db.ts

import mongo from 'mongodb';

const MongoClient = mongo.MongoClient;
let client: mongo.MongoClient = null;
let db: mongo.Db = null;

type State = {
  _id: string;
  height: number;
};

const getDbo = async () => {
  if (db) {
    return db;
  }
  client = await MongoClient.connect(process.env.BMAP_MONGO_URL, {
    minPoolSize: 1,
    maxPoolSize: 10,
  });
  db = client.db('bmap');
  return db;
};

const closeDb = async () => {
  if (client !== null) {
    try {
      await client.close();
    } catch (_e) {
      console.error('Failed to close DB');
      return;
    }
    client = null;
  }
};

async function getCollectionCounts(fromTimestamp: number): Promise<Record<string, number>[]> {
  const dbo = await getDbo();
  const collections = await dbo.listCollections().toArray();

  const countPromises = collections.map(async (c) => {
    let count = 0;

    if (fromTimestamp) {
      const query = { timestamp: { $gt: fromTimestamp } };
      count = await dbo.collection(c.name).countDocuments(query);
    } else {
      count = await dbo.collection(c.name).estimatedDocumentCount();
    }
    return [c.name, count];
  });

  const countsArray = await Promise.all(countPromises);
  return Object.fromEntries(countsArray) as Record<string, number>[];
}

async function getCurrentBlockHeight(): Promise<number> {
  const _dbo = await getDbo();
  const state = await getState();
  return state ? state.height : 0;
}

async function getState(): Promise<State | undefined> {
  const dbo = await getDbo();
  return await dbo.collection('_state').findOne<State>({});
}

export { closeDb, getCollectionCounts, getCurrentBlockHeight, getDbo, getState };

// db.c.createIndex({
//   "MAP.app": 1,
//   "MAP.type": 1,
// })

// db.c.createIndex({
//   "MAP.app": 1,
//   "MAP.type": 1,
//   "blk.t": -1,
// })

// db.c.createIndex({
//   "MAP.app": 1,
//   "MAP.type": 1,
//   "blk.i": -1,
// })