From 135aceb72f4f4de1694c22f653d95fd6c5015745 Mon Sep 17 00:00:00 2001
From: Kujtim Hoxha <kujtimii.h@gmail.com>
Date: Fri, 27 Jun 2025 17:46:51 +0200
Subject: [PATCH] feat: add dynamic model switching with agent provider updates

---
 internal/app/app.go         |  4 ++
 internal/llm/agent/agent.go | 98 +++++++++++++++++++++++++++++++++++++
 internal/tui/tui.go         |  7 +++
 3 files changed, 109 insertions(+)

diff --git a/internal/app/app.go b/internal/app/app.go
index b096c1b4f5612901a1cedeaa2ee758b666cda517..6dd1b9916d593c6f0e053aaef6714723f8fd5c60 100644
--- a/internal/app/app.go
+++ b/internal/app/app.go
@@ -168,3 +168,7 @@ func (app *App) Shutdown() {
 	}
 	app.CoderAgent.CancelAll()
 }
+
+func (app *App) UpdateAgentModel() error {
+	return app.CoderAgent.UpdateModel()
+}
diff --git a/internal/llm/agent/agent.go b/internal/llm/agent/agent.go
index 8c6faf8c4a06bbef5da279847cd14ce2314648cd..8312b0f8965a5d02f7ce049abff50953cc56e422 100644
--- a/internal/llm/agent/agent.go
+++ b/internal/llm/agent/agent.go
@@ -56,6 +56,7 @@ type Service interface {
 	IsSessionBusy(sessionID string) bool
 	IsBusy() bool
 	Summarize(ctx context.Context, sessionID string) error
+	UpdateModel() error
 }
 
 type agent struct {
@@ -805,3 +806,100 @@ func (a *agent) CancelAll() {
 		return true
 	})
 }
+
+func (a *agent) UpdateModel() error {
+	cfg := config.Get()
+
+	// Get current provider configuration
+	currentProviderCfg := config.GetAgentProvider(a.agentCfg.ID)
+	if currentProviderCfg.ID == "" {
+		return fmt.Errorf("provider for agent %s not found in config", a.agentCfg.Name)
+	}
+
+	// Check if provider has changed
+	if string(currentProviderCfg.ID) != a.providerID {
+		// Provider changed, need to recreate the main provider
+		model := config.GetAgentModel(a.agentCfg.ID)
+		if model.ID == "" {
+			return fmt.Errorf("model not found for agent %s", a.agentCfg.Name)
+		}
+
+		promptID := agentPromptMap[a.agentCfg.ID]
+		if promptID == "" {
+			promptID = prompt.PromptDefault
+		}
+
+		opts := []provider.ProviderClientOption{
+			provider.WithModel(a.agentCfg.Model),
+			provider.WithSystemMessage(prompt.GetPrompt(promptID, currentProviderCfg.ID)),
+			provider.WithMaxTokens(model.DefaultMaxTokens),
+		}
+
+		newProvider, err := provider.NewProviderV2(currentProviderCfg, opts...)
+		if err != nil {
+			return fmt.Errorf("failed to create new provider: %w", err)
+		}
+
+		// Update the provider and provider ID
+		a.provider = newProvider
+		a.providerID = string(currentProviderCfg.ID)
+	}
+
+	// Check if small model provider has changed (affects title and summarize providers)
+	smallModelCfg := cfg.Models.Small
+	var smallModelProviderCfg config.ProviderConfig
+
+	for _, p := range cfg.Providers {
+		if p.ID == smallModelCfg.Provider {
+			smallModelProviderCfg = p
+			break
+		}
+	}
+
+	if smallModelProviderCfg.ID == "" {
+		return fmt.Errorf("provider %s not found in config", smallModelCfg.Provider)
+	}
+
+	// Check if summarize provider has changed
+	if string(smallModelProviderCfg.ID) != a.summarizeProviderID {
+		var smallModel config.Model
+		for _, m := range smallModelProviderCfg.Models {
+			if m.ID == smallModelCfg.ModelID {
+				smallModel = m
+				break
+			}
+		}
+		if smallModel.ID == "" {
+			return fmt.Errorf("model %s not found in provider %s", smallModelCfg.ModelID, smallModelProviderCfg.ID)
+		}
+
+		// Recreate title provider
+		titleOpts := []provider.ProviderClientOption{
+			provider.WithModel(config.SmallModel),
+			provider.WithSystemMessage(prompt.GetPrompt(prompt.PromptTitle, smallModelProviderCfg.ID)),
+			provider.WithMaxTokens(40),
+		}
+		newTitleProvider, err := provider.NewProviderV2(smallModelProviderCfg, titleOpts...)
+		if err != nil {
+			return fmt.Errorf("failed to create new title provider: %w", err)
+		}
+
+		// Recreate summarize provider
+		summarizeOpts := []provider.ProviderClientOption{
+			provider.WithModel(config.SmallModel),
+			provider.WithSystemMessage(prompt.GetPrompt(prompt.PromptSummarizer, smallModelProviderCfg.ID)),
+			provider.WithMaxTokens(smallModel.DefaultMaxTokens),
+		}
+		newSummarizeProvider, err := provider.NewProviderV2(smallModelProviderCfg, summarizeOpts...)
+		if err != nil {
+			return fmt.Errorf("failed to create new summarize provider: %w", err)
+		}
+
+		// Update the providers and provider ID
+		a.titleProvider = newTitleProvider
+		a.summarizeProvider = newSummarizeProvider
+		a.summarizeProviderID = string(smallModelProviderCfg.ID)
+	}
+
+	return nil
+}
diff --git a/internal/tui/tui.go b/internal/tui/tui.go
index 032b481eeaad75531debe7dc453efe19b866dd8d..e3c974ca002529ce1ac90f420afcc5eedf2a45fd 100644
--- a/internal/tui/tui.go
+++ b/internal/tui/tui.go
@@ -173,6 +173,13 @@ func (a *appModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 	// Model Switch
 	case models.ModelSelectedMsg:
 		config.UpdatePreferredModel(config.LargeModel, msg.Model)
+
+		// Update the agent with the new model/provider configuration
+		if err := a.app.UpdateAgentModel(); err != nil {
+			logging.ErrorPersist(fmt.Sprintf("Failed to update agent model: %v", err))
+			return a, util.ReportError(fmt.Errorf("model changed to %s but failed to update agent: %v", msg.Model.ModelID, err))
+		}
+
 		return a, util.ReportInfo(fmt.Sprintf("Model changed to %s", msg.Model.ModelID))
 
 	// File Picker