feat(domains): migrate upload_file (safeJs), download (validated dir), print_to_pdf

1 files changed, 186 insertions, 0 deletions

diff --git a/src/domains/files.ts b/src/domains/files.ts
new file mode 100644
index 0000000..f0cb6b0
--- /dev/null
+++ b/src/domains/files.ts
@@ -0,0 +1,186 @@
+import { access, constants, stat, readFile, writeFile } from "node:fs/promises";
+import { basename } from "node:path";
+import { Type } from "typebox";
+import type { BrowserClient } from "../client";
+import { type Result, err, ok } from "../util/result";
+import { defineBrowserTool, type ToolErr, type ToolOk } from "../util/tool";
+import { safeJs } from "../util/js-template";
+import { pdfPath } from "../util/paths";
+
+const UploadArgs = Type.Object({
+  selector: Type.String({ description: "CSS selector of the file <input>" }),
+  filePath: Type.String({ description: "Absolute path to the file to upload" }),
+});
+
+const verifyReadable = async (filePath: string): Promise<Result<void, ToolErr>> => {
+  try {
+    await access(filePath, constants.R_OK);
+    return ok(undefined);
+  } catch (e) {
+    return err({
+      kind: "io_error",
+      message: `Cannot read file: ${filePath} (${e instanceof Error ? e.message : String(e)})`,
+    });
+  }
+};
+
+const tryCdpUpload = async (
+  client: BrowserClient,
+  selector: string,
+  filePath: string,
+): Promise<Result<void, ToolErr>> => {
+  const doc = await client.session().call("DOM.getDocument", { depth: -1 });
+  if (!doc.success) return err({ kind: "cdp_error", message: doc.error.message });
+  // CDP boundary cast: DOM.getDocument returns { root: { nodeId: number } }
+  const root = (doc.data as { root: { nodeId: number } }).root;
+  const q = await client.session().call("DOM.querySelector", { nodeId: root.nodeId, selector });
+  if (!q.success) return err({ kind: "cdp_error", message: q.error.message });
+  // CDP boundary cast: DOM.querySelector returns { nodeId: number }
+  const nodeId = (q.data as { nodeId: number }).nodeId;
+  if (!nodeId) return err({ kind: "invalid_state", message: `Selector matched 0 file inputs: ${selector}` });
+  const set = await client.session().call("DOM.setFileInputFiles", { files: [filePath], nodeId });
+  if (!set.success) return err({ kind: "cdp_error", message: set.error.message });
+  const verify = await client.evaluateJs(safeJs`document.querySelector(${selector})?.files?.length || 0`);
+  if (!verify.success) return err({ kind: "cdp_error", message: verify.error.message });
+  if (Number(verify.data ?? 0) === 0) {
+    return err({ kind: "invalid_state", message: "CDP upload reported success but file count is 0" });
+  }
+  return ok(undefined);
+};
+
+const inferMime = (name: string): string => {
+  if (name.endsWith(".png")) return "image/png";
+  if (name.endsWith(".jpg") || name.endsWith(".jpeg")) return "image/jpeg";
+  if (name.endsWith(".pdf")) return "application/pdf";
+  if (name.endsWith(".json")) return "application/json";
+  return "text/plain";
+};
+
+const jsFallbackUpload = async (
+  client: BrowserClient,
+  selector: string,
+  filePath: string,
+): Promise<Result<void, ToolErr>> => {
+  const buf = await readFile(filePath);
+  const st = await stat(filePath);
+  const name = basename(filePath);
+  const mime = inferMime(name);
+  const expr = safeJs`
+    (() => {
+      const input = document.querySelector(${selector});
+      if (!input || input.type !== 'file') throw new Error('File input not found');
+      const bin = atob(${buf.toString("base64")});
+      const bytes = new Uint8Array(bin.length);
+      for (let i = 0; i < bin.length; i++) bytes[i] = bin.charCodeAt(i);
+      const file = new File([bytes], ${name}, { type: ${mime}, lastModified: ${st.mtimeMs} });
+      const dt = new DataTransfer();
+      dt.items.add(file);
+      input.files = dt.files;
+      input.dispatchEvent(new Event('change', { bubbles: true }));
+      return input.files.length;
+    })()
+  `;
+  const r = await client.evaluateJs(expr);
+  if (!r.success) return err({ kind: "cdp_error", message: r.error.message });
+  if (!Number(r.data ?? 0)) return err({ kind: "invalid_state", message: "JS fallback set 0 files" });
+  return ok(undefined);
+};
+
+export const uploadFileTool = defineBrowserTool({
+  name: "browser_upload_file",
+  label: "Browser Upload File",
+  description: "Set files on a file <input> via CDP, with a JS-DataTransfer fallback for stubborn pages.",
+  promptSnippet: "Upload a file to a file input",
+  promptGuidelines: [
+    "File path must be absolute and readable.",
+    "Selector must match a file input.",
+  ],
+  parameters: UploadArgs,
+  async handler(args, { client }): Promise<Result<ToolOk, ToolErr>> {
+    const readable = await verifyReadable(args.filePath);
+    if (!readable.success) return readable;
+    const cdp = await tryCdpUpload(client, args.selector, args.filePath);
+    if (cdp.success) {
+      return ok({
+        text: `Uploaded ${args.filePath} via CDP`,
+        details: { mode: "cdp", filePath: args.filePath },
+      });
+    }
+    const js = await jsFallbackUpload(client, args.selector, args.filePath);
+    if (js.success) {
+      return ok({
+        text: `Uploaded ${args.filePath} via JS DataTransfer`,
+        details: { mode: "js", filePath: args.filePath },
+      });
+    }
+    return err({
+      kind: "cdp_error",
+      message: `Both CDP and JS fallback failed. CDP: ${cdp.error.message}; JS: ${js.error.message}`,
+    });
+  },
+});
+
+const DownloadArgs = Type.Object({
+  downloadPath: Type.String({ description: "Absolute path to a writable directory where downloads should be saved" }),
+});
+
+export const downloadTool = defineBrowserTool({
+  name: "browser_download",
+  label: "Browser Download",
+  description: "Configure Chrome's download behavior: set the save directory and disable the save-as prompt.",
+  promptSnippet: "Configure download directory",
+  promptGuidelines: [
+    "Pass an absolute path to an existing writable directory.",
+    "Affects all subsequent downloads on this browser.",
+  ],
+  parameters: DownloadArgs,
+  async handler(args, { client }): Promise<Result<ToolOk, ToolErr>> {
+    try {
+      const s = await stat(args.downloadPath);
+      if (!s.isDirectory()) {
+        return err({ kind: "io_error", message: `Not a directory: ${args.downloadPath}` });
+      }
+      await access(args.downloadPath, constants.W_OK);
+    } catch (e) {
+      return err({
+        kind: "io_error",
+        message: `Download path unusable: ${e instanceof Error ? e.message : String(e)}`,
+      });
+    }
+    const r = await client.session().callBrowser("Browser.setDownloadBehavior", {
+      behavior: "allow",
+      downloadPath: args.downloadPath,
+      eventsEnabled: true,
+    });
+    if (!r.success) return err({ kind: "cdp_error", message: r.error.message });
+    return ok({
+      text: `Downloads will save to: ${args.downloadPath}`,
+      details: { downloadPath: args.downloadPath },
+    });
+  },
+});
+
+const PrintPdfArgs = Type.Object({
+  outputPath: Type.Optional(Type.String({ description: "Where to save the PDF. Default: tmpdir + uuid." })),
+});
+
+export const printToPdfTool = defineBrowserTool({
+  name: "browser_print_to_pdf",
+  label: "Browser Print to PDF",
+  description: "Print the current page to a PDF file using Chrome's Page.printToPDF.",
+  promptSnippet: "Print the current page to PDF",
+  promptGuidelines: ["Default output path is in tmpdir; pass outputPath to control."],
+  parameters: PrintPdfArgs,
+  async handler(args, { client }): Promise<Result<ToolOk, ToolErr>> {
+    const r = await client.session().call("Page.printToPDF", {
+      printBackground: true,
+      preferCSSPageSize: true,
+    });
+    if (!r.success) return err({ kind: "cdp_error", message: r.error.message });
+    // CDP boundary cast: Page.printToPDF returns { data: string } (base64-encoded PDF)
+    const data = (r.data as { data: string }).data;
+    const path = args.outputPath ?? pdfPath(client.namespace);
+    await writeFile(path, Buffer.from(data, "base64"));
+    return ok({ text: `PDF saved: ${path}`, details: { path } });
+  },
+});