Add message branching

Updated the behaviour of commands:

- `lmcli edit`
  - by default create a new branch/message branch with the edited contents
  - add --in-place to avoid creating a branch
  - no longer delete messages after the edited message
  - only do the edit, don't fetch a new response
- `lmcli retry`
  - create a new branch rather than replacing old messages
  - add --offset to change where to retry from

pkg/cmd/new.go

@@ -15,42 +15,43 @@ func NewCmd(ctx *lmcli.Context) *cobra.Command {
 		Short: "Start a new conversation",
 		Long:  `Start a new conversation with the Large Language Model.`,
 		RunE: func(cmd *cobra.Command, args []string) error {
-			messageContents := inputFromArgsOrEditor(args, "# What would you like to say?\n", "")
-			if messageContents == "" {
+			input := inputFromArgsOrEditor(args, "# Start a new conversation below\n", "")
+			if input == "" {
 				return fmt.Errorf("No message was provided.")
 			}
 
-			conversation := &model.Conversation{}
-			err := ctx.Store.SaveConversation(conversation)
-			if err != nil {
-				return fmt.Errorf("Could not save new conversation: %v", err)
+			var messages []model.Message
+
+			// TODO: probably just make this part of the conversation
+			system := ctx.GetSystemPrompt()
+			if system != "" {
+				messages = append(messages, model.Message{
+					Role:    model.MessageRoleSystem,
+					Content: system,
+				})
 			}
 
-			messages := []model.Message{
-				{
-					ConversationID: conversation.ID,
-					Role:           model.MessageRoleSystem,
-					Content:        ctx.GetSystemPrompt(),
-				},
-				{
-					ConversationID: conversation.ID,
-					Role:           model.MessageRoleUser,
-					Content:        messageContents,
-				},
+			messages = append(messages, model.Message{
+				Role:    model.MessageRoleUser,
+				Content: input,
+			})
+
+			conversation, messages, err := ctx.Store.StartConversation(messages...)
+			if err != nil {
+				return fmt.Errorf("Could not start a new conversation: %v", err)
 			}
 
-			cmdutil.HandleConversationReply(ctx, conversation, true, messages...)
+			cmdutil.HandleReply(ctx, &messages[len(messages)-1], true)
 
-			title, err := cmdutil.GenerateTitle(ctx, conversation)
+			title, err := cmdutil.GenerateTitle(ctx, messages)
 			if err != nil {
-				lmcli.Warn("Could not generate title for conversation: %v\n", err)
+				lmcli.Warn("Could not generate title for conversation %s: %v\n", conversation.ShortName.String, err)
 			}
 
 			conversation.Title = title
-
-			err = ctx.Store.SaveConversation(conversation)
+			err = ctx.Store.UpdateConversation(conversation)
 			if err != nil {
-				lmcli.Warn("Could not save conversation after generating title: %v\n", err)
+				lmcli.Warn("Could not save conversation title: %v\n", err)
 			}
 			return nil
 		},