Export everything about a person

import { mkdir, writeFile } from "node:fs/promises";

const API = "https://api.replyful.com";
const headers = { Authorization: `Bearer ${process.env.REPLYFUL_API_KEY}` };

// Calls the API. On 429 it waits as long as Retry-After says, then tries again.
async function call(path, init) {
  for (;;) {
    const res = await fetch(`${API}${path}`, { headers, ...init });
    if (res.status !== 429) {
      return res;
    }
    const seconds = Number(res.headers.get("Retry-After") ?? "1");
    await new Promise((resolve) => setTimeout(resolve, seconds * 1000));
  }
}

// Returns every item of a list by following nextCursor.
async function listAll(path) {
  const items = [];
  let cursor = null;
  do {
    const url = new URL(path, API);
    url.searchParams.set("limit", "100");
    if (cursor) {
      url.searchParams.set("startingAfter", cursor);
    }
    const res = await call(url.pathname + url.search);
    if (!res.ok) {
      throw new Error(`${path}: ${res.status} ${await res.text()}`);
    }
    const page = await res.json();
    items.push(...page.data);
    cursor = page.hasMore ? page.nextCursor : null;
  } while (cursor);
  return items;
}

// Asks the API for a download link, then fetches the file without the API key.
async function download(attachment, dir) {
  const res = await call(`/v1/attachments/${attachment.id}/content`, {
    redirect: "manual",
  });
  const location = res.headers.get("Location");
  if (res.status !== 302 || !location) {
    throw new Error(`Attachment ${attachment.id}: ${res.status}`);
  }
  const file = await fetch(location);
  if (!file.ok) {
    throw new Error(`Attachment ${attachment.id}: download failed`);
  }
  const name = `${attachment.id}-${attachment.filename.replace(/[^\w.-]/g, "_")}`;
  await writeFile(`${dir}/${name}`, Buffer.from(await file.arrayBuffer()));
}

async function exportContact(contact) {
  const dir = `export/${contact.id}`;
  await mkdir(`${dir}/attachments`, { recursive: true });

  const sessions = await listAll(`/v1/contacts/${contact.id}/sessions`);

  const tickets = await listAll(
    `/v1/tickets?contactId=${contact.id}&sort=createdAt`,
  );
  for (const ticket of tickets) {
    for (const conversation of ticket.conversations) {
      conversation.messages = await listAll(
        `/v1/conversations/${conversation.id}/messages`,
      );
      for (const message of conversation.messages) {
        for (const attachment of message.attachments) {
          await download(attachment, `${dir}/attachments`);
        }
      }
    }
  }

  await writeFile(
    `${dir}/export.json`,
    JSON.stringify({ contact, sessions, tickets }, null, 2),
  );
  console.log(`${contact.id}: ${tickets.length} tickets, saved to ${dir}`);
}

const email = process.argv[2];
if (!email) {
  throw new Error("Usage: node export-contact.mjs <email>");
}

// Can be more than one contact, see "Good to know".
const contacts = await listAll(`/v1/contacts?email=${encodeURIComponent(email)}`);
for (const contact of contacts) {
  await exportContact(contact);
}
console.log(`Exported ${contacts.length} contact(s).`);