add get ticket

internal/services/ticket_service/service.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"net/url"
 	"strings"
+	"time"
 
 	"evening_detective_server/internal/repos/tickets_repo"
 )
@@ -18,6 +19,7 @@ const maxTicketsPerRequest = 100
 var (
 	ErrInvalidTicketCount = errors.New("количество билетов должно быть от 1 до 100")
 	ErrInvalidBaseURL     = errors.New("необходимо настроить APP_BASE_URL — публичный адрес приложения")
+	ErrTicketNotFound     = tickets_repo.ErrTicketNotFound
 )
 
 type Ticket struct {
@@ -25,6 +27,16 @@ type Ticket struct {
 	URL string
 }
 
+type Page struct {
+	ID         int
+	Status     string
+	GameName   string
+	StartAt    time.Time
+	Location   *string
+	GameStatus string
+	UsedAt     *time.Time
+}
+
 type Service struct {
 	repo       *tickets_repo.Repo
 	appBaseURL string
@@ -71,6 +83,26 @@ func (s *Service) Issue(ctx context.Context, gameID, count int) ([]*Ticket, erro
 	return tickets, nil
 }
 
+func (s *Service) Get(ctx context.Context, token string) (*Page, error) {
+	hash, err := tokenHash(token)
+	if err != nil {
+		return nil, ErrTicketNotFound
+	}
+	info, err := s.repo.GetByHash(ctx, hash)
+	if err != nil {
+		return nil, err
+	}
+	return &Page{
+		ID:         info.ID,
+		Status:     info.Status,
+		GameName:   info.GameName,
+		StartAt:    info.StartAt,
+		Location:   info.Location,
+		GameStatus: info.GameStatus,
+		UsedAt:     info.UsedAt,
+	}, nil
+}
+
 func newToken() (string, error) {
 	data := make([]byte, 32)
 	if _, err := rand.Read(data); err != nil {
@@ -79,6 +111,15 @@ func newToken() (string, error) {
 	return base64.RawURLEncoding.EncodeToString(data), nil
 }
 
+func tokenHash(token string) ([]byte, error) {
+	data, err := base64.RawURLEncoding.DecodeString(token)
+	if err != nil || len(data) != 32 {
+		return nil, ErrTicketNotFound
+	}
+	hash := sha256.Sum256([]byte(token))
+	return hash[:], nil
+}
+
 func parseBaseURL(value string) (*url.URL, error) {
 	base, err := url.Parse(strings.TrimSpace(value))
 	if err != nil || base.Host == "" || (base.Scheme != "http" && base.Scheme != "https") || base.User != nil || base.RawQuery != "" || base.Fragment != "" {