feat(tui): add AI drafting flows

internal/tui/adrsplit/testdata/TestADRSplitInputGolden.golden

@@ -0,0 +1,25 @@
+╭──────────────────────────────────────────────────────────────────────────╮
+│ SPLIT ADR INTO STORIES                                                   │
+│                                                                          │
+│   Source: paste  left/right                                              │
+│   ADR markdown:                                                          │
+│     # ADR 0007                                                           │
+│                                                                          │
+│     Use the local store directly.                                        │
+│                                                                          │
+│                                                                          │
+│                                                                          │
+│                                                                          │
+│                                                                          │
+│   UTF-8 bytes: 41 / 65536                                                │
+│   Max stories: 8  left/right (1-20)                                      │
+│                                                                          │
+│   [ Cancel ]                                                             │
+│ > [ Propose stories ]                                                    │
+│                                                                          │
+│                                                                          │
+│                                                                          │
+│                                                                          │
+│                                                                          │
+│ tab navigate | esc close                                                 │
+╰──────────────────────────────────────────────────────────────────────────╯

internal/tui/adrsplit/view.go

@@ -0,0 +1,275 @@
+package adrsplit
+
+import (
+	"fmt"
+	"strings"
+
+	"charm.land/bubbles/v2/textarea"
+	"charm.land/bubbles/v2/textinput"
+	"charm.land/lipgloss/v2"
+	"github.com/charmbracelet/x/ansi"
+
+	"github.com/RandomCodeSpace/kb/internal/board"
+	"github.com/RandomCodeSpace/kb/internal/tui/formview"
+)
+
+const maxPaneWidth = 100
+
+// View renders the overlay without its board background.
+func (m *Model) View(width, height int) string {
+	if !m.open {
+		return ""
+	}
+	frame, _, _ := m.frame(width, height)
+	return lipgloss.Place(max(width, 1), max(height, 1), lipgloss.Center, lipgloss.Center, frame)
+}
+
+// Overlay composes the split review over the current board/detail surface.
+func (m *Model) Overlay(background string, width, height int) string {
+	if !m.open {
+		return background
+	}
+	width, height = max(width, 1), max(height, 1)
+	frame, paneWidth, paneHeight := m.frame(width, height)
+	return lipgloss.NewCompositor(
+		lipgloss.NewLayer(background),
+		lipgloss.NewLayer(frame).X(max((width-paneWidth)/2, 0)).Y(max((height-paneHeight)/2, 0)).Z(3),
+	).Render()
+}
+
+func (m *Model) frame(width, height int) (string, int, int) {
+	width, height = max(width, 1), max(height, 1)
+	paneWidth := min(max(width-4, 18), maxPaneWidth, width)
+	paneHeight := min(max(height-2, 7), height)
+	innerWidth := max(paneWidth-4, 1)
+	bodyHeight := max(paneHeight-4, 1)
+	body := m.bodyLines(innerWidth)
+	focusLine := focusedLine(body)
+	maxScroll := max(len(body)-bodyHeight, 0)
+	if focusLine < m.scroll {
+		m.scroll = focusLine
+	}
+	if focusLine >= m.scroll+bodyHeight {
+		m.scroll = focusLine - bodyHeight + 1
+	}
+	m.scroll = min(max(m.scroll, 0), maxScroll)
+	end := min(m.scroll+bodyHeight, len(body))
+	visible := make([]string, 0, bodyHeight)
+	for _, line := range body[m.scroll:end] {
+		visible = append(visible, fit(line, innerWidth))
+	}
+	for len(visible) < bodyHeight {
+		visible = append(visible, "")
+	}
+	footer := "tab navigate | esc close"
+	if m.guardClose {
+		footer = "D discard | esc stay"
+	} else if m.operation != "" {
+		footer = m.operation + "... | esc cancel"
+	} else if m.adding {
+		footer = m.status
+	} else if m.status != "" {
+		prefix := "status: "
+		if m.statusIsError {
+			prefix = "error: "
+		}
+		footer = prefix + sanitize(m.status)
+	}
+	content := strings.Join(visible, "\n") + "\n" + fit(footer, innerWidth)
+	frame := lipgloss.NewStyle().
+		Border(lipgloss.RoundedBorder()).
+		Padding(0, 1).
+		Width(innerWidth).
+		Height(paneHeight - 2).
+		Render(content)
+	frame = fitBlock(frame, width, height)
+	return frame, lipgloss.Width(frame), lipgloss.Height(frame)
+}
+
+func (m *Model) bodyLines(width int) []string {
+	if m.stage == stageInput {
+		return m.inputLines(width)
+	}
+	return m.reviewLines(width)
+}
+
+func (m *Model) inputLines(width int) []string {
+	source := "paste"
+	if m.source == sourceFile {
+		source = "file"
+	}
+	lines := []string{
+		"SPLIT ADR INTO STORIES",
+		"",
+		m.choiceLine("source", "Source", source+"  left/right"),
+	}
+	if m.source == sourcePaste {
+		lines = append(lines, m.areaBlock("adr", "ADR markdown", m.adr, width, 8)...)
+		lines = append(lines, fmt.Sprintf("  UTF-8 bytes: %d / %d", len([]byte(m.adr.Value())), maxADRBytes))
+	} else {
+		lines = append(lines, m.inputLine("file", "ADR file", m.filePath, width))
+		lines = append(lines, "  read is bounded before AI receives the file")
+	}
+	lines = append(lines,
+		m.choiceLine("max", "Max stories", fmt.Sprintf("%d  left/right (1-20)", m.max)),
+		"",
+		m.actionLine("cancel", "Cancel"),
+		m.actionLine("split", "Propose stories"),
+	)
+	return lines
+}
+
+func (m *Model) reviewLines(width int) []string {
+	lines := []string{
+		"REVIEW PROPOSED STORIES",
+		"Nothing is created until Add selected.",
+		"",
+	}
+	for i := range m.rows {
+		row := &m.rows[i]
+		mark := " "
+		if row.include {
+			mark = "x"
+		}
+		if row.created {
+			mark = "*"
+		}
+		lines = append(lines, m.choiceLine(fmt.Sprintf("include:%d", i), fmt.Sprintf("%d", i+1), "["+mark+"] include"))
+		lines = append(lines, m.inputLine(fmt.Sprintf("title:%d", i), "  Title", row.title, width))
+		lines = append(lines,
+			m.choiceLine(fmt.Sprintf("prio:%d", i), "  Priority", fmt.Sprintf("%d  left/right", row.prio)),
+			m.choiceLine(fmt.Sprintf("effort:%d", i), "  Effort", effortName(row.effort)+"  left/right"),
+		)
+		if row.created {
+			lines = append(lines, "    created")
+		} else if row.err != "" {
+			lines = append(lines, "    error: "+sanitize(row.err))
+		}
+		lines = append(lines, "")
+	}
+	lines = append(lines,
+		m.choiceLine("dest", "Destination", statusName(m.dest)+"  left/right"),
+		"",
+		m.actionLine("back", "Back to source"),
+		m.actionLine("cancel", "Close"),
+		m.actionLine("add", fmt.Sprintf("Add selected (%d)", m.selectedCount())),
+	)
+	return lines
+}
+
+func (m Model) selectedCount() int {
+	count := 0
+	for _, row := range m.rows {
+		if row.include && !row.created && strings.TrimSpace(row.title.Value()) != "" {
+			count++
+		}
+	}
+	return count
+}
+
+func (m Model) inputLine(target, label string, input textinput.Model, width int) string {
+	prefix := "  "
+	if m.focus == target {
+		prefix = "> "
+	}
+	available := max(width-len([]rune(prefix+label+": ")), 1)
+	return prefix + label + ": " + inputDisplay(input, m.focus == target, available)
+}
+
+func (m Model) choiceLine(target, label, value string) string {
+	prefix := "  "
+	if m.focus == target {
+		prefix = "> "
+	}
+	return prefix + label + ": " + sanitize(value)
+}
+
+func (m Model) actionLine(target, label string) string {
+	prefix := "  [ "
+	if m.focus == target {
+		prefix = "> [ "
+	}
+	return prefix + sanitize(label) + " ]"
+}
+
+func (m Model) areaBlock(target, label string, area textarea.Model, width, rows int) []string {
+	prefix := "  "
+	if m.focus == target {
+		prefix = "> "
+	}
+	lines := []string{prefix + label + ":"}
+	return append(lines, areaDisplay(area, m.focus == target, width, rows)...)
+}
+
+func inputDisplay(input textinput.Model, focused bool, width int) string {
+	return formview.Input(input, focused, width, sanitize, cursorViewport)
+}
+
+func areaDisplay(area textarea.Model, focused bool, width, rows int) []string {
+	return formview.Area(area, focused, width, rows, sanitize, cursorViewport)
+}
+
+func cursorViewport(value string, position, width int) string {
+	if width <= 0 {
+		return ""
+	}
+	if width == 1 {
+		return "|"
+	}
+	runes := []rune(value)
+	position = min(max(position, 0), len(runes))
+	start := max(position-width+2, 0)
+	end := min(start+width-1, len(runes))
+	visible := append([]rune(nil), runes[start:end]...)
+	cursor := position - start
+	if cursor >= len(visible) {
+		visible = append(visible, '|')
+	} else {
+		visible = append(visible[:cursor], append([]rune{'|'}, visible[cursor:]...)...)
+	}
+	return ansi.Truncate(string(visible), width, "")
+}
+
+func focusedLine(lines []string) int {
+	for i, line := range lines {
+		if strings.HasPrefix(line, ">") {
+			return i
+		}
+	}
+	return 0
+}
+
+func statusName(status board.Status) string {
+	switch status {
+	case board.StatusTodo:
+		return "To Do"
+	case board.StatusDoing:
+		return "Doing"
+	case board.StatusDone:
+		return "Done"
+	case board.StatusCancelled:
+		return "Cancelled"
+	default:
+		return sanitize(string(status))
+	}
+}
+
+func effortName(value string) string {
+	if value == "" {
+		return "none"
+	}
+	return value
+}
+
+func fit(line string, width int) string { return ansi.Truncate(line, max(width, 0), "") }
+
+func fitBlock(block string, width, height int) string {
+	lines := strings.Split(block, "\n")
+	if len(lines) > height {
+		lines = lines[:height]
+	}
+	for i := range lines {
+		lines[i] = fit(lines[i], width)
+	}
+	return strings.Join(lines, "\n")
+}