// Package database define database operation functions
package database

import (
	"context"
	"sync"
	"time"

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

var (
	mongoOnce          sync.Once
	_globalMongoClient *mongo.Client
	_globalMongoMu     sync.RWMutex
)

// MongoDBClient returns the global MongoDB client.It's safe for concurrent use.
func MongoDBClient() *mongo.Client {
	_globalMongoMu.RLock()
	client := _globalMongoClient
	_globalMongoMu.RUnlock()
	return client
}

// GetMongoDBInstance return instance of MongoDB client
func GetMongoDBInstance(ctx context.Context, mongoDBURI string) *mongo.Client {
	mongoOnce.Do(func() {
		_globalMongoClient = initMongoDBClient(ctx, mongoDBURI)
	})
	return _globalMongoClient
}

// initMongoDBClient return successfully initialized MongoDB client
func initMongoDBClient(ctx context.Context, mongoDBURI string) *mongo.Client {
	ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
	defer cancel()
	mongoDBClient, err := mongo.Connect(ctx, options.Client().ApplyURI(mongoDBURI))
	if err != nil {
		panic(err)
	}
	return mongoDBClient
}