feat: complete cmpp platform phases 0-5

gateway/internal/connection/reconnector.go

@@ -0,0 +1,44 @@
+package connection
+
+import (
+	"context"
+	"time"
+)
+
+type DialFunc func(context.Context) error
+
+type Reconnector struct {
+	MaxAttempts int
+	Delay       time.Duration
+	Dial        DialFunc
+}
+
+func (r Reconnector) Connect(ctx context.Context) (int, error) {
+	attempts := r.MaxAttempts
+	if attempts <= 0 {
+		attempts = 1
+	}
+
+	var lastErr error
+	for attempt := 1; attempt <= attempts; attempt++ {
+		if err := ctx.Err(); err != nil {
+			return attempt - 1, err
+		}
+
+		if err := r.Dial(ctx); err != nil {
+			lastErr = err
+			if attempt < attempts && r.Delay > 0 {
+				select {
+				case <-ctx.Done():
+					return attempt, ctx.Err()
+				case <-time.After(r.Delay):
+				}
+			}
+			continue
+		}
+
+		return attempt, nil
+	}
+
+	return attempts, lastErr
+}

gateway/internal/connection/reconnector_test.go

@@ -0,0 +1,47 @@
+package connection
+
+import (
+	"context"
+	"errors"
+	"testing"
+)
+
+func TestReconnectorRetriesAfterDisconnect(t *testing.T) {
+	failures := 0
+	reconnector := Reconnector{
+		MaxAttempts: 3,
+		Dial: func(context.Context) error {
+			failures++
+			if failures < 2 {
+				return errors.New("simulated disconnect")
+			}
+			return nil
+		},
+	}
+
+	attempts, err := reconnector.Connect(context.Background())
+	if err != nil {
+		t.Fatalf("connect after retry: %v", err)
+	}
+	if attempts != 2 {
+		t.Fatalf("expected success on second attempt, got %d", attempts)
+	}
+}
+
+func TestReconnectorReturnsLastError(t *testing.T) {
+	expected := errors.New("still disconnected")
+	reconnector := Reconnector{
+		MaxAttempts: 2,
+		Dial: func(context.Context) error {
+			return expected
+		},
+	}
+
+	attempts, err := reconnector.Connect(context.Background())
+	if !errors.Is(err, expected) {
+		t.Fatalf("expected last error, got %v", err)
+	}
+	if attempts != 2 {
+		t.Fatalf("expected two attempts, got %d", attempts)
+	}
+}