feat(workflow): add altenate merge tool and translate workflow node and engine errors across locales

src/js/workflow/nodes/alternate-merge-node.ts

@@ -0,0 +1,50 @@
+import { ClassicPreset } from 'rete';
+import { BaseWorkflowNode } from './base-node';
+import { pdfSocket } from '../sockets';
+import type { SocketData } from '../types';
+import { extractAllPdfs } from '../types';
+import { interleavePdfs } from '../../utils/alternate-merge.js';
+import { loadPdfDocument } from '../../utils/load-pdf-document.js';
+import { wfError } from '../errors';
+
+export class AlternateMergeNode extends BaseWorkflowNode {
+  readonly category = 'Organize & Manage' as const;
+  readonly icon = 'ph-shuffle';
+  readonly description = 'Interleave pages from multiple PDFs';
+
+  constructor() {
+    super('Alternate Merge');
+    this.addInput('pdf', new ClassicPreset.Input(pdfSocket, 'PDFs', true));
+    this.addOutput(
+      'pdf',
+      new ClassicPreset.Output(pdfSocket, 'Interleaved PDF')
+    );
+  }
+
+  async data(
+    inputs: Record<string, SocketData[]>
+  ): Promise<Record<string, SocketData>> {
+    const allInputs = Object.values(inputs).flat();
+    const allPdfs = extractAllPdfs(allInputs);
+    if (allPdfs.length < 2) {
+      throw new Error(wfError('alternateMergeNeedsTwo'));
+    }
+
+    const filesToMerge = allPdfs.map((p) => ({
+      name: p.filename,
+      data: p.bytes.slice().buffer as ArrayBuffer,
+    }));
+
+    const mergedBytes = await interleavePdfs(filesToMerge);
+    const document = await loadPdfDocument(mergedBytes);
+
+    return {
+      pdf: {
+        type: 'pdf',
+        document,
+        bytes: mergedBytes,
+        filename: 'alternated-mixed.pdf',
+      },
+    };
+  }
+}