package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"os"
	"os/exec"
	"regexp"
	"runtime"
	"strconv"
	"strings"
	"time"

	"github.com/charmbracelet/bubbles/textinput"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/glamour"
	"github.com/charmbracelet/lipgloss"
	"github.com/muesli/termenv"
)

type question struct {
	key     string
	title   string
	prompt  string
	def     string
	secret  bool
	example string
	options []string
}

var questions = []question{
	{"PLATFORM_ACCOUNT", "Autonomy Studio account", "Enter the email address used in Autonomy Studio.", "", false, "name@example.com", nil},
	{"PLATFORM_REGISTRATION_CODE", "Registration code", "Enter the 6-digit code created in Launcher Platform management.", "", false, "000000", nil},
	{"USAGE_TYPE", "Usage type", "Select how this device will be used.", "개인용", false, "", []string{"개인용", "교보재용"}},
	{"DEVICE_HOSTNAME", "Device hostname", "Hostname to register this device with. Press Enter to keep the detected hostname.", "", false, "", nil},
	{"WORKSPACE_ROOT", "Workspace", "Which directory should the platform expose as the workspace?", "~/autonomy-studio/workspaces", false, "", nil},
	{"CAMERA_VIDEO_DEVICE", "Video device", "Which V4L2 camera device should be used?", "/dev/video0", false, "/dev/video0", nil},
}

type model struct {
	input                        textinput.Model
	envPath                      string
	index                        int
	values                       map[string]string
	choices                      map[string]int
	provision                    map[string]string
	provisionSummary             string
	showProvision                bool
	loading                      bool
	err                          error
	done                         bool
	width                        int
	height                       int
}

type provisionResultMsg struct {
	values  map[string]string
	summary string
	err     error
}

var (
	accent        = lipgloss.Color("81")
	accentStrong  = lipgloss.Color("87")
	muted         = lipgloss.Color("245")
	panelBorder   = lipgloss.Color("240")
	panelStyle    = lipgloss.NewStyle().Border(lipgloss.RoundedBorder()).BorderForeground(panelBorder).Padding(1, 2)
	brandStyle    = lipgloss.NewStyle().Bold(true).Foreground(accentStrong)
	titleStyle    = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("255"))
	promptStyle   = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("255"))
	valueStyle    = lipgloss.NewStyle().Foreground(lipgloss.Color("229"))
	mutedStyle    = lipgloss.NewStyle().Foreground(muted)
	errStyle      = lipgloss.NewStyle().Foreground(lipgloss.Color("203"))
	okStyle       = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("42"))
	inputStyle    = lipgloss.NewStyle().Border(lipgloss.RoundedBorder()).BorderForeground(accent).Padding(0, 1)
	keyStyle      = lipgloss.NewStyle().Foreground(lipgloss.Color("244"))
	selectedStyle = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("255")).Background(lipgloss.Color("24")).Padding(0, 1)
	optionStyle   = lipgloss.NewStyle().Foreground(lipgloss.Color("250")).Padding(0, 1)
)

func init() {
	lipgloss.SetColorProfile(termenv.ANSI256)
}

func envDefault(key, fallback string) string {
	if value := os.Getenv(key); value != "" {
		return value
	}
	return fallback
}

func initialModel(envPath string) model {
	input := textinput.New()
	input.Prompt = ""
	input.CharLimit = 512
	input.Width = 56
	input.Focus()
	values := map[string]string{}
	m := model{input: input, envPath: envPath, values: values, choices: map[string]int{}, provision: map[string]string{}, width: 86, height: 24}
	m.loadQuestion()
	return m
}

func (m *model) loadQuestion() {
	q := questions[m.index]
	value := envDefault(q.key, questionDefault(q))
	if existing, ok := m.values[q.key]; ok {
		value = existing
	}
	if len(q.options) > 0 {
		m.choices[q.key] = optionIndex(q.options, value)
		m.input.SetValue("")
		return
	}
	if _, ok := m.values[q.key]; ok {
		m.input.SetValue(value)
	} else if q.key == "DEVICE_HOSTNAME" || q.key == "WORKSPACE_ROOT" {
		m.input.SetValue(value)
	} else {
		m.input.SetValue("")
	}
	m.input.Placeholder = q.example
	m.input.EchoMode = textinput.EchoNormal
	if q.secret {
		m.input.EchoMode = textinput.EchoPassword
		m.input.EchoCharacter = '*'
	}
}

func questionDefault(q question) string {
	if q.key == "DEVICE_HOSTNAME" {
		hostname, _ := os.Hostname()
		if strings.TrimSpace(hostname) != "" {
			return strings.TrimSpace(hostname)
		}
	}
	if q.key == "WORKSPACE_ROOT" {
		return envDefault("WORKSPACE_ROOT", "~/autonomy-studio/workspaces")
	}
	return q.def
}

func questionExample(q question) string {
	return q.example
}

func (m model) Init() tea.Cmd {
	return textinput.Blink
}

func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case provisionResultMsg:
		m.loading = false
		if msg.err != nil {
			m.err = msg.err
			return m, nil
		}
		m.err = nil
		m.provision = msg.values
		m.provisionSummary = msg.summary
		m.showProvision = true
		return m, nil
	case tea.WindowSizeMsg:
		m.width = msg.Width
		m.height = msg.Height
		m.input.Width = max(28, min(64, msg.Width-24))
	case tea.KeyMsg:
		if isTerminalColorResponse(msg.String()) {
			return m, nil
		}
		if m.loading {
			switch msg.String() {
			case "ctrl+c", "esc":
				return m, tea.Quit
			}
			return m, nil
		}
		if m.showProvision {
			switch msg.String() {
			case "ctrl+c", "esc":
				return m, tea.Quit
			case "enter":
				m.showProvision = false
				m.index++
				m.loadQuestion()
				return m, nil
			case "left":
				m.showProvision = false
				m.index = 2
				m.loadQuestion()
				return m, nil
			}
			return m, nil
		}
		switch msg.String() {
		case "ctrl+c", "esc":
			return m, tea.Quit
		case "enter":
			q := questions[m.index]
			value := m.currentValue()
			if err := m.validate(q, value); err != nil {
				m.err = err
				break
			}
			m.err = nil
			m.values[q.key] = value
			if q.key == "WORKSPACE_ROOT" {
				account := strings.TrimSpace(m.values["PLATFORM_ACCOUNT"])
				registrationCode := strings.TrimSpace(m.values["PLATFORM_REGISTRATION_CODE"])
				usageType := strings.TrimSpace(m.values["USAGE_TYPE"])
				deviceHostname := strings.TrimSpace(m.values["DEVICE_HOSTNAME"])
				workspaceRoot := strings.TrimSpace(value)
				m.loading = true
				return m, provisionWithRegistrationCode(account, registrationCode, usageType, deviceHostname, workspaceRoot, m.width)
			}
			if m.index == len(questions)-1 {
				m.err = m.writeEnv()
				m.done = m.err == nil
				return m, tea.Quit
			}
			m.index++
			m.loadQuestion()
		case "backspace", "ctrl+h", "ctrl+?":
			m.err = nil
		case "up":
			if len(questions[m.index].options) > 0 {
				m.prevChoice()
			}
		case "down":
			if len(questions[m.index].options) > 0 {
				m.nextChoice()
			}
		case "left":
			if m.index > 0 {
				m.values[questions[m.index].key] = m.currentValue()
				m.index--
				m.loadQuestion()
				m.err = nil
				return m, nil
			}
		}
	}

	if len(questions[m.index].options) > 0 {
		return m, nil
	}
	var cmd tea.Cmd
	m.input, cmd = m.input.Update(msg)
	m.input.SetValue(sanitizeInput(m.input.Value()))
	return m, cmd
}

func (m model) currentValue() string {
	q := questions[m.index]
	if len(q.options) > 0 {
		index := m.choices[q.key]
		if index < 0 || index >= len(q.options) {
			index = optionIndex(q.options, questionDefault(q))
		}
		return q.options[index]
	}
	value := strings.TrimSpace(sanitizeInput(m.input.Value()))
	if value == "" {
		return questionDefault(q)
	}
	return value
}

func (m *model) nextChoice() {
	q := questions[m.index]
	if len(q.options) == 0 {
		return
	}
	m.choices[q.key] = (m.choices[q.key] + 1) % len(q.options)
	m.err = nil
}

func (m *model) prevChoice() {
	q := questions[m.index]
	if len(q.options) == 0 {
		return
	}
	next := m.choices[q.key] - 1
	if next < 0 {
		next = len(q.options) - 1
	}
	m.choices[q.key] = next
	m.err = nil
}

func optionIndex(options []string, value string) int {
	for i, option := range options {
		if strings.EqualFold(option, value) {
			return i
		}
	}
	return 0
}

func (m model) validate(q question, value string) error {
	if q.key == "PLATFORM_ACCOUNT" && !strings.Contains(value, "@") {
		return fmt.Errorf("Enter the account email address.")
	}
	if q.key == "PLATFORM_REGISTRATION_CODE" && !regexp.MustCompile(`^\d{6}$`).MatchString(strings.TrimSpace(value)) {
		return fmt.Errorf("Enter the 6-digit registration code.")
	}
	return nil
}

func isTerminalColorResponse(value string) bool {
	return strings.Contains(value, "rgb:") || strings.HasPrefix(value, "]10;") || strings.HasPrefix(value, "]11;")
}

func sanitizeInput(value string) string {
	value = stripAfter(value, "\x1b]10;")
	value = stripAfter(value, "\x1b]11;")
	value = stripAfter(value, "]10;")
	value = stripAfter(value, "]11;")
	value = stripAfter(value, "rgb:")
	if value == "]" || value == "\\" || value == "\x1b\\" {
		return ""
	}
	return strings.ReplaceAll(value, "\x1b\\", "")
}

func stripAfter(value string, marker string) string {
	if index := strings.Index(value, marker); index >= 0 {
		return value[:index]
	}
	return value
}

func shellQuote(value string) string {
	return "'" + strings.ReplaceAll(value, "'", "'\\''") + "'"
}

func provisionDevice(account string, password string, usageType string, deviceHostname string, workspaceRoot string, width int) tea.Cmd {
	return func() tea.Msg {
		values, summary, err := fetchProvision(account, password, usageType, deviceHostname, workspaceRoot, width)
		return provisionResultMsg{values: values, summary: summary, err: err}
	}
}

func buildProvisionDevice(deviceHostname string, workspaceRoot string, usageType string) map[string]string {
	device := detectDevice()
	if strings.TrimSpace(deviceHostname) != "" {
		device["hostname"] = strings.TrimSpace(deviceHostname)
	}
	sshUser := envDefault("PLATFORM_AGENT_USER", envDefault("USER", ""))
	if sshUser != "" {
		device["sshUser"] = sshUser
	}
	device["workspaceRoot"] = strings.TrimSpace(workspaceRoot)
	device["usageType"] = normalizeUsageType(usageType)
	return device
}

func provisionWithRegistrationCode(account string, registrationCode string, usageType string, deviceHostname string, workspaceRoot string, width int) tea.Cmd {
	return func() tea.Msg {
		account = strings.TrimSpace(account)
		registrationCode = strings.TrimSpace(registrationCode)
		usageType = normalizeUsageType(usageType)
		if strings.TrimSpace(workspaceRoot) == "" {
			workspaceRoot = "~/autonomy-studio/workspaces"
		}
		if account == "" || registrationCode == "" {
			return provisionResultMsg{err: fmt.Errorf("Autonomy Studio account and registration code are required.")}
		}
		baseURL := strings.TrimRight(strings.TrimSpace(envDefault("PLATFORM_PROVISION_URL", "https://portal-api.autonomystudio.net/api/provision")), "/")
		if baseURL == "" {
			return provisionResultMsg{err: fmt.Errorf("PLATFORM_PROVISION_URL is required for device registration.")}
		}

		device := buildProvisionDevice(deviceHostname, workspaceRoot, usageType)
		payload := map[string]any{
			"account":       account,
			"userCode":      registrationCode,
			"hostname":      device["hostname"],
			"os":            device["os"],
			"arch":          device["arch"],
			"kernel":        device["kernel"],
			"distro":        device["distro"],
			"usageType":     usageType,
			"sshUser":       device["sshUser"],
			"workspaceRoot": workspaceRoot,
			"device":        device,
		}
		body, status, err := postProvision(baseURL+"/device-authorizations/consume", payload)
		if err != nil {
			return provisionResultMsg{err: fmt.Errorf("Device registration failed: %w", err)}
		}
		if status < 200 || status >= 300 {
			return provisionResultMsg{err: fmt.Errorf("Device registration failed: HTTP %d: %s", status, strings.TrimSpace(string(body)))}
		}
		values, err := parseProvisionValues(body)
		if err != nil {
			return provisionResultMsg{err: err}
		}
		return provisionResultMsg{values: values, summary: renderProvisionSummary(values, device, usageType, "Registered", width)}
	}
}

func fetchProvision(account string, password string, usageType string, deviceHostname string, workspaceRoot string, width int) (map[string]string, string, error) {
	account = strings.TrimSpace(account)
	password = strings.TrimSpace(password)
	usageType = normalizeUsageType(usageType)
	deviceHostname = strings.TrimSpace(deviceHostname)
	workspaceRoot = strings.TrimSpace(workspaceRoot)
	if workspaceRoot == "" {
		workspaceRoot = "~/autonomy-studio/workspaces"
	}
	if account == "" || password == "" {
		return nil, "", fmt.Errorf("Autonomy Studio account and password are required.")
	}
	url := strings.TrimSpace(envDefault("PLATFORM_PROVISION_URL", "https://portal-api.autonomystudio.net/api/provision"))
	if url == "" {
		return nil, "", fmt.Errorf("PLATFORM_PROVISION_URL is required for account provisioning.")
	}

	device := detectDevice()
	if deviceHostname != "" {
		device["hostname"] = deviceHostname
	}
	sshUser := envDefault("PLATFORM_AGENT_USER", envDefault("USER", ""))
	if sshUser != "" {
		device["sshUser"] = sshUser
	}
	device["workspaceRoot"] = workspaceRoot
	payload := map[string]any{
		"account":       account,
		"password":      password,
		"hostname":      device["hostname"],
		"os":            device["os"],
		"arch":          device["arch"],
		"kernel":        device["kernel"],
		"distro":        device["distro"],
		"device":        device,
		"usageType":     usageType,
		"sshUser":       sshUser,
		"workspaceRoot": workspaceRoot,
	}
	device["usageType"] = usageType
	respBody, status, err := postProvision(url, payload)
	if err != nil {
		return nil, "", fmt.Errorf("Provision request failed: %w", err)
	}
	if status == http.StatusBadRequest {
		legacyPayload := map[string]any{
			"account":       account,
			"password":      password,
			"hostname":      device["hostname"],
			"usageType":     usageType,
			"sshUser":       sshUser,
			"workspaceRoot": workspaceRoot,
		}
		respBody, status, err = postProvision(url, legacyPayload)
		if err != nil {
			return nil, "", fmt.Errorf("Provision retry failed: %w", err)
		}
	}
	if status < 200 || status >= 300 {
		detail := strings.TrimSpace(string(respBody))
		if detail != "" {
			return nil, "", fmt.Errorf("Provision request failed: HTTP %d: %s", status, detail)
		}
		return nil, "", fmt.Errorf("Provision request failed: HTTP %d", status)
	}

	values, err := parseProvisionValues(respBody)
	if err != nil {
		return nil, "", err
	}
	return values, renderProvisionSummary(values, device, usageType, "Received", width), nil
}

func parseProvisionValues(respBody []byte) (map[string]string, error) {
	var data map[string]any
	if err := json.Unmarshal(respBody, &data); err != nil {
		return nil, fmt.Errorf("Provision response must be JSON.")
	}
	values := map[string]string{}
	setProvision(values, "INSTALL_TAILSCALE", firstBool(data, "installTailscale", "install_tailscale", "tailscaleEnabled", "tailscale_enabled"))
	setProvision(values, "TAILSCALE_AUTH_KEY", firstString(data, "tailscaleAuthKey", "tailscale_auth_key", "authKey", "auth_key"))
	setProvision(values, "TAILSCALE_LOGIN_SERVER", firstString(data, "tailscaleLoginServer", "tailscale_login_server", "loginServer", "login_server"))
	setProvision(values, "TAILSCALE_HOSTNAME", firstString(data, "tailscaleHostname", "tailscale_hostname", "hostname"))
	setProvision(values, "TAILSCALE_EXTRA_ARGS", firstString(data, "tailscaleExtraArgs", "tailscale_extra_args", "extraArgs", "extra_args"))
	setProvision(values, "AGENT_GATEWAY_TOKEN", firstString(data, "agentGatewayToken", "agent_gateway_token", "gatewayToken", "gateway_token"))
	if values["INSTALL_TAILSCALE"] == "" && values["TAILSCALE_AUTH_KEY"] != "" {
		values["INSTALL_TAILSCALE"] = "true"
	}
	return values, nil
}

func normalizeUsageType(value string) string {
	switch strings.ToLower(strings.TrimSpace(value)) {
	case "교보재용", "use for class", "class", "education", "educational", "training", "classroom":
		return "class"
	default:
		return "personal"
	}
}

func postProvision(url string, payload map[string]any) ([]byte, int, error) {
	body, err := json.Marshal(payload)
	if err != nil {
		return nil, 0, err
	}
	req, err := http.NewRequest(http.MethodPost, url, bytes.NewReader(body))
	if err != nil {
		return nil, 0, err
	}
	req.Header.Set("Content-Type", "application/json")

	client := &http.Client{Timeout: 20 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		return nil, 0, err
	}
	defer resp.Body.Close()
	respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 1<<20))
	return respBody, resp.StatusCode, nil
}

func detectDevice() map[string]string {
	hostname, _ := os.Hostname()
	device := map[string]string{
		"hostname": hostname,
		"os":       runtime.GOOS,
		"arch":     runtime.GOARCH,
		"kernel":   strings.TrimSpace(runOutput("uname", "-r")),
		"distro":   osReleasePrettyName(),
	}
	if device["kernel"] == "" {
		device["kernel"] = "-"
	}
	if device["distro"] == "" {
		device["distro"] = runtime.GOOS
	}
	return device
}

func runOutput(name string, args ...string) string {
	output, err := exec.Command(name, args...).Output()
	if err != nil {
		return ""
	}
	return string(output)
}

func osReleasePrettyName() string {
	content, err := os.ReadFile("/etc/os-release")
	if err != nil {
		return ""
	}
	for _, line := range strings.Split(string(content), "\n") {
		key, value, ok := strings.Cut(line, "=")
		if !ok || key != "PRETTY_NAME" {
			continue
		}
		value = strings.Trim(value, `"`)
		return strings.TrimSpace(value)
	}
	return ""
}

func setProvision(values map[string]string, key string, value string) {
	if strings.TrimSpace(value) != "" {
		values[key] = strings.TrimSpace(value)
	}
}

func firstString(data map[string]any, keys ...string) string {
	for _, key := range keys {
		if value, ok := data[key]; ok {
			switch v := value.(type) {
			case string:
				return v
			case float64:
				return strconv.FormatFloat(v, 'f', -1, 64)
			case bool:
				if v {
					return "true"
				}
				return "false"
			}
		}
	}
	return ""
}

func firstBool(data map[string]any, keys ...string) string {
	for _, key := range keys {
		if value, ok := data[key]; ok {
			switch v := value.(type) {
			case bool:
				if v {
					return "true"
				}
				return "false"
			case string:
				switch strings.ToLower(strings.TrimSpace(v)) {
				case "true", "1", "yes", "y", "on":
					return "true"
				case "false", "0", "no", "n", "off":
					return "false"
				}
			}
		}
	}
	return ""
}

func renderProvisionSummary(values map[string]string, device map[string]string, usageType string, status string, width int) string {
	authKeyStatus := "not provided"
	if values["TAILSCALE_AUTH_KEY"] != "" {
		authKeyStatus = "received"
	}
	loginServer := displayValue(valueOrDash(values["TAILSCALE_LOGIN_SERVER"]))
	hostname := valueOrDash(values["TAILSCALE_HOSTNAME"])
	extraArgs := valueOrDash(values["TAILSCALE_EXTRA_ARGS"])
	gatewayTokenStatus := "not provided"
	if values["AGENT_GATEWAY_TOKEN"] != "" {
		gatewayTokenStatus = "received"
	}
	installTailscale := valueOr(values["INSTALL_TAILSCALE"], "false")

	header := renderMarkdown(fmt.Sprintf(`# Provisioning Summary

Status: **%s**

## Network
`, status), width)

	rows := [][2]string{
		{"Usage type", normalizeUsageType(usageType)},
		{"Device hostname", valueOrDash(device["hostname"])},
		{"Device OS", valueOrDash(device["distro"])},
		{"Architecture", valueOrDash(device["arch"])},
		{"Kernel", valueOrDash(device["kernel"])},
		{"Install Tailscale", installTailscale},
		{"Tailscale auth key", authKeyStatus},
		{"Login server", loginServer},
		{"Tailscale hostname", hostname},
		{"Extra args", extraArgs},
		{"Agent gateway token", gatewayTokenStatus},
	}
	return strings.TrimSpace(header + "\n" + renderSummaryTable(rows, width) + "\n\n" + mutedStyle.Render("These values will be applied when installation starts."))
}

func renderMarkdown(markdown string, width int) string {
	renderer, err := glamour.NewTermRenderer(
		glamour.WithStandardStyle("dark"),
		glamour.WithWordWrap(max(40, width-14)),
	)
	if err != nil {
		return markdown
	}
	rendered, err := renderer.Render(markdown)
	if err != nil {
		return markdown
	}
	return strings.TrimSpace(rendered)
}

func renderSummaryTable(rows [][2]string, width int) string {
	tableWidth := min(max(56, width-18), 82)
	labelWidth := 22
	valueWidth := max(18, tableWidth-labelWidth-7)
	headerStyle := lipgloss.NewStyle().Bold(true).Foreground(accent)
	keyStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("250"))
	valueStyle := lipgloss.NewStyle().Foreground(lipgloss.Color("229"))
	borderStyle := lipgloss.NewStyle().
		Border(lipgloss.NormalBorder()).
		BorderForeground(lipgloss.Color("238")).
		Padding(0, 1)

	lines := []string{
		headerStyle.Width(labelWidth).Render("Setting") + "  " + headerStyle.Width(valueWidth).Render("Value"),
		mutedStyle.Render(strings.Repeat("─", labelWidth) + "  " + strings.Repeat("─", valueWidth)),
	}
	for _, row := range rows {
		lines = append(lines,
			keyStyle.Width(labelWidth).Render(row[0])+"  "+
				valueStyle.Width(valueWidth).Render(clip(row[1], valueWidth)),
		)
	}
	return borderStyle.Width(tableWidth).Render(strings.Join(lines, "\n"))
}

func clip(value string, width int) string {
	if width < 4 || len(value) <= width {
		return value
	}
	return value[:width-3] + "..."
}

func valueOr(value string, fallback string) string {
	if strings.TrimSpace(value) == "" {
		return fallback
	}
	return strings.TrimSpace(value)
}

func valueOrDash(value string) string {
	return valueOr(value, "-")
}

func displayValue(value string) string {
	return strings.ReplaceAll(value, "://", "[:]//")
}

func (m model) writeEnv() error {
	lines := make([]string, 0, len(questions))
	defaults := map[string]string{
		"PLATFORM_AGENT_DIR":      envDefault("PLATFORM_AGENT_DIR", "/opt/platform-agent"),
		"PLATFORM_AGENT_SERVICE":  envDefault("PLATFORM_AGENT_SERVICE", "platform-agent"),
		"PLATFORM_AGENT_USER":     envDefault("PLATFORM_AGENT_USER", envDefault("USER", "ubuntu")),
		"PLATFORM_AGENT_REPO_URL": envDefault("PLATFORM_AGENT_REPO_URL", ""),
		"ROBOT_STACK":             envDefault("ROBOT_STACK", "autoware"),
		"ROS_DOMAIN_ID":           envDefault("ROS_DOMAIN_ID", "0"),
		"CAMERA_ENABLED":          envDefault("CAMERA_ENABLED", "true"),
		"CAMERA_SIGNALING_URL":    envDefault("CAMERA_SIGNALING_URL", "ws://127.0.0.1:3000"),
		"KASMVNC_GEOMETRY":        envDefault("KASMVNC_GEOMETRY", "1600x900"),
	}
	for key, value := range defaults {
		lines = append(lines, fmt.Sprintf("%s=%s", key, shellQuote(value)))
	}
	for key, value := range m.provision {
		lines = append(lines, fmt.Sprintf("%s=%s", key, shellQuote(value)))
	}
	for _, q := range questions {
		if q.key == "PLATFORM_ACCOUNT" || q.key == "PLATFORM_REGISTRATION_CODE" || q.key == "PLATFORM_PASSWORD" {
			continue
		}
		value := strings.TrimSpace(m.values[q.key])
		if value == "" {
			value = questionDefault(q)
		}
		lines = append(lines, fmt.Sprintf("%s=%s", q.key, shellQuote(value)))
	}
	return os.WriteFile(m.envPath, []byte(strings.Join(lines, "\n")+"\n"), 0600)
}

func (m model) View() string {
	contentWidth := min(max(64, m.width-8), 92)
	innerWidth := contentWidth - 6

	var b strings.Builder
	b.WriteString(header(m.index, len(questions), innerWidth) + "\n\n")

	if m.loading {
		b.WriteString(statusPanel("Registering platform", "Validating the account and registration code.", innerWidth) + "\n\n")
		b.WriteString(mutedStyle.Render("Please keep this terminal open.  Esc cancels setup."))
		return renderShell(b.String(), contentWidth)
	}

	if m.showProvision {
		b.WriteString(okStyle.Render("Connection settings received") + "\n")
		b.WriteString(mutedStyle.Render("Review the detected device and network settings before continuing.") + "\n\n")
		b.WriteString(m.provisionSummary + "\n")
		if m.err != nil {
			b.WriteString("\n" + errStyle.Render(m.err.Error()) + "\n")
		}
		b.WriteString("\n" + footerHint("Enter", "continue", "←", "previous", "Esc", "cancel"))
		return renderShell(b.String(), contentWidth)
	}

	q := questions[m.index]

	if answers := recentAnswers(m); len(answers) > 0 {
		b.WriteString(answerSummary(answers, innerWidth) + "\n\n")
	}

	b.WriteString(sectionLabel(stepName(m.index)) + "\n")
	b.WriteString(promptStyle.Render(q.title) + "\n")
	b.WriteString(mutedStyle.Render(wrap(q.prompt, innerWidth)) + "\n")
	if example := questionExample(q); example != "" {
		b.WriteString(keyStyle.Render("Example  ") + mutedStyle.Render(example) + "\n")
	}
	b.WriteString("\n")
	if len(q.options) > 0 {
		b.WriteString(renderOptions(q.options, m.choices[q.key], innerWidth) + "\n")
	} else {
		b.WriteString(inputStyle.Width(innerWidth-2).Render(m.input.View()) + "\n")
	}

	if m.err != nil {
		b.WriteString("\n" + errStyle.Render(m.err.Error()) + "\n")
	}

	if len(q.options) > 0 {
		b.WriteString("\n" + footerHint("↑/↓", "select", "Enter", nextAction(m.index), "←", "previous", "Esc", "cancel"))
	} else {
		b.WriteString("\n" + footerHint("Enter", nextAction(m.index), "←", "previous", "Esc", "cancel"))
	}

	return renderShell(b.String(), contentWidth)
}

func renderOptions(options []string, selected int, width int) string {
	lines := make([]string, len(options))
	for i, option := range options {
		if i == selected {
			lines[i] = selectedStyle.Width(width - 2).Render("●  " + option)
		} else {
			lines[i] = optionStyle.Width(width - 2).Render("○  " + option)
		}
	}
	return strings.Join(lines, "\n\n")
}

func header(index, total, width int) string {
	steps := []string{"Device", "Connection", "Services"}
	current := 0
	switch {
	case index >= 3:
		current = 2
	case index >= 2:
		current = 1
	}
	parts := make([]string, 0, len(steps))
	for i, step := range steps {
		label := fmt.Sprintf(" %d  %s ", i+1, step)
		switch {
		case i < current:
			parts = append(parts, lipgloss.NewStyle().Foreground(lipgloss.Color("42")).Render("✓"+label))
		case i == current:
			parts = append(parts, lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("255")).Background(lipgloss.Color("24")).Render(label))
		default:
			parts = append(parts, mutedStyle.Render(label))
		}
	}
	return brandStyle.Render("AUTONOMY STUDIO") + "\n" +
		titleStyle.Render("Platform Agent Setup") + "\n\n" +
		strings.Join(parts, mutedStyle.Render(" ─ "))
}

func recentAnswers(m model) []string {
	start := max(0, m.index-2)
	lines := []string{}
	for i := start; i < m.index; i++ {
		q := questions[i]
		value := m.values[q.key]
		if q.secret && value != "" {
			value = "********"
		}
		if value == "" {
			value = questionDefault(q)
		}
		lines = append(lines, q.title+"\t"+value)
	}
	return lines
}

func renderShell(content string, width int) string {
	return lipgloss.NewStyle().Margin(1, 2).Render(panelStyle.Width(width).Render(content))
}

func sectionLabel(value string) string {
	return lipgloss.NewStyle().Bold(true).Foreground(accent).Render(strings.ToUpper(value))
}

func stepName(index int) string {
	switch {
	case index < 2:
		return "Device"
	case index == 2:
		return "Connection"
	default:
		return "Services"
	}
}

func nextAction(index int) string {
	if index == len(questions)-1 {
		return "install"
	}
	return "next"
}

func footerHint(parts ...string) string {
	items := make([]string, 0, len(parts)/2)
	for i := 0; i+1 < len(parts); i += 2 {
		items = append(items, lipgloss.NewStyle().Bold(true).Foreground(accent).Render(parts[i])+mutedStyle.Render(" "+parts[i+1]))
	}
	return strings.Join(items, mutedStyle.Render("   ·   "))
}

func answerSummary(answers []string, width int) string {
	rows := make([]string, 0, len(answers))
	for _, answer := range answers {
		key, value, ok := strings.Cut(answer, "\t")
		if ok {
			rows = append(rows, mutedStyle.Width(22).Render(key)+valueStyle.Render(clip(value, max(18, width-27))))
		}
	}
	if len(rows) == 0 {
		return ""
	}
	return lipgloss.NewStyle().Border(lipgloss.NormalBorder()).BorderForeground(panelBorder).Padding(0, 1).Render(strings.Join(rows, "\n"))
}

func statusPanel(title, description string, width int) string {
	spinner := lipgloss.NewStyle().Bold(true).Foreground(accentStrong).Render("◌")
	return lipgloss.NewStyle().Border(lipgloss.RoundedBorder()).BorderForeground(accent).Padding(1, 2).Width(width - 2).Render(
		spinner + "  " + promptStyle.Render(title) + "\n" + mutedStyle.Render(wrap(description, width-10)),
	)
}

func wrap(text string, width int) string {
	return lipgloss.NewStyle().Width(width).Render(text)
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

func main() {
	if len(os.Args) < 2 {
		fmt.Fprintln(os.Stderr, "usage: installer-tui <env-output-path>")
		os.Exit(2)
	}
	program := tea.NewProgram(initialModel(os.Args[1]), tea.WithAltScreen())
	finalModel, err := program.Run()
	if err != nil {
		fmt.Fprintln(os.Stderr, err)
		os.Exit(1)
	}
	if m, ok := finalModel.(model); ok && !m.done {
		os.Exit(130)
	}
}