// WebSocket signaling. Two kinds of WS clients:
//   agent  -> authenticates with machine enroll_token, waits for session requests
//   viewer -> authenticated technician, requests a session to a machine
// The server brokers consent and relays SDP/ICE. Media never traverses the server.
const R = require('./repos');
const A = require('./auth');
const { currentUser, audit } = require('./session');
const { onlineAgents, liveSessions, pendingShares, meetingRooms, roomToDmCall, roomHost, transcriptBuffers, transcriptSubs } = require('./presence');
const W = require('./webhooks');
const CHAT = require('./chat');

function onConnection(ws, req) {
  const hb = setInterval(() => {
    if (ws.readyState === 1) { try { ws.ping(); } catch {} } else { clearInterval(hb); }
  }, 25000);
  ws.on('message', (raw) => {
    let m; try { m = JSON.parse(raw); } catch { return; }
    handle(ws, m, req);
  });
  ws.on('close', () => { clearInterval(hb); cleanup(ws); });
}

function handle(ws, m, req) {
  switch (m.type) {
    // --- Logged-in user registers this socket for live chat delivery ---
    case 'chat-hello': {
      const u = currentUser(req); // identity from the cookie/Bearer on the WS upgrade
      if (!u) return ws.send(JSON.stringify({ type: 'error', message: 'unauthorized' }));
      ws._chatUserId = u.id; ws._chatTeamId = u.team_id;
      CHAT.register(u.id, ws);
      ws.send(JSON.stringify({ type: 'chat-ready' }));
      break;
    }
    // Recipient's client acknowledges a DM was delivered → mark it + tell the sender.
    case 'chat-delivered': {
      if (!ws._chatUserId || !m.id) break;
      const msg = R.messages.byId(m.id);
      if (!msg || msg.conversation_id || msg.team_id !== ws._chatTeamId) break; // DMs only
      if (msg.recipient_id !== ws._chatUserId) break; // only the recipient can ack
      if (!msg.delivered_at) { R.messages.markDelivered(m.id); try { CHAT.pushToUser(msg.sender_id, { type: 'chat-delivered', id: m.id }); } catch (_) {} }
      break;
    }
    // --- Meetings (mesh): create a room, join by code, relay SDP/ICE peer-to-peer ---
    case 'meeting-create': {
      let code; do { code = A.numericCode(6); } while (meetingRooms.has(code));
      meetingRooms.set(code, new Map());
      const cu = currentUser(req); if (cu) roomHost.set(code, cu.id); // ad-hoc meeting: creator = host
      ws.send(JSON.stringify({ type: 'meeting-created', room: code }));
      break;
    }
    case 'meeting-join': {
      const room = String(m.room || '').trim();
      let peers = meetingRooms.get(room);
      // A scheduled meeting's room is created lazily on first join (its code lives in the DB).
      if (!peers) {
        const sched = R.scheduledMeetings.byCode(room);
        if (sched && !sched.ended_at) { peers = new Map(); meetingRooms.set(room, peers); }
      }
      if (!peers) return ws.send(JSON.stringify({ type: 'error', message: 'Meeting not found' }));
      const peerId = A.token(6);
      const name = String(m.name || 'Guest').slice(0, 60);
      ws.kind = 'meeting'; ws._meetingRoom = room; ws._peerId = peerId; ws._peerName = name;
      // Host = the meeting's creator. roomHost is set on call/meeting creation; scheduled meetings fall back to created_by.
      let hostUserId = roomHost.get(room);
      if (hostUserId === undefined) { try { const s = R.scheduledMeetings.byCode(room); if (s) { hostUserId = s.created_by; roomHost.set(room, hostUserId); } } catch (_) {} }
      const ju = currentUser(req);
      ws._meetingUserId = ju ? ju.id : null; // for per-user transcript ownership
      const isHost = !!(ju && hostUserId && ju.id === hostUserId);
      // Tell the newcomer who's already here (they initiate offers to existing peers)…
      ws.send(JSON.stringify({ type: 'meeting-joined', room, peerId, isHost, peers: [...peers.entries()].map(([id, p]) => ({ peerId: id, name: p.name })) }));
      // …and tell existing peers a newcomer arrived.
      for (const [, p] of peers) { if (p.ws.readyState === 1) p.ws.send(JSON.stringify({ type: 'meeting-peer-joined', peerId, name })); }
      peers.set(peerId, { ws, name });
      const tsubs = transcriptSubs.get(room); if (tsubs && tsubs.size > 0) ws.send(JSON.stringify({ type: 'meeting-transcribe-state', active: true })); // catch up: already transcribing
      break;
    }
    case 'meeting-signal': {
      const peers = ws._meetingRoom && meetingRooms.get(ws._meetingRoom);
      if (!peers) return;
      const target = peers.get(m.to);
      if (target && target.ws.readyState === 1) target.ws.send(JSON.stringify({ type: 'meeting-signal', from: ws._peerId, data: m.data }));
      break;
    }
    // Relay a peer's mic/cam state to everyone else in the room (for the tile mute icon).
    case 'meeting-state': {
      const peers = ws._meetingRoom && meetingRooms.get(ws._meetingRoom);
      if (!peers) return;
      for (const [id, p] of peers) { if (id !== ws._peerId && p.ws.readyState === 1) p.ws.send(JSON.stringify({ type: 'meeting-peer-state', peerId: ws._peerId, muted: !!m.muted, camOff: !!m.camOff })); }
      break;
    }
    // Relay a peer's screen-share on/off to everyone else (for the tile badge + single-share rule).
    case 'meeting-screen': {
      const peers = ws._meetingRoom && meetingRooms.get(ws._meetingRoom);
      if (!peers) return;
      for (const [id, p] of peers) { if (id !== ws._peerId && p.ws.readyState === 1) p.ws.send(JSON.stringify({ type: 'meeting-peer-screen', from: ws._peerId, on: !!m.on })); }
      break;
    }
    // Host: set whether multiple people may share their screen at once.
    case 'meeting-sharemode': {
      const peers = ws._meetingRoom && meetingRooms.get(ws._meetingRoom);
      if (!peers) return;
      for (const [id, p] of peers) { if (id !== ws._peerId && p.ws.readyState === 1) p.ws.send(JSON.stringify({ type: 'meeting-sharemode', multi: !!m.multi })); }
      break;
    }
    // Host starts/stops recording → tell everyone so they see (and hear) the "being recorded" notice.
    case 'meeting-recording': {
      const peers = ws._meetingRoom && meetingRooms.get(ws._meetingRoom);
      if (!peers) return;
      for (const [id, p] of peers) { if (id !== ws._peerId && p.ws.readyState === 1) p.ws.send(JSON.stringify({ type: 'meeting-recording', on: !!m.on, by: ws._peerName || 'The host' })); }
      break;
    }
    // A participant subscribes/unsubscribes to a transcript copy. While ≥1 subscriber, EVERY client
    // transcribes its own mic (full conversation); each subscriber gets their own private copy.
    // Unsubscribing only drops YOUR copy — it never stops anyone else's.
    case 'meeting-transcribe': {
      const room = ws._meetingRoom; const peers = room && meetingRooms.get(room);
      if (!peers) return; const uid = ws._meetingUserId; if (!uid) return;
      let subs = transcriptSubs.get(room); if (!subs) { subs = new Set(); transcriptSubs.set(room, subs); }
      if (m.on) subs.add(uid); else { try { require('./calls').finalizeTranscript(room, uid); } catch (_) {} } // finalize writes + removes the sub
      const active = subs.size > 0;
      for (const [, p] of peers) { if (p.ws.readyState === 1) p.ws.send(JSON.stringify({ type: 'meeting-transcribe-state', active })); }
      break;
    }
    // A participant's recognized speech segment → appended to the room's shared transcript buffer.
    case 'meeting-transcript': {
      const room = ws._meetingRoom; if (!room || !meetingRooms.get(room)) return;
      const text = String(m.text || '').slice(0, 1000).trim(); if (!text) return;
      let buf = transcriptBuffers.get(room); if (!buf) { buf = []; transcriptBuffers.set(room, buf); }
      buf.push({ t: Date.now(), speaker: ws._peerName || 'Guest', text });
      if (buf.length > 8000) buf.shift();
      break;
    }
    // Host: mute everyone else in the room.
    case 'meeting-muteall': {
      const peers = ws._meetingRoom && meetingRooms.get(ws._meetingRoom);
      if (!peers) return;
      for (const [id, p] of peers) { if (id !== ws._peerId && p.ws.readyState === 1) p.ws.send(JSON.stringify({ type: 'meeting-muteall', by: ws._peerId })); }
      break;
    }
    // Host: transfer host to another peer (broadcast the new host to the room).
    case 'meeting-host': {
      const peers = ws._meetingRoom && meetingRooms.get(ws._meetingRoom);
      if (!peers || !m.to) return;
      for (const [, p] of peers) { if (p.ws.readyState === 1) p.ws.send(JSON.stringify({ type: 'meeting-host', hostPeerId: m.to })); }
      break;
    }
    case 'meeting-leave': {
      leaveMeeting(ws);
      break;
    }
    // --- Agent comes online ---
    case 'agent-hello': {
      const machine = R.machines.byEnrollToken(m.enrollToken);
      if (!machine) return ws.send(JSON.stringify({ type: 'error', message: 'invalid enroll token' }));
      ws.kind = 'agent'; ws.machineId = machine.id;
      onlineAgents.set(machine.id, { ws, machine });
      R.machines.touch(machine.id);
      ws.send(JSON.stringify({ type: 'agent-registered', machineId: machine.id, name: machine.name }));
      break;
    }
    // --- Technician requests control of a machine ---
    case 'viewer-connect': {
      const u = currentUser(req); // cookie sent on WS upgrade
      if (!u) return ws.send(JSON.stringify({ type: 'error', message: 'unauthorized' }));
      const agent = onlineAgents.get(m.machineId);
      const machine = R.machines.inTenant(m.machineId, u.team_id);
      if (!machine) return ws.send(JSON.stringify({ type: 'error', message: 'no such machine' }));
      if (!agent) return ws.send(JSON.stringify({ type: 'error', message: 'machine offline' }));
      if (u.role === 'viewer' && false) {} // view-only still allowed to watch; control gated agent-side
      const sessionId = A.token(8);
      ws.kind = 'viewer'; ws.sessionId = sessionId;
      liveSessions.set(sessionId, { agentWs: agent.ws, viewerWs: ws, machine, user: u });
      audit({ team_id: u.team_id, user_id: u.id, user_email: u.email, machine_id: machine.id, machine_name: machine.name, action: 'session_requested' });
      // Ask the agent for consent (or auto-grant if unattended policy is on)
      agent.ws.sessionId = sessionId;
      agent.ws.send(JSON.stringify({
        type: 'session-request', sessionId,
        technician: u.email, unattended: !!machine.unattended,
      }));
      ws.send(JSON.stringify({ type: 'session-pending', sessionId, machineName: machine.name }));
      break;
    }
    // --- Agent grants/denies consent ---
    case 'consent': {
      const sess = liveSessions.get(m.sessionId);
      if (!sess) return;
      if (m.granted) {
        audit({ team_id: sess.machine.team_id, user_id: sess.user.id, user_email: sess.user.email, machine_id: sess.machine.id, machine_name: sess.machine.name, action: 'consent_granted', detail: sess.ticket ? 'Ticket ' + sess.ticket : (sess.machine.id ? null : 'Direct session') });
        try {
          R.sessionsLog.create({ id: m.sessionId, tenantId: sess.machine.team_id, agentEmail: sess.user.email, agentName: sess.agentName || sess.user.email, ticket: sess.ticket || null });
        } catch (e) { /* duplicate consent */ }
        try { W.emit('session.started', sess.machine.team_id, { sessionId: m.sessionId, agent_email: sess.user.email, agent_name: sess.agentName || sess.user.email, ticket: sess.ticket || null, started_at: Date.now() }); } catch (_) {}
        sess.viewerWs.send(JSON.stringify({ type: 'session-ready', sessionId: m.sessionId }));
        sess.agentWs.send(JSON.stringify({ type: 'start-stream', sessionId: m.sessionId }));
      } else {
        audit({ team_id: sess.machine.team_id, user_id: sess.user.id, user_email: sess.user.email, machine_id: sess.machine.id, machine_name: sess.machine.name, action: 'consent_denied', detail: sess.ticket ? 'Ticket ' + sess.ticket : (sess.machine.id ? null : 'Direct session') });
        sess.viewerWs.send(JSON.stringify({ type: 'session-denied', sessionId: m.sessionId }));
        liveSessions.delete(m.sessionId);
      }
      break;
    }
    // --- No-install: end user opens /share, gets a one-time code ---
    case 'share-create': {
      let code;
      do { code = A.numericCode(6); } while (pendingShares.has(code));
      const sessionId = A.token(8);
      ws.kind = 'sharer'; ws.shareCode = code; ws.sessionId = sessionId;
      pendingShares.set(code, { sharerWs: ws, sessionId });
      ws.send(JSON.stringify({ type: 'share-code', code }));
      break;
    }
    // --- Logged-in agent enters the code (+ ticket) to connect ---
    case 'code-connect': {
      const agent = currentUser(req); // identity from the agent's authenticated session
      if (!agent) {
        return ws.send(JSON.stringify({ type: 'error', message: 'Please sign in as an agent first' }));
      }
      const ticket = String(m.ticket || '').trim() || null; // optional: direct sessions have no ticket
      const pend = pendingShares.get(String(m.code || '').trim());
      if (!pend || pend.sharerWs.readyState !== 1) {
        return ws.send(JSON.stringify({ type: 'error', message: 'Invalid or expired code' }));
      }
      pendingShares.delete(pend.sharerWs.shareCode);
      const sessionId = pend.sessionId;
      ws.kind = 'viewer'; ws.sessionId = sessionId;
      const agentName = agent.name || agent.email;
      const machine = { id: null, name: 'Support session ' + pend.sharerWs.shareCode, team_id: agent.team_id };
      const user = { id: agent.id, email: agent.email, team_id: agent.team_id };
      liveSessions.set(sessionId, { agentWs: pend.sharerWs, viewerWs: ws, machine, user, ticket, agentName });
      pend.sharerWs.sessionId = sessionId;
      audit({ team_id: agent.team_id, user_id: agent.id, user_email: agent.email, machine_name: machine.name, action: 'code_session_requested', detail: (ticket ? 'Ticket ' + ticket : 'Direct session (no ticket)') + ' · agent ' + agentName });
      pend.sharerWs.send(JSON.stringify({ type: 'share-request', sessionId, technician: agentName, ticket }));
      ws.send(JSON.stringify({ type: 'code-pending', sessionId }));
      break;
    }
    // --- Relay WebRTC signaling between the two peers ---
    case 'offer': case 'answer': case 'ice-candidate': {
      const sess = liveSessions.get(m.sessionId || ws.sessionId);
      if (!sess) return;
      const peer = ws === sess.agentWs ? sess.viewerWs : sess.agentWs;
      if (peer && peer.readyState === 1) peer.send(JSON.stringify(m));
      break;
    }
    case 'transcript': {
      const sess = liveSessions.get(m.sessionId || ws.sessionId);
      if (!sess) return;
      const peer = ws === sess.agentWs ? sess.viewerWs : sess.agentWs;
      if (peer && peer.readyState === 1) peer.send(JSON.stringify(m));
      break;
    }
    case 'recording': {
      const sess = liveSessions.get(m.sessionId || ws.sessionId);
      if (!sess) return;
      const peer = ws === sess.agentWs ? sess.viewerWs : sess.agentWs;
      if (peer && peer.readyState === 1) peer.send(JSON.stringify(m));
      break;
    }
    case 'end-session': {
      endSession(ws.sessionId, m.reason || null);
      break;
    }
  }
}

function endSession(sessionId, reason) {
  const sess = liveSessions.get(sessionId);
  if (!sess) return;
  try { R.sessionsLog.end(sessionId); } catch (e) {}
  try {
    const row = R.sessionsLog.byId(sessionId);
    if (row) W.emit('session.ended', sess.machine.team_id, { sessionId: row.id, agent_email: row.agent_email,
      agent_name: row.agent_name, ticket: row.ticket, started_at: row.started_at, ended_at: row.ended_at,
      duration_ms: row.ended_at ? row.ended_at - row.started_at : null });
  } catch (e) {}
  audit({ team_id: sess.machine.team_id, user_id: sess.user.id, user_email: sess.user.email, machine_id: sess.machine.id, machine_name: sess.machine.name, action: 'session_ended', detail: sess.ticket ? 'Ticket ' + sess.ticket : (sess.machine.id ? null : 'Direct session') });
  [sess.agentWs, sess.viewerWs].forEach((p) => {
    if (p && p.readyState === 1) p.send(JSON.stringify({ type: 'session-ended', sessionId, reason: reason || null }));
  });
  liveSessions.delete(sessionId);
}

function leaveMeeting(ws) {
  const room = ws._meetingRoom;
  if (!room) return;
  const peers = meetingRooms.get(room);
  ws._meetingRoom = null;
  const pid = ws._peerId;
  if (!peers) return;
  try { require('./calls').finalizeTranscript(room, ws._meetingUserId); } catch (_) {} // save THIS user's transcript
  peers.delete(pid);
  // 1:1 call: when either party leaves, end it for everyone (a DM call has no "remaining" call).
  if (roomToDmCall.has(room)) {
    for (const [, p] of peers) { if (p.ws.readyState === 1) { try { p.ws.send(JSON.stringify({ type: 'meeting-ended' })); } catch (_) {} p._meetingRoom = null; } }
    meetingRooms.delete(room);
    try { require('./calls').finalizeTranscript(room); } catch (_) {} // any remaining buffers (safety)
    roomHost.delete(room);
    try { require('./calls').endCallByRoom(room); } catch (_) {}
    return;
  }
  for (const [, p] of peers) { if (p.ws.readyState === 1) p.ws.send(JSON.stringify({ type: 'meeting-peer-left', peerId: pid })); }
  if (peers.size === 0) {
    meetingRooms.delete(room);
    try { require('./calls').finalizeTranscript(room); } catch (_) {} // before endCallByRoom clears the maps
    roomHost.delete(room);
    try { require('./calls').endCallByRoom(room); } catch (_) {}
  }
}

function cleanup(ws) {
  CHAT.unregister(ws);
  leaveMeeting(ws);
  if (ws.kind === 'agent' && ws.machineId) onlineAgents.delete(ws.machineId);
  if (ws.kind === 'sharer' && ws.shareCode) pendingShares.delete(ws.shareCode);
  if (ws.sessionId) {
    for (const [sid, sess] of liveSessions) {
      if (sess.agentWs === ws || sess.viewerWs === ws) endSession(sid);
    }
  }
}

module.exports = { onConnection };