
+  );
+}
+
+interface TableRowSkeletonProps {
+  columnCount?: number;
+}
+
+export function TableRowSkeleton({ columnCount = 4 }: TableRowSkeletonProps) {
+  return (
+    <tr aria-hidden="true">
+      {Array.from({ length: columnCount }).map((_, i) => (
+        <td key={i} className="px-4 py-3">
+          <Skeleton />
+        </td>
+      ))}
+    </tr>
+  );
+}
+
+export default Skeleton;

frontend/module/components/status-badge/StatusBadge.tsx

@@ -0,0 +1,42 @@
+"use client";
+
+type StatusSize = "sm" | "md";
+
+interface StatusBadgeProps {
+  status: string;
+  size?: StatusSize;
+}
+
+const STATUS_STYLES: Record<string, string> = {
+  PENDING: "bg-gray-100 text-gray-700",
+  ANALYZING: "bg-blue-100 text-blue-700",
+  VERIFIED: "bg-green-100 text-green-700",
+  FLAGGED: "bg-orange-100 text-orange-700",
+  REJECTED: "bg-red-100 text-red-700",
+  OPEN: "bg-blue-100 text-blue-700",
+  UNDER_REVIEW: "bg-amber-100 text-amber-700",
+  RESOLVED: "bg-green-100 text-green-700",
+};
+
+function toTitleCase(str: string): string {
+  return str
+    .toLowerCase()
+    .replace(/_/g, " ")
+    .replace(/\b\w/g, (c) => c.toUpperCase());
+}
+
+export default function StatusBadge({ status, size = "md" }: StatusBadgeProps) {
+  const style = STATUS_STYLES[status] ?? "bg-gray-100 text-gray-600";
+  const sizeClass = size === "sm" ? "px-1.5 py-0.5 text-xs" : "px-2.5 py-1 text-sm";
+  const label = toTitleCase(status);
+
+  return (
+    <span
+      role="status"
+      aria-label={label}
+      className={`inline-flex items-center rounded-full font-medium ${style} ${sizeClass}`}
+    >
+      {label}
+    </span>
+  );
+}