1 files changed, 94 insertions, 0 deletions
diff --git a/backend/auth/session.go b/backend/auth/session.go
new file mode 100644
index 0000000..f480bff
--- /dev/null
+++ b/backend/auth/session.go
@@ -0,0 +1,94 @@
+package auth
+
+import (
+	"errors"
+	"net/http"
+	"os"
+
+	"github.com/gorilla/sessions"
+	"github.com/labstack/echo-contrib/session"
+	"github.com/labstack/echo/v4"
+)
+
+const (
+	sessionName      = "feedaka_session"
+	sessionUserIDKey = "user_id"
+	// Session duration: 7 days
+	sessionMaxAge = 7 * 24 * 60 * 60
+)
+
+var (
+	ErrNoSession             = errors.New("no session found")
+	ErrNoUserIDInSession     = errors.New("no user_id in session")
+	ErrNoSessionSecretEnvVar = errors.New("FEEDAKA_SESSION_SECRET environment variable is not set")
+)
+
+type SessionConfig struct {
+	store *sessions.CookieStore
+}
+
+func NewSessionConfig() (*SessionConfig, error) {
+	secret := os.Getenv("FEEDAKA_SESSION_SECRET")
+	if secret == "" {
+		return nil, ErrNoSessionSecretEnvVar
+	}
+	useNonSecureCookie := os.Getenv("FEEDAKA_DEV_NON_SECURE_COOKIE") == "1"
+
+	store := sessions.NewCookieStore([]byte(secret))
+	store.Options = &sessions.Options{
+		Path:     "/",
+		MaxAge:   sessionMaxAge,
+		HttpOnly: true,
+		Secure:   !useNonSecureCookie,
+		SameSite: http.SameSiteDefaultMode,
+	}
+
+	return &SessionConfig{
+		store: store,
+	}, nil
+}
+
+func (c *SessionConfig) GetStore() *sessions.CookieStore {
+	return c.store
+}
+
+func (c *SessionConfig) SetUserID(ctx echo.Context, userID int64) error {
+	sess, err := session.Get(sessionName, ctx)
+	if err != nil {
+		return err
+	}
+
+	sess.Values[sessionUserIDKey] = userID
+	return sess.Save(ctx.Request(), ctx.Response())
+}
+
+func (c *SessionConfig) GetUserID(ctx echo.Context) (int64, error) {
+	sess, err := session.Get(sessionName, ctx)
+	if err != nil {
+		return 0, ErrNoSession
+	}
+
+	userIDVal, ok := sess.Values[sessionUserIDKey]
+	if !ok {
+		return 0, ErrNoUserIDInSession
+	}
+
+	userID, ok := userIDVal.(int64)
+	if !ok {
+		return 0, ErrNoUserIDInSession
+	}
+
+	return userID, nil
+}
+
+func (c *SessionConfig) DestroySession(ctx echo.Context) error {
+	sess, err := session.Get(sessionName, ctx)
+	if err != nil {
+		// If there's no session, nothing to destroy
+		return nil
+	}
+
+	// Set MaxAge to -1 to delete the session
+	sess.Options.MaxAge = -1
+	return sess.Save(ctx.Request(), ctx.Response())
+}