add frontend template + GET /users/{userRef} route

backend/db/user.go

@@ -5,8 +5,10 @@ import (
 	"regexp"
 
 	"emperror.dev/errors"
+	"github.com/bwmarrin/discordgo"
 	"github.com/georgysavva/scany/pgxscan"
 	"github.com/jackc/pgconn"
+	"github.com/jackc/pgx/v4"
 	"github.com/rs/xid"
 )
 
@@ -27,8 +29,9 @@ type User struct {
 var usernameRegex = regexp.MustCompile(`[\w-.]{2,40}`)
 
 const (
-	ErrUsernameTaken = errors.Sentinel("username is already taken")
+	ErrUserNotFound = errors.Sentinel("user not found")
 
+	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")
@@ -66,3 +69,69 @@ func (db *DB) CreateUser(ctx context.Context, username string) (u User, err erro
 
 	return u, nil
 }
+
+// DiscordUser fetches a user by Discord user ID.
+func (db *DB) DiscordUser(ctx context.Context, discordID string) (u User, err error) {
+	sql, args, err := sq.Select("*").From("users").Where("discord = ?", discordID).ToSql()
+	if err != nil {
+		return u, errors.Wrap(err, "building sql")
+	}
+
+	err = pgxscan.Get(ctx, db, &u, sql, args...)
+	if err != nil {
+		if errors.Cause(err) == pgx.ErrNoRows {
+			return u, ErrUserNotFound
+		}
+		return u, errors.Cause(err)
+	}
+
+	return u, nil
+}
+
+func (u *User) UpdateFromDiscord(ctx context.Context, db pgxscan.Querier, du *discordgo.User) error {
+	builder := sq.Update("users").
+		Set("discord_username", du.String()).
+		Where("id = ?", u.ID).
+		Suffix("RETURNING *")
+
+	if u.AvatarSource == nil || *u.AvatarSource == "discord" {
+		builder = builder.
+			Set("avatar_source", "discord").
+			Set("avatar_url", du.AvatarURL("1024"))
+	}
+
+	sql, args, err := builder.ToSql()
+	if err != nil {
+		return errors.Wrap(err, "building sql")
+	}
+
+	return pgxscan.Get(ctx, db, u, sql, args...)
+}
+
+// User gets a user by ID.
+func (db *DB) User(ctx context.Context, id xid.ID) (u User, err error) {
+	err = pgxscan.Get(ctx, db, &u, "select * from users where id = $1", id)
+	if err != nil {
+		if errors.Cause(err) == pgx.ErrNoRows {
+			return u, ErrUserNotFound
+		}
+
+		return u, errors.Cause(err)
+	}
+
+	return u, nil
+}
+
+// Username gets a user by username.
+func (db *DB) Username(ctx context.Context, name string) (u User, err error) {
+	err = pgxscan.Get(ctx, db, &u, "select * from users where username = $1", name)
+	if err != nil {
+		if errors.Cause(err) == pgx.ErrNoRows {
+			return u, ErrUserNotFound
+		}
+
+		return u, errors.Cause(err)
+	}
+
+	return u, nil
+}