package internal

import (
	"crypto/rand"
	"encoding/base64"
	"fmt"
	"log"
	"math/big"
	"os/exec"
	"runtime"
	"strconv"
	"path/filepath"
	"strings"
	"unicode/utf16"
	"unicode/utf8"

	"charm.land/bubbletea/v2"
	"charm.land/lipgloss/v2"
	"u-tabs/internal/style"
)

// Model 主模型
type Model struct {
	activeGroup int
	cursor      int
	selected    map[int]bool
	inputBuf    string
	width       int
	height      int
	launched    string
	history     HistoryState
	pendingCmd  string // Linux: 退出后执行的命令
}

func NewModel() *Model {
	return &Model{
		activeGroup: 0,
		selected:    make(map[int]bool),
	}
}

func (m *Model) Init() tea.Cmd {
	return nil
}

// totalTabs 包含 HISTORY 的总 Tab 数
func (m *Model) totalTabs() int {
	return len(Groups) + 1
}

func (m *Model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.KeyPressMsg:
		return m.handleKey(msg.String())
	case tea.WindowSizeMsg:
		m.width = msg.Width
		m.height = msg.Height
	case ScanCompleteMsg:
		m.history.Projects = msg.Projects
		m.history.Loaded = true
		m.history.Scanning = false
		total := 0
		for _, pd := range msg.Projects {
			total += len(pd.Sessions)
		}
		m.launched = fmt.Sprintf("refreshed: %d projects, %d sessions", len(msg.Projects), total)
		if len(msg.UpdatedIDs) > 0 {
			return m, m.nextSummaryCmd()
		}
		return m, nil
	case SummaryResultMsg:
		m.applySummary(msg.SessionID, msg.Summary, msg.Completed, msg.Pending)
		return m, m.nextSummaryCmd()
	}
	return m, nil
}

// --- 按键分发 ---

func (m *Model) handleKey(s string) (*Model, tea.Cmd) {
	// 全局按键
	switch s {
	case "q", "ctrl+c":
		return m, tea.Quit
	}

	// 数字键跳转 Tab
	if len(s) == 1 && s[0] >= '1' && s[0] <= '9' {
		idx, _ := strconv.Atoi(s)
		if idx <= m.totalTabs() {
			m.activeGroup = idx - 1
			m.cursor = 0
			m.inputBuf = ""
			return m, m.onTabSwitch()
		}
	}

	// HISTORY Tab: tab/left/right 用于面板切换
	if m.IsHistoryTab() {
		return m.handleHistoryKey(s)
	}

	// Workspace Tab 按键
	switch s {
	case "tab", "right", "l":
		m.activeGroup = (m.activeGroup + 1) % m.totalTabs()
		m.cursor = 0
		m.inputBuf = ""
		return m, m.onTabSwitch()
	case "shift+tab", "left", "h":
		m.activeGroup = (m.activeGroup - 1 + m.totalTabs()) % m.totalTabs()
		m.cursor = 0
		m.inputBuf = ""
		return m, m.onTabSwitch()
	}

	return m.handleWorkspaceKey(s)
}

func (m *Model) onTabSwitch() tea.Cmd {
	if m.IsHistoryTab() && !m.history.Loaded && !m.history.Scanning {
		m.history.Scanning = true
		return ScanSessionsCmd()
	}
	return nil
}

// --- Workspace Tab 按键 ---

func (m *Model) handleWorkspaceKey(s string) (*Model, tea.Cmd) {
	switch s {
	case "up", "k":
		m.moveCursor(-1)
	case "down", "j":
		m.moveCursor(1)
	case " ":
		m.toggleMultiSelect()
	case "enter":
		if m.inputBuf != "" {
			return m.launchByInput()
		}
		return m.launchSelected()
	default:
		if len(s) == 1 && s[0] >= '0' && s[0] <= '9' {
			m.inputBuf += s
		}
	}
	return m, nil
}

// --- HISTORY Tab 按键 ---

func (m *Model) handleHistoryKey(s string) (*Model, tea.Cmd) {
	switch s {
	case "up", "k":
		if m.history.FocusPanel == 0 {
			m.moveHistoryDir(-1)
		} else {
			m.moveHistorySess(-1)
		}
	case "down", "j":
		if m.history.FocusPanel == 0 {
			m.moveHistoryDir(1)
		} else {
			m.moveHistorySess(1)
		}
	case "tab", "right", "l":
		if m.history.FocusPanel < 1 {
			m.history.FocusPanel = 1
		}
	case "shift+tab", "left", "h":
		if m.history.FocusPanel > 0 {
			m.history.FocusPanel = 0
		}
	case "enter":
		if m.history.FocusPanel == 0 {
			// 在左栏按 enter 切到中栏
			m.history.FocusPanel = 1
		} else {
			return m.resumeSelected()
		}
	case "n":
		return m.newSessionFromHistory()
	case "r", "f5":
		m.history.Scanning = true
		return m, ScanSessionsCmd()
	}
	return m, nil
}

func (m *Model) moveHistoryDir(dir int) {
	if len(m.history.Projects) == 0 {
		return
	}
	m.history.DirCursor += dir
	maxDir := len(m.history.Projects) + 1 // 含"全部"
	if m.history.DirCursor < 0 {
		m.history.DirCursor = maxDir - 1
	}
	if m.history.DirCursor >= maxDir {
		m.history.DirCursor = 0
	}
	m.history.SessCursor = 0
}

func (m *Model) moveHistorySess(dir int) {
	sessions := m.currentSessions()
	if len(sessions) == 0 {
		return
	}
	m.history.SessCursor += dir
	if m.history.SessCursor < 0 {
		m.history.SessCursor = len(sessions) - 1
	}
	if m.history.SessCursor >= len(sessions) {
		m.history.SessCursor = 0
	}
}

func (m *Model) currentSessions() []*Session {
	if len(m.history.Projects) == 0 {
		return nil
	}
	if m.history.DirCursor == 0 {
		// "全部" — 合并所有目录的会话
		var all []*Session
		for _, pd := range m.history.Projects {
			all = append(all, pd.Sessions...)
		}
		return all
	}
	idx := m.history.DirCursor - 1
	if idx < len(m.history.Projects) {
		return m.history.Projects[idx].Sessions
	}
	return nil
}

func (m *Model) currentSession() *Session {
	sessions := m.currentSessions()
	if len(sessions) == 0 || m.history.SessCursor >= len(sessions) {
		return nil
	}
	return sessions[m.history.SessCursor]
}

func (m *Model) resumeSelected() (*Model, tea.Cmd) {
	s := m.currentSession()
	if s == nil {
		return m, nil
	}
	if runtime.GOOS == "windows" {
		go resumeSession(s)
	} else {
		cwd := s.Cwd
		title := s.CustomTitle
		if title == "" {
			title = s.ID[:8]
		}
		m.pendingCmd = fmt.Sprintf(`printf '\033]0;resume: %s\007' && echo "=== Resuming: %s ===" && cd "%s" && claude -r %s`, title, title, cwd, s.ID)
	}
	m.launched = "resume: " + s.CustomTitle
	return m, nil
}

func (m *Model) newSessionFromHistory() (*Model, tea.Cmd) {
	s := m.currentSession()
	if s == nil {
		return m, nil
	}
	cwd := s.Cwd
	if runtime.GOOS == "windows" {
		cwd = strings.ReplaceAll(cwd, "/", "\\")
	}
	title := filepath.Base(cwd) + " - new"
	if runtime.GOOS == "windows" {
		script := fmt.Sprintf(`$Host.UI.RawUI.WindowTitle = "%s"
Write-Host "=== New Session @ %s ===" -ForegroundColor Cyan
cd "%s"
claude --permission-mode bypassPermissions`, title, cwd, cwd)
		launchInWtWithTitle(cwd, title, script)
	} else {
		m.pendingCmd = fmt.Sprintf(`printf '\033]0;%s\007' && echo "=== New Session @ %s ===" && cd "%s" && claude --permission-mode bypassPermissions`, title, cwd, cwd)
	}
	m.launched = "new: " + filepath.Base(cwd)
	return m, nil
}


// --- AI 摘要 ---

func (m *Model) applySummary(sessionID, summary string, completed, pending []string) {
	if summary == "" {
		return
	}
	for _, pd := range m.history.Projects {
		for _, s := range pd.Sessions {
			if s.ID == sessionID {
				s.AISummary = summary
				s.Completed = completed
				s.Pending = pending
				saveSummaryToCache(sessionID, summary, completed, pending)
				return
			}
		}
	}
}

func (m *Model) nextSummaryCmd() tea.Cmd {
	for _, pd := range m.history.Projects {
		for _, s := range pd.Sessions {
			needSummary := s.AISummary == "" && s.FirstMsg != ""
			needDetail := s.AISummary != "" && len(s.Completed) == 0 && len(s.Pending) == 0
			if (needSummary || needDetail) && s.FilePath != "" {
				return generateSummaryCmd(s.FilePath, s.ID)
			}
		}
	}
	return nil
}
// --- Workspace 光标 ---

func (m *Model) moveCursor(dir int) {
	svcs := WorkspacesByGroup(Groups[m.activeGroup].Label)
	if len(svcs) == 0 {
		return
	}
	m.cursor += dir
	if m.cursor < 0 {
		m.cursor = len(svcs) - 1
	}
	if m.cursor >= len(svcs) {
		m.cursor = 0
	}
}

func (m *Model) toggleMultiSelect() {
	svcs := WorkspacesByGroup(Groups[m.activeGroup].Label)
	if m.cursor < len(svcs) {
		idx := svcs[m.cursor].Index
		if m.selected[idx] {
			delete(m.selected, idx)
		} else {
			m.selected[idx] = true
		}
	}
}

func (m *Model) launchSelected() (*Model, tea.Cmd) {
	if len(m.selected) > 0 {
		var launched []string
		for idx := range m.selected {
			ws := &AllWorkspaces[idx]
			m.LaunchWorkspace(*ws)
			launched = append(launched, ws.Title)
		}
		m.launched = strings.Join(launched, ", ")
		m.selected = make(map[int]bool)
		return m, nil
	}
	svcs := WorkspacesByGroup(Groups[m.activeGroup].Label)
	if m.cursor < len(svcs) {
		ws := svcs[m.cursor]
		m.LaunchWorkspace(ws)
		m.launched = ws.Title
	}
	return m, nil
}

func (m *Model) launchByInput() (*Model, tea.Cmd) {
	num, err := strconv.Atoi(m.inputBuf)
	if err != nil {
		m.inputBuf = ""
		return m, nil
	}
	ws := FindByNumber(num)
	if ws != nil {
		m.LaunchWorkspace(*ws)
		m.launched = ws.Title
	}
	m.inputBuf = ""
	return m, nil
}

// --- View ---

func (m *Model) View() tea.View {
	v := tea.NewView(m.render())
	v.AltScreen = true
	v.MouseMode = tea.MouseModeCellMotion
	v.WindowTitle = "u-tabs"
	return v
}

func (m *Model) render() string {
	if m.width == 0 {
		return "loading..."
	}

	var b strings.Builder

	// ── header: title + tabs ──
	b.WriteString(style.TitleStyle.Render(" u-tabs "))
	sep := style.TabSep.Render(" | ")

	// Workspace Tabs
	for i, g := range Groups {
		if i > 0 {
			b.WriteString(sep)
		}
		label := fmt.Sprintf(" %s %s ", g.Label, g.Desc)
		if i == m.activeGroup {
			gs, ok := style.GroupStyles[g.Label]
			if ok {
				b.WriteString(lipgloss.NewStyle().
					Bold(true).Background(style.BgPanel).Foreground(gs.GetForeground()).
					Render(label))
			} else {
				b.WriteString(style.TabActiveStyle.Render(label))
			}
		} else {
			b.WriteString(style.TabInactiveStyle.Render(label))
		}
	}

	// HISTORY Tab
	b.WriteString(sep)
	histLabel := " HISTORY 历史 "
	if m.IsHistoryTab() {
		gs := style.GroupStyles["HISTORY"]
		b.WriteString(lipgloss.NewStyle().
			Bold(true).Background(style.BgPanel).Foreground(gs.GetForeground()).
			Render(histLabel))
	} else {
		b.WriteString(style.TabInactiveStyle.Render(histLabel))
	}

	b.WriteString("\n")
	b.WriteString(lipgloss.NewStyle().Foreground(style.BgPanel).Render(strings.Repeat("─", m.width)))
	b.WriteString("\n")

	// ── 内容区 ──
	if m.IsHistoryTab() {
		b.WriteString(m.renderHistory())
	} else {
		b.WriteString(m.renderWorkspace())
	}

	// ── footer ──
	b.WriteString("\n")
	if m.inputBuf != "" {
		b.WriteString(style.InputStyle.Render(fmt.Sprintf(" ▶ num:%s [Enter]go [Esc]cancel", m.inputBuf)))
	}
	if m.launched != "" {
		b.WriteString(lipgloss.NewStyle().Foreground(style.Accent).Render(fmt.Sprintf(" ✓ %s", m.launched)))
		m.launched = ""
	}
	b.WriteString("\n")

	helpParts := m.renderHelp()
	b.WriteString(" " + strings.Join(helpParts, "  "))

	if hint := ConfigHint(); hint != "" {
		b.WriteString("\n" + hint)
	}
	return b.String()
}

func (m *Model) renderHelp() []string {
	if m.IsHistoryTab() {
		return []string{
			m.fmtHelp("j/k", "sel"),
			m.fmtHelp("Tab", "→panel"),
			m.fmtHelp("Enter", "resume"),
		m.fmtHelp("n", "new"),
				m.fmtHelp("1-"+fmt.Sprintf("%d", m.totalTabs()), "tab"),
			m.fmtHelp("r/F5", "refresh"),
			m.fmtHelp("q", "quit"),
		}
	}
	return []string{
		m.fmtHelp("j/k", "sel"),
		m.fmtHelp("Enter", "run"),
		m.fmtHelp("Space", "multi"),
		m.fmtHelp("Tab", "group"),
		m.fmtHelp("q", "quit"),
	}
}

// --- Workspace 渲染 ---

func (m *Model) renderWorkspace() string {
	listW := max(42, min(65, m.width*55/100))
	detailW := max(30, m.width-listW-3)

	g := Groups[m.activeGroup]
	gs, _ := style.GroupStyles[g.Label]
	svcs := WorkspacesByGroup(g.Label)
	if len(svcs) == 0 {
		return style.SubtitleStyle.Render("  empty")
	}

	// 预留 header(2) + footer(2)，面板边框+标题占 3 行
	availH := max(3, m.height-4-3)
	start, end := viewport(m.cursor, len(svcs), availH)

	// 左栏: 列表
	var left strings.Builder
	innerW := listW - 4

	// 计算 title 最大宽度用于对齐
	maxTitleW := 0
	for _, ws := range svcs {
		if tw := stringWidth(ws.Title); tw > maxTitleW {
			maxTitleW = tw
		}
	}

	for i := start; i < end; i++ {
		ws := svcs[i]
		cur := " "
		if i == m.cursor {
			cur = "▸"
		}
		mark := " "
		if m.selected[ws.Index] {
			mark = "✓"
		}

		paddedTitle := padRightByWidth(ws.Title, maxTitleW)

		if i == m.cursor {
			// 选中行：纯文本，让 SelStyle 统一着色
			prefix := cur + " " + mark + " " + fmt.Sprintf("%02d", ws.N) + " "
			remainW := max(10, innerW-len(prefix))
			text := truncateByWidth(paddedTitle+"  "+ws.Prompt, remainW)
			left.WriteString(style.SelStyle.Width(innerW).Render(prefix + text))
		} else {
			// 非选中行：子样式着色
			markStr := " "
			if m.selected[ws.Index] {
				markStr = style.MarkStyle.Render("✓")
			}
			num := style.NumStyle.Render(fmt.Sprintf("%02d", ws.N))
			prefix := cur + " " + markStr + " " + num + " "
			remainW := max(10, innerW-lipgloss.Width(prefix))
			text := truncateByWidth(paddedTitle+"  "+ws.Prompt, remainW)
			left.WriteString(style.NormStyle.Render(prefix + text))
		}
		left.WriteString("\n")
	}

	groupHeader := gs.Render(fmt.Sprintf(" %s · %d ", g.Label, len(svcs)))
	listBox := lipgloss.NewStyle().
		Border(lipgloss.NormalBorder()).
		BorderForeground(style.BgPanel).
		Width(listW).
		Padding(0, 1).
		Render(groupHeader + "\n" + left.String())

	// 右栏: 详情
	var right strings.Builder
	if m.cursor < len(svcs) {
		ws := svcs[m.cursor]

		right.WriteString(style.DetailTitle.Render(" detail "))
		right.WriteString(lipgloss.NewStyle().Foreground(style.BgPanel).Render(strings.Repeat("─", detailW-10)))
		right.WriteString("\n\n")

		rows := []struct {
			key string
			val string
			sty lipgloss.Style
		}{
			{"dir", ws.Dir, style.ValStyle},
			{"no", fmt.Sprintf("%02d · %s", ws.N, ws.Group), style.NumStyle},
			{"desc", ws.Prompt, style.ValStyle},
			{"tech", ws.Tech, style.TechStyle},
			{"deploy", ws.Deploy, style.DeployStyle},
		}
		for _, r := range rows {
			right.WriteString("  ")
			right.WriteString(style.KeyStyle.Render(r.key))
			right.WriteString("  ")
			right.WriteString(r.sty.Render(r.val))
			right.WriteString("\n")
		}

		right.WriteString("\n")
		right.WriteString(lipgloss.NewStyle().Foreground(style.BgPanel).Render("  " + strings.Repeat("─", detailW-6)))
		right.WriteString("\n")
		hintCmd := "wt"
			if runtime.GOOS != "windows" {
				hintCmd = "bash"
			}
			right.WriteString(lipgloss.NewStyle().Foreground(style.Accent).Italic(true).Render("  $ "+hintCmd+" → CC @"+ws.Title))
		right.WriteString("\n")
		right.WriteString(lipgloss.NewStyle().Foreground(style.Dim).Render("  [Enter]start  [Space]multi"))
	} else {
		right.WriteString(lipgloss.NewStyle().Foreground(style.Dim).Render(" ← select to view"))
	}

	detailBox := lipgloss.NewStyle().
		Border(lipgloss.NormalBorder()).
		BorderForeground(style.BgPanel).
		Width(detailW).
		Padding(0, 1).
		Render(right.String())

	return lipgloss.JoinHorizontal(lipgloss.Left, listBox, " ", detailBox)
}

// --- HISTORY 三栏渲染 ---

func (m *Model) renderHistory() string {
	if !m.history.Loaded && !m.history.Scanning {
		return style.ScanningStyle.Render("  press Tab to load sessions...")
	}
	if len(m.history.Projects) == 0 && m.history.Scanning {
		return style.ScanningStyle.Render("  scanning sessions...")
	}
	if len(m.history.Projects) == 0 {
		return style.SubtitleStyle.Render("  no sessions found")
	}

	// 三个独立面板，Width() 含边框，内容宽度 = Width - 2
	avail := m.width - 8
	dirW := max(18, avail*20/100)
	sessW := max(28, avail*40/100)
	detailW := avail - dirW - sessW
	listH := max(3, m.height-7)

	dirCw := dirW - 2
	sessCw := sessW - 2
	detailCw := detailW - 2

	dirLines := m.dirColumnLines(dirCw, listH-1)
	sessLines := m.sessColumnLines(sessCw, listH-1)
	detailLines := m.detailColumnLines(detailCw, listH-1)

	// 统一高度：补空行到相同行数
	maxRows := min(listH-1, max(max(len(dirLines), len(sessLines)), len(detailLines)))
	padLines := func(lines []string, w int) string {
		for len(lines) < maxRows {
			lines = append(lines, strings.Repeat(" ", w))
		}
		return strings.Join(lines, "\n")
	}

	panelSty := lipgloss.NewStyle().
		Border(lipgloss.RoundedBorder()).
		BorderForeground(style.BgPanel)

	dirBox := panelSty.Width(dirW).Render(
		style.DetailTitle.Render("dirs") + "\n" + padLines(dirLines, dirCw))
	sessBox := panelSty.Width(sessW).Render(
		style.DetailTitle.Render("sessions") + "\n" + padLines(sessLines, sessCw))
	detailBox := panelSty.Width(detailW).Render(
		style.DetailTitle.Render("detail") + "\n" + padLines(detailLines, detailCw))

	return lipgloss.JoinHorizontal(lipgloss.Top, dirBox, " ", sessBox, " ", detailBox)
}

func (m *Model) dirColumnLines(w, listH int) []string {
	var lines []string
	total := len(m.history.Projects) + 1
	start, end := viewport(m.history.DirCursor, total, listH)

	prefixW := 3 // " " + cur(1) + " "

	buildDirLine := func(cur, name, cnt string, selected bool) string {
		cntW := stringWidth(cnt)
		nameW := max(2, w-prefixW-cntW)
		name = truncateByWidth(name, nameW)
		line := " " + cur + " " + padRightByWidth(name, nameW) + cnt
		sty := style.NormStyle
		if selected {
			sty = style.SelStyle
		}
		return sty.Render(padRightByWidth(truncateByWidth(line, w), w))
	}

	if start == 0 {
		totalSess := 0
		for _, pd := range m.history.Projects {
			totalSess += len(pd.Sessions)
		}
		cur := " "
		if m.history.DirCursor == 0 {
			cur = "▸"
		}
		lines = append(lines, buildDirLine(cur, "全部", fmt.Sprintf("(%d)", totalSess),
			m.history.DirCursor == 0 && m.history.FocusPanel == 0))
	}

	for i := 0; i < len(m.history.Projects); i++ {
		if i+1 < start || i+1 >= end {
			continue
		}
		pd := m.history.Projects[i]
		cur := " "
		if m.history.DirCursor == i+1 {
			cur = "▸"
		}
		lines = append(lines, buildDirLine(cur, pd.DirShort, fmt.Sprintf("(%d)", len(pd.Sessions)),
			m.history.DirCursor == i+1 && m.history.FocusPanel == 0))
	}
	return lines
}

func (m *Model) sessColumnLines(w, listH int) []string {
	sessions := m.currentSessions()
	if len(sessions) == 0 {
		return []string{style.SubtitleStyle.Render(fitWidth("  no sessions", w))}
	}

	prefixW := 15 // " " + cur(2) + timeStr(11) + " "
	textW := max(8, w-prefixW)

	// 预渲染每个 session 为 1~N 行
	type sessBlock struct {
		lines []string
	}
	var blocks []sessBlock
	totalLines := 0
	curLineOffset := 0

	for i, s := range sessions {
		cur := "  "
		if i == m.history.SessCursor {
			cur = "▸ "
		}
		timeStr := s.StartTime.Local().Format("01-02 15:04")
		title := s.DisplayTitle()

		wrapped := wrapByWidth(title, textW)
		if len(wrapped) == 0 {
			wrapped = []string{""}
		}

		sty := style.NormStyle
		if i == m.history.SessCursor && m.history.FocusPanel == 1 {
			sty = style.SelStyle
		}

		var blockLines []string
		for li, part := range wrapped {
			var line string
			if li == 0 {
				line = fmt.Sprintf(" %s%s %s", cur, timeStr, part)
			} else {
				line = strings.Repeat(" ", prefixW) + part
			}
			blockLines = append(blockLines, sty.Render(padRightByWidth(truncateByWidth(line, w), w)))
		}

		if i == m.history.SessCursor {
			curLineOffset = totalLines
		}
		totalLines += len(blockLines)
		blocks = append(blocks, sessBlock{lines: blockLines})
	}

	// 按总行数做 viewport
	startLine, endLine := viewport(curLineOffset, totalLines, listH)

	var allLines []string
	for _, b := range blocks {
		allLines = append(allLines, b.lines...)
	}
	if endLine > len(allLines) {
		endLine = len(allLines)
	}
	return allLines[startLine:endLine]
}

func (m *Model) detailColumnLines(w, listH int) []string {
	s := m.currentSession()
	if s == nil {
		return []string{lipgloss.NewStyle().Foreground(style.Dim).Render(fitWidth(" ← select to view", w))}
	}

	sepSty := lipgloss.NewStyle().Foreground(style.BgPanel)
	var lines []string

	// Title
	lines = append(lines, style.DetailTitle.Render(fitWidth(" "+s.DisplayTitle(), w)))

	// Separator
	lines = append(lines, sepSty.Render(fitWidth(strings.Repeat("─", w), w)))

	// Key-value rows
	kvRows := []struct{ k, v string }{
		{"dir", s.Cwd},
		{"time", fmt.Sprintf("%s ~ %s", s.StartTime.Local().Format("01-02 15:04"), s.EndTime.Local().Format("15:04"))},
		{"msgs", fmt.Sprintf("%d", s.MsgCount)},
	}
	for _, r := range kvRows {
		line := fmt.Sprintf("  %-4s %s", r.k, r.v)
		lines = append(lines, style.NormStyle.Render(fitWidth(line, w)))
	}

	// Summary
	if summary := s.DisplaySummary(); summary != "" {
		lines = append(lines, sepSty.Render(fitWidth(strings.Repeat("─", w), w)))
		lines = append(lines, style.SessionSummaryStyle.Render(fitWidth("  "+summary, w)))
	}

	// Completed items
	if len(s.Completed) > 0 {
		lines = append(lines, sepSty.Render(fitWidth(strings.Repeat("─", w), w)))
		lines = append(lines, lipgloss.NewStyle().Foreground(style.Success).Bold(true).Render(fitWidth(" ✓ 已完成", w)))
		for _, item := range s.Completed {
			lines = append(lines, style.NormStyle.Render(fitWidth("   · "+cleanText(item), w)))
		}
	}

	// Pending items
	if len(s.Pending) > 0 {
		lines = append(lines, sepSty.Render(fitWidth(strings.Repeat("─", w), w)))
		lines = append(lines, lipgloss.NewStyle().Foreground(style.Warning).Bold(true).Render(fitWidth(" ○ 待办", w)))
		for _, item := range s.Pending {
			lines = append(lines, style.NormStyle.Render(fitWidth("   · "+cleanText(item), w)))
		}
	}

	// Hint
	lines = append(lines, lipgloss.NewStyle().Foreground(style.Dim).Render(fitWidth("  [Enter]resume", w)))

	if len(lines) > listH {
		lines = lines[:listH]
	}
	return lines
}

// --- 工具 ---

func (m *Model) fmtHelp(key, desc string) string {
	return lipgloss.NewStyle().Foreground(style.Accent).Render(key) +
		lipgloss.NewStyle().Foreground(style.Dim).Render(":" + desc)
}

// viewport 返回 [start, end) 区间，保证 cursor 在可见范围内
func viewport(cursor, total, height int) (int, int) {
	if total <= height {
		return 0, total
	}
	half := height / 2
	start := cursor - half
	if start < 0 {
		start = 0
	}
	end := start + height
	if end > total {
		end = total
		start = end - height
		if start < 0 {
			start = 0
		}
	}
	return start, end
}

// stringWidth 返回字符串的终端显示宽度
func stringWidth(s string) int {
	w := 0
	for _, r := range s {
		w += runeWidth(r)
	}
	return w
}

// padRightByWidth 补空格到指定视觉宽度
func padRightByWidth(s string, targetW int) string {
	w := stringWidth(s)
	if w >= targetW {
		return s
	}
	return s + strings.Repeat(" ", targetW-w)
}

// wrapByWidth 按显示宽度换行，返回多行文本
func wrapByWidth(s string, maxW int) []string {
	if maxW <= 0 || s == "" {
		return []string{s}
	}
	var lines []string
	for s != "" {
		cut := truncateByWidth(s, maxW)
		lines = append(lines, cut)
		s = s[len(cut):]
	}
	return lines
}

// fitWidth 截断并填充到精确视觉宽度
func fitWidth(s string, w int) string {
	return padRightByWidth(truncateByWidth(s, w), w)
}

// truncateByWidth 按显示宽度截断字符串，不切断多字节字符
func truncateByWidth(s string, maxW int) string {
	w := 0
	for i := 0; i < len(s); {
		r, size := utf8.DecodeRuneInString(s[i:])
		rw := runeWidth(r)
		if w+rw > maxW {
			return s[:i]
		}
		w += rw
		i += size
	}
	return s
}

// runeWidth 返回单个 rune 的终端显示宽度 (CJK=2, 其他=1)
func runeWidth(r rune) int {
	if r >= 0x1100 &&
		(r <= 0x115F || r == 0x2329 || r == 0x232A ||
			(r >= 0x2E80 && r <= 0xA4CF && r != 0x303F) ||
			(r >= 0xAC00 && r <= 0xD7A3) ||
			(r >= 0xF900 && r <= 0xFAFF) ||
			(r >= 0xFE10 && r <= 0xFE19) ||
			(r >= 0xFE30 && r <= 0xFE6F) ||
			(r >= 0xFF01 && r <= 0xFF60) ||
			(r >= 0xFFE0 && r <= 0xFFE6) ||
			(r >= 0x20000 && r <= 0x2FFFD) ||
			(r >= 0x30000 && r <= 0x3FFFD)) {
		return 2
	}
	return 1
}

func launchInWtWithTitle(dir, tabTitle, script string) {
	if runtime.GOOS == "windows" {
		encoded := encodePSCommand(script)
		color := fmt.Sprintf("#%02X%02X%02X", randRange(80, 255), randRange(80, 255), randRange(80, 255))
		args := []string{"-w", "0", "-d", dir, "--tabColor", color}
		if tabTitle != "" {
			args = append(args, "--title", tabTitle)
		}
		args = append(args, "pwsh", "-NoExit", "-EncodedCommand", encoded)
		cmd := exec.Command("wt.exe", args...)
		if err := cmd.Start(); err != nil {
			log.Printf("[u-tabs] launch fail: %v", err)
		}
	}
}

func (m *Model) LaunchWorkspace(ws Workspace) {
	script := buildLaunchScript(ws)
	if runtime.GOOS != "windows" {
		m.pendingCmd = "cd '" + ws.Dir + "' && " + script
		return
	}
	launchInWtWithTitle(ws.Dir, "", script)
}

// GetPendingCmd 返回退出后需执行的命令（Linux 用）
func (m *Model) GetPendingCmd() string {
	return m.pendingCmd
}

func resumeSession(s *Session) {
	cwd := s.Cwd
	if runtime.GOOS == "windows" {
		cwd = strings.ReplaceAll(s.Cwd, "/", "\\")
	}
	title := s.CustomTitle
	if title == "" {
		title = s.ID[:8]
	}
	var script string
	if runtime.GOOS == "windows" {
		script = fmt.Sprintf(`$Host.UI.RawUI.WindowTitle = "resume: %s"
Write-Host "=== Resuming: %s ===" -ForegroundColor Cyan
cd "%s"
claude -r %s --permission-mode bypassPermissions`, title, title, cwd, s.ID)
	} else {
		script = fmt.Sprintf(`printf '\033]0;resume: %s\007' && echo "=== Resuming: %s ===" && cd "%s" && claude -r %s`, title, title, cwd, s.ID)
	}
	launchInWtWithTitle(cwd, "", script)
}

func buildLaunchScript(ws Workspace) string {
	if runtime.GOOS == "windows" {
		return fmt.Sprintf(`$Host.UI.RawUI.WindowTitle = "%s"
Write-Host "=== %s ===" -ForegroundColor Cyan
Write-Host "Prompt: %s" -ForegroundColor Yellow
cd "%s"
claude --name "%s" --permission-mode bypassPermissions`,
			ws.Title, ws.Title, ws.Prompt, ws.Dir, ws.Title)
	}
	return fmt.Sprintf(`printf '\033]0;%s\007' && echo "=== %s ===" && echo "Prompt: %s" && cd "%s" && claude --name "%s"`,
		ws.Title, ws.Title, ws.Prompt, ws.Dir, ws.Title)
}

func encodePSCommand(script string) string {
	u16 := utf16.Encode([]rune(script))
	b := make([]byte, len(u16)*2)
	for i, r := range u16 {
		b[i*2] = byte(r)
		b[i*2+1] = byte(r >> 8)
	}
	return base64.StdEncoding.EncodeToString(b)
}

func randRange(min, max int) int {
	n, _ := rand.Int(rand.Reader, big.NewInt(int64(max-min)))
	return min + int(n.Int64())
}