feat(tui): command completion and fuzzy matching in cmdbar

Author: engalar

tui/cmdbar.go

@@ -8,15 +8,32 @@ import (
 	"github.com/charmbracelet/lipgloss"
 )
 
+var allCommands = []struct {
+	name string
+	desc string
+}{
+	{"callers", "show callers of selected element"},
+	{"callees", "show callees of selected element"},
+	{"context", "show context of selected element"},
+	{"impact", "show impact of selected element"},
+	{"refs", "show references to selected element"},
+	{"diagram", "open diagram in browser"},
+	{"search", "full-text search: search <keyword>"},
+	{"run", "run MDL file: run <file.mdl>"},
+	{"check", "check MDL syntax: check <file.mdl>"},
+}
+
 // CmdBar is the bottom command input bar activated by ":".
 type CmdBar struct {
-	input   textinput.Model
-	visible bool
+	input             textinput.Model
+	visible           bool
+	candidates        []string
+	selectedCandidate int
 }
 
 func NewCmdBar() CmdBar {
 	ti := textinput.New()
-	ti.Placeholder = "command (run, check, callers, callees, context, impact, refs, diagram, search <kw>)"
+	ti.Placeholder = "command (callers, callees, context, impact, refs, diagram, search, run, check)"
 	ti.Prompt = ": "
 	ti.CharLimit = 200
 	return CmdBar{input: ti}
@@ -26,11 +43,15 @@ func (c *CmdBar) Show() {
 	c.visible = true
 	c.input.SetValue("")
 	c.input.Focus()
+	c.candidates = nil
+	c.selectedCandidate = 0
 }
 
 func (c *CmdBar) Hide() {
 	c.visible = false
 	c.input.Blur()
+	c.candidates = nil
+	c.selectedCandidate = 0
 }
 
 func (c CmdBar) IsVisible() bool { return c.visible }
@@ -48,19 +69,124 @@ func (c CmdBar) Command() (verb string, rest string) {
 	return verb, rest
 }
 
+func (c *CmdBar) filterCandidates() {
+	verb, _ := c.Command()
+	if verb == "" {
+		c.candidates = nil
+		return
+	}
+	var result []string
+	for _, cmd := range allCommands {
+		if strings.HasPrefix(cmd.name, verb) || strings.Contains(cmd.name, verb) {
+			result = append(result, cmd.name)
+		}
+	}
+	// If exact match, no need to show candidates
+	if len(result) == 1 && result[0] == verb {
+		c.candidates = nil
+		return
+	}
+	c.candidates = result
+	if c.selectedCandidate >= len(c.candidates) {
+		c.selectedCandidate = 0
+	}
+}
+
+// ApplyCompletion applies the selected candidate if one is highlighted and not yet complete.
+// Returns true if completion was applied (caller should not submit yet).
+func (c *CmdBar) ApplyCompletion() bool {
+	if len(c.candidates) > 0 && c.selectedCandidate < len(c.candidates) {
+		verb, _ := c.Command()
+		candidate := c.candidates[c.selectedCandidate]
+		if verb != candidate {
+			c.input.SetValue(candidate + " ")
+			c.input.CursorEnd()
+			c.candidates = nil
+			c.selectedCandidate = 0
+			return true
+		}
+	}
+	return false
+}
+
 func (c CmdBar) Update(msg tea.Msg) (CmdBar, tea.Cmd) {
+	if keyMsg, ok := msg.(tea.KeyMsg); ok {
+		switch keyMsg.String() {
+		case "tab":
+			if len(c.candidates) > 0 {
+				chosen := c.candidates[c.selectedCandidate]
+				c.input.SetValue(chosen + " ")
+				c.input.CursorEnd()
+				c.candidates = nil
+				c.selectedCandidate = 0
+			}
+			return c, nil
+		case "up":
+			if len(c.candidates) > 0 {
+				c.selectedCandidate--
+				if c.selectedCandidate < 0 {
+					c.selectedCandidate = len(c.candidates) - 1
+				}
+			}
+			return c, nil
+		case "down":
+			if len(c.candidates) > 0 {
+				c.selectedCandidate++
+				if c.selectedCandidate >= len(c.candidates) {
+					c.selectedCandidate = 0
+				}
+			}
+			return c, nil
+		}
+	}
 	var cmd tea.Cmd
 	c.input, cmd = c.input.Update(msg)
+	c.filterCandidates()
 	return c, cmd
 }
 
 func (c CmdBar) View() string {
 	if !c.visible {
 		return lipgloss.NewStyle().
 			Foreground(lipgloss.Color("240")).
-			Render(" :run  :check  :callers  :callees  :context  :impact  :refs  :diagram  :search")
+			Render(" :callers  :callees  :context  :impact  :refs  :diagram  :search  :run  :check")
 	}
-	return lipgloss.NewStyle().
+
+	inputLine := lipgloss.NewStyle().
 		Bold(true).Foreground(lipgloss.Color("214")).
 		Render(c.input.View())
+
+	if len(c.candidates) == 0 {
+		return inputLine
+	}
+
+	// Show up to 5 candidates
+	maxShow := min(5, len(c.candidates))
+
+	normalStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("240"))
+	highlightStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("63")).Bold(true)
+
+	var lines []string
+	lines = append(lines, inputLine)
+	for i := 0; i < maxShow; i++ {
+		name := c.candidates[i]
+		// Find description
+		desc := ""
+		for _, cmd := range allCommands {
+			if cmd.name == name {
+				desc = cmd.desc
+				break
+			}
+		}
+		entry := "  " + name
+		if desc != "" {
+			entry += "  " + desc
+		}
+		if i == c.selectedCandidate {
+			lines = append(lines, highlightStyle.Render(entry))
+		} else {
+			lines = append(lines, normalStyle.Render(entry))
+		}
+	}
+	return strings.Join(lines, "\n")
 }

tui/model.go

@@ -193,6 +193,9 @@ func (m Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 				m.cmdbar.Hide()
 				return m, nil
 			case "enter":
+				if m.cmdbar.ApplyCompletion() {
+					return m, nil
+				}
 				verb, rest := m.cmdbar.Command()
 				m.cmdbar.Hide()
 				return m, m.dispatchCommand(verb, rest)