// Close removes the peer from the model and closes the underlying connection if possible.
// Implements the protocol.Model interface.
func (m *Model) Close(node protocol.NodeID, err error) {
	l.Infof("Connection to %s closed: %v", node, err)
	events.Default.Log(events.NodeDisconnected, map[string]string{
		"id":    node.String(),
		"error": err.Error(),
	})

	m.pmut.Lock()
	m.rmut.RLock()
	for _, repo := range m.nodeRepos[node] {
		m.repoFiles[repo].Replace(node, nil)
	}
	m.rmut.RUnlock()

	conn, ok := m.rawConn[node]
	if ok {
		if conn, ok := conn.(*tls.Conn); ok {
			// If the underlying connection is a *tls.Conn, Close() does more
			// than it says on the tin. Specifically, it sends a TLS alert
			// message, which might block forever if the connection is dead
			// and we don't have a deadline site.
			conn.SetWriteDeadline(time.Now().Add(250 * time.Millisecond))
		}
		conn.Close()
	}
	delete(m.protoConn, node)
	delete(m.rawConn, node)
	delete(m.nodeVer, node)
	m.pmut.Unlock()
}

// IndexUpdate is called for incremental updates to connected nodes' indexes.
// Implements the protocol.Model interface.
func (m *Model) IndexUpdate(nodeID protocol.NodeID, repo string, fs []protocol.FileInfo) {
	if debug {
		l.Debugf("IDXUP(in): %s / %q: %d files", nodeID, repo, len(fs))
	}

	if !m.repoSharedWith(repo, nodeID) {
		l.Infof("Update for unexpected repository ID %q sent from node %q; ensure that the repository exists and that this node is selected under \"Share With\" in the repository configuration.", repo, nodeID)
		return
	}

	for i := range fs {
		lamport.Default.Tick(fs[i].Version)
	}

	m.rmut.RLock()
	r, ok := m.repoFiles[repo]
	m.rmut.RUnlock()
	if ok {
		r.Update(nodeID, fs)
	} else {
		l.Fatalf("IndexUpdate for nonexistant repo %q", repo)
	}

	events.Default.Log(events.RemoteIndexUpdated, map[string]interface{}{
		"node":    nodeID.String(),
		"repo":    repo,
		"items":   len(fs),
		"version": r.LocalVersion(nodeID),
	})
}

func (d *Discoverer) Hint(node string, addrs []string) {
	resAddrs := resolveAddrs(addrs)
	var id protocol.NodeID
	id.UnmarshalText([]byte(node))
	d.registerNode(nil, Node{
		Addresses: resAddrs,
		ID:        id[:],
	})
}

// Index is called when a new node is connected and we receive their full index.
// Implements the protocol.Model interface.
func (m *Model) Index(nodeID protocol.NodeID, repo string, fs []protocol.FileInfo) {
	if debug {
		l.Debugf("IDX(in): %s %q: %d files", nodeID, repo, len(fs))
	}

	if !m.repoSharedWith(repo, nodeID) {
		events.Default.Log(events.RepoRejected, map[string]string{
			"repo": repo,
			"node": nodeID.String(),
		})
		l.Warnf("Unexpected repository ID %q sent from node %q; ensure that the repository exists and that this node is selected under \"Share With\" in the repository configuration.", repo, nodeID)
		return
	}

	m.rmut.RLock()
	files, ok := m.repoFiles[repo]
	ignores, _ := m.repoIgnores[repo]
	m.rmut.RUnlock()

	if !ok {
		l.Fatalf("Index for nonexistant repo %q", repo)
	}

	for i := 0; i < len(fs); {
		lamport.Default.Tick(fs[i].Version)
		if ignores.Match(fs[i].Name) {
			fs[i] = fs[len(fs)-1]
			fs = fs[:len(fs)-1]
		} else {
			i++
		}
	}

	files.Replace(nodeID, fs)

	events.Default.Log(events.RemoteIndexUpdated, map[string]interface{}{
		"node":    nodeID.String(),
		"repo":    repo,
		"items":   len(fs),
		"version": files.LocalVersion(nodeID),
	})
}

// Close removes the peer from the model and closes the underlying connection if possible.
// Implements the protocol.Model interface.
func (m *Model) Close(node protocol.NodeID, err error) {
	l.Infof("Connection to %s closed: %v", node, err)
	events.Default.Log(events.NodeDisconnected, map[string]string{
		"id":    node.String(),
		"error": err.Error(),
	})

	m.pmut.Lock()
	m.rmut.RLock()
	for _, repo := range m.nodeRepos[node] {
		m.repoFiles[repo].Replace(node, nil)
	}
	m.rmut.RUnlock()

	conn, ok := m.rawConn[node]
	if ok {
		conn.Close()
	}
	delete(m.protoConn, node)
	delete(m.rawConn, node)
	delete(m.nodeVer, node)
	m.pmut.Unlock()
}

func (d *Discoverer) registerNode(addr net.Addr, node Node) bool {
	var addrs []string
	for _, a := range node.Addresses {
		var nodeAddr string
		if len(a.IP) > 0 {
			nodeAddr = fmt.Sprintf("%s:%d", net.IP(a.IP), a.Port)
			addrs = append(addrs, nodeAddr)
		} else if addr != nil {
			ua := addr.(*net.UDPAddr)
			ua.Port = int(a.Port)
			nodeAddr = ua.String()
			addrs = append(addrs, nodeAddr)
		}
	}
	if len(addrs) == 0 {
		if debug {
			l.Debugln("discover: no valid address for", node.ID)
		}
	}
	if debug {
		l.Debugf("discover: register: %s -> %#v", node.ID, addrs)
	}
	var id protocol.NodeID
	copy(id[:], node.ID)
	d.registryLock.Lock()
	_, seen := d.registry[id]
	d.registry[id] = addrs
	d.registryLock.Unlock()

	if !seen {
		events.Default.Log(events.NodeDiscovered, map[string]interface{}{
			"node":  id.String(),
			"addrs": addrs,
		})
	}
	return !seen
}