Return success if adding a user who is already a friend.

	"encoding/json"

	"fmt"

	"go.uber.org/zap"

	"github.com/lib/pq"

)

func friendAdd(logger *zap.Logger, db *sql.DB, ns *NotificationService, userID string, handle string, friendID string) error {

func friendAdd(logger *zap.Logger, db *sql.DB, ns *NotificationService, userID string, handle string, friendID string) (err error) {

	tx, txErr := db.Begin()

	if txErr != nil {

		return txErr

	isFriendAccept := false

	updatedAt := nowMs()

	var err error

	defer func() {

		if err != nil {

			if rollbackErr := tx.Rollback(); rollbackErr != nil { // don't override value of err

				logger.Error("Could not rollback transaction", zap.Error(rollbackErr))

			}

			if e, ok := err.(*pq.Error); ok && e.Code == "23505" {

				// Ignore error if it is dbErrorUniqueViolation,

				// which is the case if we are adding users that already have a relationship.

				logger.Warn("CODE", zap.Any("code", e.Code), zap.String("msg", e.Message))

				err = nil

			}

		} else {

			if e := tx.Commit(); e != nil {

				logger.Error("Could not commit transaction", zap.Error(e))