feat(tools): 2.0 phase 5 wave 2 - pdf depth (21 tools) (#220)

apps/api/src/routes/tools/remove-pages.ts

@@ -0,0 +1,61 @@
+import { writeFile } from "node:fs/promises";
+import { join } from "node:path";
+import { qpdfPageCount, qpdfPagesSpecUnchecked } from "@snapotter/doc-engine";
+import type { FastifyInstance } from "fastify";
+import { z } from "zod";
+import { compressPageRuns, parsePageSpec } from "../../lib/page-spec.js";
+import { createToolRoute } from "../tool-factory.js";
+
+const rangeField = z
+  .string()
+  .max(200)
+  .regex(/^[0-9rz][0-9rz,-]*$/i, "Invalid page range");
+
+const settingsSchema = z.object({
+  pages: rangeField,
+});
+
+export function registerRemovePages(app: FastifyInstance) {
+  createToolRoute(app, {
+    toolId: "remove-pages",
+    settingsSchema,
+    process: async () => {
+      throw new Error("remove-pages is v2-only");
+    },
+    processV2: async (ctx) => {
+      const settings = settingsSchema.parse(ctx.settings);
+      const input = ctx.inputs[0];
+      const base = input.filename.replace(/\.[^.]+$/, "");
+      const inPath = join(ctx.scratchDir, `in-${input.filename.replace(/[^A-Za-z0-9._-]/g, "_")}`);
+      await writeFile(inPath, input.buffer);
+
+      ctx.report(10, "Analyzing pages");
+      const total = await qpdfPageCount(inPath);
+      const removeSet = parsePageSpec(settings.pages, total);
+
+      // Build the keep list: all pages NOT in the remove set
+      const keepPages: number[] = [];
+      for (let i = 1; i <= total; i++) {
+        if (!removeSet.has(i)) {
+          keepPages.push(i);
+        }
+      }
+
+      if (keepPages.length === 0) {
+        throw new Error("Cannot remove every page from the document");
+      }
+
+      const keepSpec = compressPageRuns(keepPages);
+      const outPath = join(ctx.scratchDir, `${base}_removed.pdf`);
+      ctx.report(30, "Removing pages");
+      await qpdfPagesSpecUnchecked(inPath, keepSpec, outPath);
+      ctx.report(90, "Done");
+
+      return {
+        scratchPath: outPath,
+        filename: `${base}_removed.pdf`,
+        contentType: "application/pdf",
+      };
+    },
+  });
+}