package identity

import (
	"context"
	"errors"
	"strings"
	"unicode"
	"unicode/utf8"
)

var ErrInvalidDisplayName = errors.New("invalid display name")

func ValidateDisplayName(name string) (string, error) {
	name = strings.TrimSpace(name)
	if !utf8.ValidString(name) || utf8.RuneCountInString(name) < 1 || utf8.RuneCountInString(name) > 80 {
		return "", ErrInvalidDisplayName
	}
	for _, r := range name {
		if unicode.IsControl(r) {
			return "", ErrInvalidDisplayName
		}
	}
	return name, nil
}

// The principal comes from authenticated middleware. Callers cannot select another account.
func (r *Repository) UpdateDisplayName(ctx context.Context, principal Principal, name string) error {
	name, err := ValidateDisplayName(name)
	if err != nil {
		return err
	}
	if principal.Issuer == "" || principal.Subject == "" {
		return ErrAccessDenied
	}
	result, err := r.pool.Exec(ctx, `UPDATE user_account ua SET display_name=$3, updated_at=now()
 FROM tenant t WHERE ua.tenant_id=t.id AND t.status='active' AND ua.status='active'
 AND ua.oidc_issuer=$1 AND ua.oidc_subject=$2`, principal.Issuer, principal.Subject, name)
	if err != nil {
		return err
	}
	if result.RowsAffected() == 0 {
		return ErrAccountNotFound
	}
	return nil
}