package main

import (
	"archive/zip"
	"bufio"
	"bytes"
	"crypto/sha1"
	"crypto/sha256"
	"encoding/base64"
	"errors"
	"fmt"
	"io"
	"log"
	"math/rand"
	"net/http"
	"os"
	"os/exec"
	"path"
	"path/filepath"
	"runtime"
	"sort"
	"strconv"
	"strings"
	"time"
	"unicode"
	"unicode/utf8"

	tea "github.com/charmbracelet/bubbletea"
	"github.com/mattn/go-runewidth"
	"github.com/pelletier/go-toml/v2"
	"golang.org/x/term"
)

var (
	initServiceNameArg string
	invocationArgs     []string
)

func main() {
	commands := defaultCommands()
	args := os.Args[1:]
	if len(args) > 0 && args[0] == "--" {
		args = args[1:]
	}

	invocationArgs = args

	if len(args) == 0 {
		printUsage(commands)
		return
	}

	if isHelpFlag(args[0]) {
		printUsage(commands)
		return
	}

	initServiceNameArg = ""
	if args[0] == "init" && len(args) > 1 {
		initServiceNameArg = args[1]
	}

	if args[0] == "menu" {
		if err := tea.NewProgram(newModel()).Start(); err != nil {
			log.Fatal(err)
		}
		return
	}

	if err := runCommandByName(commands, args[0]); err != nil {
		log.Fatal(err)
	}
}

func defaultCommands() []command {
	return []command{
		{name: "init", description: "start a new PocketBase project", action: runInit},
		{name: "dev", description: "run the PocketBase binary locally", action: runDev},
		{name: "setup", description: "provision the remote server and install PocketBase", action: runSetup},
		{name: "deploy", description: "sync migrations/hooks/static assets (runs setup if needed)", action: runDeploy},
		{name: "logs", description: "show PocketBase logs", action: runLogs},
		{name: "secrets", description: "manage deployment secrets", action: runSecrets},
	}
}

type commandAction func() error

type command struct {
	name        string
	description string
	action      commandAction
}

func runCommandByName(commands []command, name string) error {
	for _, cmd := range commands {
		if cmd.name == name {
			return cmd.action()
		}
	}
	return fmt.Errorf("unknown command %q", name)
}

func printUsage(commands []command) {
	fmt.Println("Usage: pb <command> [options]")
	fmt.Println()
	fmt.Println("Options:")
	fmt.Println("  -h, --help     show this help message")
	fmt.Println()
	fmt.Println("Commands:")
	for _, cmd := range commands {
		fmt.Printf("  %-10s %s\n", cmd.name, cmd.description)
	}
	fmt.Println()
	fmt.Println("Use \"pb menu\" for an interactive helper.")
}

func isHelpFlag(arg string) bool {
	return arg == "-h" || arg == "--help"
}

func newModel() model {
	return model{commands: defaultCommands()}
}

type model struct {
	commands    []command
	cursor      int
	status      string
	running     bool
	lastCommand string
}

type commandResultMsg struct {
	name string
	err  error
}

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

func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	switch msg := msg.(type) {
	case tea.KeyMsg:
		switch msg.String() {
		case "ctrl+c", "q":
			return m, tea.Quit
		case "up", "k":
			if m.running {
				return m, nil
			}
			if m.cursor > 0 {
				m.cursor--
			} else {
				m.cursor = len(m.commands) - 1
			}
			return m, nil
		case "down", "j":
			if m.running {
				return m, nil
			}
			if m.cursor < len(m.commands)-1 {
				m.cursor++
			} else {
				m.cursor = 0
			}
			return m, nil
		case "enter":
			if m.running {
				return m, nil
			}
			selected := m.commands[m.cursor]
			m.running = true
			m.lastCommand = selected.name
			m.status = fmt.Sprintf("Running %s...", selected.name)
			return m, runCommand(selected)
		}
	case commandResultMsg:
		m.running = false
		if msg.err != nil {
			m.status = fmt.Sprintf("%s failed: %v", msg.name, msg.err)
		} else {
			m.status = fmt.Sprintf("%s finished successfully", msg.name)
		}
		return m, nil
	}
	return m, nil
}

func (m model) View() string {
	var b strings.Builder
	b.WriteString("PocketBase deployment helper\n\n")
	for idx, cmd := range m.commands {
		cursor := " "
		if m.cursor == idx {
			cursor = ">"
		}
		b.WriteString(fmt.Sprintf("%s %s\n    %s\n", cursor, cmd.name, cmd.description))
	}
	b.WriteString("\n")
	if m.status != "" {
		b.WriteString(fmt.Sprintf("%s\n\n", m.status))
	}
	if m.running {
		b.WriteString("(running... press ctrl+c to abort)\n")
	}
	b.WriteString("↑/↓ to navigate, enter to run, q to quit\n")
	return b.String()
}

func runCommand(cmd command) tea.Cmd {
	return func() tea.Msg {
		return commandResultMsg{name: cmd.name, err: cmd.action()}
	}
}

func runInit() error {
	cwd, err := os.Getwd()
	if err != nil {
		return err
	}

	pbPath := filepath.Join(cwd, "pb.toml")
	if _, err := os.Stat(pbPath); err == nil {
		return fmt.Errorf("pb.toml already exists, aborting")
	} else if !errors.Is(err, os.ErrNotExist) {
		return err
	}

	defaultName := generateServiceName()
	serviceName, err := resolveServiceName(defaultName)
	if err != nil {
		return err
	}

	if err := writePBConfig(pbPath, serviceName); err != nil {
		return err
	}

	targetDir := filepath.Join(cwd, "bin")
	if err := os.MkdirAll(targetDir, 0o755); err != nil {
		return err
	}
	if err := os.WriteFile(filepath.Join(targetDir, ".keep"), []byte{}, 0o644); err != nil {
		return err
	}

	binaryPath := filepath.Join(targetDir, pocketbaseBinaryName(runtime.GOOS))
	if err := ensurePocketbaseBinary(defaultPocketbaseVersion, runtime.GOOS, runtime.GOARCH, binaryPath); err != nil {
		return err
	}

	if err := ensureGitignoreEntries(filepath.Join(cwd, ".gitignore"), []string{"bin/pocketbase", "pb_data", ".env", ".DS_store"}); err != nil {
		return err
	}

	fmt.Printf("Initialized PocketBase project %q\n", serviceName)
	return nil
}

func runDev() error {
	cwd, err := os.Getwd()
	if err != nil {
		return err
	}

	binaryPath := filepath.Join(cwd, "bin", pocketbaseBinaryName(runtime.GOOS))
	if err := ensurePocketbaseBinary(defaultPocketbaseVersion, runtime.GOOS, runtime.GOARCH, binaryPath); err != nil {
		return err
	}

	overrides, err := loadEnv(filepath.Join(cwd, ".env"))
	if err != nil {
		return err
	}

	cmd := exec.Command(binaryPath, "serve")
	cmd.Args = append(cmd.Args, "--dir", filepath.Join(cwd, "pb_data"))
	cmd.Args = append(cmd.Args, "--hooksDir", filepath.Join(cwd, "pb_hooks"))
	cmd.Args = append(cmd.Args, "--migrationsDir", filepath.Join(cwd, "pb_migrations"))
	cmd.Args = append(cmd.Args, "--publicDir", filepath.Join(cwd, "pb_public"))
	cmd.Dir = cwd
	cmd.Env = mergeEnv(overrides)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	cmd.Stdin = os.Stdin

	fmt.Println("starting PocketBase development server")
	return cmd.Run()
}

const (
	defaultPocketbaseVersion = "0.35.1"
	defaultPocketbaseVolume  = "pb_data"
)

func init() {
	rand.Seed(time.Now().UnixNano())
	log.SetFlags(0)
	log.SetPrefix("")
}

func writePBConfig(path, serviceName string) error {
	const tmpl = `[server]
ip = "127.0.0.1"
port = 8090
domain = "example.com"

[pocketbase]
version = "%s"
service = "%s"
volume = "%s"
`
	return os.WriteFile(path, []byte(fmt.Sprintf(tmpl, defaultPocketbaseVersion, serviceName, defaultPocketbaseVolume)), 0o644)
}

func generateServiceName() string {
	adjectives := []string{"sunny", "silent", "cobalt", "rusty", "plush", "brisk", "sage", "glow"}
	nouns := []string{"harbor", "delta", "bloom", "atlas", "ripple", "ember", "lumen", "orbit"}
	adjective := adjectives[rand.Intn(len(adjectives))]
	noun := nouns[rand.Intn(len(nouns))]
	return fmt.Sprintf("%s-%s", adjective, noun)
}

func promptServiceName(defaultName string) (string, error) {
	prompt := fmt.Sprintf("%sService name%s [%s]: ", headerColor, remoteColorReset, defaultName)
	input, err := readEditableLine(prompt)
	if err != nil {
		return "", err
	}
	input = normalizePromptInput(input)
	input = strings.TrimSpace(input)
	if input == "" {
		return defaultName, nil
	}
	return input, nil
}

func resolveServiceName(defaultName string) (string, error) {
	if override := strings.TrimSpace(initServiceNameArg); override != "" {
		initServiceNameArg = ""
		return override, nil
	}
	return promptServiceName(defaultName)
}

func shouldConfirmServerConfig(ctx *deploymentContext) (bool, error) {
	exists, err := remoteDirExists(ctx.serverIP, ctx.serviceDir)
	if err != nil {
		fmt.Fprintf(os.Stderr, "warning: unable to verify remote service at %s: %v\n", ctx.serviceDir, err)
		return true, nil
	}
	return !exists, nil
}

func ensureServerConfigConfirmed(ctx *deploymentContext) (*deploymentContext, bool, error) {
	needsConfirm, err := shouldConfirmServerConfig(ctx)
	if err != nil {
		return nil, false, err
	}
	if !needsConfirm {
		return ctx, false, nil
	}

	if err := confirmServerConfig(ctx.configPath); err != nil {
		return nil, false, err
	}
	newCtx, err := buildDeploymentContext()
	if err != nil {
		return nil, false, err
	}
	return newCtx, true, nil
}

func confirmServerConfig(pbPath string) error {
	cfg, err := loadPBConfig(pbPath)
	if err != nil {
		return err
	}

	fmt.Printf("Confirm remote server settings (press Enter to keep the current value):\n")

	ipDefault := cfg.Server.IP
	if ipDefault == "" {
		ipDefault = "127.0.0.1"
	}
	ip, err := promptWithDefault("Server IP", ipDefault)
	if err != nil {
		return err
	}

	portDefault := cfg.Server.Port
	if portDefault <= 0 {
		portDefault = 8090
	}
	port, err := promptPort("Server port", portDefault)
	if err != nil {
		return err
	}

	domainDefault := cfg.Server.Domain
	if domainDefault == "" {
		domainDefault = "example.com"
	}
	domain, err := promptWithDefault("Server domain", domainDefault)
	if err != nil {
		return err
	}

	cfg.Server.IP = ip
	cfg.Server.Port = port
	cfg.Server.Domain = domain
	if err := savePBConfig(pbPath, cfg); err != nil {
		return err
	}

	return nil
}

func promptWithDefault(label, defaultValue string) (string, error) {
	var suffix string
	if defaultValue != "" {
		suffix = fmt.Sprintf(" [%s]: ", defaultValue)
	} else {
		suffix = ": "
	}
	prompt := fmt.Sprintf("%s%s%s%s", headerColor, label, remoteColorReset, suffix)
	input, err := readEditableLine(prompt)
	if err != nil {
		return "", err
	}
	input = normalizePromptInput(input)
	input = strings.TrimSpace(input)
	if input == "" {
		return defaultValue, nil
	}
	return input, nil
}

func promptPort(label string, defaultValue int) (int, error) {
	if defaultValue <= 0 {
		defaultValue = 8090
	}

	for {
		prompt := fmt.Sprintf("%s%s%s [%d]: ", headerColor, label, remoteColorReset, defaultValue)
		input, err := readEditableLine(prompt)
		if err != nil {
			return 0, err
		}
		input = normalizePromptInput(input)
		value := strings.TrimSpace(input)
		if value == "" {
			return defaultValue, nil
		}
		port, err := strconv.Atoi(value)
		if err != nil || port <= 0 || port > 65535 {
			fmt.Println("  please enter a valid port between 1 and 65535")
			continue
		}
		return port, nil
	}
}

func normalizePromptInput(raw string) string {
	var buf []rune
	for i := 0; i < len(raw); {
		r, size := utf8.DecodeRuneInString(raw[i:])
		if size == 0 {
			break
		}
		if r == '\r' || r == '\n' {
			break
		}
		if r == 0x1b {
			nextIndex, final := skipEscapeSequence(raw, i)
			if nextIndex <= i {
				i++
				continue
			}
			i = nextIndex
			if final == 0x7f || final == 0x08 {
				buf = deletePreviousWord(buf)
			}
			continue
		}
		if r == 0x17 {
			buf = deletePreviousWord(buf)
			i += size
			continue
		}
		if r == 0x7f || r == 0x08 {
			if len(buf) > 0 {
				buf = buf[:len(buf)-1]
			}
			i += size
			continue
		}
		buf = append(buf, r)
		i += size
	}
	return string(buf)
}

func readEditableLine(prompt string) (string, error) {
	fd := int(os.Stdin.Fd())
	reader := bufio.NewReader(os.Stdin)
	if !term.IsTerminal(fd) {
		line, err := reader.ReadString('\n')
		if err != nil {
			return "", err
		}
		line = strings.TrimRight(line, "\r\n")
		return line, nil
	}

	oldState, err := term.MakeRaw(fd)
	if err != nil {
		return "", err
	}
	defer term.Restore(fd, oldState)

	var buf []rune
	var lastWidth int
	fmt.Print(prompt)

	for {
		r, _, err := reader.ReadRune()
		if err != nil {
			return "", err
		}

		switch {
		case r == '\r' || r == '\n':
			fmt.Print("\r\n")
			return string(buf), nil
		case r == 0x03:
			fmt.Fprint(os.Stderr, "\r\n")
			return "", errors.New("input interrupted")
		case r == 0x04:
			fmt.Println()
			return "", io.EOF
		case r == 0x7f || r == 0x08:
			if len(buf) > 0 {
				buf = buf[:len(buf)-1]
				redrawEditableLine(prompt, buf, &lastWidth)
			}
		case r == 0x17:
			buf = deletePreviousWord(buf)
			redrawEditableLine(prompt, buf, &lastWidth)
		case r == 0x1b:
			final, err := readEscapeFinal(reader)
			if err != nil {
				return "", err
			}
			if final == 0x7f || final == 0x08 {
				buf = deletePreviousWord(buf)
				redrawEditableLine(prompt, buf, &lastWidth)
			}
		default:
			if r < 0x20 {
				continue
			}
			buf = append(buf, r)
			redrawEditableLine(prompt, buf, &lastWidth)
		}
	}
}

func readEscapeFinal(reader *bufio.Reader) (rune, error) {
	b, err := reader.ReadByte()
	if err != nil {
		return 0, err
	}
	if b == '[' || b == 'O' {
		for {
			c, err := reader.ReadByte()
			if err != nil {
				return 0, err
			}
			if isCSIFinalByte(rune(c)) {
				return rune(c), nil
			}
		}
	}
	return rune(b), nil
}

func redrawEditableLine(prompt string, buf []rune, lastWidth *int) {
	fmt.Print("\r")
	fmt.Print(prompt)
	text := string(buf)
	fmt.Print(text)
	width := runewidth.StringWidth(text)
	if *lastWidth > width {
		fmt.Print(strings.Repeat(" ", *lastWidth-width))
		fmt.Print("\r")
		fmt.Print(prompt)
		fmt.Print(text)
	}
	*lastWidth = width
}

func skipEscapeSequence(raw string, escIndex int) (int, rune) {
	i := escIndex + 1
	if i >= len(raw) {
		return i, 0
	}
	next, size := utf8.DecodeRuneInString(raw[i:])
	i += size
	if next == '[' || next == 'O' {
		for i < len(raw) {
			code, codeSize := utf8.DecodeRuneInString(raw[i:])
			if codeSize == 0 {
				break
			}
			i += codeSize
			if isCSIFinalByte(code) {
				return i, code
			}
		}
		return i, 0
	}
	return i, next
}

func isCSIFinalByte(r rune) bool {
	return 0x40 <= r && r <= 0x7e
}

func deletePreviousWord(buf []rune) []rune {
	i := len(buf)
	for i > 0 && unicode.IsSpace(buf[i-1]) {
		i--
	}
	for i > 0 && !unicode.IsSpace(buf[i-1]) {
		i--
	}
	return buf[:i]
}

func pocketbaseBinaryName(goos string) string {
	if goos == "windows" {
		return "pocketbase.exe"
	}
	return "pocketbase"
}

func downloadPocketbase(version, goos, goarch, dest string) error {
	url, binaryName, err := releaseAssetURL(version, goos, goarch)
	if err != nil {
		return err
	}

	resp, err := http.Get(url)
	if err != nil {
		return fmt.Errorf("failed to download %s: %w", url, err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("unexpected status %s while downloading %s", resp.Status, url)
	}

	tmpFile, err := os.CreateTemp("", "pocketbase-*.zip")
	if err != nil {
		return err
	}
	defer os.Remove(tmpFile.Name())
	defer tmpFile.Close()

	label := fmt.Sprintf("Downloading PocketBase v%s (%s/%s)", version, goos, goarch)
	if err := downloadWithProgress(tmpFile, resp.Body, resp.ContentLength, label); err != nil {
		return err
	}

	if err := extractBinary(tmpFile.Name(), binaryName, dest); err != nil {
		return err
	}

	return os.Chmod(dest, 0o755)
}

func ensurePocketbaseBinary(version, goos, goarch, dest string) error {
	if _, err := os.Stat(dest); err == nil {
		return nil
	} else if !errors.Is(err, os.ErrNotExist) {
		return err
	}

	fmt.Println("PocketBase binary missing; downloading...")
	return downloadPocketbase(version, goos, goarch, dest)
}

func downloadWithProgress(dst io.Writer, src io.Reader, total int64, label string) error {
	const chunkSize = 32 * 1024
	buf := make([]byte, chunkSize)
	var downloaded int64
	lastPercent := int64(-1)

	updateProgress := func(force bool) {
		if total > 0 {
			percent := downloaded * 100 / total
			if force || percent != lastPercent {
				fmt.Printf("\r%s %3d%%", label, percent)
				lastPercent = percent
			}
		} else {
			fmt.Printf("\r%s %s downloaded", label, formatBytes(downloaded))
		}
	}

	for {
		n, err := src.Read(buf)
		if n > 0 {
			if _, writeErr := dst.Write(buf[:n]); writeErr != nil {
				fmt.Println()
				return writeErr
			}
			downloaded += int64(n)
			updateProgress(false)
		}

		if err != nil {
			if err == io.EOF {
				break
			}
			fmt.Println()
			return err
		}
	}

	updateProgress(true)
	fmt.Println()
	return nil
}

func formatBytes(b int64) string {
	const unit = 1024
	if b < unit {
		return fmt.Sprintf("%d B", b)
	}
	div, exp := int64(unit), 0
	for n := b / unit; n >= unit; n /= unit {
		div *= unit
		exp++
	}
	return fmt.Sprintf("%.1f %cB", float64(b)/float64(div), "KMGTPE"[exp])
}

func releaseAssetURL(version, goos, goarch string) (string, string, error) {
	osName := map[string]string{
		"darwin":  "darwin",
		"linux":   "linux",
		"windows": "windows",
	}
	archName := map[string]string{
		"amd64": "amd64",
		"386":   "386",
		"arm64": "arm64",
		"arm":   "armv7",
	}

	osPart, ok := osName[goos]
	if !ok {
		return "", "", fmt.Errorf("unsupported GOOS: %s", goos)
	}
	archPart, ok := archName[goarch]
	if !ok {
		return "", "", fmt.Errorf("unsupported GOARCH: %s", goarch)
	}

	filename := fmt.Sprintf("pocketbase_%s_%s_%s.zip", version, osPart, archPart)
	url := fmt.Sprintf("https://github.com/pocketbase/pocketbase/releases/download/v%s/%s", version, filename)
	return url, pocketbaseBinaryName(goos), nil
}

func extractBinary(zipPath, binaryName, dest string) error {
	r, err := zip.OpenReader(zipPath)
	if err != nil {
		return err
	}
	defer r.Close()

	for _, f := range r.File {
		if filepath.Base(f.Name) != binaryName {
			continue
		}

		if err := os.MkdirAll(filepath.Dir(dest), 0o755); err != nil {
			return err
		}

		src, err := f.Open()
		if err != nil {
			return err
		}
		defer src.Close()

		out, err := os.OpenFile(dest, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0o755)
		if err != nil {
			return err
		}
		defer out.Close()

		if _, err := io.Copy(out, src); err != nil {
			return err
		}

		return nil
	}
	return fmt.Errorf("binary %s not found in archive", binaryName)
}

func ensureGitignoreEntries(path string, entries []string) error {
	var existing = make(map[string]struct{})
	var original []byte
	if data, err := os.ReadFile(path); err == nil {
		original = data
		for _, line := range strings.Split(string(data), "\n") {
			trimmed := strings.TrimSpace(line)
			if trimmed != "" {
				existing[trimmed] = struct{}{}
			}
		}
	} else if !errors.Is(err, os.ErrNotExist) {
		return err
	}

	builder := &strings.Builder{}
	if len(original) > 0 {
		builder.Write(original)
		if !strings.HasSuffix(string(original), "\n") {
			builder.WriteByte('\n')
		}
	}

	var added bool
	for _, entry := range entries {
		if _, seen := existing[entry]; seen {
			continue
		}
		builder.WriteString(entry)
		builder.WriteByte('\n')
		added = true
	}

	if !added {
		return nil
	}

	return os.WriteFile(path, []byte(builder.String()), 0o644)
}

func loadEnv(path string) (map[string]string, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		if errors.Is(err, os.ErrNotExist) {
			return nil, nil
		}
		return nil, err
	}

	env := make(map[string]string)
	for _, line := range strings.Split(string(data), "\n") {
		if key, value, ok := parseEnvLine(line); ok {
			env[key] = value
		}
	}
	return env, nil
}

func mergeEnv(overrides map[string]string) []string {
	envMap := make(map[string]string)
	for _, kv := range os.Environ() {
		parts := strings.SplitN(kv, "=", 2)
		key := parts[0]
		value := ""
		if len(parts) > 1 {
			value = parts[1]
		}
		envMap[key] = value
	}
	for key, value := range overrides {
		envMap[key] = value
	}

	keys := make([]string, 0, len(envMap))
	for key := range envMap {
		keys = append(keys, key)
	}
	sort.Strings(keys)

	env := make([]string, 0, len(keys))
	for _, key := range keys {
		env = append(env, fmt.Sprintf("%s=%s", key, envMap[key]))
	}
	return env
}

const (
	defaultServiceDirTemplate = "/root/pb/{service}"
	defaultEnvFileTemplate    = "/root/pb/{service}/.env"
	totalSetupSteps           = 5
	remoteWindowSize          = 10
	remoteIndent              = "   "
	remoteLineColor           = "\033[96m"
	headerColor               = "\033[95m"
	localTimeColor            = "\033[92m"
	remoteColorReset          = "\033[0m"
)

type pbToml struct {
	Server     serverConfig     `toml:"server"`
	PocketBase pocketBaseConfig `toml:"pocketbase"`
}

type serverConfig struct {
	IP     string `toml:"ip"`
	Port   int    `toml:"port"`
	Domain string `toml:"domain"`
}

type pocketBaseConfig struct {
	Version     string `toml:"version"`
	ServiceName string `toml:"service"`
	Volume      string `toml:"volume"`
}

type deploymentContext struct {
	serverIP       string
	domain         string
	port           int
	serviceName    string
	version        string
	serviceDir     string
	envFile        string
	unitServiceDir string
	unitEnvFile    string
	volume         string
	unitVolume     string
	configPath     string
}

func buildDeploymentContext() (*deploymentContext, error) {
	cwd, err := os.Getwd()
	if err != nil {
		return nil, err
	}

	configPath := filepath.Join(cwd, "pb.toml")
	cfg, err := loadPBConfig(configPath)
	if err != nil {
		return nil, err
	}

	serviceName := cfg.PocketBase.ServiceName
	if serviceName == "" {
		return nil, fmt.Errorf("pb.toml missing [pocketbase].service")
	}

	serverIP := cfg.Server.IP
	if serverIP == "" {
		return nil, fmt.Errorf("pb.toml missing [server].ip")
	}

	domain := cfg.Server.Domain
	if domain == "" {
		return nil, fmt.Errorf("pb.toml missing [server].domain")
	}

	port := cfg.Server.Port
	if port <= 0 {
		return nil, fmt.Errorf("pb.toml server.port must be greater than zero")
	}

	version := cfg.PocketBase.Version
	if version == "" {
		version = defaultPocketbaseVersion
	}

	serviceDir := renderServiceTemplate(defaultServiceDirTemplate, serviceName)
	envFile := renderServiceTemplate(defaultEnvFileTemplate, serviceName)
	unitServiceDir := renderServiceTemplate(defaultServiceDirTemplate, "%i")
	unitEnvFile := renderServiceTemplate(defaultEnvFileTemplate, "%i")
	volumeTemplate := cfg.PocketBase.Volume
	if volumeTemplate == "" {
		volumeTemplate = defaultPocketbaseVolume
	}
	volume := resolveVolumePath(volumeTemplate, serviceDir, serviceName)
	unitVolume := resolveVolumePath(volumeTemplate, unitServiceDir, "%i")

	return &deploymentContext{
		serverIP:       serverIP,
		domain:         domain,
		port:           port,
		serviceName:    serviceName,
		version:        version,
		serviceDir:     serviceDir,
		envFile:        envFile,
		unitServiceDir: unitServiceDir,
		unitEnvFile:    unitEnvFile,
		volume:         volume,
		unitVolume:     unitVolume,
		configPath:     configPath,
	}, nil
}

func runSetup() error {
	ctx, err := buildDeploymentContext()
	if err != nil {
		return err
	}

	ctx, _, err = ensureServerConfigConfirmed(ctx)
	if err != nil {
		return err
	}

	defer closeSSHControlMaster(ctx.serverIP)
	start := time.Now()

	if err := performSetup(ctx); err != nil {
		return err
	}

	fmt.Printf("\nSetup complete; PocketBase should be reachable at https://%s\n", ctx.domain)
	fmt.Printf("Total setup time: %s%s%s\n", localTimeColor, time.Since(start).Round(time.Millisecond), remoteColorReset)
	return nil
}

func performSetup(ctx *deploymentContext) error {
	step := 1
	printStep(step, totalSetupSteps, "validating configuration")
	remoteOS, err := runSSHOutput(ctx.serverIP, "uname -s")
	if err != nil {
		return fmt.Errorf("failed to determine remote OS: %w", err)
	}
	if !strings.EqualFold(remoteOS, "linux") {
		return fmt.Errorf("unsupported remote OS %q", remoteOS)
	}

	arch, err := detectRemoteArch(ctx.serverIP)
	if err != nil {
		return err
	}

	assetName := pocketbaseAsset(ctx.version, "linux", arch)
	assetURL := fmt.Sprintf("https://github.com/pocketbase/pocketbase/releases/download/v%s/%s", ctx.version, assetName)

	step++
	printStep(step, totalSetupSteps, "configuring firewall")
	if err := runSSHCommand(ctx.serverIP, firewallScript()); err != nil {
		return fmt.Errorf("firewall setup failed: %w", err)
	}

	step++
	printStep(step, totalSetupSteps, "installing caddy")
	if err := runSSHCommand(ctx.serverIP, caddyScript(ctx.domain, ctx.port, ctx.serviceName)); err != nil {
		return fmt.Errorf("caddy setup failed: %w", err)
	}

	step++
	printStep(step, totalSetupSteps, "deploying PocketBase binary")
	if err := runSSHCommand(ctx.serverIP, pocketbaseSetupScript(ctx.serviceDir, ctx.envFile, ctx.version, assetURL, ctx.volume, ctx.port)); err != nil {
		return fmt.Errorf("PocketBase setup failed: %w", err)
	}

	step++
	printStep(step, totalSetupSteps, "configuring systemd service")
	if err := runSSHCommand(ctx.serverIP, systemdScript(ctx.unitServiceDir, ctx.unitEnvFile, ctx.serviceName)); err != nil {
		return fmt.Errorf("systemd setup failed: %w", err)
	}

	return nil
}

func runDeploy() error {
	ctx, err := buildDeploymentContext()
	if err != nil {
		return err
	}
	defer func() {
		closeSSHControlMaster(ctx.serverIP)
	}()
	start := time.Now()

	binaryPath := filepath.Join(ctx.serviceDir, "pocketbase")
	exists, err := remoteBinaryExists(ctx.serverIP, binaryPath)
	if err != nil {
		fmt.Fprintf(os.Stderr, "warning: Unable to contact remote server %s: %v\n", ctx.serverIP, err)
	}

	if err != nil || !exists {
		fmt.Println("PocketBase binary missing on remote; running setup")
		ctx, prompted, err := ensureServerConfigConfirmed(ctx)
		if err != nil {
			return err
		}
		if prompted {
			start = time.Now()
		}
		if err := performSetup(ctx); err != nil {
			return err
		}
	}

	dirs := []string{"pb_public", "pb_migrations", "pb_hooks"}
	if err := syncLocalDirectories(ctx.serverIP, ctx.serviceDir, dirs); err != nil {
		return fmt.Errorf("failed to sync local directories: %w", err)
	}

	if err := restartPocketBaseService(ctx); err != nil {
		return err
	}

	fmt.Printf("\nDeployment complete; PocketBase should be reachable at https://%s\n", ctx.domain)
	fmt.Printf("Total deployment time: %s%s%s\n", localTimeColor, time.Since(start).Round(time.Millisecond), remoteColorReset)
	return nil
}

func runLogs() error {
	ctx, err := buildDeploymentContext()
	if err != nil {
		return err
	}
	defer closeSSHControlMaster(ctx.serverIP)

	logPath := filepath.Join(ctx.serviceDir, fmt.Sprintf("%s.log", ctx.serviceName))
	script := fmt.Sprintf(`set -euo pipefail
log=%s
if [ ! -f "$log" ]; then
  echo "log file not found: $log" >&2
  exit 1
fi
tail -n 25 -F "$log"
`, shellQuote(logPath))
	return runSSHRawCommand(ctx.serverIP, script)
}

func runSecrets() error {
	if len(invocationArgs) < 2 {
		return fmt.Errorf("usage: pb secrets <list|set|delete> [arguments]")
	}

	ctx, err := buildDeploymentContext()
	if err != nil {
		return err
	}
	defer closeSSHControlMaster(ctx.serverIP)

	subcommand := invocationArgs[1]
	args := invocationArgs[2:]
	switch subcommand {
	case "list":
		if len(args) != 0 {
			return fmt.Errorf("usage: pb secrets list")
		}
		return runSecretsList(ctx)
	case "set":
		if len(args) == 0 {
			return fmt.Errorf("usage: pb secrets set KEY=VALUE...")
		}
		return runSecretsSet(ctx, args)
	case "delete":
		if len(args) == 0 {
			return fmt.Errorf("usage: pb secrets delete KEY...")
		}
		return runSecretsDelete(ctx, args)
	default:
		return fmt.Errorf("unknown secrets subcommand %q", subcommand)
	}
}

func runSecretsList(ctx *deploymentContext) error {
	lines, err := loadRemoteEnvLines(ctx)
	if err != nil {
		return err
	}

	type secretRow struct {
		key    string
		digest string
	}

	var rows []secretRow
	for _, line := range lines {
		if key, value, ok := parseEnvLine(line); ok {
			rows = append(rows, secretRow{
				key:    key,
				digest: secretDigest(value),
			})
		}
	}
	if len(rows) == 0 {
		fmt.Println("no secrets found")
		return nil
	}
	sort.Slice(rows, func(i, j int) bool {
		return rows[i].key < rows[j].key
	})
	nameWidth := len("NAME")
	for _, row := range rows {
		if lw := len(row.key); lw > nameWidth {
			nameWidth = lw
		}
	}
	fmt.Printf("%s%-*s  %s%s\n", headerColor, nameWidth, "NAME", "DIGEST", remoteColorReset)
	for _, row := range rows {
		fmt.Printf("%-*s  %s\n", nameWidth, row.key, row.digest)
	}
	return nil
}

func secretDigest(value string) string {
	sum := sha256.Sum256([]byte(value))
	// Return only a prefix so the table stays narrow but still reveals changes.
	const shortBytes = 6
	return fmt.Sprintf("%x", sum[:shortBytes])
}

type envAssignment struct {
	key   string
	value string
}

func runSecretsSet(ctx *deploymentContext, pairs []string) error {
	var assignments []envAssignment
	for _, pair := range pairs {
		idx := strings.Index(pair, "=")
		if idx <= 0 {
			return fmt.Errorf("invalid assignment %q, expected KEY=VALUE", pair)
		}
		key := strings.TrimSpace(pair[:idx])
		if key == "" {
			return fmt.Errorf("invalid assignment %q: empty key", pair)
		}
		if !isEnvKey(key) {
			return fmt.Errorf("invalid env key %q", key)
		}
		assignments = append(assignments, envAssignment{key: key, value: pair[idx+1:]})
	}

	lines, err := loadRemoteEnvLines(ctx)
	if err != nil {
		return err
	}

	updated := applyEnvAssignments(lines, assignments)
	if err := writeRemoteEnvLines(ctx, updated); err != nil {
		return err
	}

	if err := restartPocketBaseService(ctx); err != nil {
		return err
	}

	fmt.Printf("updated %d secrets and restarted PocketBase\n", len(assignments))
	return nil
}

func runSecretsDelete(ctx *deploymentContext, keys []string) error {
	var normalized []string
	for _, key := range keys {
		key = strings.TrimSpace(key)
		if key == "" {
			return fmt.Errorf("invalid empty key")
		}
		if !isEnvKey(key) {
			return fmt.Errorf("invalid env key %q", key)
		}
		normalized = append(normalized, key)
	}

	lines, err := loadRemoteEnvLines(ctx)
	if err != nil {
		return err
	}

	updated := removeEnvKeys(lines, normalized)
	if err := writeRemoteEnvLines(ctx, updated); err != nil {
		return err
	}

	if err := restartPocketBaseService(ctx); err != nil {
		return err
	}

	fmt.Printf("removed %d secrets and restarted PocketBase\n", len(normalized))
	return nil
}

func loadRemoteEnvLines(ctx *deploymentContext) ([]string, error) {
	data, err := readRemoteEnvFile(ctx)
	if err != nil {
		return nil, err
	}
	data = strings.ReplaceAll(data, "\r\n", "\n")
	data = strings.TrimRightFunc(data, func(r rune) bool {
		return r == '\n' || r == '\r'
	})
	if data == "" {
		return nil, nil
	}
	return strings.Split(data, "\n"), nil
}

func readRemoteEnvFile(ctx *deploymentContext) (string, error) {
	script := fmt.Sprintf(`set -euo pipefail
if [ -f %s ]; then
  cat %s
fi
`, shellQuote(ctx.envFile), shellQuote(ctx.envFile))
	return runSSHCollect(ctx.serverIP, script)
}

func writeRemoteEnvLines(ctx *deploymentContext, lines []string) error {
	content := strings.Join(lines, "\n")
	if content != "" && !strings.HasSuffix(content, "\n") {
		content += "\n"
	}
	dir := filepath.Dir(ctx.envFile)
	encoded := base64.StdEncoding.EncodeToString([]byte(content))
	script := fmt.Sprintf(`set -euo pipefail
mkdir -p %s
cat <<'EOF' | base64 -d > %s
%s
EOF
`, shellQuote(dir), shellQuote(ctx.envFile), encoded)
	return runSSHCommand(ctx.serverIP, script)
}

func applyEnvAssignments(lines []string, assignments []envAssignment) []string {
	if len(assignments) == 0 {
		return lines
	}
	assignMap := make(map[string]string, len(assignments))
	order := make([]string, 0, len(assignments))
	for _, assign := range assignments {
		if _, seen := assignMap[assign.key]; !seen {
			order = append(order, assign.key)
		}
		assignMap[assign.key] = assign.value
	}

	inserted := make(map[string]bool, len(assignMap))
	var out []string
	for _, line := range lines {
		if key, _, ok := parseEnvLine(line); ok {
			if value, exists := assignMap[key]; exists {
				if !inserted[key] {
					out = append(out, fmt.Sprintf("%s=%s", key, value))
					inserted[key] = true
				}
				continue
			}
		}
		out = append(out, line)
	}

	for _, key := range order {
		if inserted[key] {
			continue
		}
		out = append(out, fmt.Sprintf("%s=%s", key, assignMap[key]))
		inserted[key] = true
	}

	return out
}

func removeEnvKeys(lines []string, keys []string) []string {
	if len(keys) == 0 {
		return lines
	}
	targets := make(map[string]struct{}, len(keys))
	for _, key := range keys {
		targets[key] = struct{}{}
	}

	var out []string
	for _, line := range lines {
		if key, _, ok := parseEnvLine(line); ok {
			if _, remove := targets[key]; remove {
				continue
			}
		}
		out = append(out, line)
	}
	return out
}

func remoteBinaryExists(server, path string) (bool, error) {
	script := fmt.Sprintf(`if [ -f %q ]; then printf yes; else printf no; fi`, path)
	output, err := runSSHOutput(server, script)
	if err != nil {
		return false, err
	}
	return strings.TrimSpace(output) == "yes", nil
}

func remoteDirExists(server, path string) (bool, error) {
	script := fmt.Sprintf(`if [ -d %q ]; then printf yes; else printf no; fi`, path)
	output, err := runSSHOutput(server, script)
	if err != nil {
		return false, err
	}
	return strings.TrimSpace(output) == "yes", nil
}

func loadPBConfig(path string) (*pbToml, error) {
	data, err := os.ReadFile(path)
	if err != nil {
		return nil, err
	}

	var cfg pbToml
	if err := toml.Unmarshal(data, &cfg); err != nil {
		return nil, fmt.Errorf("failed to parse pb.toml: %w", err)
	}
	return &cfg, nil
}

func savePBConfig(path string, cfg *pbToml) error {
	data, err := toml.Marshal(cfg)
	if err != nil {
		return err
	}
	return os.WriteFile(path, data, 0o644)
}

func printStep(idx, total int, message string) {
	fmt.Printf("Step %d/%d: %s\n", idx, total, message)
}

func renderServiceTemplate(tpl, serviceName string) string {
	return strings.ReplaceAll(tpl, "{service}", serviceName)
}

func resolveVolumePath(volumeTemplate, baseDir, serviceName string) string {
	value := renderServiceTemplate(volumeTemplate, serviceName)
	if value == "" {
		return baseDir
	}
	if strings.HasPrefix(value, "/") {
		return value
	}
	return path.Join(baseDir, value)
}

func translateMachineArch(value string) (string, error) {
	machine := strings.TrimSpace(strings.ToLower(value))

	switch machine {
	case "x86_64", "amd64":
		return "amd64", nil
	case "i386", "i486", "i586", "i686":
		return "386", nil
	case "armv7l":
		return "armv7", nil
	case "armv6l":
		return "arm", nil
	case "aarch64", "arm64":
		return "arm64", nil
	}
	return "", fmt.Errorf("unsupported remote architecture %q", value)
}

func detectRemoteArch(server string) (string, error) {
	probes := []string{
		"uname -m",
		"arch",
	}
	var lastErr error
	for _, probe := range probes {
		output, err := runSSHOutput(server, probe)
		if err != nil {
			lastErr = fmt.Errorf("%s failed: %w", probe, err)
			continue
		}

		arch, err := translateMachineArch(output)
		if err != nil {
			lastErr = fmt.Errorf("%s -> %w", probe, err)
			continue
		}
		return arch, nil
	}
	if lastErr != nil {
		return "", fmt.Errorf("failed to determine remote architecture: %w", lastErr)
	}
	return "", fmt.Errorf("failed to determine remote architecture")
}

func pocketbaseAsset(version, osName, arch string) string {
	return fmt.Sprintf("pocketbase_%s_%s_%s.zip", version, osName, arch)
}

func firewallScript() string {
	return fmt.Sprintf(`set -euo pipefail
if ! command -v ufw >/dev/null; then
  apt-get update -y
  apt-get install -y ufw
fi
ufw allow OpenSSH
ufw allow 80/tcp
ufw allow 443/tcp
ufw --force enable
`)
}

func caddyScript(domain string, port int, serviceName string) string {
	return fmt.Sprintf(`set -euo pipefail
if ! command -v caddy >/dev/null; then
  apt-get update -y
  apt-get install -y curl gnupg2
  curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/gpg.key' | gpg --dearmor -o /usr/share/keyrings/caddy-stable-archive-keyring.gpg
  curl -1sLf 'https://dl.cloudsmith.io/public/caddy/stable/debian.deb.txt' > /etc/apt/sources.list.d/caddy-stable.list
  apt-get update -y
  apt-get install -y caddy
fi
mkdir -p /etc/caddy/sites
cat <<'EOF' > /etc/caddy/Caddyfile
import /etc/caddy/sites/*.caddy
EOF
cat <<'EOF' > /etc/caddy/sites/pb-%s.caddy
%s {
  request_body {
    max_size 10MB
  }
  encode gzip
  reverse_proxy 127.0.0.1:%d {
    transport http {
      read_timeout 360s
    }
  }
}
EOF
systemctl daemon-reload
systemctl enable --now caddy.service
systemctl reload-or-restart caddy.service
`, serviceName, domain, port)
}

func pocketbaseSetupScript(serviceDir, envFile, version, assetURL, volume string, port int) string {
	return fmt.Sprintf(`set -euo pipefail
service_dir="%s"
mkdir -p "$service_dir"
apt-get update -y
apt-get install -y curl unzip
binary="%s/pocketbase"
if [ ! -x "$binary" ]; then
  tmp=$(mktemp)
  curl -fsSL -o "$tmp" "%s"
  unzip -p "$tmp" pocketbase > "$binary"
  chmod +x "$binary"
  rm -f "$tmp"
fi
env_file="%s"
data_dir="%[5]s"
current_port=""
current_data_dir=""
	if [ -f "$env_file" ]; then
  current_port=$(grep '^PORT=' "$env_file" | head -n 1 | cut -d= -f2 || true)
  current_data_dir=$(grep '^POCKETBASE_DATA_DIR=' "$env_file" | head -n 1 | cut -d= -f2 || true)
 fi
if [ -n "$data_dir" ]; then
  mkdir -p "$data_dir"
fi
if [ "$current_port" != "%d" ] || [ "$current_data_dir" != "%[5]s" ]; then
  cat <<'EOF' > "$env_file"
PORT=%d
POCKETBASE_DATA_DIR=%[5]s
EOF
fi
`, serviceDir, serviceDir, assetURL, envFile, volume, port, port)
}

func systemdScript(serviceDir, envFile, serviceName string) string {
	return fmt.Sprintf(`set -euo pipefail
cat <<'EOF' > /etc/systemd/system/pb@.service
[Unit]
Description = PocketBase instance %%i
After = network.target

[Service]
Type             = simple
User             = root
Group            = root
LimitNOFILE      = 4096
Restart          = always
RestartSec       = 5s
StandardOutput   = append:%s/%%i.log
StandardError    = append:%s/%%i.log
WorkingDirectory = %s
EnvironmentFile  = %s
ExecStart        = %s/pocketbase serve --dir="${POCKETBASE_DATA_DIR}" --http="127.0.0.1:${PORT}"

[Install]
WantedBy = multi-user.target
EOF
	systemctl daemon-reload
	systemctl --no-block enable --now pb@%s
	systemctl --no-block restart pb@%s
`, serviceDir, serviceDir, serviceDir, envFile, serviceDir, serviceName, serviceName)
}

func systemdRestartScript(serviceName string) string {
	return fmt.Sprintf(`set -euo pipefail
systemctl --no-block restart pb@%s
`, serviceName)
}

func restartPocketBaseService(ctx *deploymentContext) error {
	if err := runSSHCommand(ctx.serverIP, systemdRestartScript(ctx.serviceName)); err != nil {
		return fmt.Errorf("systemd restart failed: %w", err)
	}
	return nil
}

func runSSHCommand(server, script string) error {
	remoteCmd := fmt.Sprintf("bash --noprofile --norc -c %s", shellQuote(script))
	cmd := exec.Command("ssh", append(sshArgs(server), remoteCmd)...)
	stdoutPipe, err := cmd.StdoutPipe()
	if err != nil {
		return err
	}
	cmd.Stderr = os.Stderr
	if err := cmd.Start(); err != nil {
		return err
	}

	done := make(chan error, 1)
	go func() {
		done <- filterEnvStream(stdoutPipe, os.Stdout)
	}()

	waitErr := cmd.Wait()
	pipeErr := <-done
	if waitErr != nil {
		return waitErr
	}
	return pipeErr
}

func runSSHRawCommand(server, script string) error {
	remoteCmd := fmt.Sprintf("bash --noprofile --norc -c %s", shellQuote(script))
	cmd := exec.Command("ssh", append(sshArgs(server), remoteCmd)...)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	return cmd.Run()
}

func runSSHOutput(server, script string) (string, error) {
	remoteCmd := fmt.Sprintf("bash --noprofile --norc -c %s", shellQuote(script))
	cmd := exec.Command("ssh", append(sshArgs(server), remoteCmd)...)
	var out bytes.Buffer
	cmd.Stdout = &out
	cmd.Stderr = os.Stderr
	if err := cmd.Run(); err != nil {
		return "", err
	}
	filtered := stripLeadingEnvLines(out.String())
	return strings.TrimSpace(filtered), nil
}

func runSSHCollect(server, script string) (string, error) {
	remoteCmd := fmt.Sprintf("bash --noprofile --norc -c %s", shellQuote(script))
	cmd := exec.Command("ssh", append(sshArgs(server), remoteCmd)...)
	var out bytes.Buffer
	cmd.Stdout = &out
	cmd.Stderr = os.Stderr
	if err := cmd.Run(); err != nil {
		return "", err
	}
	return out.String(), nil
}

func syncLocalDirectories(server, remoteBase string, dirs []string) error {
	var toSync []string
	for _, dir := range dirs {
		localPath := filepath.Join(".", dir)
		info, err := os.Stat(localPath)
		if err != nil {
			if errors.Is(err, os.ErrNotExist) {
				fmt.Printf("- %s does not exist locally, skipping\n", dir)
				continue
			}
			return err
		}
		if !info.IsDir() {
			fmt.Printf("- %s exists but is not a directory, skipping\n", dir)
			continue
		}

		toSync = append(toSync, dir+"/")
	}

	if len(toSync) == 0 {
		return nil
	}

	rsyncCmd := rsyncSSHCommand(server)
	remotePath := fmt.Sprintf("root@%s:%s", server, remoteBase)
	args := append([]string{"-e", rsyncCmd, "-avz", "--delete", "--relative"}, toSync...)
	args = append(args, remotePath)
	cmd := exec.Command("rsync", args...)
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	return cmd.Run()
}

func rsyncSSHCommand(server string) string {
	args := sshSharedArgs(server)
	return fmt.Sprintf("ssh %s", strings.Join(args, " "))
}

func sshArgs(server string) []string {
	args := append([]string(nil), sshSharedArgs(server)...)
	return append(args, fmt.Sprintf("root@%s", server))
}

func sshSharedArgs(server string) []string {
	return []string{
		"-o", "BatchMode=yes",
		"-o", "StrictHostKeyChecking=accept-new",
		"-o", "ControlMaster=auto",
		"-o", fmt.Sprintf("ControlPath=%s", sshControlPath(server)),
		"-o", "ControlPersist=5m",
	}
}

func sshControlPath(server string) string {
	sum := sha1.Sum([]byte(server))
	return filepath.Join(sshControlDir(), fmt.Sprintf("pb-ssh-%x.sock", sum))
}

func sshControlDir() string {
	if dir := os.Getenv("PB_SSH_CONTROL_DIR"); dir != "" {
		return dir
	}
	if runtime.GOOS == "windows" {
		return os.TempDir()
	}
	return "/tmp"
}

func closeSSHControlMaster(server string) {
	args := append([]string(nil), sshSharedArgs(server)...)
	args = append(args, "-O", "exit", fmt.Sprintf("root@%s", server))
	_ = exec.Command("ssh", args...).Run()
}

func filterEnvStream(r io.Reader, w io.Writer) error {
	scanner := bufio.NewScanner(r)
	scanner.Buffer(make([]byte, 0, 64*1024), 2*1024*1024)
	skipping := true
	window := newRemoteWindow(w)
	for scanner.Scan() {
		line := scanner.Text()
		if skipping && isEnvLine(line) {
			continue
		}
		if skipping {
			skipping = false
		}
		if err := window.add(line); err != nil {
			return err
		}
	}
	if err := scanner.Err(); err != nil {
		return err
	}
	return nil
}

type remoteWindow struct {
	w         io.Writer
	lines     []string
	prevCount int
}

func newRemoteWindow(w io.Writer) *remoteWindow {
	return &remoteWindow{w: w}
}

func (rw *remoteWindow) add(line string) error {
	rw.lines = append(rw.lines, line)
	if len(rw.lines) > remoteWindowSize {
		rw.lines = rw.lines[1:]
	}
	return rw.flush()
}

func (rw *remoteWindow) flush() error {
	if rw.prevCount > 0 {
		if _, err := fmt.Fprintf(rw.w, "\033[%dA", rw.prevCount); err != nil {
			return err
		}
	}
	for _, line := range rw.lines {
		if _, err := fmt.Fprintf(rw.w, "\033[2K\r%s%s%s%s\n", remoteLineColor, remoteIndent, line, remoteColorReset); err != nil {
			return err
		}
	}
	rw.prevCount = len(rw.lines)
	return nil
}

func stripLeadingEnvLines(input string) string {
	scanner := bufio.NewScanner(strings.NewReader(input))
	scanner.Buffer(make([]byte, 0, 64*1024), 2*1024*1024)
	skipping := true
	var builder strings.Builder
	addedLine := false
	for scanner.Scan() {
		line := scanner.Text()
		if skipping && isEnvLine(line) {
			continue
		}
		if skipping {
			skipping = false
		}
		if addedLine {
			builder.WriteByte('\n')
		}
		builder.WriteString(line)
		addedLine = true
	}
	if err := scanner.Err(); err != nil {
		return input
	}
	return builder.String()
}

func parseEnvLine(line string) (string, string, bool) {
	trimmed := strings.TrimSpace(line)
	if trimmed == "" || strings.HasPrefix(trimmed, "#") {
		return "", "", false
	}
	idx := strings.Index(trimmed, "=")
	if idx <= 0 {
		return "", "", false
	}
	key := strings.TrimSpace(trimmed[:idx])
	if !isEnvKey(key) {
		return "", "", false
	}
	value := strings.TrimSpace(trimmed[idx+1:])
	return key, value, true
}

func isEnvKey(key string) bool {
	if key == "" {
		return false
	}
	for i, r := range key {
		if i == 0 {
			if r != '_' && !unicode.IsLetter(r) {
				return false
			}
			continue
		}
		if r != '_' && !unicode.IsLetter(r) && !unicode.IsDigit(r) {
			return false
		}
	}
	return true
}

func isEnvLine(line string) bool {
	trimmed := strings.TrimSpace(line)
	if trimmed == "" {
		return true
	}
	idx := strings.IndexRune(trimmed, '=')
	if idx <= 0 {
		return false
	}
	return isEnvKey(trimmed[:idx])
}

func shellQuote(value string) string {
	if value == "" {
		return "''"
	}
	var builder strings.Builder
	builder.WriteByte('\'')
	for _, r := range value {
		if r == '\'' {
			builder.WriteString("'\"'\"'")
			continue
		}
		builder.WriteRune(r)
	}
	builder.WriteByte('\'')
	return builder.String()
}