Tweaks/cleanups to conversation management in tui

- Pass around message/conversation values instead of pointers where it
makes more sense, and store values instead of pointers in the globally
(within the TUI) shared `App` (pointers provide no utility here).

- Split conversation persistence into separate conversation/message
  saving stages

pkg/conversation/repo.go

@@ -25,6 +25,7 @@ type Repo interface {
 	CreateConversation(title string) (*Conversation, error)
 	UpdateConversation(*Conversation) error
 	DeleteConversation(*Conversation) error
+	DeleteConversationById(id uint) error
 
 	GetMessageByID(messageID uint) (*Message, error)
 
@@ -71,7 +72,7 @@ func NewRepo(db *gorm.DB) (Repo, error) {
 	return &repo{db, _sqids}, nil
 }
 
-type conversationListItem struct {
+type ConversationListItem struct {
 	ID            uint
 	ShortName     string
 	Title         string
@@ -80,7 +81,7 @@ type conversationListItem struct {
 
 type ConversationList struct {
 	Total int
-	Items []conversationListItem
+	Items []ConversationListItem
 }
 
 // LoadConversationList loads existing conversations, ordered by the date
@@ -95,7 +96,7 @@ func (s *repo) LoadConversationList() (ConversationList, error) {
 	}
 
 	for _, c := range convos {
-		list.Items = append(list.Items, conversationListItem{
+		list.Items = append(list.Items, ConversationListItem{
 			ID:            c.ID,
 			ShortName:     c.ShortName.String,
 			Title:         c.Title,
@@ -147,7 +148,7 @@ func (s *repo) GetConversationByID(id uint) (*Conversation, error) {
 func (s *repo) CreateConversation(title string) (*Conversation, error) {
 	// Create the new conversation
 	c := &Conversation{Title: title}
-	err := s.db.Save(c).Error
+	err := s.db.Create(c).Error
 	if err != nil {
 		return nil, err
 	}
@@ -172,12 +173,18 @@ func (s *repo) DeleteConversation(c *Conversation) error {
 	if c == nil || c.ID == 0 {
 		return fmt.Errorf("Conversation is nil or invalid (missing ID)")
 	}
-	// Delete messages first
-	err := s.db.Where("conversation_id = ?", c.ID).Delete(&Message{}).Error
+	return s.DeleteConversationById(c.ID)
+}
+
+func (s *repo) DeleteConversationById(id uint) error {
+	if id == 0 {
+		return fmt.Errorf("Invalid conversation ID: %d", id)
+	}
+	err := s.db.Where("conversation_id = ?", id).Delete(&Message{}).Error
 	if err != nil {
 		return err
 	}
-	return s.db.Delete(c).Error
+	return s.db.Where("id = ?", id).Delete(&Conversation{}).Error
 }
 
 func (s *repo) SaveMessage(m Message) (*Message, error) {
@@ -186,6 +193,7 @@ func (s *repo) SaveMessage(m Message) (*Message, error) {
 	}
 	newMessage := m
 	newMessage.ID = 0
+	newMessage.CreatedAt = time.Now()
 	return &newMessage, s.db.Create(&newMessage).Error
 }
 
@@ -234,12 +242,15 @@ func (s *repo) Reply(to *Message, messages ...Message) ([]Message, error) {
 			savedMessages = append(savedMessages, message)
 			currentParent = &message
 		}
-
-		to.Conversation.LastMessageAt = savedMessages[len(savedMessages)-1].CreatedAt
-		s.UpdateConversation(to.Conversation)
 		return nil
 	})
 
+	if err != nil {
+		return savedMessages, err
+	}
+
+	to.Conversation.LastMessageAt = savedMessages[len(savedMessages)-1].CreatedAt
+	err = s.UpdateConversation(to.Conversation)
 	return savedMessages, err
 }