实现报销材料合并预览与差旅概要（07-27-yang-jun-reimbursement-readiness）

server/src/routes/reimbursements.js

@@ -75,6 +75,14 @@ const REIMBURSEMENT_LIST_QUERY_SCHEMA = z.object({
 const REIMBURSEMENT_UPDATE_BODY_SCHEMA = z.object({
   reimbursementDate: z.string().regex(/^\d{4}-\d{2}-\d{2}$/).optional(),
   description: z.string().trim().max(500).nullable().optional(),
+  travelPurpose: z.string().trim().max(200).nullable().optional(),
+  travelLocation: z.string().trim().max(200).nullable().optional(),
+  travelStartDate: z.string().regex(/^\d{4}-\d{2}-\d{2}$/).nullable().optional(),
+  travelEndDate: z.string().regex(/^\d{4}-\d{2}-\d{2}$/).nullable().optional(),
+}).superRefine((value, ctx) => {
+  if (value.travelStartDate && value.travelEndDate && value.travelStartDate > value.travelEndDate) {
+    ctx.addIssue({ code: z.ZodIssueCode.custom, message: "invalid_date_range", path: ["travelEndDate"] });
+  }
 });
 
 const REIMBURSEMENT_ATTACHMENT_DELETE_BODY_SCHEMA = z
@@ -86,7 +94,6 @@ const REIMBURSEMENT_ATTACHMENT_PREVIEW_BODY_SCHEMA = z
   .object({ reason: z.string().trim().max(200).optional() })
   .strict();
 const REIMBURSEMENT_MATERIAL_PREVIEW_BODY_SCHEMA = REIMBURSEMENT_ATTACHMENT_PREVIEW_BODY_SCHEMA;
-const REIMBURSEMENT_MATERIAL_PREVIEW_PAGE_SCHEMA = z.coerce.number().int().min(0).max(39);
 
 function resolveSignedFileOrigin(config, request) {
   const configured = String(config.appOrigin ?? "")
@@ -123,9 +130,16 @@ const REIMBURSEMENT_CREATE_BODY_SCHEMA = z
     description: z.string().max(500).optional(),
     templateId: z.string().uuid().optional(),
     linkedTravelRequestId: z.string().uuid().optional(),
+    travelPurpose: z.string().trim().max(200).optional(),
+    travelLocation: z.string().trim().max(200).optional(),
+    travelStartDate: z.string().regex(/^\d{4}-\d{2}-\d{2}$/).optional(),
+    travelEndDate: z.string().regex(/^\d{4}-\d{2}-\d{2}$/).optional(),
   })
   .strict()
   .superRefine((value, ctx) => {
+    if (value.travelStartDate && value.travelEndDate && value.travelStartDate > value.travelEndDate) {
+      ctx.addIssue({ code: z.ZodIssueCode.custom, message: "invalid_date_range", path: ["travelEndDate"] });
+    }
     if (value.templateId && value.linkedTravelRequestId) {
       ctx.addIssue({
         code: z.ZodIssueCode.custom,
@@ -1540,6 +1554,18 @@ async function reimbursementRoutes(fastify) {
           timeZone: fastify.config.appTimezone,
         });
 
+        const linkedTravelCities = linkedTravelRequestRecord
+          ? [...new Set(linkedTravelRequestRecord.segments.flatMap((segment) => [segment.from_city, segment.to_city]).filter(Boolean))]
+          : [];
+        const travelPurpose = body.travelPurpose?.trim() || linkedTravelRequestRecord?.purpose || null;
+        const travelLocation = body.travelLocation?.trim() || linkedTravelCities.join("、") || null;
+        const travelStartDate = body.travelStartDate
+          ? parseDateOnlyString(body.travelStartDate)
+          : linkedTravelRequestRecord?.start_date ?? null;
+        const travelEndDate = body.travelEndDate
+          ? parseDateOnlyString(body.travelEndDate)
+          : linkedTravelRequestRecord?.end_date ?? null;
+
         const created = await tx.reimbursementForm.create({
           data: {
             form_number: issued.documentNumber,
@@ -1549,6 +1575,10 @@ async function reimbursementRoutes(fastify) {
             reimbursement_date: parseDateOnlyString(reimbursementDate),
             description: resolvedDescription,
             linked_travel_request_id: linkedTravelRequestRecord?.id ?? null,
+            travel_purpose: travelPurpose,
+            travel_location: travelLocation,
+            travel_start_date: travelStartDate,
+            travel_end_date: travelEndDate,
             created_by: request.employee.id,
             updated_by: request.employee.id,
           },
@@ -1562,6 +1592,10 @@ async function reimbursementRoutes(fastify) {
             owner_id: true,
             submitter_id: true,
             linked_travel_request_id: true,
+            travel_purpose: true,
+            travel_location: true,
+            travel_start_date: true,
+            travel_end_date: true,
             travel_request: {
               select: {
                 id: true,
@@ -1658,6 +1692,12 @@ async function reimbursementRoutes(fastify) {
         totalAmount: toMoneyString(reimbursement.total_amount),
         linkedTravelRequestId: reimbursement.linked_travel_request_id ?? null,
         linkedTravelRequest: mapLinkedTravelRequestSummary(reimbursement.travel_request),
+        travelSummary: {
+          purpose: reimbursement.travel_purpose ?? null,
+          location: reimbursement.travel_location ?? null,
+          startDate: toDateOnlyString(reimbursement.travel_start_date),
+          endDate: toDateOnlyString(reimbursement.travel_end_date),
+        },
         items: Array.isArray(reimbursement.items) ? reimbursement.items.map(mapCreatedReimbursementItem) : [],
       });
     },
@@ -2061,6 +2101,10 @@ async function reimbursementRoutes(fastify) {
           paid_at: true,
           project_id: true,
           linked_travel_request_id: true,
+          travel_purpose: true,
+          travel_location: true,
+          travel_start_date: true,
+          travel_end_date: true,
           paid_by_employee: {
             select: {
               id: true,
@@ -2261,6 +2305,12 @@ async function reimbursementRoutes(fastify) {
         },
         orderBy: [{ created_at: "desc" }, { id: "desc" }],
       });
+      const travelItems = reimbursement.items.filter((item) => item.expense_type?.category === "travel");
+      const travelItemDates = travelItems
+        .map((item) => item.expense_date)
+        .filter(Boolean)
+        .sort((left, right) => left.getTime() - right.getTime());
+      const isTravelReimbursement = Boolean(reimbursement.linked_travel_request_id || travelItems.length);
 
       return sendData(reply, request, {
         id: reimbursement.id,
@@ -2297,6 +2347,13 @@ async function reimbursementRoutes(fastify) {
         project: reimbursement.project ? { id: reimbursement.project.id, projectNo: reimbursement.project.project_no, name: reimbursement.project.name } : null,
         linkedTravelRequestId: reimbursement.linked_travel_request_id ?? null,
         linkedTravelRequest: mapLinkedTravelRequestSummary(reimbursement.travel_request),
+        travelSummary: {
+          isTravel: isTravelReimbursement,
+          purpose: reimbursement.travel_purpose ?? (isTravelReimbursement ? reimbursement.description : null),
+          location: reimbursement.travel_location ?? null,
+          startDate: toDateOnlyString(reimbursement.travel_start_date ?? travelItemDates[0] ?? null),
+          endDate: toDateOnlyString(reimbursement.travel_end_date ?? travelItemDates.at(-1) ?? null),
+        },
         owner: reimbursement.owner,
         submitter: reimbursement.submitter,
         items: reimbursement.items.map((item) => ({
@@ -2357,7 +2414,7 @@ async function reimbursementRoutes(fastify) {
 
       const updated = await fastify.prisma.$transaction(async (tx) => {
         const reimbursementRows = await tx.$queryRaw`
-          SELECT id, owner_id, submitter_id, status
+          SELECT id, owner_id, submitter_id, department_id, status, travel_start_date, travel_end_date
           FROM "reimbursement_forms"
           WHERE id = ${reimbursementId}::uuid
           FOR UPDATE
@@ -2392,6 +2449,20 @@ async function reimbursementRoutes(fastify) {
 
         const nextDescription =
           body.description === undefined ? undefined : body.description?.trim() || null;
+        const nextTravelStartDate = body.travelStartDate === undefined
+          ? reimbursement.travel_start_date
+          : body.travelStartDate ? parseDateOnlyString(body.travelStartDate) : null;
+        const nextTravelEndDate = body.travelEndDate === undefined
+          ? reimbursement.travel_end_date
+          : body.travelEndDate ? parseDateOnlyString(body.travelEndDate) : null;
+        if (nextTravelStartDate && nextTravelEndDate && nextTravelStartDate > nextTravelEndDate) {
+          throw new AppError({
+            code: "VALID_001",
+            message: "参数校验失败",
+            statusCode: 400,
+            details: { travelEndDate: "invalid_date_range" },
+          });
+        }
 
         return tx.reimbursementForm.update({
           where: { id: reimbursementId },
@@ -2400,6 +2471,10 @@ async function reimbursementRoutes(fastify) {
               ? { reimbursement_date: parseDateOnlyString(body.reimbursementDate) }
               : {}),
             ...(body.description !== undefined ? { description: nextDescription } : {}),
+            ...(body.travelPurpose !== undefined ? { travel_purpose: body.travelPurpose?.trim() || null } : {}),
+            ...(body.travelLocation !== undefined ? { travel_location: body.travelLocation?.trim() || null } : {}),
+            ...(body.travelStartDate !== undefined ? { travel_start_date: nextTravelStartDate } : {}),
+            ...(body.travelEndDate !== undefined ? { travel_end_date: nextTravelEndDate } : {}),
             updated_by: request.employee.id,
           },
           select: {
@@ -2408,6 +2483,10 @@ async function reimbursementRoutes(fastify) {
             reimbursement_date: true,
             description: true,
             total_amount: true,
+            travel_purpose: true,
+            travel_location: true,
+            travel_start_date: true,
+            travel_end_date: true,
           },
         });
       });
@@ -2418,6 +2497,12 @@ async function reimbursementRoutes(fastify) {
         reimbursementDate: updated.reimbursement_date.toISOString().slice(0, 10),
         description: updated.description,
         totalAmount: toMoneyString(updated.total_amount),
+        travelSummary: {
+          purpose: updated.travel_purpose,
+          location: updated.travel_location,
+          startDate: toDateOnlyString(updated.travel_start_date),
+          endDate: toDateOnlyString(updated.travel_end_date),
+        },
       });
     },
   );
@@ -3003,6 +3088,7 @@ async function reimbursementRoutes(fastify) {
               storage_path: true,
               mime_type: true,
               file_size: true,
+              file_sha256: true,
             },
           },
           attachments: {
@@ -3012,6 +3098,7 @@ async function reimbursementRoutes(fastify) {
               storage_path: true,
               mime_type: true,
               file_size: true,
+              file_sha256: true,
               governance_status: true,
               sensitivity_level: true,
               attachment_type: true,
@@ -3043,6 +3130,7 @@ async function reimbursementRoutes(fastify) {
           storagePath: invoice.storage_path,
           mimeType: invoice.mime_type,
           fileSize: invoice.file_size,
+          fileSha256: invoice.file_sha256,
         })),
         ...reimbursement.attachments.map((attachment, index) => ({
           id: attachment.id,
@@ -3051,6 +3139,7 @@ async function reimbursementRoutes(fastify) {
           storagePath: attachment.storage_path,
           mimeType: attachment.mime_type,
           fileSize: attachment.file_size,
+          fileSha256: attachment.file_sha256,
         })),
       ];
       if (materials.some((material) => !ATTACHMENT_MIME_ALLOWLIST.has(material.mimeType))) {
@@ -3079,22 +3168,14 @@ async function reimbursementRoutes(fastify) {
       }
 
       const origin = resolveSignedFileOrigin(fastify.config, request);
-      const pages = created.bundle.pages.map((page, pageIndex) => {
-        const previewToken = signPayload({
-          purpose: "reimbursement_material_preview",
-          reimbursementId,
-          bundleId: created.bundleId,
-          pageIndex,
-          actorId: request.employee.id,
-          exp: expiresAt,
-        }, fastify.config.jwtSecret);
-        return {
-          url: `${origin}/api/reimbursements/${reimbursementId}/materials/preview/${created.bundleId}/${pageIndex}?previewToken=${encodeURIComponent(previewToken)}`,
-          materialType: page.materialType,
-          materialIndex: page.materialIndex,
-          pageNumber: page.pageNumber,
-        };
-      });
+      const previewToken = signPayload({
+        purpose: "reimbursement_material_preview",
+        reimbursementId,
+        bundleId: created.bundleId,
+        actorId: request.employee.id,
+        exp: expiresAt,
+      }, fastify.config.jwtSecret);
+      const signedUrl = `${origin}/api/reimbursements/${reimbursementId}/materials/preview/${created.bundleId}?previewToken=${encodeURIComponent(previewToken)}`;
 
       try {
         await fastify.prisma.auditLog.create({
@@ -3106,7 +3187,7 @@ async function reimbursementRoutes(fastify) {
             extra: {
               invoiceCount: reimbursement.invoice_pool_items.length,
               attachmentCount: reimbursement.attachments.length,
-              pageCount: pages.length,
+              pageCount: created.bundle.pageCount,
               reason,
               expiresAt,
             },
@@ -3119,30 +3200,31 @@ async function reimbursementRoutes(fastify) {
 
       return sendData(reply, request, {
         expiresAt: new Date(expiresAt).toISOString(),
-        pages,
+        signedUrl,
+        originalName: "reimbursement-materials-preview.pdf",
+        mimeType: "application/pdf",
+        fileSize: created.fileSize,
+        pageCount: created.bundle.pageCount,
       });
     },
   );
 
   fastify.get(
-    "/reimbursements/:id/materials/preview/:bundleId/:pageIndex",
+    "/reimbursements/:id/materials/preview/:bundleId",
     {},
     async (request, reply) => {
       const reimbursementId = parseReimbursementId(request.params?.id);
       const parsedBundleId = UUID_SCHEMA.safeParse(request.params?.bundleId);
-      const parsedPageIndex = REIMBURSEMENT_MATERIAL_PREVIEW_PAGE_SCHEMA.safeParse(request.params?.pageIndex);
       const previewToken = typeof request.query?.previewToken === "string" ? request.query.previewToken : "";
       const verified = previewToken ? verifyToken(previewToken, fastify.config.jwtSecret) : { ok: false };
       const payload = verified.ok ? verified.payload : null;
       const parsedActorId = UUID_SCHEMA.safeParse(payload?.actorId);
       if (
         !parsedBundleId.success ||
-        !parsedPageIndex.success ||
         !verified.ok ||
         payload?.purpose !== "reimbursement_material_preview" ||
         payload?.reimbursementId !== reimbursementId ||
         payload?.bundleId !== parsedBundleId.data ||
-        payload?.pageIndex !== parsedPageIndex.data ||
         typeof payload?.exp !== "number" ||
         payload.exp <= Date.now() ||
         !parsedActorId.success
@@ -3150,10 +3232,7 @@ async function reimbursementRoutes(fastify) {
         throw new AppError({ code: "PERM_001", message: "无权限", statusCode: 403 });
       }
 
-      const resolved = materialPreviewStore.getPage({
-        bundleId: parsedBundleId.data,
-        pageIndex: parsedPageIndex.data,
-      });
+      const resolved = materialPreviewStore.getBundle({ bundleId: parsedBundleId.data });
       if (
         !resolved ||
         resolved.bundle.reimbursementId !== reimbursementId ||
@@ -3170,19 +3249,17 @@ async function reimbursementRoutes(fastify) {
           targetType: "reimbursement",
           targetId: reimbursementId,
           extra: {
-            materialId: resolved.page.materialId,
-            materialType: resolved.page.materialType,
-            materialIndex: resolved.page.materialIndex,
-            pageNumber: resolved.page.pageNumber,
+            pageCount: resolved.bundle.pageCount,
           },
         }),
       });
 
-      reply.type("image/png");
+      reply.type("application/pdf");
       reply.header("cache-control", "private, no-store");
       reply.header("referrer-policy", "no-referrer");
-      reply.header("content-disposition", "inline");
-      return reply.send(resolved.page.buffer);
+      reply.header("content-disposition", 'inline; filename="reimbursement-materials-preview.pdf"');
+      reply.header("content-length", String(resolved.artifact.buffer.length));
+      return reply.send(resolved.artifact.buffer);
     },
   );
 
@@ -3526,7 +3603,8 @@ async function reimbursementRoutes(fastify) {
       const submitResult = await fastify.prisma.$transaction(async (tx) => {
         let budgetCheck = null;
         const reimbursementRows = await tx.$queryRaw`
-          SELECT id, owner_id, submitter_id, department_id, reimbursement_date, status, form_number, total_amount
+          SELECT id, owner_id, submitter_id, department_id, reimbursement_date, status, form_number, total_amount,
+                 linked_travel_request_id, travel_purpose, travel_location, travel_start_date, travel_end_date
           FROM "reimbursement_forms"
           WHERE id = ${reimbursementId}::uuid
           FOR UPDATE
@@ -3554,6 +3632,30 @@ async function reimbursementRoutes(fastify) {
 
         ensureNonNegativeAmount(reimbursement.total_amount);
 
+        const travelItem = await tx.reimbursementItem.findFirst({
+          where: {
+            reimbursement_id: reimbursementId,
+            expense_type: { category: "travel" },
+          },
+          select: { id: true },
+        });
+        if (travelItem || reimbursement.linked_travel_request_id) {
+          const missingTravelFields = [
+            ["travelPurpose", reimbursement.travel_purpose],
+            ["travelLocation", reimbursement.travel_location],
+            ["travelStartDate", reimbursement.travel_start_date],
+            ["travelEndDate", reimbursement.travel_end_date],
+          ].filter(([, value]) => !value).map(([field]) => field);
+          if (missingTravelFields.length) {
+            throw new AppError({
+              code: "VALID_001",
+              message: "参数校验失败",
+              statusCode: 400,
+              details: { travelSummary: "incomplete", missingFields: missingTravelFields },
+            });
+          }
+        }
+
         const activeInstance = await tx.workflowInstance.findFirst({
           where: {
             entity_type: "reimbursement",

server/src/services/reimbursementMaterialPdf.js

@@ -0,0 +1,100 @@
+const crypto = require("node:crypto");
+const { PDFDocument } = require("pdf-lib");
+const sharp = require("sharp");
+
+const FIXED_PDF_DATE = new Date("2000-01-01T00:00:00.000Z");
+const PDF_CREATOR = "hyb-oa";
+const PDF_PRODUCER = "hyb-oa reimbursement material merger";
+
+function materialCollectionHash(materials, mergerVersion) {
+  const hash = crypto.createHash("sha256");
+  hash.update(String(mergerVersion));
+  for (const material of materials) {
+    hash.update("\0");
+    hash.update([
+      material.materialType,
+      material.id,
+      material.fileSha256 ?? "",
+      material.mimeType,
+      String(material.fileSize),
+    ].join("\u001f"));
+  }
+  return hash.digest("hex");
+}
+
+async function normalizeImageForPdf(source, limits) {
+  const image = sharp(source, { failOn: "error", limitInputPixels: limits.maxImagePixels }).rotate();
+  const metadata = await image.metadata();
+  if (!metadata.width || !metadata.height || metadata.width * metadata.height > limits.maxImagePixels) {
+    throw new Error("material_preview_image_invalid");
+  }
+  const normalized = await image
+    .flatten({ background: "#ffffff" })
+    .jpeg({ quality: 90, chromaSubsampling: "4:4:4", mozjpeg: false })
+    .toBuffer();
+  return { buffer: normalized, width: metadata.width, height: metadata.height };
+}
+
+function fitPage(width, height) {
+  const maxSide = 842;
+  const scale = Math.min(1, maxSide / Math.max(width, height));
+  return { width: Math.max(1, width * scale), height: Math.max(1, height * scale) };
+}
+
+async function mergeMaterialsToPdf(materials, limits) {
+  const output = await PDFDocument.create();
+  output.setCreationDate(FIXED_PDF_DATE);
+  output.setModificationDate(FIXED_PDF_DATE);
+  output.setCreator(PDF_CREATOR);
+  output.setProducer(PDF_PRODUCER);
+  output.setTitle("Reimbursement Material Preview");
+  output.setSubject("Derived preview; originals retained separately");
+
+  let pageCount = 0;
+  for (const material of materials) {
+    const source = Buffer.from(material.source);
+    if (material.mimeType === "application/pdf") {
+      let input;
+      try {
+        input = await PDFDocument.load(source, { updateMetadata: false });
+      } catch {
+        throw new Error("material_preview_pdf_invalid");
+      }
+      const indices = input.getPageIndices();
+      if (!indices.length || pageCount + indices.length > limits.maxPages) {
+        throw new Error(indices.length ? "material_preview_page_limit" : "material_preview_pdf_empty");
+      }
+      const pages = await output.copyPages(input, indices);
+      pages.forEach((page) => output.addPage(page));
+      pageCount += pages.length;
+      continue;
+    }
+
+    if (pageCount + 1 > limits.maxPages) throw new Error("material_preview_page_limit");
+    let normalized;
+    try {
+      normalized = await normalizeImageForPdf(source, limits);
+    } catch (error) {
+      if (error?.message === "material_preview_image_invalid") throw error;
+      throw new Error("material_preview_image_invalid");
+    }
+    const embedded = await output.embedJpg(normalized.buffer);
+    const size = fitPage(normalized.width, normalized.height);
+    const page = output.addPage([size.width, size.height]);
+    page.drawImage(embedded, { x: 0, y: 0, width: size.width, height: size.height });
+    pageCount += 1;
+  }
+
+  if (!pageCount) throw new Error("material_preview_empty");
+  const bytes = await output.save({
+    useObjectStreams: true,
+    addDefaultPage: false,
+    objectsPerTick: 50,
+    updateFieldAppearances: false,
+  });
+  const buffer = Buffer.from(bytes);
+  if (buffer.length > limits.maxOutputBytes) throw new Error("material_preview_output_size_limit");
+  return { buffer, pageCount };
+}
+
+module.exports = { materialCollectionHash, mergeMaterialsToPdf };

server/src/services/reimbursementMaterialPreview.js

@@ -1,23 +1,17 @@
 const crypto = require("node:crypto");
-const fs = require("node:fs/promises");
-const os = require("node:os");
 const path = require("node:path");
-const { promisify } = require("node:util");
-const { execFile } = require("node:child_process");
-const sharp = require("sharp");
-
-const execFileAsync = promisify(execFile);
+const { Worker } = require("node:worker_threads");
+const { materialCollectionHash } = require("./reimbursementMaterialPdf");
 
+const MATERIAL_PREVIEW_MERGER_VERSION = "pdf-v1";
 const MATERIAL_PREVIEW_LIMITS = Object.freeze({
   maxMaterials: 20,
   maxSourceBytes: 50 * 1024 * 1024,
   maxPages: 40,
-  maxPageWidth: 1800,
-  maxPagePixels: 40_000_000,
-  maxOutputBytes: 40 * 1024 * 1024,
-  maxCacheBytes: 80 * 1024 * 1024,
-  rasterDpi: 144,
-  rasterTimeoutMs: 20_000,
+  maxImagePixels: 40_000_000,
+  maxOutputBytes: 50 * 1024 * 1024,
+  maxCacheBytes: 100 * 1024 * 1024,
+  mergeTimeoutMs: 20_000,
 });
 
 class MaterialPreviewError extends Error {
@@ -28,183 +22,137 @@ class MaterialPreviewError extends Error {
   }
 }
 
-function pageNumberFromName(fileName) {
-  const matched = fileName.match(/-(\d+)\.png$/i);
-  return matched ? Number(matched[1]) : Number.MAX_SAFE_INTEGER;
-}
-
-async function normalizePreviewImage(buffer, limits = MATERIAL_PREVIEW_LIMITS) {
-  try {
-    return await sharp(buffer, { failOn: "error", limitInputPixels: limits.maxPagePixels })
-      .rotate()
-      .resize({ width: limits.maxPageWidth, withoutEnlargement: true })
-      .png({ compressionLevel: 8, adaptiveFiltering: true })
-      .toBuffer();
-  } catch {
-    throw new MaterialPreviewError("material_preview_image_invalid");
-  }
-}
-
-async function rasterizePdfWithPoppler(buffer, limits = MATERIAL_PREVIEW_LIMITS) {
-  const tempDir = await fs.mkdtemp(path.join(os.tmpdir(), "hyb-oa-material-preview-"));
-  const sourcePath = path.join(tempDir, "source.pdf");
-  const outputPrefix = path.join(tempDir, "page");
-
-  try {
-    await fs.writeFile(sourcePath, buffer, { flag: "wx" });
-    try {
-      await execFileAsync(
-        "pdftoppm",
-        [
-          "-png",
-          "-r",
-          String(limits.rasterDpi),
-          "-f",
-          "1",
-          "-l",
-          String(limits.maxPages + 1),
-          "-scale-to-x",
-          String(limits.maxPageWidth),
-          "-scale-to-y",
-          "-1",
-          sourcePath,
-          outputPrefix,
-        ],
-        {
-          timeout: limits.rasterTimeoutMs,
-          maxBuffer: 1024 * 1024,
-          windowsHide: true,
-        },
-      );
-    } catch (error) {
-      if (error?.code === "ENOENT") {
-        throw new MaterialPreviewError("material_preview_rasterizer_unavailable");
+function runMergeWorker(materials, limits) {
+  return new Promise((resolve, reject) => {
+    const worker = new Worker(path.join(__dirname, "reimbursementMaterialPreviewWorker.js"), {
+      workerData: { materials, limits },
+    });
+    const timeout = setTimeout(() => {
+      worker.terminate().catch(() => {});
+      reject(new MaterialPreviewError("material_preview_merge_timeout"));
+    }, limits.mergeTimeoutMs);
+    timeout.unref?.();
+    worker.once("message", (message) => {
+      clearTimeout(timeout);
+      if (!message?.ok) {
+        reject(new MaterialPreviewError(message?.code || "material_preview_merge_failed"));
+        return;
       }
-      if (error?.killed || error?.signal) {
-        throw new MaterialPreviewError("material_preview_raster_timeout");
+      resolve({ buffer: Buffer.from(message.bytes), pageCount: message.pageCount });
+    });
+    worker.once("error", () => {
+      clearTimeout(timeout);
+      reject(new MaterialPreviewError("material_preview_merge_failed"));
+    });
+    worker.once("exit", (code) => {
+      if (code !== 0) {
+        clearTimeout(timeout);
+        reject(new MaterialPreviewError("material_preview_merge_failed"));
       }
-      throw new MaterialPreviewError("material_preview_pdf_invalid");
-    }
-
-    const fileNames = (await fs.readdir(tempDir))
-      .filter((fileName) => /^page-\d+\.png$/i.test(fileName))
-      .sort((left, right) => pageNumberFromName(left) - pageNumberFromName(right));
-    if (!fileNames.length) {
-      throw new MaterialPreviewError("material_preview_pdf_empty");
-    }
-
-    const pages = [];
-    for (const fileName of fileNames) {
-      pages.push(await normalizePreviewImage(await fs.readFile(path.join(tempDir, fileName)), limits));
-    }
-    return pages;
-  } finally {
-    await fs.rm(tempDir, { recursive: true, force: true });
-  }
+    });
+  });
 }
 
 function createReimbursementMaterialPreviewStore(options = {}) {
   const limits = { ...MATERIAL_PREVIEW_LIMITS, ...(options.limits ?? {}) };
-  const rasterizePdf = options.rasterizePdf ?? ((buffer) => rasterizePdfWithPoppler(buffer, limits));
-  const normalizeImage = options.normalizeImage ?? ((buffer) => normalizePreviewImage(buffer, limits));
+  const mergePdf = options.mergePdf ?? ((materials) => runMergeWorker(materials, limits));
   const now = options.now ?? (() => Date.now());
   const randomUUID = options.randomUUID ?? (() => crypto.randomUUID());
-  const bundles = new Map();
+  const grants = new Map();
+  const artifacts = new Map();
+  const pendingArtifacts = new Map();
   let cachedBytes = 0;
 
   function deleteBundle(bundleId) {
-    const bundle = bundles.get(bundleId);
-    if (!bundle) return;
-    cachedBytes -= bundle.outputBytes;
-    bundles.delete(bundleId);
+    const grant = grants.get(bundleId);
+    if (!grant) return;
+    grants.delete(bundleId);
+    const stillUsed = [...grants.values()].some((candidate) => candidate.cacheKey === grant.cacheKey);
+    if (!stillUsed) {
+      const artifact = artifacts.get(grant.cacheKey);
+      if (artifact) cachedBytes -= artifact.buffer.length;
+      artifacts.delete(grant.cacheKey);
+    }
   }
 
   function pruneExpired() {
     const current = now();
-    for (const [bundleId, bundle] of bundles) {
-      if (bundle.expiresAt <= current) deleteBundle(bundleId);
+    for (const [bundleId, grant] of grants) {
+      if (grant.expiresAt <= current) deleteBundle(bundleId);
     }
   }
 
   async function createBundle({ actorId, reimbursementId, materials, expiresAt, readSource }) {
     pruneExpired();
-    if (!Array.isArray(materials) || materials.length === 0) {
-      throw new MaterialPreviewError("material_preview_empty");
-    }
-    if (materials.length > limits.maxMaterials) {
-      throw new MaterialPreviewError("material_preview_material_limit");
-    }
-    const sourceBytes = materials.reduce((sum, material) => sum + Number(material.fileSize ?? 0), 0);
-    if (!Number.isSafeInteger(sourceBytes) || sourceBytes <= 0 || sourceBytes > limits.maxSourceBytes) {
+    if (!Array.isArray(materials) || !materials.length) throw new MaterialPreviewError("material_preview_empty");
+    if (materials.length > limits.maxMaterials) throw new MaterialPreviewError("material_preview_material_limit");
+    const declaredBytes = materials.reduce((sum, material) => sum + Number(material.fileSize ?? 0), 0);
+    if (!Number.isSafeInteger(declaredBytes) || declaredBytes <= 0 || declaredBytes > limits.maxSourceBytes) {
       throw new MaterialPreviewError("material_preview_source_size_limit");
     }
 
-    const pages = [];
-    let outputBytes = 0;
-    let actualSourceBytes = 0;
-    for (const material of materials) {
-      const source = await readSource(material);
-      if (!Buffer.isBuffer(source) || source.length === 0) {
-        throw new MaterialPreviewError("material_preview_source_missing");
+    const collectionHash = materialCollectionHash(materials, MATERIAL_PREVIEW_MERGER_VERSION);
+    const cacheKey = `${reimbursementId}:${collectionHash}:${MATERIAL_PREVIEW_MERGER_VERSION}`;
+    let artifact = artifacts.get(cacheKey);
+    if (!artifact) {
+      let pending = pendingArtifacts.get(cacheKey);
+      if (!pending) pending = (async () => {
+      const loaded = [];
+      let actualBytes = 0;
+      for (const material of materials) {
+        const source = await readSource(material);
+        if (!Buffer.isBuffer(source) || !source.length) throw new MaterialPreviewError("material_preview_source_missing");
+        actualBytes += source.length;
+        if (actualBytes > limits.maxSourceBytes) throw new MaterialPreviewError("material_preview_source_size_limit");
+        loaded.push({ ...material, source });
       }
-      actualSourceBytes += source.length;
-      if (actualSourceBytes > limits.maxSourceBytes) {
-        throw new MaterialPreviewError("material_preview_source_size_limit");
+      let generated;
+      try {
+        generated = await mergePdf(loaded);
+      } catch (error) {
+        if (error instanceof MaterialPreviewError) throw error;
+        throw new MaterialPreviewError(error?.message || "material_preview_merge_failed");
       }
-      const renderedPages = material.mimeType === "application/pdf"
-        ? await rasterizePdf(source)
-        : [await normalizeImage(source)];
-      for (let index = 0; index < renderedPages.length; index += 1) {
-        if (pages.length >= limits.maxPages) {
-          throw new MaterialPreviewError("material_preview_page_limit");
+      if (!Buffer.isBuffer(generated?.buffer) || !generated.buffer.length) {
+        throw new MaterialPreviewError("material_preview_merge_failed");
+      }
+      if (generated.buffer.length > limits.maxOutputBytes) throw new MaterialPreviewError("material_preview_output_size_limit");
+      if (cachedBytes + generated.buffer.length > limits.maxCacheBytes) {
+        pruneExpired();
+        if (cachedBytes + generated.buffer.length > limits.maxCacheBytes) {
+          throw new MaterialPreviewError("material_preview_cache_limit");
         }
-        const image = renderedPages[index];
-        outputBytes += image.length;
-        if (outputBytes > limits.maxOutputBytes) {
-          throw new MaterialPreviewError("material_preview_output_size_limit");
-        }
-        pages.push({
-          buffer: image,
-          materialId: material.id,
-          materialType: material.materialType,
-          materialIndex: material.materialIndex,
-          pageNumber: index + 1,
-        });
-      }
-    }
-
-    if (cachedBytes + outputBytes > limits.maxCacheBytes) {
-      pruneExpired();
-      if (cachedBytes + outputBytes > limits.maxCacheBytes) {
-        throw new MaterialPreviewError("material_preview_cache_limit");
       }
+      artifacts.set(cacheKey, generated);
+      cachedBytes += generated.buffer.length;
+      return generated;
+      })().finally(() => pendingArtifacts.delete(cacheKey));
+      pendingArtifacts.set(cacheKey, pending);
+      artifact = await pending;
     }
 
     const bundleId = randomUUID();
-    const bundle = { actorId, reimbursementId, expiresAt, outputBytes, pages };
-    bundles.set(bundleId, bundle);
-    cachedBytes += outputBytes;
+    const bundle = { actorId, reimbursementId, expiresAt, cacheKey, collectionHash, pageCount: artifact.pageCount };
+    grants.set(bundleId, bundle);
     const timer = setTimeout(() => deleteBundle(bundleId), Math.max(1, expiresAt - now()));
     timer.unref?.();
-    return { bundleId, bundle };
+    return { bundleId, bundle, fileSize: artifact.buffer.length };
   }
 
-  function getPage({ bundleId, pageIndex }) {
+  function getBundle({ bundleId }) {
     pruneExpired();
-    const bundle = bundles.get(bundleId);
-    if (!bundle || !Number.isInteger(pageIndex) || pageIndex < 0 || pageIndex >= bundle.pages.length) {
-      return null;
-    }
-    return { bundle, page: bundle.pages[pageIndex] };
+    const bundle = grants.get(bundleId);
+    const artifact = bundle ? artifacts.get(bundle.cacheKey) : null;
+    return bundle && artifact ? { bundle, artifact } : null;
   }
 
-  return { createBundle, getPage, deleteBundle };
+  return { createBundle, getBundle, deleteBundle };
 }
 
 module.exports = {
   MATERIAL_PREVIEW_LIMITS,
+  MATERIAL_PREVIEW_MERGER_VERSION,
   MaterialPreviewError,
   createReimbursementMaterialPreviewStore,
-  normalizePreviewImage,
-  rasterizePdfWithPoppler,
+  runMergeWorker,
 };

server/src/services/reimbursementMaterialPreviewWorker.js

@@ -0,0 +1,11 @@
+const { parentPort, workerData } = require("node:worker_threads");
+const { mergeMaterialsToPdf } = require("./reimbursementMaterialPdf");
+
+mergeMaterialsToPdf(workerData.materials, workerData.limits)
+  .then(({ buffer, pageCount }) => {
+    const bytes = Uint8Array.from(buffer);
+    parentPort.postMessage({ ok: true, bytes, pageCount }, [bytes.buffer]);
+  })
+  .catch((error) => {
+    parentPort.postMessage({ ok: false, code: error?.message || "material_preview_merge_failed" });
+  });