package tui import ( "context" "errors" "fmt" "io" "math" "strings" "agentu/internal/agent" "agentu/internal/llm" "github.com/charmbracelet/bubbles/spinner" "github.com/charmbracelet/bubbles/textarea" "github.com/charmbracelet/bubbles/viewport" tea "github.com/charmbracelet/bubbletea" "github.com/charmbracelet/lipgloss" ) const ( minInputLines = 1 maxInputLines = 6 ) type Options struct { ModelName string Yolo bool ThemeMode ThemeMode ModelManager ModelManager } type ModelManager interface { CurrentProvider() string CurrentModel() string CurrentThinking() string CurrentSessionID() string CurrentSessionName() string Info() string SetProvider(name string) (string, error) SetModel(model string) (string, error) SetThinking(level string) (string, error) Save() error Resume(id string) error Rename(name string) (string, error) Sessions() (string, error) NewSession() (string, error) } func Run(ctx context.Context, assistant *agent.Agent, opts Options) error { model := newModel(ctx, assistant, opts) _, err := tea.NewProgram(model, tea.WithAltScreen()).Run() return err } type role string const ( roleUser role = "user" roleAssistant role = "assistant" roleTool role = "tool" roleError role = "error" roleSystem role = "system" ) type message struct { role role content string } type model struct { ctx context.Context agent *agent.Agent modelName string yolo bool models ModelManager theme theme styles styles viewport viewport.Model input textarea.Model spinner spinner.Model width int height int messages []message status string running bool cancel context.CancelFunc events <-chan tea.Msg // Session picker state picking bool pickerItems []pickerItem pickerCursor int } type pickerItem struct { id string name string detail string isCurrent bool } type assistantChunkMsg string type toolLogMsg string type turnStartedMsg struct{} type turnDoneMsg struct { err error } var errOpenPicker = fmt.Errorf("open picker") type slashCommand struct { Name string Description string } var slashCommands = []slashCommand{ {Name: "/clear", Description: "reset context"}, {Name: "/exit", Description: "quit"}, {Name: "/quit", Description: "quit"}, {Name: "/model", Description: "model/provider/thinking"}, {Name: "/sessions", Description: "list sessions"}, {Name: "/resume", Description: "resume session"}, {Name: "/rename", Description: "rename session"}, {Name: "/new", Description: "new session"}, } func newModel(ctx context.Context, assistant *agent.Agent, opts Options) model { mode := opts.ThemeMode if mode == "" { mode = ThemeLight } th := themeForMode(mode) st := th.styles() input := textarea.New() input.Placeholder = "Message agentu..." input.Prompt = "" input.ShowLineNumbers = false input.MaxHeight = maxInputLines input.SetHeight(minInputLines) input.SetWidth(80) applyTextareaTheme(&input, th) input.Focus() spin := spinner.New( spinner.WithSpinner(spinner.Line), ) vp := viewport.New(80, 20) vp.Style = st.Viewport vp.SetContent("") return model{ ctx: ctx, agent: assistant, modelName: opts.ModelName, yolo: opts.Yolo, models: opts.ModelManager, theme: th, styles: st, viewport: vp, input: input, spinner: spin, status: "ready", } } func (m model) Init() tea.Cmd { m.syncMessages() return textarea.Blink } // syncMessages rebuilds the TUI display messages from the agent's conversation history. func (m *model) syncMessages() { if m.agent == nil { return } msgs := m.agent.Messages() m.messages = m.messages[:0] for _, msg := range msgs { switch msg.Role { case llm.RoleUser: m.messages = append(m.messages, message{role: roleUser, content: msg.Content}) case llm.RoleAssistant: if msg.Content != "" { m.messages = append(m.messages, message{role: roleAssistant, content: msg.Content}) } case llm.RoleTool: text := cleanToolLog(msg.Content) if text != "" { m.messages = append(m.messages, message{role: roleTool, content: text}) } } } m.refreshViewport(true) } func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) { var cmds []tea.Cmd switch msg := msg.(type) { case tea.WindowSizeMsg: m.width = msg.Width m.height = msg.Height m.resize() m.refreshViewport(true) return m, nil case spinner.TickMsg: if !m.running { return m, nil } var cmd tea.Cmd m.spinner, cmd = m.spinner.Update(msg) return m, cmd case tea.KeyMsg: if m.picking { return m.updatePicker(msg) } switch msg.String() { case "ctrl+c": if m.cancel != nil { m.cancel() } return m, tea.Quit case "esc": if m.running && m.cancel != nil { m.cancel() m.status = "canceling..." return m, nil } case "enter": if m.running { return m, nil } return m.submit() case "alt+enter", "ctrl+j": return m.insertInputNewline() } case assistantChunkMsg: m.appendAssistantChunk(string(msg)) m.status = "streaming..." m.refreshViewport(true) return m, m.waitForEvent() case toolLogMsg: text := cleanToolLog(string(msg)) if text != "" { m.messages = append(m.messages, message{role: roleTool, content: text}) m.status = text m.refreshViewport(true) } return m, m.waitForEvent() case turnDoneMsg: m.running = false m.events = nil m.cancel = nil if msg.err != nil { m.messages = append(m.messages, message{role: roleError, content: msg.err.Error()}) m.status = "error" } else { m.status = "ready" } // Auto-save session after turn completes if m.models != nil { _ = m.models.Save() } m.resize() m.refreshViewport(true) cmds = append(cmds, textarea.Blink) } if keyMsg, ok := msg.(tea.KeyMsg); ok { if isViewportKey(keyMsg.String()) { nextViewport, cmd := m.viewport.Update(msg) m.viewport = nextViewport return m, cmd } if !m.running { nextInput, cmd := m.input.Update(msg) m.input = nextInput m.afterInputChanged() return m, cmd } return m, nil } if !m.running { nextInput, cmd := m.input.Update(msg) m.input = nextInput m.afterInputChanged() cmds = append(cmds, cmd) } nextViewport, cmd := m.viewport.Update(msg) m.viewport = nextViewport cmds = append(cmds, cmd) return m, tea.Batch(cmds...) } func (m model) View() string { if m.width <= 0 || m.height <= 0 { return "agentu" } if m.picking { parts := []string{m.viewport.View()} parts = append(parts, m.pickerView(), m.modelMetaView(), m.footerView()) body := lipgloss.JoinVertical(lipgloss.Left, parts...) return m.styles.App.Width(m.width).Height(m.height).Render(body) } parts := []string{m.viewport.View()} if activity := m.activityView(); activity != "" { parts = append(parts, activity) } parts = append(parts, m.inputView(), m.modelMetaView(), m.footerView()) body := lipgloss.JoinVertical(lipgloss.Left, parts...) return m.styles.App.Width(m.width).Height(m.height).Render(body) } func (m *model) submit() (tea.Model, tea.Cmd) { input := strings.TrimSpace(m.input.Value()) if input == "" { return *m, nil } switch input { case "/exit", "/quit": return *m, tea.Quit case "/clear": m.agent.Clear() m.messages = []message{{role: roleSystem, content: "Context cleared."}} m.input.SetValue("") m.afterInputChanged() m.status = "ready" m.refreshViewport(true) return *m, nil case "/model": return m.runLocalCommand(input) } if strings.HasPrefix(input, "/") { return m.runLocalCommand(input) } m.messages = append(m.messages, message{role: roleUser, content: input}) m.input.SetValue("") m.afterInputChanged() m.running = true m.status = "thinking..." m.resize() m.refreshViewport(true) turnCtx, cancel := context.WithCancel(m.ctx) m.cancel = cancel events := make(chan tea.Msg, 256) m.events = events start := func() tea.Msg { go func() { defer close(events) out := eventWriter{ctx: turnCtx, events: events, assistant: true} logs := eventWriter{ctx: turnCtx, events: events} err := m.agent.RunTurn(turnCtx, input, out, logs) if errors.Is(err, context.Canceled) { err = nil } select { case events <- turnDoneMsg{err: err}: case <-turnCtx.Done(): } }() return turnStartedMsg{} } return *m, tea.Batch(start, m.waitForEvent(), m.spinner.Tick) } func (m *model) insertInputNewline() (tea.Model, tea.Cmd) { enter := tea.KeyMsg{Type: tea.KeyEnter} nextInput, cmd := m.input.Update(enter) m.input = nextInput m.afterInputChanged() return *m, cmd } func (m model) waitForEvent() tea.Cmd { events := m.events if events == nil { return nil } return func() tea.Msg { msg, ok := <-events if !ok { return turnDoneMsg{} } return msg } } func (m *model) appendAssistantChunk(chunk string) { if chunk == "" { return } if len(m.messages) == 0 || m.messages[len(m.messages)-1].role != roleAssistant { m.messages = append(m.messages, message{role: roleAssistant}) } m.messages[len(m.messages)-1].content += chunk } func (m *model) resize() { width := max(40, m.width) inputWidth := max(20, width-m.styles.InputBox.GetHorizontalFrameSize()) m.input.SetWidth(inputWidth) m.syncInputHeight() activityHeight := 0 if m.running { activityHeight = 1 } inputHeight := m.inputBlockHeight() footerHeight := 2 m.viewport.Width = width m.viewport.Height = max(4, m.height-activityHeight-inputHeight-footerHeight) m.viewport.Style = m.styles.Viewport } func (m *model) refreshViewport(bottom bool) { m.viewport.SetContent(m.renderMessages()) if bottom { m.viewport.GotoBottom() } } func (m model) renderMessages() string { width := max(40, m.width) contentWidth := width parts := make([]string, 0, len(m.messages)) for _, msg := range m.messages { content := strings.TrimRight(msg.content, "\n") if content == "" { continue } parts = append(parts, m.messageView(msg.role, content, contentWidth)) } if len(parts) == 0 { return "" } return strings.Join(parts, "\n\n") } func (m model) messageView(r role, content string, width int) string { label := roleLabel(r) style := m.styles.AssistantMsg labelStyle := m.styles.SystemLabel switch r { case roleUser: style = m.styles.UserMessage case roleTool: style = m.styles.ToolMessage labelStyle = m.styles.ToolLabel case roleError: style = m.styles.ErrorMessage labelStyle = m.styles.ErrorLabel case roleSystem: style = m.styles.SystemMessage labelStyle = m.styles.SystemLabel } bodyContent := content if r == roleAssistant { bodyWidth := max(minMarkdownWidth, width-style.GetHorizontalFrameSize()) bodyContent = renderMarkdown(content, bodyWidth, m.theme) } bodyWidth := messageBodyWidth(bodyContent, width, style) if r == roleUser { bodyWidth = width } body := style.Width(bodyWidth).Render(bodyContent) if label == "" { return body } labelLine := labelStyle.Render(label) return lipgloss.JoinVertical(lipgloss.Left, labelLine, body) } func messageBodyWidth(content string, maxWidth int, style lipgloss.Style) int { maxWidth = max(1, maxWidth) contentWidth := 1 for _, line := range strings.Split(content, "\n") { contentWidth = max(contentWidth, lipgloss.Width(line)) } return min(maxWidth, contentWidth+style.GetHorizontalFrameSize()) } func roleLabel(r role) string { switch r { case roleUser: return "" case roleAssistant: return "" case roleTool: return "Tool" case roleError: return "Error" case roleSystem: return "Note" default: return string(r) } } func (m model) modelMetaView() string { mode := "read-only tools" if m.yolo { mode = "yolo tools" } modelName := m.modelName parts := []string{} if m.models != nil { if sessionName := m.models.CurrentSessionName(); sessionName != "" { parts = append(parts, "session "+sessionName) } if provider := m.models.CurrentProvider(); provider != "" { parts = append(parts, "provider "+provider) } modelName = m.models.CurrentModel() if currentThinking := m.models.CurrentThinking(); currentThinking != "" && currentThinking != "unset" { parts = append(parts, "thinking "+currentThinking) } } parts = append([]string{modelName, mode}, parts...) parts = append(parts, "theme "+string(m.theme.Mode)) line := fitLine(strings.Join(parts, " · "), max(1, m.width-2)) return m.styles.ModelMeta.Width(max(1, m.width)).Render(line) } func (m model) inputView() string { suggestions := m.slashSuggestionsView() box := m.styles.InputBox.Width(max(20, m.width-2)).Render(m.input.View()) if suggestions != "" { return lipgloss.JoinVertical(lipgloss.Left, suggestions, box) } return box } func (m model) activityView() string { if !m.running { return "" } status := strings.TrimSpace(m.status) if status == "" || status == "ready" { status = "working..." } line := fitLine(fmt.Sprintf("%s Working · %s · esc cancels", m.spinner.View(), status), max(1, m.width-2)) return m.styles.Activity.Width(max(1, m.width)).Render(line) } func (m model) footerView() string { hint := "enter send · ctrl+j newline · alt+enter newline · / commands" if m.running { hint = "esc cancel · ctrl+c quit" } return m.styles.Footer.Width(max(1, m.width)).Render(fitLine(hint, max(1, m.width-2))) } type eventWriter struct { ctx context.Context events chan<- tea.Msg assistant bool } func (w eventWriter) Write(p []byte) (int, error) { if len(p) == 0 { return 0, nil } text := string(append([]byte(nil), p...)) var msg tea.Msg if w.assistant { msg = assistantChunkMsg(text) } else { msg = toolLogMsg(text) } select { case w.events <- msg: return len(p), nil case <-w.ctx.Done(): return 0, w.ctx.Err() } } func cleanToolLog(text string) string { text = strings.TrimSpace(text) text = strings.TrimPrefix(text, "[tool]") return strings.TrimSpace(text) } func isViewportKey(key string) bool { switch key { case "pgup", "pgdown", "ctrl+up", "ctrl+down": return true default: return false } } func (m *model) afterInputChanged() { m.syncInputHeight() if m.width > 0 && m.height > 0 { m.resize() m.refreshViewport(true) } } func (m *model) syncInputHeight() { m.input.SetHeight(m.desiredInputHeight()) } func (m model) desiredInputHeight() int { value := m.input.Value() if value == "" { return minInputLines } textWidth := max(1, m.input.Width()) lines := 0 for _, line := range strings.Split(value, "\n") { displayWidth := lipgloss.Width(line) wrapped := int(math.Ceil(float64(max(1, displayWidth)) / float64(textWidth))) lines += max(1, wrapped) } return min(max(lines, minInputLines), maxInputLines) } func (m model) inputBlockHeight() int { height := m.input.Height() + m.styles.InputBox.GetVerticalFrameSize() if m.showSlashSuggestions() { height += m.slashSuggestionCount() } return height } func (m model) slashSuggestionCount() int { prefix := strings.TrimSpace(m.input.Value()) count := 0 for _, command := range slashCommands { if strings.HasPrefix(command.Name, prefix) { count++ } } if count == 0 { count = 1 // "No matching commands" } return count } func (m model) showSlashSuggestions() bool { value := strings.TrimSpace(m.input.Value()) return strings.HasPrefix(value, "/") && !strings.Contains(value, " ") } func (m model) slashSuggestionsView() string { if !m.showSlashSuggestions() { return "" } prefix := strings.TrimSpace(m.input.Value()) var parts []string for _, command := range slashCommands { if !strings.HasPrefix(command.Name, prefix) { continue } parts = append(parts, fmt.Sprintf("%s %s", command.Name, command.Description)) } if len(parts) == 0 { parts = append(parts, "No matching commands") } return m.styles.CommandHint.Width(max(20, m.width-2)).Render(strings.Join(parts, "\n")) } func (m model) modelInfo() string { if m.models != nil { return m.models.Info() } mode := "read-only tools" if m.yolo { mode = "yolo tools" } return fmt.Sprintf("model: %s\nmode: %s\ntheme: %s", m.modelName, mode, m.theme.Mode) } func fitLine(text string, width int) string { width = max(1, width) if lipgloss.Width(text) <= width { return text } if width <= 3 { return strings.Repeat(".", width) } target := width - 3 used := 0 var b strings.Builder for _, r := range text { next := lipgloss.Width(string(r)) if used+next > target { break } b.WriteRune(r) used += next } return b.String() + "..." } func (m *model) runLocalCommand(input string) (tea.Model, tea.Cmd) { output, err := m.handleLocalCommand(input) if err == errOpenPicker { m.openSessionPicker() return *m, nil } role := roleSystem status := "command" if err != nil { output = err.Error() role = roleError status = "command error" } m.input.SetValue("") m.afterInputChanged() m.status = status // Rebuild display from agent history (matters after /resume and /new) m.syncMessages() // Append command output after synced history m.messages = append(m.messages, message{role: role, content: output}) m.refreshViewport(true) return *m, nil } func (m model) handleLocalCommand(input string) (string, error) { fields := strings.Fields(input) if len(fields) == 0 { return "", fmt.Errorf("empty command") } switch fields[0] { case "/model": return m.handleModelCommand(fields[1:]) case "/sessions": return m.handleSessionsCommand() case "/resume": return m.handleResumeCommand(fields[1:]) case "/rename": return m.handleRenameCommand(fields[1:]) case "/new": return m.handleNewCommand() default: return "", fmt.Errorf("unknown command: %s", fields[0]) } } func (m model) handleModelCommand(args []string) (string, error) { if m.models == nil { if len(args) > 0 { return "", fmt.Errorf("model switching is not configured") } return m.modelInfo(), nil } if len(args) == 0 || args[0] == "help" { return m.models.Info(), nil } if len(args) == 1 { return m.models.SetModel(args[0]) } switch args[0] { case "provider": if len(args) != 2 { return "", fmt.Errorf("usage: /model provider ") } return m.models.SetProvider(args[1]) case "model": if len(args) != 2 { return "", fmt.Errorf("usage: /model model ") } return m.models.SetModel(args[1]) case "thinking": if len(args) != 2 { return "", fmt.Errorf("usage: /model thinking ") } return m.models.SetThinking(args[1]) default: return "", fmt.Errorf("unknown /model command %q", args[0]) } } func (m model) handleSessionsCommand() (string, error) { if m.models == nil { return "", fmt.Errorf("session management is not configured") } return m.models.Sessions() } func (m model) handleResumeCommand(args []string) (string, error) { if m.models == nil { return "", fmt.Errorf("session management is not configured") } if len(args) > 0 { id := strings.TrimSpace(args[0]) if err := m.models.Resume(id); err != nil { return "", err } return fmt.Sprintf("Resumed session %q.", m.models.CurrentSessionName()), nil } // No args — open interactive picker (handled in runLocalCommand) return "", errOpenPicker } func (m model) handleRenameCommand(args []string) (string, error) { if m.models == nil { return "", fmt.Errorf("session management is not configured") } if len(args) == 0 { return "", fmt.Errorf("usage: /rename ") } name := strings.Join(args, " ") return m.models.Rename(name) } func (m model) handleNewCommand() (string, error) { if m.models == nil { return "", fmt.Errorf("session management is not configured") } return m.models.NewSession() } func (m *model) openSessionPicker() { if m.models == nil { return } output, err := m.models.Sessions() if err != nil { m.messages = append(m.messages, message{role: roleError, content: err.Error()}) return } // Parse session list into picker items m.pickerItems = m.pickerItems[:0] m.pickerCursor = 0 for _, line := range strings.Split(output, "\n") { line = strings.TrimSpace(line) if line == "" || line == "Sessions:" || strings.HasPrefix(line, "No saved") { continue } // Format: " id name date msgs (current)" fields := strings.Fields(line) if len(fields) < 2 { continue } id := fields[0] isCurrent := strings.Contains(line, "(current)") // Reconstruct display m.pickerItems = append(m.pickerItems, pickerItem{ id: id, name: line, isCurrent: isCurrent, }) } if len(m.pickerItems) == 0 { m.messages = append(m.messages, message{role: roleSystem, content: "No saved sessions."}) m.refreshViewport(true) return } // Skip current session in picker, pre-select next one for i, item := range m.pickerItems { if !item.isCurrent { m.pickerCursor = i break } } m.picking = true m.input.SetValue("") m.input.Blur() m.refreshViewport(true) } func (m *model) updatePicker(msg tea.KeyMsg) (tea.Model, tea.Cmd) { switch msg.String() { case "ctrl+c", "esc": m.picking = false m.input.Focus() return *m, textarea.Blink case "up", "k": if m.pickerCursor > 0 { m.pickerCursor-- } return *m, nil case "down", "j": if m.pickerCursor < len(m.pickerItems)-1 { m.pickerCursor++ } return *m, nil case "enter": if m.pickerCursor >= 0 && m.pickerCursor < len(m.pickerItems) { item := m.pickerItems[m.pickerCursor] m.picking = false m.input.Focus() if err := m.models.Resume(item.id); err != nil { m.messages = append(m.messages, message{role: roleError, content: err.Error()}) } else { m.syncMessages() m.messages = append(m.messages, message{role: roleSystem, content: fmt.Sprintf("Resumed session %q.", m.models.CurrentSessionName())}) } m.refreshViewport(true) } return *m, textarea.Blink } return *m, nil } func (m model) pickerView() string { if !m.picking || len(m.pickerItems) == 0 { return "" } width := max(40, m.width-4) var b strings.Builder b.WriteString(m.styles.Muted.Render("Select a session (↑/↓ navigate, enter select, esc cancel)")) b.WriteString("\n\n") for i, item := range m.pickerItems { line := item.name if item.isCurrent { line += " (current)" } if i == m.pickerCursor { b.WriteString(m.styles.UserLabel.Render("▸ " + line)) } else { b.WriteString(m.styles.Muted.Render(" " + line)) } b.WriteString("\n") } return m.styles.InputBox.Width(width).Render(b.String()) } var _ io.Writer = eventWriter{}