import {
  Bson,
  MongoClient,
} from "https://deno.land/x/mongo@LATEST_VERSION/mod.ts";

const client = new MongoClient();
// Connecting to a Local Database
await client.connect("mongodb://127.0.0.1:27017");
// Connecting to a Mongo Atlas Database
await client.connect({
  db: "<db_name>",
  tls: true,
  servers: [
    {
      host: "<db_cluster_url>",
      port: 27017,
    },
  ],
  credential: {
    username: "<username>",
    password: "<password>",
    db: "<db_name>",
    mechanism: "SCRAM-SHA-1",
  },
});
// Connect using srv url
await client.connect(
  "mongodb+srv://<username>:<password>@<db_cluster_url>/<db_name>?authMechanism=SCRAM-SHA-1",
);

// Defining schema interface
interface UserSchema {
  _id: ObjectId;
  username: string;
  password: string;
}
const db = client.database("test");
const users = db.collection<UserSchema>("users");

const insertId = await users.insertOne({
  username: "user1",
  password: "pass1",
});
const insertIds = await users.insertMany([
  {
    username: "user1",
    password: "pass1",
  },
  {
    username: "user2",
    password: "pass2",
  },
]);

const user1 = await users.findOne({ _id: insertId });
const all_users = await users.find({ username: { $ne: null } }).toArray();
// find by ObjectId
const user1_id = await users.findOne({
  _id: new ObjectId("SOME OBJECTID STRING"),
});

const count = await users.countDocuments({ username: { $ne: null } });
const estimatedCount = await users.estimatedDocumentCount({
  username: { $ne: null },
});

const docs = await users.aggregate([
  { $match: { username: "many" } },
  { $group: { _id: "$username", total: { $sum: 1 } } },
]).toArray();

const { matchedCount, modifiedCount, upsertedId } = await users.updateOne(
  { username: { $ne: null } },
  { $set: { username: "USERNAME" } },
);
const { matchedCount, modifiedCount, upsertedId } = await users.updateMany(
  { username: { $ne: null } },
  { $set: { username: "USERNAME" } },
);

const { matchedCount, modifiedCount, upsertedId } = await users.replaceOne(
  { username: "a" },
  {
    username: "user1",
    password: "pass1",
  }, // new document
);

const deleteCount = await users.deleteOne({ _id: insertId });
const deleteCount2 = await users.deleteMany({ username: "test" });

const cursor = users.find();
// Skip & Limit
cursor.skip(10).limit(10);
// iterate results
for await (const user of cursor) {
  console.log(user);
}
// or save results to array (uses more memory)
const users = await cursor.toArray();

// Upload
const bucket = new GridFSBucket(db);
const upstream = bucket.openUploadStream("test.txt");
const writer = upstream.getWriter();
writer.write(fileContents);
await writer.close();
// Download
const file = await new Response(bucket.openDownloadStream(id)).text();