// Package menu implements the main BBS menu and command dispatch.
//
// This replaces MENU.C from the original TAG-BBS. The original used
// a FOREVER loop reading single keystrokes and dispatching to *Com()
// functions (ACom, BCom, MCom, PCom, etc.) via a switch statement.
//
// The modernized version uses the same single-keypress model — a user
// presses a letter and the command runs immediately, no Enter required.
// Commands are organized into a dispatch table rather than a monolithic
// switch, making it easy to add new commands or adjust access levels.
//
// The menu prompt shows the system name and user handle, mirroring the
// original's: "SYSTEM NAME Menu [?] "
package menu

import (
	"fmt"
	"log"
	"os"
	"strings"
	"time"

	"github.com/urit/urit/internal/auth"
	"github.com/urit/urit/internal/config"
	"github.com/urit/urit/internal/models"
	"github.com/urit/urit/internal/session"
	"github.com/urit/urit/internal/store"
)

const (
	idleTimeout = 120 * time.Second
	inputTimeout = 60 * time.Second
)

// Context holds everything a menu command needs to operate.
// This replaces the original's global variables (extern struct System,
// extern struct User, extern long Time_*, etc.).
type Context struct {
	Sess   *session.Session
	User   *models.User
	Store  store.Store
	Cfg    *config.Config
	Auth   *auth.Result
	Nodes  NodeManager  // Node management (list, disconnect, message)
	Tokens WebTokenizer // Web access token generation (for HTTP downloads)
	Chat   ChatAgent    // Inter-node chat
}

// WebTokenizer generates web access tokens for HTTP file downloads.
// Implemented by the server, used by the menu layer to let telnet
// users authenticate their browser sessions.
type WebTokenizer interface {
	GenerateWebToken(userID int64, userName string, secLibrary int) (token string, err error)
	HTTPAddress() string
}

// ChatAgent provides inter-node chat operations.
// Implemented by the server, used by the menu layer to let users
// page and chat with other connected nodes.
type ChatAgent interface {
	EnterChat(node int) <-chan string
	LinkChat(nodeA, nodeB int) bool
	SendChat(fromNode int, msg string) bool
	EndChat(node int)
	ChatPartner(node int) int
	IsInChat(node int) bool
}

// command defines a single menu entry.
type command struct {
	Key         byte   // The keystroke that triggers it
	Label       string // Display name
	Description string // One-line help text
	MinSec      int    // Minimum SecStatus required (0 = everyone)
	GuestOK     bool   // Whether guests can use it
	Handler     func(ctx *Context) error
}

// commands is the dispatch table. Order here determines help display order.
// This replaces the switch(toupper(input&0x7f)) block in MENU.C.
// Populated in init() to avoid an initialization cycle (cmdHelp references commands).
var commands []command

func init() {
	commands = []command{
		// Accessible to all including guests
		{'?', "Help", "Show command list", 0, true, cmdHelp},
		{'I', "Info", "System information", 0, true, cmdInfo},
		{'S', "Stats", "System statistics", 0, true, cmdStats},
		{'T', "Time", "Time statistics", 0, true, cmdTime},
		{'W', "Who", "Who's online", 0, true, cmdWho},

		// Require an account (no guests)
		{'A', "Account", "Your account info", 0, false, cmdAccount},
		{'P', "Mail", "Private mail", 0, false, cmdMail},
		{'M', "Messages", "Message boards", 0, false, cmdMessages},
		{'B', "Bulletins", "Bulletin listings", 0, false, cmdBulletins},
		{'L', "Library", "File library", 0, false, cmdLibrary},
		{'D', "Download", "Get web download link", 0, false, cmdDownloadToken},
		{'C', "Chat", "Page/chat with other users", 0, false, cmdChat},
		{'U', "Users", "User listings", 0, false, cmdUsers},
		{'F', "Feedback", "Send note to sysop", 0, false, cmdFeedback},

		// Guest-only: create permanent account (replaces JCom)
		{'J', "Join", "Create a permanent account", 0, true, cmdJoin},

		// Available to everyone
		{'G', "Goodbye", "Log off", 0, true, cmdGoodbye},

		// Sysop only
		{'E', "Sysop", "Sysop management menu", 255, false, cmdSysopMenu},
	}
}

// Run is the main menu loop. It replaces the FOREVER loop in Menu().
//
// The original's flow was:
//   1. Clear_Online_Status() — reset time tracking
//   2. Check mail count and auto-enter mail if waiting
//   3. FOREVER: print prompt, ReadChar, dispatch via switch
//
// Our flow matches this but uses the dispatch table instead of a switch.
func Run(ctx *Context) {
	// Display the main menu help file if it exists (first time)
	ctx.Sess.SendFile(ctx.Cfg.System.Screens + "mainmenu.ans")

	for {
		// Print the prompt — mirrors: "SYSTEM_NAME Menu [?] "
		ctx.Sess.Color(session.AnsiFgCyan)
		ctx.Sess.Printf("\r\n%s ", ctx.Cfg.System.Name)
		ctx.Sess.Color(session.AnsiFgBrightWhite)
		ctx.Sess.Printf("[%s]", ctx.User.Name)
		ctx.Sess.Color(session.AnsiFgCyan)
		ctx.Sess.WriteString(" [?] ")
		ctx.Sess.Color(session.AnsiReset)

		// Single keypress — no Enter required, just like the original
		ch, err := ctx.Sess.ReadKey(idleTimeout)
		if err != nil {
			// Timeout or disconnect
			if err == session.ErrTimeout {
				ctx.Sess.WriteString("\r\nIdle timeout — goodbye!\r\n")
				ctx.Sess.Close(session.DisconnectTimeout)
			}
			return
		}

		// Check time remaining (replaces Check_Online_Status())
		ctx.Sess.CheckTime()

		// Find and run the matching command
		handled := false
		upper := toUpper(ch)

		for _, cmd := range commands {
			if cmd.Key != upper {
				continue
			}

			// Security check
			if cmd.MinSec > 0 && ctx.User.SecStatus < cmd.MinSec {
				// Hidden command — don't even acknowledge the keystroke.
				// Matches the original: if(User.Sec_Status<255) return FAILURE;
				handled = true
				break
			}

			// Guest check
			if !cmd.GuestOK && ctx.Auth.IsGuest {
				// J (Join) is the exception — it's GuestOK but only
				// useful for guests. Other non-guest commands silently
				// reject guests. But let's be friendly about it.
				if cmd.Key == 'J' {
					// J is guest-OK, so this won't hit. But other
					// non-guest commands get a message.
				}
				ctx.Sess.Color(session.AnsiFgYellow)
				ctx.Sess.WriteString("(Registered users only)\r\n")
				ctx.Sess.Color(session.AnsiReset)
				handled = true
				break
			}

			// J (Join) only makes sense for guests
			if cmd.Key == 'J' && !ctx.Auth.IsGuest {
				handled = true
				break
			}

			// Run the command
			ctx.Sess.Color(session.AnsiFgBrightWhite)
			ctx.Sess.WriteString(cmd.Label + "\r\n")
			ctx.Sess.Color(session.AnsiReset)

			if err := cmd.Handler(ctx); err != nil {
				// Command signaled exit (goodbye, disconnect, etc.)
				return
			}
			handled = true
			break
		}

		if !handled {
			// Unrecognized key — silently ignore, just like the original's
			// default: command_accepted=FAILURE; continue;
			continue
		}
	}
}

// errGoodbye is a sentinel used by cmdGoodbye to signal normal exit.
var errGoodbye = fmt.Errorf("goodbye")

// --- Command implementations ---
// Each replaces one of the original's *Com() functions.

// cmdHelp displays the command list.
// Replaces: case '?': MenuSend("MainMenu.Help")
func cmdHelp(ctx *Context) error {
	// Try the screen file first — if the sysop has installed a custom
	// help file, display it instead of the generated list.
	helpPath := ctx.Cfg.System.Screens + "help.ans"
	if _, err := os.Stat(helpPath); err == nil {
		ctx.Sess.SendFile(helpPath)
		return nil
	}

	// Fall back to generated help from the command table
	ctx.Sess.NewLine()
	ctx.Sess.Color(session.AnsiFgGreen, session.AnsiBold)
	ctx.Sess.WriteString("Available Commands\r\n")
	ctx.Sess.Color(session.AnsiReset)
	ctx.Sess.WriteString(strings.Repeat("─", 40) + "\r\n")

	for _, cmd := range commands {
		// Skip hidden commands the user can't access
		if cmd.MinSec > 0 && ctx.User.SecStatus < cmd.MinSec {
			continue
		}
		if !cmd.GuestOK && ctx.Auth.IsGuest {
			continue
		}
		if cmd.Key == 'J' && !ctx.Auth.IsGuest {
			continue
		}

		ctx.Sess.Color(session.AnsiFgBrightWhite)
		ctx.Sess.Printf("  [%c] ", cmd.Key)
		ctx.Sess.Color(session.AnsiFgCyan)
		ctx.Sess.Printf("%-12s", cmd.Label)
		ctx.Sess.Color(session.AnsiFgBrightBlack)
		ctx.Sess.Printf("%s\r\n", cmd.Description)
	}
	ctx.Sess.Color(session.AnsiReset)
	return nil
}

// cmdInfo displays system statistics.
// Replaces: ICom() → Report_Stat() from STATISTI.C
func cmdInfo(ctx *Context) error {
	ctx.Sess.NewLine()
	ctx.Sess.Color(session.AnsiFgGreen, session.AnsiBold)
	ctx.Sess.WriteString("System Information\r\n")
	ctx.Sess.Color(session.AnsiReset)
	ctx.Sess.WriteString(strings.Repeat("─", 40) + "\r\n")

	ctx.Sess.Printf("  System:  %s\r\n", ctx.Cfg.System.Name)
	ctx.Sess.Printf("  Sysop:   %s\r\n", ctx.Cfg.System.Sysop)
	ctx.Sess.Printf("  Version: URIT BBS v0.2.0\r\n")

	userCount, _ := ctx.Store.CountUsers()
	boards, _ := ctx.Store.ListBoards()
	libs, _ := ctx.Store.ListLibraries()
	ctx.Sess.Printf("  Users:   %d registered\r\n", userCount)
	ctx.Sess.Printf("  Boards:  %d\r\n", len(boards))
	ctx.Sess.Printf("  Libraries: %d\r\n", len(libs))

	ctx.Sess.NewLine()
	return nil
}

// cmdStats displays system statistics.
// Replaces: Report_Stat() from STATISTI.C
//
// The original displayed very basic stats (system name, sysop, first
// online date). Ours shows activity counters and the recent call log,
// which is much more useful.
func cmdStats(ctx *Context) error {
	stats, _ := ctx.Store.GetAllStats()
	ctx.Sess.NewLine()
	ctx.Sess.Color(session.AnsiFgGreen, session.AnsiBold)
	ctx.Sess.WriteString("System Statistics\r\n")
	ctx.Sess.Color(session.AnsiReset)
	ctx.Sess.WriteString(strings.Repeat("─", 40) + "\r\n")

	ctx.Sess.Printf("  Total calls:    %d\r\n", stats["total_calls"])
	ctx.Sess.Printf("    Guest:        %d\r\n", stats["guest_calls"])
	ctx.Sess.Printf("    New:          %d\r\n", stats["new_calls"])
	ctx.Sess.Printf("    Validated:    %d\r\n", stats["valid_calls"])
	ctx.Sess.Printf("  New accounts:   %d\r\n", stats["new_accounts"])
	ctx.Sess.Printf("  Messages posted:%d\r\n", stats["messages_posted"])
	ctx.Sess.Printf("  Mail sent:      %d\r\n", stats["mail_sent"])

	totalSecs := stats["total_time_secs"]
	if totalSecs > 0 {
		hours := totalSecs / 3600
		mins := (totalSecs % 3600) / 60
		ctx.Sess.Printf("  Total time:     %dh %dm\r\n", hours, mins)
	}

	ctx.Sess.NewLine()

	// Recent callers — show last 10
	entries, _ := ctx.Store.ListCallLog(10)
	if len(entries) > 0 {
		ctx.Sess.Color(session.AnsiFgGreen, session.AnsiBold)
		ctx.Sess.WriteString("Recent Activity\r\n")
		ctx.Sess.Color(session.AnsiReset)
		ctx.Sess.WriteString(strings.Repeat("─", 40) + "\r\n")

		for _, e := range entries {
			ts := e.CreatedAt.Format("Jan 02 3:04PM")
			ctx.Sess.Color(session.AnsiFgBrightBlack)
			ctx.Sess.Printf("  %s ", ts)
			ctx.Sess.Color(session.AnsiReset)

			switch e.Event {
			case "login":
				ctx.Sess.Color(session.AnsiFgGreen)
				ctx.Sess.Printf("%-12s", e.UserName)
				ctx.Sess.Color(session.AnsiFgBrightBlack)
				ctx.Sess.Printf(" logged in\r\n")
			case "logoff":
				ctx.Sess.Color(session.AnsiFgCyan)
				ctx.Sess.Printf("%-12s", e.UserName)
				ctx.Sess.Color(session.AnsiFgBrightBlack)
				ctx.Sess.Printf(" %s\r\n", e.Detail)
			default:
				ctx.Sess.Printf("%-12s %s\r\n", e.UserName, e.Event)
			}
			ctx.Sess.Color(session.AnsiReset)
		}
		ctx.Sess.NewLine()
	}

	return nil
}

// cmdTime displays time statistics.
// Replaces: TCom() from MENU.C
func cmdTime(ctx *Context) error {
	ctx.Sess.CheckTime()

	ctx.Sess.NewLine()
	ctx.Sess.Printf("  Connected:  %s\r\n", ctx.Sess.ConnectedAt.Format("3:04 PM"))
	ctx.Sess.Printf("  Current:    %s\r\n", time.Now().Format("3:04 PM"))
	remaining := ctx.Sess.TimeRemaining()
	ctx.Sess.Printf("  Remaining:  %d min %d sec\r\n",
		int(remaining.Minutes()), int(remaining.Seconds())%60)
	ctx.Sess.NewLine()
	return nil
}

// cmdWho shows who is currently online.
// Not in the original (single-user system), but a natural multi-user feature.
func cmdWho(ctx *Context) error {
	ctx.Sess.NewLine()
	ctx.Sess.Color(session.AnsiFgGreen, session.AnsiBold)
	ctx.Sess.WriteString("Who's Online\r\n")
	ctx.Sess.Color(session.AnsiReset)
	ctx.Sess.WriteString(strings.Repeat("─", 50) + "\r\n")

	if ctx.Nodes == nil {
		ctx.Sess.WriteString("  (node list unavailable)\r\n")
	} else {
		nodes := ctx.Nodes.ActiveNodes()
		if len(nodes) == 0 {
			ctx.Sess.WriteString("  (no one online)\r\n")
		} else {
			ctx.Sess.Color(session.AnsiFgBrightBlack)
			ctx.Sess.Printf("  %-6s %-20s %s\r\n", "Node", "User", "Connected")
			ctx.Sess.WriteString(strings.Repeat("─", 50) + "\r\n")
			ctx.Sess.Color(session.AnsiReset)

			for _, n := range nodes {
				name := n.UserName
				if name == "" {
					name = "(connecting)"
				}
				// Highlight the current user's own node
				if n.Node == ctx.Sess.Node {
					ctx.Sess.Color(session.AnsiFgBrightWhite)
				}
				elapsed := time.Since(n.ConnectedAt).Truncate(time.Second)
				ctx.Sess.Printf("  %-6d %-20s %s\r\n", n.Node, name, elapsed)
				if n.Node == ctx.Sess.Node {
					ctx.Sess.Color(session.AnsiReset)
				}
			}
			ctx.Sess.NewLine()
			ctx.Sess.Color(session.AnsiFgBrightBlack)
			ctx.Sess.Printf("  %d node(s) active\r\n", len(nodes))
			ctx.Sess.Color(session.AnsiReset)
		}
	}
	ctx.Sess.NewLine()
	return nil
}

// cmdAccount displays the user's own account info.
// Replaces: ACom() from ACOM.C
func cmdAccount(ctx *Context) error {
	u := ctx.User
	ctx.Sess.NewLine()
	ctx.Sess.Color(session.AnsiFgGreen, session.AnsiBold)
	ctx.Sess.WriteString("Your Account\r\n")
	ctx.Sess.Color(session.AnsiReset)
	ctx.Sess.WriteString(strings.Repeat("─", 40) + "\r\n")

	ctx.Sess.Printf("  Account:   #%d\r\n", u.ID)
	ctx.Sess.Printf("  Username:  %s\r\n", u.Name)
	ctx.Sess.Printf("  Status:    %s (level %d)\r\n", u.StatusLabel(), u.SecStatus)
	ctx.Sess.Printf("  Security:  Board=%d Library=%d Bulletin=%d\r\n",
		u.SecBoard, u.SecLibrary, u.SecBulletin)
	ctx.Sess.NewLine()
	ctx.Sess.Printf("  Messages posted: %d\r\n", u.MessagesPosted)
	ctx.Sess.Printf("  Mail sent:       %d\r\n", u.MailSent)
	ctx.Sess.Printf("  Mail received:   %d\r\n", u.MailReceived)
	ctx.Sess.Printf("  Uploads:         %d\r\n", u.Uploads)
	ctx.Sess.Printf("  Downloads:       %d\r\n", u.Downloads)
	if u.LastOn != nil {
		ctx.Sess.Printf("  Last on:         %s\r\n", u.LastOn.Format("Jan 02, 2006 3:04 PM"))
	}
	ctx.Sess.NewLine()

	// Sub-menu for account actions (password change)
	ctx.Sess.WriteString("  [C] Change password  [Q] Return to main menu\r\n\r\n")

	for {
		ctx.Sess.WriteString("  Account> ")
		ch, err := ctx.Sess.ReadKey(idleTimeout)
		if err != nil {
			return nil
		}
		switch toUpper(ch) {
		case 'C':
			ctx.Sess.WriteString("Change password\r\n")
			if err := changePassword(ctx); err != nil {
				return nil
			}
			return nil
		case 'Q', '\x1b':
			ctx.Sess.WriteString("Return\r\n")
			return nil
		}
	}
}

// changePassword lets a user change their own password.
// Not in the original (sysop edited passwords via Edit_Accounts).
func changePassword(ctx *Context) error {
	ctx.Sess.Color(session.AnsiFgCyan)
	ctx.Sess.WriteString("  Current password: ")
	ctx.Sess.Color(session.AnsiReset)

	current, err := ctx.Sess.ReadLineNoEcho(72, inputTimeout)
	if err != nil {
		return err
	}

	if !auth.CheckPassword(ctx.User.PasswordHash, current) {
		ctx.Sess.WriteString("  Incorrect password.\r\n")
		return nil
	}

	ctx.Sess.Color(session.AnsiFgCyan)
	ctx.Sess.WriteString("  New password:     ")
	ctx.Sess.Color(session.AnsiReset)

	newPass, err := ctx.Sess.ReadLineNoEcho(72, inputTimeout)
	if err != nil {
		return err
	}
	if len(newPass) < 4 {
		ctx.Sess.WriteString("  Password must be at least 4 characters.\r\n")
		return nil
	}

	ctx.Sess.Color(session.AnsiFgCyan)
	ctx.Sess.WriteString("  Confirm password: ")
	ctx.Sess.Color(session.AnsiReset)

	confirm, err := ctx.Sess.ReadLineNoEcho(72, inputTimeout)
	if err != nil {
		return err
	}
	if newPass != confirm {
		ctx.Sess.WriteString("  Passwords do not match.\r\n")
		return nil
	}

	hash, err := auth.HashPassword(newPass)
	if err != nil {
		ctx.Sess.WriteString("  Error hashing password.\r\n")
		return nil
	}

	ctx.User.PasswordHash = hash
	if err := ctx.Store.UpdateUser(ctx.User); err != nil {
		ctx.Sess.WriteString("  Error saving password.\r\n")
		log.Printf("[Node %d] Password save error: %v", ctx.Sess.Node, err)
		return nil
	}

	ctx.Sess.Color(session.AnsiFgGreen)
	ctx.Sess.WriteString("  Password changed successfully.\r\n")
	ctx.Sess.Color(session.AnsiReset)
	return nil
}

// cmdMail is defined in mail.go — the full private mail subsystem.

// cmdMessages is defined in messages.go — the full message board subsystem.

// cmdBulletins is defined in bulletins.go — the full bulletin subsystem.

// cmdLibrary is defined in library.go — the full file library subsystem.

// cmdDownloadToken generates a web access token for HTTP file downloads.
// This is the bridge between the telnet session and the HTTP file server.
// The user gets a URL they can open in their browser to download files
// with their security level applied.
func cmdDownloadToken(ctx *Context) error {
	if ctx.Tokens == nil {
		ctx.Sess.WriteString("  Web downloads are not available.\r\n")
		return nil
	}

	httpAddr := ctx.Tokens.HTTPAddress()
	if httpAddr == "" {
		ctx.Sess.WriteString("  HTTP server is not enabled.\r\n")
		return nil
	}

	token, err := ctx.Tokens.GenerateWebToken(
		ctx.User.ID, ctx.User.Name, ctx.User.SecLibrary)
	if err != nil {
		ctx.Sess.WriteString("  Error generating token.\r\n")
		return nil
	}

	ctx.Sess.NewLine()
	ctx.Sess.Color(session.AnsiFgGreen, session.AnsiBold)
	ctx.Sess.WriteString("Web Download Access\r\n")
	ctx.Sess.Color(session.AnsiReset)
	ctx.Sess.WriteString(strings.Repeat("─", 40) + "\r\n")
	ctx.Sess.WriteString("  Open this URL in your browser:\r\n\r\n")
	ctx.Sess.Color(session.AnsiFgBrightWhite)
	ctx.Sess.Printf("  http://%s/libraries?token=%s\r\n", httpAddr, token)
	ctx.Sess.Color(session.AnsiReset)
	ctx.Sess.NewLine()
	ctx.Sess.Color(session.AnsiFgBrightBlack)
	ctx.Sess.WriteString("  Token valid for 1 hour.\r\n")
	ctx.Sess.WriteString("  Your library access level will apply.\r\n")
	ctx.Sess.Color(session.AnsiReset)
	ctx.Sess.NewLine()

	return nil
}

// cmdUsers displays user listings.
// Replaces: UCom() from UCOM.C
func cmdUsers(ctx *Context) error {
	ctx.Sess.NewLine()
	ctx.Sess.Color(session.AnsiFgGreen, session.AnsiBold)
	ctx.Sess.WriteString("User Listings\r\n")
	ctx.Sess.Color(session.AnsiReset)
	ctx.Sess.WriteString(strings.Repeat("─", 40) + "\r\n")

	const pageSize = 20
	offset := 0

	for {
		users, err := ctx.Store.ListUsers(offset, pageSize)
		if err != nil {
			ctx.Sess.WriteString("  Error loading users.\r\n")
			return nil
		}
		if len(users) == 0 {
			if offset == 0 {
				ctx.Sess.WriteString("  No registered users.\r\n")
			} else {
				ctx.Sess.WriteString("  End of list.\r\n")
			}
			break
		}

		for _, u := range users {
			lastOn := "never"
			if u.LastOn != nil {
				lastOn = u.LastOn.Format("Jan 02, 2006")
			}
			ctx.Sess.Printf("  [%3d] %-22s %-8s Last on %s\r\n",
				u.ID, u.Name, u.StatusLabel(), lastOn)
		}

		if len(users) < pageSize {
			break
		}

		ctx.Sess.WriteString("\r\n  [M]ore  [Q]uit  ")
		ch, err := ctx.Sess.ReadKey(idleTimeout)
		if err != nil {
			return nil
		}
		if toUpper(ch) != 'M' {
			ctx.Sess.WriteString("Quit\r\n")
			break
		}
		ctx.Sess.WriteString("More\r\n")
		offset += pageSize
	}

	ctx.Sess.NewLine()
	return nil
}

// cmdFeedback sends a note to the sysop.
// Replaces: case 'F': Mail_Reply_To(System.Mail_List,1)
func cmdFeedback(ctx *Context) error {
	ctx.Sess.NewLine()
	ctx.Sess.WriteString("Send a note to the sysop.\r\n\r\n")

	ctx.Sess.Color(session.AnsiFgCyan)
	ctx.Sess.WriteString("Subject: ")
	ctx.Sess.Color(session.AnsiReset)

	title, err := ctx.Sess.ReadLine("", 60, inputTimeout)
	if err != nil {
		return nil
	}
	title = strings.TrimSpace(title)
	if title == "" {
		ctx.Sess.WriteString("Cancelled.\r\n")
		return nil
	}

	ctx.Sess.WriteString("Enter your message (blank line to finish):\r\n")
	body, err := readMultiLine(ctx.Sess, 20)
	if err != nil {
		return nil
	}
	if body == "" {
		ctx.Sess.WriteString("Cancelled.\r\n")
		return nil
	}

	// Find the sysop (user ID 1 by convention, same as the original)
	sysop, err := ctx.Store.GetUser(1)
	if err != nil || sysop == nil {
		ctx.Sess.WriteString("  Error: sysop account not found.\r\n")
		return nil
	}

	mail := &models.Mail{
		Title:     title,
		Author:    ctx.User.Name,
		FromID:    ctx.User.ID,
		ToID:      sysop.ID,
		Recipient: sysop.Name,
		Body:      body,
	}

	if err := ctx.Store.CreateMail(mail); err != nil {
		ctx.Sess.WriteString("  Error sending feedback.\r\n")
		log.Printf("[Node %d] Feedback error: %v", ctx.Sess.Node, err)
		return nil
	}

	ctx.User.MailSent++
	ctx.Store.UpdateUser(ctx.User)
	ctx.Store.IncrementStat("mail_sent", 1)

	ctx.Sess.Color(session.AnsiFgGreen)
	ctx.Sess.WriteString("Feedback sent to sysop.\r\n")
	ctx.Sess.Color(session.AnsiReset)
	ctx.Sess.NewLine()
	return nil
}

// cmdJoin lets a guest create a permanent account.
// Replaces: JCom() from JCOM.C
func cmdJoin(ctx *Context) error {
	if !ctx.Auth.IsGuest {
		return nil
	}

	ctx.Sess.NewLine()
	ctx.Sess.Printf("Join %s as a permanent member.\r\n\r\n", ctx.Cfg.System.Name)

	yes, err := ctx.Sess.Confirm("Become a permanent member? (Y/N) ", inputTimeout)
	if err != nil || !yes {
		ctx.Sess.WriteString("Not joining.\r\n")
		return nil
	}

	// Show join screen
	ctx.Sess.SendFile(ctx.Cfg.System.Screens + "join.ans")

	ctx.Sess.Color(session.AnsiFgCyan)
	ctx.Sess.WriteString("Choose a username: ")
	ctx.Sess.Color(session.AnsiReset)

	name, err := ctx.Sess.ReadLine("", 30, inputTimeout)
	if err != nil {
		return nil
	}
	name = strings.TrimSpace(name)
	if len(name) < 2 {
		ctx.Sess.WriteString("Name too short. Cancelled.\r\n")
		return nil
	}

	// Check availability
	existing, _ := ctx.Store.GetUserByName(name)
	if existing != nil {
		ctx.Sess.WriteString("That name is already taken.\r\n")
		return nil
	}

	// Check account limit
	count, _ := ctx.Store.CountUsers()
	if count >= ctx.Cfg.Users.MaxAccounts {
		ctx.Sess.WriteString("Sorry, maximum accounts reached.\r\n")
		return nil
	}

	ctx.Sess.Color(session.AnsiFgCyan)
	ctx.Sess.WriteString("Choose a password: ")
	ctx.Sess.Color(session.AnsiReset)

	pass, err := ctx.Sess.ReadLineNoEcho(72, inputTimeout)
	if err != nil {
		return nil
	}
	if len(pass) < 4 {
		ctx.Sess.WriteString("Password must be at least 4 characters.\r\n")
		return nil
	}

	ctx.Sess.Color(session.AnsiFgCyan)
	ctx.Sess.WriteString("Confirm password:  ")
	ctx.Sess.Color(session.AnsiReset)

	confirm, err := ctx.Sess.ReadLineNoEcho(72, inputTimeout)
	if err != nil {
		return nil
	}
	if pass != confirm {
		ctx.Sess.WriteString("Passwords do not match.\r\n")
		return nil
	}

	// Optional comments to sysop (matches original's 3 comment lines)
	ctx.Sess.WriteString("\r\nEnter a comment for the sysop (blank to skip):\r\n")
	comments, _ := ctx.Sess.ReadLine("", 80, inputTimeout)

	hash, err := auth.HashPassword(pass)
	if err != nil {
		ctx.Sess.WriteString("Error creating account.\r\n")
		return nil
	}

	now := time.Now()
	newUser := &models.User{
		Name:         name,
		PasswordHash: hash,
		Comments:     strings.TrimSpace(comments),
		Active:       true,
		SecStatus:    ctx.Cfg.Users.NewSecurity.Status,
		SecBoard:     ctx.Cfg.Users.NewSecurity.Board,
		SecLibrary:   ctx.Cfg.Users.NewSecurity.Library,
		SecBulletin:  ctx.Cfg.Users.NewSecurity.Bulletin,
		TimeLimit:    int64(ctx.Cfg.Users.NewTimeLimit),
		LastOn:       &now,
	}

	if err := ctx.Store.CreateUser(newUser); err != nil {
		ctx.Sess.WriteString("Error saving account.\r\n")
		return nil
	}

	// Upgrade the session from guest to the new user
	ctx.User = newUser
	ctx.Auth.User = newUser
	ctx.Auth.IsGuest = false
	ctx.Auth.IsNew = true
	ctx.Sess.TimeLimit = time.Duration(newUser.TimeLimit) * time.Second

	ctx.Sess.NewLine()
	ctx.Sess.Color(session.AnsiFgGreen, session.AnsiBold)
	ctx.Sess.Printf("Account created: %s (ID #%d)\r\n", newUser.Name, newUser.ID)
	ctx.Sess.Color(session.AnsiFgYellow)
	ctx.Sess.WriteString("Your account is NEW and must be validated by the sysop.\r\n")
	ctx.Sess.Color(session.AnsiReset)

	ctx.Sess.SendFile(ctx.Cfg.System.Screens + "joined.ans")
	ctx.Sess.NewLine()
	return nil
}

// cmdGoodbye logs the user off.
// Replaces: case 'G': return(STANDARD_LOGOFF)
func cmdGoodbye(ctx *Context) error {
	ctx.Sess.NewLine()

	// Save user data before logging off (like the original's Save_Account)
	if !ctx.Auth.IsGuest && ctx.User.ID > 0 {
		now := time.Now()
		ctx.User.LastOn = &now
		ctx.Store.UpdateUser(ctx.User)
	}

	ctx.Sess.SendFile(ctx.Cfg.System.Screens + "goodbye.ans")

	ctx.Sess.Color(session.AnsiFgYellow)
	ctx.Sess.Printf("Goodbye, %s! Thanks for calling %s.\r\n",
		ctx.User.Name, ctx.Cfg.System.Name)
	ctx.Sess.Color(session.AnsiReset)

	ctx.Sess.Close(session.DisconnectNormal)
	return errGoodbye
}

// --- Helpers ---

// readMultiLine reads multiple lines of input until a blank line.
// Replaces the original's multi-line comment input pattern.
func readMultiLine(sess *session.Session, maxLines int) (string, error) {
	var lines []string
	for i := 0; i < maxLines; i++ {
		sess.Printf("%2d> ", i+1)
		line, err := sess.ReadLine("", 78, inputTimeout)
		if err != nil {
			return strings.Join(lines, "\n"), err
		}
		if strings.TrimSpace(line) == "" {
			break
		}
		lines = append(lines, line)
	}
	return strings.Join(lines, "\n"), nil
}

// toUpper converts a byte to uppercase. Handles the &0x7f masking
// the original did on serial input to strip high bit.
func toUpper(ch byte) byte {
	ch &= 0x7f
	if ch >= 'a' && ch <= 'z' {
		return ch - 32
	}
	return ch
}