func TestAcquireTimeoutSanity(t *testing.T) {
	t.Parallel()

	config := pgx.ConnPoolConfig{
		ConnConfig:     *defaultConnConfig,
		MaxConnections: 1,
	}

	// case 1: default 0 value
	pool, err := pgx.NewConnPool(config)
	if err != nil {
		t.Fatalf("Expected NewConnPool with default config.AcquireTimeout not to fail, instead it failed with '%v'", err)
	}
	pool.Close()

	// case 2: negative value
	config.AcquireTimeout = -1 * time.Second
	_, err = pgx.NewConnPool(config)
	if err == nil {
		t.Fatal("Expected NewConnPool with negative config.AcquireTimeout to fail, instead it did not")
	}

	// case 3: positive value
	config.AcquireTimeout = 1 * time.Second
	pool, err = pgx.NewConnPool(config)
	if err != nil {
		t.Fatalf("Expected NewConnPool with positive config.AcquireTimeout not to fail, instead it failed with '%v'", err)
	}
	defer pool.Close()
}

func getConfig() pgx.ConnPoolConfig {
	var err interface{}
	var connPoolConfig pgx.ConnPoolConfig

	connPoolConfig.ConnConfig, err = pgx.ParseEnvLibpq()
	if err != nil {
		log.Fatalf("Postgresql connection information missing from the environment: %v", err)
	}
	connPoolConfig.MaxConnections = 10

	return connPoolConfig
}

func createConnPool() (*pgx.ConnPool, error) {
	var config pgx.ConnPoolConfig
	var err error
	config.ConnConfig, err = pgx.ParseEnvLibpq()
	if err != nil {
		return nil, err
	}

	if config.Host == "" {
		config.Host = "localhost"
	}

	if config.User == "" {
		config.User = os.Getenv("USER")
	}

	if config.Database == "" {
		config.Database = "pgxdata"
	}

	config.TLSConfig = nil
	config.UseFallbackTLS = false
	config.MaxConnections = 10

	return pgx.NewConnPool(config)
}

func initDatabase(dbHost string, dbUser string, dbPass string, dbName string, dbPort uint16, maxConnectionsInPool int) (*pgx.ConnPool, error) {

	var successOrFailure string = "OK"

	var config pgx.ConnPoolConfig

	config.Host = dbHost
	config.User = dbUser
	config.Password = dbPass
	config.Database = dbName
	config.Port = dbPort

	config.MaxConnections = maxConnectionsInPool

	config.AfterConnect = func(eachConn *pgx.Conn) error {

		worldSelectStmt = mustPrepare(eachConn, "worldSelectStmt", "SELECT id, randomNumber FROM World WHERE id = $1")
		worldUpdateStmt = mustPrepare(eachConn, "worldUpdateStmt", "UPDATE World SET randomNumber = $1 WHERE id = $2")
		fortuneSelectStmt = mustPrepare(eachConn, "fortuneSelectStmt", "SELECT id, message FROM Fortune")

		return nil
	}

	fmt.Println("--------------------------------------------------------------------------------------------")

	connPool, err := pgx.NewConnPool(config)
	if err != nil {
		successOrFailure = "FAILED"
		log.Println("Connecting to database ", dbName, " as user ", dbUser, " ", successOrFailure, ": \n ", err)
	} else {
		log.Println("Connecting to database ", dbName, " as user ", dbUser, ": ", successOrFailure)

		log.Println("Fetching one record to test if db connection is valid...")
		var w World
		n := randomWorldNum()
		if errPing := connPool.QueryRow("worldSelectStmt", n).Scan(&w.Id, &w.RandomNumber); errPing != nil {
			log.Fatalf("Error scanning world row: %s", errPing)
		}
		log.Println("OK")
	}

	fmt.Println("--------------------------------------------------------------------------------------------")

	return connPool, err

}

func initDatabase(dbHost string, dbUser string, dbPass string, dbName string, dbPort uint16, maxConnectionsInPool int) (*pgx.ConnPool, error) {

	var successOrFailure string = "OK"

	var config pgx.ConnPoolConfig

	config.Host = dbHost
	config.User = dbUser
	config.Password = dbPass
	config.Database = dbName
	config.Port = dbPort

	config.MaxConnections = maxConnectionsInPool

	config.AfterConnect = func(conn *pgx.Conn) error {
		worldSelectStmt = mustPrepare(conn, "worldSelectStmt", "SELECT id, randomNumber FROM World WHERE id = $1")
		worldUpdateStmt = mustPrepare(conn, "worldUpdateStmt", "UPDATE World SET randomNumber = $1 WHERE id = $2")
		fortuneSelectStmt = mustPrepare(conn, "fortuneSelectStmt", "SELECT id, message FROM Fortune")

		// Disable synchronous commit for the current db connection
		// as a performance optimization.
		// See http://www.postgresql.org/docs/current/static/runtime-config-wal.html
		// for details.
		if _, err := conn.Exec("SET synchronous_commit TO OFF"); err != nil {
			log.Fatalf("Error when disabling synchronous commit")
		}

		return nil
	}

	fmt.Println("--------------------------------------------------------------------------------------------")

	connPool, err := pgx.NewConnPool(config)
	if err != nil {
		successOrFailure = "FAILED"
		log.Println("Connecting to database ", dbName, " as user ", dbUser, " ", successOrFailure, ": \n ", err)
	} else {
		log.Println("Connecting to database ", dbName, " as user ", dbUser, ": ", successOrFailure)

		log.Println("Fetching one record to test if db connection is valid...")
		var w World
		n := randomWorldNum()
		if errPing := connPool.QueryRow("worldSelectStmt", n).Scan(&w.Id, &w.RandomNumber); errPing != nil {
			log.Fatalf("Error scanning world row: %s", errPing)
		}
		log.Println("OK")
	}

	fmt.Println("--------------------------------------------------------------------------------------------")

	return connPool, err

}

func extractConfig() pgx.ConnPoolConfig {
	var config pgx.ConnPoolConfig

	config.Host = os.Getenv("CHAT_DB_HOST")
	if config.Host == "" {
		config.Host = "localhost"
	}

	config.User = os.Getenv("CHAT_DB_USER")
	if config.User == "" {
		config.User = os.Getenv("USER")
	}

	config.Password = os.Getenv("CHAT_DB_PASSWORD")

	config.Database = os.Getenv("CHAT_DB_DATABASE")
	if config.Database == "" {
		config.Database = "postgres"
	}

	return config
}