Initial commit: email-openclaw bridge v1

Full pipeline: IMAP ingress -> OpenClaw dispatch -> callback -> SMTP reply.
SQLite stateful storage with idempotency, threading, and retry logic.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

internal/database/repository_test.go

@@ -0,0 +1,105 @@
+package database_test
+
+import (
+	"testing"
+
+	"thuanle.me/claw-email-bridge/internal/database"
+)
+
+// Test matrix #5: Duplicate message_id → không tạo task mới.
+func TestDuplicateMessageID(t *testing.T) {
+	tdb := database.NewTestDB(t)
+
+	task1 := &database.Task{
+		TaskUUID:  "uuid-1",
+		ThreadID:  "thread-1",
+		MessageID: "msg-duplicate@test.com",
+		Sender:    "user@test.com",
+		Subject:   "First email",
+		Status:    database.StatusReceived,
+	}
+	if err := database.CreateTask(tdb.DB, task1); err != nil {
+		t.Fatalf("create first task: %v", err)
+	}
+
+	// Lookup should find the existing task.
+	found, err := database.FindByMessageID(tdb.DB, "msg-duplicate@test.com")
+	if err != nil {
+		t.Fatalf("find by message_id: %v", err)
+	}
+	if found == nil {
+		t.Fatal("expected to find existing task")
+	}
+	if found.TaskUUID != "uuid-1" {
+		t.Errorf("expected uuid-1, got %s", found.TaskUUID)
+	}
+
+	// Attempting to create another task with same task_uuid should fail (unique constraint).
+	task2 := &database.Task{
+		TaskUUID:  "uuid-1", // Same UUID — unique constraint violation.
+		ThreadID:  "thread-1",
+		MessageID: "msg-duplicate@test.com",
+		Sender:    "user@test.com",
+		Subject:   "Duplicate",
+		Status:    database.StatusReceived,
+	}
+	err = database.CreateTask(tdb.DB, task2)
+	if err == nil {
+		t.Error("expected error creating duplicate task_uuid, got nil")
+	}
+}
+
+func TestFindByMessageID_NotFound(t *testing.T) {
+	tdb := database.NewTestDB(t)
+
+	found, err := database.FindByMessageID(tdb.DB, "nonexistent@test.com")
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if found != nil {
+		t.Error("expected nil for nonexistent message_id")
+	}
+}
+
+func TestThreadHistory(t *testing.T) {
+	tdb := database.NewTestDB(t)
+
+	// Create two completed tasks in same thread.
+	for i, uuid := range []string{"uuid-a", "uuid-b"} {
+		task := &database.Task{
+			TaskUUID:   uuid,
+			ThreadID:   "thread-history",
+			MessageID:  uuid + "@test.com",
+			Sender:     "user@test.com",
+			Subject:    "Thread test",
+			BodyPlain:  "Message " + uuid,
+			AIResponse: "Reply " + uuid,
+			Status:     database.StatusCompleted,
+		}
+		_ = i
+		if err := database.CreateTask(tdb.DB, task); err != nil {
+			t.Fatalf("create task %s: %v", uuid, err)
+		}
+	}
+
+	// Create one non-completed task — should not appear in history.
+	task3 := &database.Task{
+		TaskUUID:  "uuid-c",
+		ThreadID:  "thread-history",
+		MessageID: "uuid-c@test.com",
+		Sender:    "user@test.com",
+		Subject:   "Pending",
+		Status:    database.StatusAIProcessing,
+	}
+	if err := database.CreateTask(tdb.DB, task3); err != nil {
+		t.Fatalf("create task: %v", err)
+	}
+
+	history, err := database.ThreadHistory(tdb.DB, "thread-history")
+	if err != nil {
+		t.Fatalf("thread history: %v", err)
+	}
+	if len(history) != 2 {
+		t.Errorf("expected 2 completed tasks in history, got %d", len(history))
+	}
+}