package main

import (
	"context"
	"fmt"
	"github.com/mongodb/mongo-go-driver/mongo"
	"log"
	"os"
)

var (
	host, username, password, database string
)

type key string

const (
	hostKey     = key("hostKey")
	usernameKey = key("usernameKey")
	passwordKey = key("passwordKey")
	databaseKey = key("databaseKey")
)

func init() {
	host = os.Getenv("TODO_MONGO_HOST")
	username = os.Getenv("TODO_MONGO_USERNAME")
	password = os.Getenv("TODO_MONGO_PASSWORD")
	database = os.Getenv("TODO_MONGO_DATABASE")
}

func main() {
	ctx := context.Background()
	ctx = context.WithValue(ctx, hostKey, host)
	ctx = context.WithValue(ctx, usernameKey, username)
	ctx = context.WithValue(ctx, passwordKey, password)
	ctx = context.WithValue(ctx, databaseKey, database)
	_, err := configDB(ctx)
	if err != nil {
		log.Fatalf("todo: database configuration failed: %v", err)
	}
}

func configDB(ctx context.Context) (*mongo.Database, error) {
	client, err := mongo.NewClient(fmt.Sprintf(
		`mongodb://%s:%s@%s/%s`,
		ctx.Value(usernameKey),
		ctx.Value(passwordKey),
		ctx.Value(hostKey),
		ctx.Value(databaseKey),
	))
	if err != nil {
		return nil, fmt.Errorf("todo: couldn't connect to mongo: %v", err)
	}
	err = client.Connect(ctx)
	if err != nil {
		return nil, fmt.Errorf("todo: mongo client couldn't connect with background context: %v", err)
	}
	todoDB := client.Database("todo")
	fmt.Println("connection string:", client.ConnectionString())
	return todoDB, nil
}