#!/usr/bin/env ts-node
import {
  DocumentData,
  Firestore,
  QueryDocumentSnapshot,
} from '@google-cloud/firestore';
import { config as setupEnv } from 'dotenv-flow';
import { sequence } from '@/utils';
import connect from '../src/config/db';
setupEnv();

/**
 * @returns {Map<string,string>} a map mapping all root level keys for a
 * collection (`collectionName`) to an id, representing one object in that
 * collection that contains that key (to do further investigation into)
 */
const discoverSchema = async ({
  firestore,
  collectionName,
}: {
  firestore: Firestore;
  collectionName: string;
}): Promise<Map<string, string>> => {
  const schemaMap = new Map<string, string>();
  const collection = firestore.collection(collectionName);
  const documents = new Array<QueryDocumentSnapshot<DocumentData>>();
  const snapshot = await collection.get();
  snapshot.forEach((doc) => {
    documents.push(doc);
  });
  await sequence(
    documents.map((doc) => async () => {
      const data = await doc.data();
      Object.keys(data).forEach((key) => {
        schemaMap.set(key, doc.id);
      });
    })
  );
  return schemaMap;
};

const main = async () => {
  await connect();
  const firestore = new Firestore();
  const schema = await discoverSchema({ firestore, collectionName: 'pages' });
  Array.from(schema.keys()).forEach((key) => {
    console.log(`${key}:`, schema.get(key));
  });
};

main().catch((error) => {
  console.error(error);
  process.exit(1);
});