tsk-9: Schedule queued message endpoint (#22)

Closes #9

Reviewed-on: phoenix/textsender-api#22
Co-authored-by: phoenix <kundeng00@pm.me>
Co-committed-by: phoenix <kundeng00@pm.me>

internal/handler/mock_store_test.go

@@ -9,6 +9,7 @@ import (
 
 	"git.kundeng.us/phoenix/textsender-models/pkg/contact"
 	"git.kundeng.us/phoenix/textsender-models/pkg/message"
+	"git.kundeng.us/phoenix/textsender-models/pkg/message/scheduling"
 )
 
 type Key struct {
@@ -200,3 +201,40 @@ func (m *MockMessageStore) MessageExists(ctx context.Context, msg *message.Messa
 
 	return exists, nil
 }
+
+type ScheduledMessageKey struct {
+	UserId uuid.UUID
+}
+
+type MockScheduledMessageStore struct {
+	ScheduledMessages      map[uuid.UUID]*scheduling.ScheduledMessage
+	ScheduledMessagesByKey map[ScheduledMessageKey]*scheduling.ScheduledMessage
+	mu                     sync.RWMutex
+	Error                  error // Optional: simulate errors
+}
+
+func NewMockScheduledMessageStore() *MockScheduledMessageStore {
+	return &MockScheduledMessageStore{
+		ScheduledMessages:      make(map[uuid.UUID]*scheduling.ScheduledMessage),
+		ScheduledMessagesByKey: make(map[ScheduledMessageKey]*scheduling.ScheduledMessage),
+	}
+}
+
+func (m *MockScheduledMessageStore) CreateScheduledMessage(ctx context.Context, schedMsg *scheduling.ScheduledMessage) error {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if m.Error != nil {
+		return m.Error
+	}
+
+	if schedMsg.Id == uuid.Nil {
+		schedMsg.Id = uuid.New()
+	}
+
+	key := ScheduledMessageKey{UserId: schedMsg.UserId}
+
+	m.ScheduledMessages[schedMsg.Id] = schedMsg
+	m.ScheduledMessagesByKey[key] = schedMsg
+	return nil
+}