tsk-19: Service login (#23)

Closes #19

Reviewed-on: phoenix/textsender-auth#23
Co-authored-by: phoenix <kundeng00@pm.me>
Co-committed-by: phoenix <kundeng00@pm.me>

internal/store/mock/service_store.go

@@ -3,11 +3,11 @@ package mock
 import (
 	"context"
 	"errors"
+	"fmt"
 	"sync"
 
-	"github.com/google/uuid"
-
 	"git.kundeng.us/phoenix/textsender-models/pkg/user"
+	"github.com/google/uuid"
 )
 
 type MockServiceUserStore struct {
@@ -53,10 +53,6 @@ func (m *MockServiceUserStore) CheckWithUsername(ctx context.Context, username s
 		return false, m.Error
 	}
 
-	if m.Error != nil {
-		return false, m.Error
-	}
-
 	var exists bool
 
 	for _, serviceUser := range m.ServiceUsers {
@@ -72,3 +68,19 @@ func (m *MockServiceUserStore) CheckWithUsername(ctx context.Context, username s
 		return exists, nil
 	}
 }
+
+func (m *MockServiceUserStore) GetWithUsername(ctx context.Context, username string) (*user.ServiceUser, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if m.Error != nil {
+		return nil, m.Error
+	}
+
+	serviceUser := m.ServiceUsersByUsername[username]
+	if serviceUser != nil {
+		return serviceUser, nil
+	} else {
+		return nil, fmt.Errorf("User not found")
+	}
+}

internal/store/service.go

@@ -11,6 +11,7 @@ import (
 
 type ServiceStore interface {
 	CheckWithUsername(ctx context.Context, username string) (bool, error)
+	GetWithUsername(ctx context.Context, username string) (*user.ServiceUser, error)
 	Create(ctx context.Context, serviceUser *user.ServiceUser) error
 }
 
@@ -37,6 +38,21 @@ func (s *PGServiceStore) CheckWithUsername(ctx context.Context, username string)
 	}
 }
 
+func (s *PGServiceStore) GetWithUsername(ctx context.Context, username string) (*user.ServiceUser, error) {
+	var serviceUser user.ServiceUser
+	query := `SELECT id, username, passphrase, created FROM service_users WHERE username = $1`
+
+	if err := s.db.QueryRow(ctx, query, username).Scan(&serviceUser.Id, &serviceUser.Username, &serviceUser.Passphrase, &serviceUser.Created); err != nil {
+		if err == pgx.ErrNoRows {
+			return nil, nil
+		} else {
+			return nil, fmt.Errorf("Error querying row: %v", err)
+		}
+	} else {
+		return &serviceUser, nil
+	}
+}
+
 func (s *PGServiceStore) Create(ctx context.Context, serviceUser *user.ServiceUser) error {
 	query := `
 		INSERT INTO service_users (username, passphrase)