// Package main is the waste-go terminal UI.
// It connects to a running daemon's IPC port and renders a three-pane layout:
// rooms/networks (left), messages with line numbers (centre), peers (right).
// Multiple networks are supported at runtime via /join; switch with ctrl+n.
package main

import (
	"bufio"
	"encoding/json"
	"flag"
	"fmt"
	"net"
	"os"
	"strconv"
	"strings"
	"time"

	"github.com/charmbracelet/bubbles/textinput"
	"github.com/charmbracelet/bubbles/viewport"
	tea "github.com/charmbracelet/bubbletea"
	"github.com/charmbracelet/lipgloss"

	"github.com/waste-go/internal/invite"
	"github.com/waste-go/internal/proto"
)

// ── styles ────────────────────────────────────────────────────────────────────

var (
	styleHeader   = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("33"))
	styleActive   = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("86"))
	styleRoom     = lipgloss.NewStyle().Foreground(lipgloss.Color("250"))
	styleNet      = lipgloss.NewStyle().Foreground(lipgloss.Color("39"))
	styleNetActive = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("51"))
	stylePeer     = lipgloss.NewStyle().Foreground(lipgloss.Color("72"))
	styleSelf     = lipgloss.NewStyle().Foreground(lipgloss.Color("86"))
	styleMsgFrom  = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("33"))
	styleMsgMe    = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("86"))
	styleMsgTime  = lipgloss.NewStyle().Foreground(lipgloss.Color("238"))
	styleLineNum  = lipgloss.NewStyle().Foreground(lipgloss.Color("238"))
	styleReaction = lipgloss.NewStyle().Foreground(lipgloss.Color("246"))
	styleTitle    = lipgloss.NewStyle().Bold(true).Foreground(lipgloss.Color("33"))
	styleBorder   = lipgloss.Color("238")
	styleStatus   = lipgloss.NewStyle().Foreground(lipgloss.Color("238"))
	styleErr      = lipgloss.NewStyle().Foreground(lipgloss.Color("196")).Bold(true)
)

const sideW = 22

// ── tea messages ──────────────────────────────────────────────────────────────

type connectedMsg struct {
	conn   net.Conn
	reader *lineReader
}
type ipcLineMsg struct{ line []byte }
type connectErrMsg struct{ err error }
type readErrMsg struct{ err error }

type lineReader struct {
	ch chan []byte
}

func newLineReader(conn net.Conn) *lineReader {
	lr := &lineReader{ch: make(chan []byte, 64)}
	go func() {
		scanner := bufio.NewScanner(conn)
		for scanner.Scan() {
			b := make([]byte, len(scanner.Bytes()))
			copy(b, scanner.Bytes())
			lr.ch <- b
		}
		close(lr.ch)
	}()
	return lr
}

func (lr *lineReader) next() tea.Cmd {
	return func() tea.Msg {
		b, ok := <-lr.ch
		if !ok {
			return readErrMsg{fmt.Errorf("daemon closed connection")}
		}
		return ipcLineMsg{b}
	}
}

// ── model ─────────────────────────────────────────────────────────────────────

// netData holds per-network state.
type netData struct {
	id         string
	name       string
	localID    proto.PeerID
	localAlias string
	rooms      []string
	activeRoom int
	peers      map[proto.PeerID]string
	peerOrder  []proto.PeerID
	knownPeers map[proto.PeerID]string // historical peers (from store)
}

func newNetData(id, name string) *netData {
	return &netData{
		id:         id,
		name:       name,
		rooms:      []string{"general"},
		peers:      make(map[proto.PeerID]string),
		knownPeers: make(map[proto.PeerID]string),
	}
}

func (n *netData) addRoom(room string) bool {
	for _, r := range n.rooms {
		if r == room {
			return false
		}
	}
	n.rooms = append(n.rooms, room)
	return true
}

// entry is a single chat message in the viewport.
type entry struct {
	mid    string
	from   string
	body   string
	at     time.Time
	fromMe bool
}

type model struct {
	ipcPort        int
	initialNetwork string // from -network flag; joined on first connect

	width, height int

	conn   net.Conn
	enc    *json.Encoder
	reader *lineReader

	nets      []*netData
	activeNet int

	// keyed by "netId:room"
	messages map[string][]entry
	unread   map[string]bool

	// mid → emoji → []alias
	reactions map[string]map[string][]string

	input    textinput.Model
	viewport viewport.Model
	vpReady  bool

	status      string
	errMsg      string
	invitePopup string
}

func newModel(ipcPort int, network string) model {
	ti := textinput.New()
	ti.Placeholder = "Type a message, or /join /net /room /react…"
	ti.Focus()
	ti.CharLimit = 2000

	return model{
		ipcPort:        ipcPort,
		initialNetwork: network,
		messages:       make(map[string][]entry),
		unread:         make(map[string]bool),
		reactions:      make(map[string]map[string][]string),
		input:          ti,
		status:         "connecting…",
	}
}

// ── accessors ─────────────────────────────────────────────────────────────────

func (m model) activeNetData() *netData {
	if m.activeNet < len(m.nets) {
		return m.nets[m.activeNet]
	}
	return nil
}

func (m model) activeNetworkID() string {
	if n := m.activeNetData(); n != nil {
		return n.id
	}
	return ""
}

func (m model) activeRoomName() string {
	n := m.activeNetData()
	if n == nil {
		return "general"
	}
	if n.activeRoom < len(n.rooms) {
		return n.rooms[n.activeRoom]
	}
	return "general"
}

func (m model) msgKey() string {
	n := m.activeNetData()
	if n == nil {
		return ":general"
	}
	return n.id + ":" + n.rooms[n.activeRoom]
}

func (m model) netByID(id string) *netData {
	for _, n := range m.nets {
		if n.id == id {
			return n
		}
	}
	return nil
}

func (m model) aliasOf(netID string, id proto.PeerID) string {
	n := m.netByID(netID)
	if n == nil {
		return shortID(id)
	}
	if id == n.localID && n.localAlias != "" {
		return n.localAlias
	}
	if a, ok := n.peers[id]; ok && a != "" {
		return a
	}
	if a, ok := n.knownPeers[id]; ok && a != "" {
		return a
	}
	return shortID(id)
}

// ── Init ──────────────────────────────────────────────────────────────────────

func (m model) Init() tea.Cmd {
	return tea.Batch(connectCmd(m.ipcPort), textinput.Blink)
}

// ── commands ──────────────────────────────────────────────────────────────────

func connectCmd(port int) tea.Cmd {
	return func() tea.Msg {
		conn, err := net.Dial("tcp", fmt.Sprintf("127.0.0.1:%d", port))
		if err != nil {
			return connectErrMsg{err}
		}
		return connectedMsg{conn: conn, reader: newLineReader(conn)}
	}
}

func sendIPC(enc *json.Encoder, msg proto.IpcMessage) tea.Cmd {
	return func() tea.Msg {
		enc.Encode(msg) //nolint:errcheck
		return nil
	}
}

// ── Update ────────────────────────────────────────────────────────────────────

func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
	var cmds []tea.Cmd

	switch msg := msg.(type) {

	case tea.WindowSizeMsg:
		m.width, m.height = msg.Width, msg.Height
		m = m.resizeViewport()

	case connectErrMsg:
		m.errMsg = fmt.Sprintf("cannot connect to daemon on :%d — is it running?", m.ipcPort)
		m.status = "disconnected"

	case connectedMsg:
		m.conn = msg.conn
		m.enc = json.NewEncoder(msg.conn)
		m.reader = msg.reader
		cmds = append(cmds, sendIPC(m.enc, proto.IpcMessage{Type: proto.CmdGetState}), m.reader.next())
		if m.initialNetwork != "" {
			m.status = "joining " + m.initialNetwork + "…"
			cmds = append(cmds, sendIPC(m.enc, proto.IpcMessage{Type: proto.CmdJoinNetwork, NetworkName: m.initialNetwork}))
		} else {
			m.status = "connected — /join <network> to start"
		}

	case ipcLineMsg:
		var evt proto.IpcMessage
		if json.Unmarshal(msg.line, &evt) == nil {
			m = m.applyEvent(evt)
		}
		cmds = append(cmds, m.reader.next())

	case readErrMsg:
		m.errMsg = "IPC disconnected: " + msg.err.Error()
		m.status = "disconnected"

	case tea.KeyMsg:
		switch {
		case msg.Type == tea.KeyCtrlC:
			return m, tea.Quit
		case msg.Type == tea.KeyEsc:
			if m.invitePopup != "" {
				m.invitePopup = ""
				return m, nil
			}
			return m, tea.Quit
		case msg.String() == "ctrl+i":
			if m.enc != nil {
				cmds = append(cmds, sendIPC(m.enc, proto.IpcMessage{
					Type:      proto.CmdGenerateInvite,
					NetworkID: m.activeNetworkID(),
				}))
			}
		case msg.String() == "ctrl+n":
			if len(m.nets) > 1 {
				m.activeNet = (m.activeNet + 1) % len(m.nets)
				m = m.refreshViewport()
			}
		case msg.Type == tea.KeyEnter:
			m, cmds = m.doSend(cmds)
		case msg.Type == tea.KeyTab:
			if n := m.activeNetData(); n != nil {
				n.activeRoom = (n.activeRoom + 1) % len(n.rooms)
				delete(m.unread, m.msgKey())
				m = m.refreshViewport()
			}
		case msg.Type == tea.KeyShiftTab:
			if n := m.activeNetData(); n != nil {
				n.activeRoom = (n.activeRoom - 1 + len(n.rooms)) % len(n.rooms)
				delete(m.unread, m.msgKey())
				m = m.refreshViewport()
			}
		default:
			var tiCmd tea.Cmd
			m.input, tiCmd = m.input.Update(msg)
			cmds = append(cmds, tiCmd)
		}

	default:
		if m.vpReady {
			var vpCmd tea.Cmd
			m.viewport, vpCmd = m.viewport.Update(msg)
			cmds = append(cmds, vpCmd)
		}
	}

	return m, tea.Batch(cmds...)
}

// ── applyEvent ────────────────────────────────────────────────────────────────

func (m model) applyEvent(evt proto.IpcMessage) model {
	switch evt.Type {

	case proto.EvtStateSnapshot:
		// Populate nets from snapshot.
		for _, ni := range evt.Networks {
			n := m.netByID(ni.NetworkID)
			if n == nil {
				n = newNetData(ni.NetworkID, ni.NetworkName)
				m.nets = append(m.nets, n)
			}
			if ni.LocalPeer != nil {
				n.localID = ni.LocalPeer.ID
				n.localAlias = ni.LocalPeer.Alias
			}
		}
		// Backward-compat: connected_peers and rooms are from first network.
		if len(evt.Networks) > 0 && len(m.nets) > 0 {
			n := m.nets[0]
			for _, p := range evt.ConnectedPeers {
				if _, ok := n.peers[p.ID]; !ok {
					n.peerOrder = append(n.peerOrder, p.ID)
				}
				n.peers[p.ID] = p.Alias
			}
			for _, r := range evt.Rooms {
				n.addRoom(r)
			}
			for _, p := range evt.KnownPeers {
				n.knownPeers[p.ID] = p.Alias
			}
		}
		m = m.updateStatus()
		m = m.refreshViewport()

	case proto.EvtNetworkJoined:
		n := m.netByID(evt.NetworkID)
		if n == nil {
			name := evt.NetworkName
			if name == "" {
				name = evt.NetworkID
			}
			n = newNetData(evt.NetworkID, name)
			m.nets = append(m.nets, n)
			m.activeNet = len(m.nets) - 1
		}
		if evt.LocalPeer != nil {
			n.localID = evt.LocalPeer.ID
			n.localAlias = evt.LocalPeer.Alias
		}
		m = m.updateStatus()
		m = m.refreshViewport()

	case proto.EvtRoomCreated:
		if n := m.netByID(evt.NetworkID); n != nil {
			n.addRoom(evt.Room)
			m = m.refreshViewport()
		}

	case proto.EvtSessionReady:
		netID := evt.NetworkID
		if netID == "" && len(m.nets) > 0 {
			netID = m.nets[0].id
		}
		if n := m.netByID(netID); n != nil && evt.PeerID != nil {
			pid := *evt.PeerID
			if _, ok := n.peers[pid]; !ok {
				n.peerOrder = append(n.peerOrder, pid)
			}
			alias := evt.Nick
			if alias == "" {
				alias = shortID(pid)
			}
			n.peers[pid] = alias
		}

	case proto.EvtPeerConnected:
		netID := evt.NetworkID
		if netID == "" && len(m.nets) > 0 {
			netID = m.nets[0].id
		}
		if n := m.netByID(netID); n != nil && evt.Peer != nil {
			pid := evt.Peer.ID
			if _, ok := n.peers[pid]; !ok {
				n.peerOrder = append(n.peerOrder, pid)
			}
			n.peers[pid] = evt.Peer.Alias
		}

	case proto.EvtPeerDisconnected:
		netID := evt.NetworkID
		if netID == "" && len(m.nets) > 0 {
			netID = m.nets[0].id
		}
		if n := m.netByID(netID); n != nil && evt.PeerID != nil {
			pid := *evt.PeerID
			delete(n.peers, pid)
			n.peerOrder = filterIDs(n.peerOrder, pid)
		}

	case proto.EvtInviteGenerated:
		m.invitePopup = evt.InviteGenerated

	case proto.EvtMessageReceived:
		if evt.Message != nil {
			msg := evt.Message
			netID := evt.NetworkID
			if netID == "" && len(m.nets) > 0 {
				netID = m.nets[0].id
			}
			n := m.netByID(netID)
			if n != nil {
				n.addRoom(msg.Room)
			}
			e := entry{
				mid:    msg.Mid,
				from:   m.aliasOf(netID, msg.From),
				body:   msg.Text,
				at:     time.UnixMilli(msg.Ts),
				fromMe: n != nil && msg.From == n.localID,
			}
			key := netID + ":" + msg.Room
			m.messages[key] = append(m.messages[key], e)
			if key != m.msgKey() {
				m.unread[key] = true
			}
			m = m.refreshViewport()
		}

	case proto.EvtHistoryLoaded:
		netID := evt.NetworkID
		if netID == "" && len(m.nets) > 0 {
			netID = m.nets[0].id
		}
		n := m.netByID(netID)
		key := netID + ":" + evt.Room
		existing := m.messages[key]
		existingMids := make(map[string]bool, len(existing))
		for _, e := range existing {
			if e.mid != "" {
				existingMids[e.mid] = true
			}
		}
		var fresh []entry
		for _, msg := range evt.Messages {
			if msg.Mid != "" && existingMids[msg.Mid] {
				continue
			}
			fromMe := n != nil && msg.From == n.localID
			fresh = append(fresh, entry{
				mid:    msg.Mid,
				from:   m.aliasOf(netID, msg.From),
				body:   msg.Text,
				at:     time.UnixMilli(msg.Ts),
				fromMe: fromMe,
			})
		}
		if len(fresh) > 0 {
			// Prepend history, then existing live messages; sort by time.
			merged := append(fresh, existing...)
			// Simple insertion sort (lists are already mostly sorted).
			for i := 1; i < len(merged); i++ {
				for j := i; j > 0 && merged[j].at.Before(merged[j-1].at); j-- {
					merged[j], merged[j-1] = merged[j-1], merged[j]
				}
			}
			m.messages[key] = merged
			if n != nil {
				n.addRoom(evt.Room)
			}
			m = m.refreshViewport()
		}

	case proto.EvtReaction:
		mid := evt.ReactionMID
		emoji := evt.ReactionEmoji
		if mid == "" || emoji == "" || evt.PeerID == nil {
			break
		}
		netID := evt.NetworkID
		if netID == "" && len(m.nets) > 0 {
			netID = m.nets[0].id
		}
		alias := m.aliasOf(netID, *evt.PeerID)
		if m.reactions[mid] == nil {
			m.reactions[mid] = make(map[string][]string)
		}
		for _, a := range m.reactions[mid][emoji] {
			if a == alias {
				return m // already recorded
			}
		}
		m.reactions[mid][emoji] = append(m.reactions[mid][emoji], alias)
		m = m.refreshViewport()
	}

	return m
}

func (m model) updateStatus() model {
	n := m.activeNetData()
	if n == nil {
		m.status = "connected — /join <network> to start"
		return m
	}
	m.status = fmt.Sprintf("● %s  ·  %s", n.localAlias, n.name)
	return m
}

// ── doSend ────────────────────────────────────────────────────────────────────

func (m model) doSend(cmds []tea.Cmd) (model, []tea.Cmd) {
	body := strings.TrimSpace(m.input.Value())
	if body == "" || m.enc == nil {
		return m, cmds
	}
	m.input.SetValue("")

	// /join <network-name>
	if strings.HasPrefix(body, "/join ") {
		name := strings.TrimSpace(strings.TrimPrefix(body, "/join "))
		if name != "" {
			cmds = append(cmds, sendIPC(m.enc, proto.IpcMessage{Type: proto.CmdJoinNetwork, NetworkName: name}))
		}
		return m, cmds
	}

	// /net <number|name> — switch active network
	if strings.HasPrefix(body, "/net ") {
		arg := strings.TrimSpace(strings.TrimPrefix(body, "/net "))
		if n, err := strconv.Atoi(arg); err == nil {
			idx := n - 1
			if idx >= 0 && idx < len(m.nets) {
				m.activeNet = idx
				m = m.updateStatus()
				m = m.refreshViewport()
			}
		} else {
			for i, net := range m.nets {
				if strings.EqualFold(net.name, arg) {
					m.activeNet = i
					m = m.updateStatus()
					m = m.refreshViewport()
					break
				}
			}
		}
		return m, cmds
	}

	// /room <name>
	if strings.HasPrefix(body, "/room ") {
		name := strings.TrimSpace(strings.TrimPrefix(body, "/room "))
		if name != "" {
			cmds = append(cmds, sendIPC(m.enc, proto.IpcMessage{
				Type:      proto.CmdCreateRoom,
				NetworkID: m.activeNetworkID(),
				Room:      name,
			}))
		}
		return m, cmds
	}

	// /react [<n>] <emoji>
	if strings.HasPrefix(body, "/react ") {
		rest := strings.TrimSpace(strings.TrimPrefix(body, "/react "))
		parts := strings.Fields(rest)
		var targetIdx int = -1 // -1 = last message
		var emoji string
		switch len(parts) {
		case 1:
			emoji = parts[0]
		case 2:
			if n, err := strconv.Atoi(parts[0]); err == nil {
				targetIdx = n - 1
			} else {
				emoji = parts[0] // fallback: treat first token as emoji
			}
			if emoji == "" {
				emoji = parts[1]
			}
		}
		if emoji == "" {
			m.errMsg = "usage: /react <emoji>  or  /react <n> <emoji>   (e.g. /react 👍  or  /react 3 ❤️)"
			return m, cmds
		}
		msgs := m.messages[m.msgKey()]
		var targetMid string
		if targetIdx == -1 && len(msgs) > 0 {
			targetMid = msgs[len(msgs)-1].mid
		} else if targetIdx >= 0 && targetIdx < len(msgs) {
			targetMid = msgs[targetIdx].mid
		}
		if targetMid == "" {
			m.errMsg = "usage: /react <emoji>  or  /react <n> <emoji>   (e.g. /react 👍  or  /react 3 ❤️)"
			return m, cmds
		}
		cmds = append(cmds, sendIPC(m.enc, proto.IpcMessage{
			Type:          proto.CmdSendReaction,
			NetworkID:     m.activeNetworkID(),
			ReactionMID:   targetMid,
			ReactionEmoji: emoji,
		}))
		return m, cmds
	}

	// Regular message
	n := m.activeNetData()
	if n == nil {
		return m, cmds
	}
	room := n.rooms[n.activeRoom]
	ipcMsg := proto.IpcMessage{
		Type:      proto.CmdSendMessage,
		NetworkID: n.id,
		Room:      room,
		Body:      body,
	}
	if strings.HasPrefix(room, "dm:") {
		recipID := proto.PeerID(strings.TrimPrefix(room, "dm:"))
		ipcMsg.To = &recipID
	}
	cmds = append(cmds, sendIPC(m.enc, ipcMsg))
	return m, cmds
}

// ── layout helpers ────────────────────────────────────────────────────────────

func (m model) vpContentWidth() int {
	w := m.width - sideW*2 - 2
	if w < 10 {
		w = 10
	}
	return w
}

func (m model) vpHeight() int {
	h := m.height - 8
	if h < 1 {
		h = 1
	}
	return h
}

func (m model) resizeViewport() model {
	if !m.vpReady {
		m.viewport = viewport.New(m.vpContentWidth(), m.vpHeight())
		m.vpReady = true
	} else {
		m.viewport.Width = m.vpContentWidth()
		m.viewport.Height = m.vpHeight()
	}
	return m.refreshViewport()
}

func (m model) refreshViewport() model {
	if !m.vpReady {
		return m
	}
	key := m.msgKey()
	var sb strings.Builder
	for i, e := range m.messages[key] {
		lineNum := styleLineNum.Render(fmt.Sprintf("[%d]", i+1))
		ts := styleMsgTime.Render(formatMsgTime(e.at))
		var from string
		if e.fromMe {
			from = styleMsgMe.Render(e.from)
		} else {
			from = styleMsgFrom.Render(e.from)
		}
		sb.WriteString(fmt.Sprintf("%s %s %s  %s\n", lineNum, ts, from, e.body))
		if e.mid != "" {
			if rxn := m.renderReactions(e.mid); rxn != "" {
				sb.WriteString(rxn + "\n")
			}
		}
	}
	m.viewport.SetContent(sb.String())
	m.viewport.GotoBottom()
	return m
}

func (m model) renderReactions(mid string) string {
	byEmoji := m.reactions[mid]
	if len(byEmoji) == 0 {
		return ""
	}
	var parts []string
	for emoji, froms := range byEmoji {
		parts = append(parts, fmt.Sprintf("%s %d", emoji, len(froms)))
	}
	return styleReaction.Render("         " + strings.Join(parts, "  "))
}

// ── view ──────────────────────────────────────────────────────────────────────

func (m model) View() string {
	if m.width == 0 {
		return "loading…\n"
	}

	innerH := m.height - 3 - 1
	if innerH < 4 {
		innerH = 4
	}

	leftBox := m.renderLeft(innerH)
	rightBox := m.renderPeers(innerH)
	centreBox := m.renderCentre(innerH)

	mainRow := lipgloss.JoinHorizontal(lipgloss.Top, leftBox, centreBox, rightBox)

	inputBox := lipgloss.NewStyle().
		Width(m.width - 2).
		Border(lipgloss.RoundedBorder()).
		BorderForeground(styleBorder).
		Render(m.input.View())

	var statusLine string
	if m.errMsg != "" {
		statusLine = styleErr.Render(" ✗ " + m.errMsg)
	} else {
		hint := "  tab: rooms · ctrl+n: nets · /join /net /room /react · ctrl+i: invite · ctrl+c: quit"
		statusLine = styleStatus.Width(m.width).Render(" " + m.status + hint)
	}

	view := lipgloss.JoinVertical(lipgloss.Left, mainRow, inputBox, statusLine)

	if m.invitePopup != "" {
		label := styleActive.Render("Invite — share this with anyone you want to add:")
		code := lipgloss.NewStyle().
			Border(lipgloss.RoundedBorder()).
			BorderForeground(lipgloss.Color("238")).
			Padding(0, 1).
			Width(m.width - 6).
			Render(m.invitePopup)
		hint := styleStatus.Render("Esc to close  ·  ctrl+c to quit")
		popup := lipgloss.NewStyle().
			Width(m.width).
			Height(m.height).
			Align(lipgloss.Center, lipgloss.Center).
			Render(lipgloss.JoinVertical(lipgloss.Left, label, "", code, "", hint))
		return popup
	}

	return view
}

func (m model) renderLeft(boxH int) string {
	innerW := sideW - 2
	contentH := boxH - 2
	sep := lipgloss.NewStyle().Foreground(styleBorder).Render(strings.Repeat("─", innerW))
	var lines []string

	// Networks section
	lines = append(lines, styleHeader.Width(innerW).Render("Networks"))
	lines = append(lines, sep)
	if len(m.nets) == 0 {
		lines = append(lines, styleRoom.Width(innerW).Render("  (none)"))
	}
	for i, n := range m.nets {
		label := n.name
		if i == m.activeNet {
			lines = append(lines, styleNetActive.Width(innerW).Render("▶ "+label))
		} else {
			lines = append(lines, styleNet.Width(innerW).Render(fmt.Sprintf("  [%d] %s", i+1, label)))
		}
	}

	lines = append(lines, sep)

	// Rooms section
	lines = append(lines, styleHeader.Width(innerW).Render("Rooms"))
	lines = append(lines, sep)
	n := m.activeNetData()
	if n == nil {
		lines = append(lines, styleRoom.Width(innerW).Render("  (no network)"))
	} else {
		for i, room := range n.rooms {
			label := roomLabel(room, n.peers)
			key := n.id + ":" + room
			if i == n.activeRoom {
				lines = append(lines, styleActive.Width(innerW).Render("▶ "+label))
			} else {
				prefix := "  "
				if m.unread[key] {
					prefix = "* "
				}
				lines = append(lines, styleRoom.Width(innerW).Render(prefix+label))
			}
		}
	}

	for len(lines) < contentH {
		lines = append(lines, strings.Repeat(" ", innerW))
	}
	content := strings.Join(lines[:min(len(lines), contentH)], "\n")
	return lipgloss.NewStyle().
		Width(sideW - 2).Height(boxH - 2).
		Border(lipgloss.RoundedBorder()).BorderForeground(styleBorder).
		Render(content)
}

func (m model) renderPeers(boxH int) string {
	innerW := sideW - 2
	contentH := boxH - 2
	var lines []string
	lines = append(lines, styleHeader.Width(innerW).Render("Peers"))
	lines = append(lines, lipgloss.NewStyle().Foreground(styleBorder).Render(strings.Repeat("─", innerW)))
	n := m.activeNetData()
	if n != nil {
		if n.localAlias != "" {
			lines = append(lines, styleSelf.Width(innerW).Render("◉ "+n.localAlias+" (me)"))
		}
		for _, pid := range n.peerOrder {
			alias := n.peers[pid]
			if alias == "" {
				alias = shortID(pid)
			}
			lines = append(lines, stylePeer.Width(innerW).Render("● "+alias))
		}
	}
	for len(lines) < contentH {
		lines = append(lines, strings.Repeat(" ", innerW))
	}
	content := strings.Join(lines[:min(len(lines), contentH)], "\n")
	return lipgloss.NewStyle().
		Width(sideW - 2).Height(boxH - 2).
		Border(lipgloss.RoundedBorder()).BorderForeground(styleBorder).
		Render(content)
}

func (m model) renderCentre(boxH int) string {
	innerW := m.vpContentWidth()
	n := m.activeNetData()
	var roomName string
	if n != nil {
		roomName = n.rooms[n.activeRoom]
	} else {
		roomName = "general"
	}
	var peerMap map[proto.PeerID]string
	if n != nil {
		peerMap = n.peers
	}
	title := styleTitle.Width(innerW).Render(" " + roomTitle(roomName, peerMap))
	divider := lipgloss.NewStyle().Foreground(styleBorder).Render(strings.Repeat("─", innerW))

	vpView := ""
	if m.vpReady {
		vpView = m.viewport.View()
	}

	content := lipgloss.JoinVertical(lipgloss.Left, title, divider, vpView)
	return lipgloss.NewStyle().
		Width(innerW).Height(boxH - 2).
		Border(lipgloss.RoundedBorder()).BorderForeground(styleBorder).
		Render(content)
}

// ── helpers ───────────────────────────────────────────────────────────────────

func shortID(id proto.PeerID) string {
	s := string(id)
	if len(s) > 8 {
		return s[:8]
	}
	return s
}

func roomLabel(room string, peers map[proto.PeerID]string) string {
	if room == "general" {
		return "#general"
	}
	if strings.HasPrefix(room, "dm:") {
		pid := proto.PeerID(strings.TrimPrefix(room, "dm:"))
		if peers != nil {
			if a, ok := peers[pid]; ok && a != "" {
				return "@ " + a
			}
		}
		return "@ " + shortID(pid)
	}
	return "#" + room
}

func roomTitle(room string, peers map[proto.PeerID]string) string {
	return roomLabel(room, peers)
}

func filterIDs(ids []proto.PeerID, remove proto.PeerID) []proto.PeerID {
	out := ids[:0]
	for _, v := range ids {
		if v != remove {
			out = append(out, v)
		}
	}
	return out
}

func formatMsgTime(t time.Time) string {
	now := time.Now()
	if t.Year() == now.Year() && t.YearDay() == now.YearDay() {
		return t.Format("15:04")
	}
	return t.Format("Jan 2 15:04")
}

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

// ── main ──────────────────────────────────────────────────────────────────────

func main() {
	ipcPort    := flag.Int("ipc", 17337, "daemon IPC port")
	network    := flag.String("network", "", "network name to join on startup (optional)")
	joinInvite := flag.String("join", "", "waste: invite string — auto-sets the network name")
	flag.Parse()

	if *joinInvite != "" {
		inv, err := invite.Decode(*joinInvite)
		if err != nil {
			fmt.Fprintln(os.Stderr, "error: invalid invite:", err)
			os.Exit(1)
		}
		*network = inv.Network
	}

	p := tea.NewProgram(
		newModel(*ipcPort, *network),
		tea.WithAltScreen(),
		tea.WithMouseCellMotion(),
	)
	if _, err := p.Run(); err != nil {
		fmt.Fprintln(os.Stderr, "tui:", err)
		os.Exit(1)
	}
}