initial commit

backend/db/db.go

@@ -0,0 +1,49 @@
+package db
+
+import (
+	"context"
+	"os"
+
+	"github.com/Masterminds/squirrel"
+	"github.com/jackc/pgx/v4/pgxpool"
+	"github.com/mediocregopher/radix/v4"
+)
+
+var sq = squirrel.StatementBuilder.PlaceholderFormat(squirrel.Dollar)
+
+type DB struct {
+	*pgxpool.Pool
+
+	Redis radix.Client
+}
+
+func New(dsn string) (*DB, error) {
+	pool, err := pgxpool.Connect(context.Background(), dsn)
+	if err != nil {
+		return nil, err
+	}
+
+	redis, err := (&radix.PoolConfig{}).New(context.Background(), "tcp", os.Getenv("REDIS"))
+	if err != nil {
+		return nil, err
+	}
+
+	db := &DB{
+		Pool:  pool,
+		Redis: redis,
+	}
+
+	return db, nil
+}
+
+// MultiCmd executes the given Redis commands in order.
+// If any return an error, the function is aborted.
+func (db *DB) MultiCmd(ctx context.Context, cmds ...radix.Action) error {
+	for _, cmd := range cmds {
+		err := db.Redis.Do(ctx, cmd)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

backend/db/user.go

@@ -0,0 +1,68 @@
+package db
+
+import (
+	"context"
+	"regexp"
+
+	"emperror.dev/errors"
+	"github.com/georgysavva/scany/pgxscan"
+	"github.com/jackc/pgconn"
+	"github.com/rs/xid"
+)
+
+type User struct {
+	ID          xid.ID
+	Username    string
+	DisplayName *string
+	Bio         *string
+
+	AvatarSource *string
+	AvatarURL    *string
+	Links        []string
+
+	Discord *string
+}
+
+// usernames must match this regex
+var usernameRegex = regexp.MustCompile(`[\w-.]{2,40}`)
+
+const (
+	ErrUsernameTaken = errors.Sentinel("username is already taken")
+
+	ErrInvalidUsername  = errors.Sentinel("username contains invalid characters")
+	ErrUsernameTooShort = errors.Sentinel("username is too short")
+	ErrUsernameTooLong  = errors.Sentinel("username is too long")
+)
+
+// CreateUser creates a user with the given username.
+func (db *DB) CreateUser(ctx context.Context, username string) (u User, err error) {
+	// check if the username is valid
+	// if not, return an error depending on what failed
+	if !usernameRegex.MatchString(username) {
+		if len(username) < 2 {
+			return u, ErrUsernameTooShort
+		} else if len(username) > 40 {
+			return u, ErrUsernameTooLong
+		}
+
+		return u, ErrInvalidUsername
+	}
+
+	sql, args, err := sq.Insert("users").Columns("id", "username").Values(xid.New(), username).Suffix("RETURNING *").ToSql()
+	if err != nil {
+		return u, errors.Wrap(err, "building sql")
+	}
+
+	err = pgxscan.Get(ctx, db, &u, sql, args...)
+	if err != nil {
+		if v, ok := errors.Cause(err).(*pgconn.PgError); ok {
+			if v.Code == "23505" { // unique constraint violation
+				return u, ErrUsernameTaken
+			}
+		}
+
+		return u, errors.Cause(err)
+	}
+
+	return u, nil
+}