package main

import (
	"context"
	"fmt"
	"log"
	"net/http"
	_ "net/http/pprof"
	"runtime"
	"time"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	go func() {
		log.Println(http.ListenAndServe("localhost:8080", nil))
	}()

	ctx := context.Background()
	uri := "mongodb://localhost:27017"
	opts := options.Client().ApplyURI(uri).SetCompressors([]string{"zstd"})

	client, err := mongo.Connect(ctx, opts)
	if err != nil {
		log.Fatalf("Error connecting to mongo server: %v", err)
	}
	defer func() {
		if err = client.Disconnect(ctx); err != nil {
			panic(err)
		}
	}()

	connectCtx, cancel := context.WithTimeout(ctx, time.Second*5)
	defer cancel()
	if err := client.Ping(connectCtx, nil); err != nil {
		log.Fatalf("Error pinging mongo server: %v\n", err)
	}

	type TestStruct struct {
		X string `bson:"x"`
	}
	collection := client.Database("leaktest").Collection("testcollection")
	if _, err := collection.InsertOne(ctx, TestStruct{X: "123"}); err != nil {
		log.Fatalf("Error intializing collection: %v\n", err)
	}

	for i := 0; i < 30; i++ {
		var doc TestStruct
		if err := collection.FindOne(ctx, bson.M{"x": "123"}).Decode(&doc); err != nil {
			log.Fatalf("Error fetching document: %v\n", err)
		}
		time.Sleep(1 * time.Second)
		runtime.GC()
		fmt.Printf("Goroutines: %d\n", runtime.NumGoroutine())
	}
}

go tool pprof -top http://localhost:8080/debug/pprof/goroutine
File: main
Type: goroutine
Time: Sep 12, 2024 at 1:39pm (PDT)
Showing nodes accounting for 388, 100% of 388 total
      flat  flat%   sum%        cum   cum%
       387 99.74% 99.74%        387 99.74%  runtime.gopark
         1  0.26%   100%          1  0.26%  runtime.goroutineProfileWithLabels
         0     0%   100%        378 97.42%  github.com/klauspost/compress/zstd.(*blockDec).startDecoder
         0     0%   100%          1  0.26%  go.mongodb.org/mongo-driver/x/mongo/driver.Operation.ExecuteExhaust
         0     0%   100%          1  0.26%  go.mongodb.org/mongo-driver/x/mongo/driver.Operation.readWireMessage
         0     0%   100%          1  0.26%  go.mongodb.org/mongo-driver/x/mongo/driver/operation.(*Hello).StreamResponse
         0     0%   100%          1  0.26%  go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*Server).check
         0     0%   100%          1  0.26%  go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*Server).update
         0     0%   100%          1  0.26%  go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*cancellListener).Listen
         0     0%   100%          1  0.26%  go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*connection).read
         0     0%   100%          1  0.26%  go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*connection).readWireMessage
         0     0%   100%          2  0.52%  go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*pool).createConnections
         0     0%   100%          2  0.52%  go.mongodb.org/mongo-driver/x/mongo/driver/topology.(*pool).createConnections.func2