add matterbridge

1 files changed, 790 insertions, 0 deletions

diff --git a/teleirc/matterbridge/vendor/go.mau.fi/whatsmeow/group.go b/teleirc/matterbridge/vendor/go.mau.fi/whatsmeow/group.go
new file mode 100644
index 0000000..c771b5a
--- /dev/null
+++ b/teleirc/matterbridge/vendor/go.mau.fi/whatsmeow/group.go
@@ -0,0 +1,790 @@
+// Copyright (c) 2021 Tulir Asokan
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+package whatsmeow
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+
+	waBinary "go.mau.fi/whatsmeow/binary"
+	"go.mau.fi/whatsmeow/types"
+	"go.mau.fi/whatsmeow/types/events"
+)
+
+const InviteLinkPrefix = "https://chat.whatsapp.com/"
+
+func (cli *Client) sendGroupIQ(ctx context.Context, iqType infoQueryType, jid types.JID, content waBinary.Node) (*waBinary.Node, error) {
+	return cli.sendIQ(infoQuery{
+		Context:   ctx,
+		Namespace: "w:g2",
+		Type:      iqType,
+		To:        jid,
+		Content:   []waBinary.Node{content},
+	})
+}
+
+// ReqCreateGroup contains the request data for CreateGroup.
+type ReqCreateGroup struct {
+	// Group names are limited to 25 characters. A longer group name will cause a 406 not acceptable error.
+	Name string
+	// You don't need to include your own JID in the participants array, the WhatsApp servers will add it implicitly.
+	Participants []types.JID
+	// A create key can be provided to deduplicate the group create notification that will be triggered
+	// when the group is created. If provided, the JoinedGroup event will contain the same key.
+	CreateKey types.MessageID
+	// Set IsParent to true to create a community instead of a normal group.
+	// When creating a community, the linked announcement group will be created automatically by the server.
+	types.GroupParent
+	// Set LinkedParentJID to create a group inside a community.
+	types.GroupLinkedParent
+}
+
+// CreateGroup creates a group on WhatsApp with the given name and participants.
+//
+// See ReqCreateGroup for parameters.
+func (cli *Client) CreateGroup(req ReqCreateGroup) (*types.GroupInfo, error) {
+	participantNodes := make([]waBinary.Node, len(req.Participants), len(req.Participants)+1)
+	for i, participant := range req.Participants {
+		participantNodes[i] = waBinary.Node{
+			Tag:   "participant",
+			Attrs: waBinary.Attrs{"jid": participant},
+		}
+	}
+	if req.CreateKey == "" {
+		req.CreateKey = GenerateMessageID()
+	}
+	if req.IsParent {
+		if req.DefaultMembershipApprovalMode == "" {
+			req.DefaultMembershipApprovalMode = "request_required"
+		}
+		participantNodes = append(participantNodes, waBinary.Node{
+			Tag: "parent",
+			Attrs: waBinary.Attrs{
+				"default_membership_approval_mode": req.DefaultMembershipApprovalMode,
+			},
+		})
+	} else if !req.LinkedParentJID.IsEmpty() {
+		participantNodes = append(participantNodes, waBinary.Node{
+			Tag:   "linked_parent",
+			Attrs: waBinary.Attrs{"jid": req.LinkedParentJID},
+		})
+	}
+	// WhatsApp web doesn't seem to include the static prefix for these
+	key := strings.TrimPrefix(req.CreateKey, "3EB0")
+	resp, err := cli.sendGroupIQ(context.TODO(), iqSet, types.GroupServerJID, waBinary.Node{
+		Tag: "create",
+		Attrs: waBinary.Attrs{
+			"subject": req.Name,
+			"key":     key,
+		},
+		Content: participantNodes,
+	})
+	if err != nil {
+		return nil, err
+	}
+	groupNode, ok := resp.GetOptionalChildByTag("group")
+	if !ok {
+		return nil, &ElementMissingError{Tag: "group", In: "response to create group query"}
+	}
+	return cli.parseGroupNode(&groupNode)
+}
+
+// UnlinkGroup removes a child group from a parent community.
+func (cli *Client) UnlinkGroup(parent, child types.JID) error {
+	_, err := cli.sendGroupIQ(context.TODO(), iqSet, parent, waBinary.Node{
+		Tag:   "unlink",
+		Attrs: waBinary.Attrs{"unlink_type": types.GroupLinkChangeTypeSub},
+		Content: []waBinary.Node{{
+			Tag:   "group",
+			Attrs: waBinary.Attrs{"jid": child},
+		}},
+	})
+	return err
+}
+
+// LinkGroup adds an existing group as a child group in a community.
+//
+// To create a new group within a community, set LinkedParentJID in the CreateGroup request.
+func (cli *Client) LinkGroup(parent, child types.JID) error {
+	_, err := cli.sendGroupIQ(context.TODO(), iqSet, parent, waBinary.Node{
+		Tag: "links",
+		Content: []waBinary.Node{{
+			Tag:   "link",
+			Attrs: waBinary.Attrs{"link_type": types.GroupLinkChangeTypeSub},
+			Content: []waBinary.Node{{
+				Tag:   "group",
+				Attrs: waBinary.Attrs{"jid": child},
+			}},
+		}},
+	})
+	return err
+}
+
+// LeaveGroup leaves the specified group on WhatsApp.
+func (cli *Client) LeaveGroup(jid types.JID) error {
+	_, err := cli.sendGroupIQ(context.TODO(), iqSet, types.GroupServerJID, waBinary.Node{
+		Tag: "leave",
+		Content: []waBinary.Node{{
+			Tag:   "group",
+			Attrs: waBinary.Attrs{"id": jid},
+		}},
+	})
+	return err
+}
+
+type ParticipantChange string
+
+const (
+	ParticipantChangeAdd     ParticipantChange = "add"
+	ParticipantChangeRemove  ParticipantChange = "remove"
+	ParticipantChangePromote ParticipantChange = "promote"
+	ParticipantChangeDemote  ParticipantChange = "demote"
+)
+
+// UpdateGroupParticipants can be used to add, remove, promote and demote members in a WhatsApp group.
+func (cli *Client) UpdateGroupParticipants(jid types.JID, participantChanges map[types.JID]ParticipantChange) (*waBinary.Node, error) {
+	content := make([]waBinary.Node, len(participantChanges))
+	i := 0
+	for participantJID, change := range participantChanges {
+		content[i] = waBinary.Node{
+			Tag: string(change),
+			Content: []waBinary.Node{{
+				Tag:   "participant",
+				Attrs: waBinary.Attrs{"jid": participantJID},
+			}},
+		}
+		i++
+	}
+	resp, err := cli.sendIQ(infoQuery{
+		Namespace: "w:g2",
+		Type:      iqSet,
+		To:        jid,
+		Content:   content,
+	})
+	if err != nil {
+		return nil, err
+	}
+	// TODO proper return value?
+	return resp, nil
+}
+
+// SetGroupPhoto updates the group picture/icon of the given group on WhatsApp.
+// The avatar should be a JPEG photo, other formats may be rejected with ErrInvalidImageFormat.
+// The bytes can be nil to remove the photo. Returns the new picture ID.
+func (cli *Client) SetGroupPhoto(jid types.JID, avatar []byte) (string, error) {
+	var content interface{}
+	if avatar != nil {
+		content = []waBinary.Node{{
+			Tag:     "picture",
+			Attrs:   waBinary.Attrs{"type": "image"},
+			Content: avatar,
+		}}
+	}
+	resp, err := cli.sendIQ(infoQuery{
+		Namespace: "w:profile:picture",
+		Type:      iqSet,
+		To:        types.ServerJID,
+		Target:    jid,
+		Content:   content,
+	})
+	if errors.Is(err, ErrIQNotAcceptable) {
+		return "", wrapIQError(ErrInvalidImageFormat, err)
+	} else if err != nil {
+		return "", err
+	}
+	if avatar == nil {
+		return "remove", nil
+	}
+	pictureID, ok := resp.GetChildByTag("picture").Attrs["id"].(string)
+	if !ok {
+		return "", fmt.Errorf("didn't find picture ID in response")
+	}
+	return pictureID, nil
+}
+
+// SetGroupName updates the name (subject) of the given group on WhatsApp.
+func (cli *Client) SetGroupName(jid types.JID, name string) error {
+	_, err := cli.sendGroupIQ(context.TODO(), iqSet, jid, waBinary.Node{
+		Tag:     "subject",
+		Content: []byte(name),
+	})
+	return err
+}
+
+// SetGroupTopic updates the topic (description) of the given group on WhatsApp.
+//
+// The previousID and newID fields are optional. If the previous ID is not specified, this will
+// automatically fetch the current group info to find the previous topic ID. If the new ID is not
+// specified, one will be generated with GenerateMessageID().
+func (cli *Client) SetGroupTopic(jid types.JID, previousID, newID, topic string) error {
+	if previousID == "" {
+		oldInfo, err := cli.GetGroupInfo(jid)
+		if err != nil {
+			return fmt.Errorf("failed to get old group info to update topic: %v", err)
+		}
+		previousID = oldInfo.TopicID
+	}
+	if newID == "" {
+		newID = GenerateMessageID()
+	}
+	attrs := waBinary.Attrs{
+		"id": newID,
+	}
+	if previousID != "" {
+		attrs["prev"] = previousID
+	}
+	content := []waBinary.Node{{
+		Tag:     "body",
+		Content: []byte(topic),
+	}}
+	if len(topic) == 0 {
+		attrs["delete"] = "true"
+		content = nil
+	}
+	_, err := cli.sendGroupIQ(context.TODO(), iqSet, jid, waBinary.Node{
+		Tag:     "description",
+		Attrs:   attrs,
+		Content: content,
+	})
+	return err
+}
+
+// SetGroupLocked changes whether the group is locked (i.e. whether only admins can modify group info).
+func (cli *Client) SetGroupLocked(jid types.JID, locked bool) error {
+	tag := "locked"
+	if !locked {
+		tag = "unlocked"
+	}
+	_, err := cli.sendGroupIQ(context.TODO(), iqSet, jid, waBinary.Node{Tag: tag})
+	return err
+}
+
+// SetGroupAnnounce changes whether the group is in announce mode (i.e. whether only admins can send messages).
+func (cli *Client) SetGroupAnnounce(jid types.JID, announce bool) error {
+	tag := "announcement"
+	if !announce {
+		tag = "not_announcement"
+	}
+	_, err := cli.sendGroupIQ(context.TODO(), iqSet, jid, waBinary.Node{Tag: tag})
+	return err
+}
+
+// GetGroupInviteLink requests the invite link to the group from the WhatsApp servers.
+//
+// If reset is true, then the old invite link will be revoked and a new one generated.
+func (cli *Client) GetGroupInviteLink(jid types.JID, reset bool) (string, error) {
+	iqType := iqGet
+	if reset {
+		iqType = iqSet
+	}
+	resp, err := cli.sendGroupIQ(context.TODO(), iqType, jid, waBinary.Node{Tag: "invite"})
+	if errors.Is(err, ErrIQNotAuthorized) {
+		return "", wrapIQError(ErrGroupInviteLinkUnauthorized, err)
+	} else if errors.Is(err, ErrIQNotFound) {
+		return "", wrapIQError(ErrGroupNotFound, err)
+	} else if errors.Is(err, ErrIQForbidden) {
+		return "", wrapIQError(ErrNotInGroup, err)
+	} else if err != nil {
+		return "", err
+	}
+	code, ok := resp.GetChildByTag("invite").Attrs["code"].(string)
+	if !ok {
+		return "", fmt.Errorf("didn't find invite code in response")
+	}
+	return InviteLinkPrefix + code, nil
+}
+
+// GetGroupInfoFromInvite gets the group info from an invite message.
+//
+// Note that this is specifically for invite messages, not invite links. Use GetGroupInfoFromLink for resolving chat.whatsapp.com links.
+func (cli *Client) GetGroupInfoFromInvite(jid, inviter types.JID, code string, expiration int64) (*types.GroupInfo, error) {
+	resp, err := cli.sendGroupIQ(context.TODO(), iqGet, jid, waBinary.Node{
+		Tag: "query",
+		Content: []waBinary.Node{{
+			Tag: "add_request",
+			Attrs: waBinary.Attrs{
+				"code":       code,
+				"expiration": expiration,
+				"admin":      inviter,
+			},
+		}},
+	})
+	if err != nil {
+		return nil, err
+	}
+	groupNode, ok := resp.GetOptionalChildByTag("group")
+	if !ok {
+		return nil, &ElementMissingError{Tag: "group", In: "response to invite group info query"}
+	}
+	return cli.parseGroupNode(&groupNode)
+}
+
+// JoinGroupWithInvite joins a group using an invite message.
+//
+// Note that this is specifically for invite messages, not invite links. Use JoinGroupWithLink for joining with chat.whatsapp.com links.
+func (cli *Client) JoinGroupWithInvite(jid, inviter types.JID, code string, expiration int64) error {
+	_, err := cli.sendGroupIQ(context.TODO(), iqSet, jid, waBinary.Node{
+		Tag: "accept",
+		Attrs: waBinary.Attrs{
+			"code":       code,
+			"expiration": expiration,
+			"admin":      inviter,
+		},
+	})
+	return err
+}
+
+// GetGroupInfoFromLink resolves the given invite link and asks the WhatsApp servers for info about the group.
+// This will not cause the user to join the group.
+func (cli *Client) GetGroupInfoFromLink(code string) (*types.GroupInfo, error) {
+	code = strings.TrimPrefix(code, InviteLinkPrefix)
+	resp, err := cli.sendGroupIQ(context.TODO(), iqGet, types.GroupServerJID, waBinary.Node{
+		Tag:   "invite",
+		Attrs: waBinary.Attrs{"code": code},
+	})
+	if errors.Is(err, ErrIQGone) {
+		return nil, wrapIQError(ErrInviteLinkRevoked, err)
+	} else if errors.Is(err, ErrIQNotAcceptable) {
+		return nil, wrapIQError(ErrInviteLinkInvalid, err)
+	} else if err != nil {
+		return nil, err
+	}
+	groupNode, ok := resp.GetOptionalChildByTag("group")
+	if !ok {
+		return nil, &ElementMissingError{Tag: "group", In: "response to group link info query"}
+	}
+	return cli.parseGroupNode(&groupNode)
+}
+
+// JoinGroupWithLink joins the group using the given invite link.
+func (cli *Client) JoinGroupWithLink(code string) (types.JID, error) {
+	code = strings.TrimPrefix(code, InviteLinkPrefix)
+	resp, err := cli.sendGroupIQ(context.TODO(), iqSet, types.GroupServerJID, waBinary.Node{
+		Tag:   "invite",
+		Attrs: waBinary.Attrs{"code": code},
+	})
+	if errors.Is(err, ErrIQGone) {
+		return types.EmptyJID, wrapIQError(ErrInviteLinkRevoked, err)
+	} else if errors.Is(err, ErrIQNotAcceptable) {
+		return types.EmptyJID, wrapIQError(ErrInviteLinkInvalid, err)
+	} else if err != nil {
+		return types.EmptyJID, err
+	}
+	groupNode, ok := resp.GetOptionalChildByTag("group")
+	if !ok {
+		return types.EmptyJID, &ElementMissingError{Tag: "group", In: "response to group link join query"}
+	}
+	return groupNode.AttrGetter().JID("jid"), nil
+}
+
+// GetJoinedGroups returns the list of groups the user is participating in.
+func (cli *Client) GetJoinedGroups() ([]*types.GroupInfo, error) {
+	resp, err := cli.sendGroupIQ(context.TODO(), iqGet, types.GroupServerJID, waBinary.Node{
+		Tag: "participating",
+		Content: []waBinary.Node{
+			{Tag: "participants"},
+			{Tag: "description"},
+		},
+	})
+	if err != nil {
+		return nil, err
+	}
+	groups, ok := resp.GetOptionalChildByTag("groups")
+	if !ok {
+		return nil, &ElementMissingError{Tag: "groups", In: "response to group list query"}
+	}
+	children := groups.GetChildren()
+	infos := make([]*types.GroupInfo, 0, len(children))
+	for _, child := range children {
+		if child.Tag != "group" {
+			cli.Log.Debugf("Unexpected child in group list response: %s", child.XMLString())
+			continue
+		}
+		parsed, parseErr := cli.parseGroupNode(&child)
+		if parseErr != nil {
+			cli.Log.Warnf("Error parsing group %s: %v", parsed.JID, parseErr)
+		}
+		infos = append(infos, parsed)
+	}
+	return infos, nil
+}
+
+// GetSubGroups gets the subgroups of the given community.
+func (cli *Client) GetSubGroups(community types.JID) ([]*types.GroupLinkTarget, error) {
+	res, err := cli.sendGroupIQ(context.TODO(), iqGet, community, waBinary.Node{Tag: "sub_groups"})
+	if err != nil {
+		return nil, err
+	}
+	groups, ok := res.GetOptionalChildByTag("sub_groups")
+	if !ok {
+		return nil, &ElementMissingError{Tag: "sub_groups", In: "response to subgroups query"}
+	}
+	var parsedGroups []*types.GroupLinkTarget
+	for _, child := range groups.GetChildren() {
+		if child.Tag == "group" {
+			parsedGroup, err := parseGroupLinkTargetNode(&child)
+			if err != nil {
+				return parsedGroups, fmt.Errorf("failed to parse group in subgroups list: %w", err)
+			}
+			parsedGroups = append(parsedGroups, &parsedGroup)
+		}
+	}
+	return parsedGroups, nil
+}
+
+// GetLinkedGroupsParticipants gets all the participants in the groups of the given community.
+func (cli *Client) GetLinkedGroupsParticipants(community types.JID) ([]types.JID, error) {
+	res, err := cli.sendGroupIQ(context.TODO(), iqGet, community, waBinary.Node{Tag: "linked_groups_participants"})
+	if err != nil {
+		return nil, err
+	}
+	participants, ok := res.GetOptionalChildByTag("linked_groups_participants")
+	if !ok {
+		return nil, &ElementMissingError{Tag: "linked_groups_participants", In: "response to community participants query"}
+	}
+	return parseParticipantList(&participants), nil
+}
+
+// GetGroupInfo requests basic info about a group chat from the WhatsApp servers.
+func (cli *Client) GetGroupInfo(jid types.JID) (*types.GroupInfo, error) {
+	return cli.getGroupInfo(context.TODO(), jid, true)
+}
+
+func (cli *Client) getGroupInfo(ctx context.Context, jid types.JID, lockParticipantCache bool) (*types.GroupInfo, error) {
+	res, err := cli.sendGroupIQ(ctx, iqGet, jid, waBinary.Node{
+		Tag:   "query",
+		Attrs: waBinary.Attrs{"request": "interactive"},
+	})
+	if errors.Is(err, ErrIQNotFound) {
+		return nil, wrapIQError(ErrGroupNotFound, err)
+	} else if errors.Is(err, ErrIQForbidden) {
+		return nil, wrapIQError(ErrNotInGroup, err)
+	} else if err != nil {
+		return nil, err
+	}
+
+	groupNode, ok := res.GetOptionalChildByTag("group")
+	if !ok {
+		return nil, &ElementMissingError{Tag: "groups", In: "response to group info query"}
+	}
+	groupInfo, err := cli.parseGroupNode(&groupNode)
+	if err != nil {
+		return groupInfo, err
+	}
+	if lockParticipantCache {
+		cli.groupParticipantsCacheLock.Lock()
+		defer cli.groupParticipantsCacheLock.Unlock()
+	}
+	participants := make([]types.JID, len(groupInfo.Participants))
+	for i, part := range groupInfo.Participants {
+		participants[i] = part.JID
+	}
+	cli.groupParticipantsCache[jid] = participants
+	return groupInfo, nil
+}
+
+func (cli *Client) getGroupMembers(ctx context.Context, jid types.JID) ([]types.JID, error) {
+	cli.groupParticipantsCacheLock.Lock()
+	defer cli.groupParticipantsCacheLock.Unlock()
+	if _, ok := cli.groupParticipantsCache[jid]; !ok {
+		_, err := cli.getGroupInfo(ctx, jid, false)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return cli.groupParticipantsCache[jid], nil
+}
+
+func (cli *Client) parseGroupNode(groupNode *waBinary.Node) (*types.GroupInfo, error) {
+	var group types.GroupInfo
+	ag := groupNode.AttrGetter()
+
+	group.JID = types.NewJID(ag.String("id"), types.GroupServer)
+	group.OwnerJID = ag.OptionalJIDOrEmpty("creator")
+
+	group.Name = ag.String("subject")
+	group.NameSetAt = ag.UnixTime("s_t")
+	group.NameSetBy = ag.OptionalJIDOrEmpty("s_o")
+
+	group.GroupCreated = ag.UnixTime("creation")
+
+	group.AnnounceVersionID = ag.OptionalString("a_v_id")
+	group.ParticipantVersionID = ag.OptionalString("p_v_id")
+
+	for _, child := range groupNode.GetChildren() {
+		childAG := child.AttrGetter()
+		switch child.Tag {
+		case "participant":
+			pcpType := childAG.OptionalString("type")
+			participant := types.GroupParticipant{
+				IsAdmin:      pcpType == "admin" || pcpType == "superadmin",
+				IsSuperAdmin: pcpType == "superadmin",
+				JID:          childAG.JID("jid"),
+			}
+			if errorCode := childAG.OptionalInt("error"); errorCode != 0 {
+				participant.Error = errorCode
+				addRequest, ok := child.GetOptionalChildByTag("add_request")
+				if ok {
+					addAG := addRequest.AttrGetter()
+					participant.AddRequest = &types.GroupParticipantAddRequest{
+						Code:       addAG.String("code"),
+						Expiration: addAG.UnixTime("expiration"),
+					}
+				}
+			}
+			group.Participants = append(group.Participants, participant)
+		case "description":
+			body, bodyOK := child.GetOptionalChildByTag("body")
+			if bodyOK {
+				topicBytes, _ := body.Content.([]byte)
+				group.Topic = string(topicBytes)
+				group.TopicID = childAG.String("id")
+				group.TopicSetBy = childAG.OptionalJIDOrEmpty("participant")
+				group.TopicSetAt = childAG.UnixTime("t")
+			}
+		case "announcement":
+			group.IsAnnounce = true
+		case "locked":
+			group.IsLocked = true
+		case "ephemeral":
+			group.IsEphemeral = true
+			group.DisappearingTimer = uint32(childAG.Uint64("expiration"))
+		case "member_add_mode":
+			modeBytes, _ := child.Content.([]byte)
+			group.MemberAddMode = types.GroupMemberAddMode(modeBytes)
+		case "linked_parent":
+			group.LinkedParentJID = childAG.JID("jid")
+		case "default_sub_group":
+			group.IsDefaultSubGroup = true
+		case "parent":
+			group.IsParent = true
+			group.DefaultMembershipApprovalMode = childAG.OptionalString("default_membership_approval_mode")
+		default:
+			cli.Log.Debugf("Unknown element in group node %s: %s", group.JID.String(), child.XMLString())
+		}
+		if !childAG.OK() {
+			cli.Log.Warnf("Possibly failed to parse %s element in group node: %+v", child.Tag, childAG.Errors)
+		}
+	}
+
+	return &group, ag.Error()
+}
+
+func parseGroupLinkTargetNode(groupNode *waBinary.Node) (types.GroupLinkTarget, error) {
+	ag := groupNode.AttrGetter()
+	jidKey := ag.OptionalJIDOrEmpty("jid")
+	if jidKey.IsEmpty() {
+		jidKey = types.NewJID(ag.String("id"), types.GroupServer)
+	}
+	return types.GroupLinkTarget{
+		JID: jidKey,
+		GroupName: types.GroupName{
+			Name:      ag.String("subject"),
+			NameSetAt: ag.UnixTime("s_t"),
+		},
+		GroupIsDefaultSub: types.GroupIsDefaultSub{
+			IsDefaultSubGroup: groupNode.GetChildByTag("default_sub_group").Tag == "default_sub_group",
+		},
+	}, ag.Error()
+}
+
+func parseParticipantList(node *waBinary.Node) (participants []types.JID) {
+	children := node.GetChildren()
+	participants = make([]types.JID, 0, len(children))
+	for _, child := range children {
+		jid, ok := child.Attrs["jid"].(types.JID)
+		if child.Tag != "participant" || !ok {
+			continue
+		}
+		participants = append(participants, jid)
+	}
+	return
+}
+
+func (cli *Client) parseGroupCreate(node *waBinary.Node) (*events.JoinedGroup, error) {
+	groupNode, ok := node.GetOptionalChildByTag("group")
+	if !ok {
+		return nil, fmt.Errorf("group create notification didn't contain group info")
+	}
+	var evt events.JoinedGroup
+	ag := node.AttrGetter()
+	evt.Reason = ag.OptionalString("reason")
+	evt.CreateKey = ag.OptionalString("key")
+	evt.Type = ag.OptionalString("type")
+	info, err := cli.parseGroupNode(&groupNode)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse group info in create notification: %w", err)
+	}
+	evt.GroupInfo = *info
+	return &evt, nil
+}
+
+func (cli *Client) parseGroupChange(node *waBinary.Node) (*events.GroupInfo, error) {
+	var evt events.GroupInfo
+	ag := node.AttrGetter()
+	evt.JID = ag.JID("from")
+	evt.Notify = ag.OptionalString("notify")
+	evt.Sender = ag.OptionalJID("participant")
+	evt.Timestamp = ag.UnixTime("t")
+	if !ag.OK() {
+		return nil, fmt.Errorf("group change doesn't contain required attributes: %w", ag.Error())
+	}
+
+	for _, child := range node.GetChildren() {
+		cag := child.AttrGetter()
+		if child.Tag == "add" || child.Tag == "remove" || child.Tag == "promote" || child.Tag == "demote" {
+			evt.PrevParticipantVersionID = cag.String("prev_v_id")
+			evt.ParticipantVersionID = cag.String("v_id")
+		}
+		switch child.Tag {
+		case "add":
+			evt.JoinReason = cag.OptionalString("reason")
+			evt.Join = parseParticipantList(&child)
+		case "remove":
+			evt.Leave = parseParticipantList(&child)
+		case "promote":
+			evt.Promote = parseParticipantList(&child)
+		case "demote":
+			evt.Demote = parseParticipantList(&child)
+		case "locked":
+			evt.Locked = &types.GroupLocked{IsLocked: true}
+		case "unlocked":
+			evt.Locked = &types.GroupLocked{IsLocked: false}
+		case "delete":
+			evt.Delete = &types.GroupDelete{Deleted: true, DeleteReason: cag.String("reason")}
+		case "subject":
+			evt.Name = &types.GroupName{
+				Name:      cag.String("subject"),
+				NameSetAt: cag.UnixTime("s_t"),
+				NameSetBy: cag.OptionalJIDOrEmpty("s_o"),
+			}
+		case "description":
+			var topicStr string
+			_, isDelete := child.GetOptionalChildByTag("delete")
+			if !isDelete {
+				topicChild := child.GetChildByTag("body")
+				topicBytes, ok := topicChild.Content.([]byte)
+				if !ok {
+					return nil, fmt.Errorf("group change description has unexpected body: %s", topicChild.XMLString())
+				}
+				topicStr = string(topicBytes)
+			}
+			var setBy types.JID
+			if evt.Sender != nil {
+				setBy = *evt.Sender
+			}
+			evt.Topic = &types.GroupTopic{
+				Topic:        topicStr,
+				TopicID:      cag.String("id"),
+				TopicSetAt:   evt.Timestamp,
+				TopicSetBy:   setBy,
+				TopicDeleted: isDelete,
+			}
+		case "announcement":
+			evt.Announce = &types.GroupAnnounce{
+				IsAnnounce:        true,
+				AnnounceVersionID: cag.String("v_id"),
+			}
+		case "not_announcement":
+			evt.Announce = &types.GroupAnnounce{
+				IsAnnounce:        false,
+				AnnounceVersionID: cag.String("v_id"),
+			}
+		case "invite":
+			link := InviteLinkPrefix + cag.String("code")
+			evt.NewInviteLink = &link
+		case "ephemeral":
+			timer := uint32(cag.Uint64("expiration"))
+			evt.Ephemeral = &types.GroupEphemeral{
+				IsEphemeral:       true,
+				DisappearingTimer: timer,
+			}
+		case "not_ephemeral":
+			evt.Ephemeral = &types.GroupEphemeral{IsEphemeral: false}
+		case "link":
+			evt.Link = &types.GroupLinkChange{
+				Type: types.GroupLinkChangeType(cag.String("link_type")),
+			}
+			groupNode, ok := child.GetOptionalChildByTag("group")
+			if !ok {
+				return nil, &ElementMissingError{Tag: "group", In: "group link"}
+			}
+			var err error
+			evt.Link.Group, err = parseGroupLinkTargetNode(&groupNode)
+			if err != nil {
+				return nil, fmt.Errorf("failed to parse group link node in group change: %w", err)
+			}
+		case "unlink":
+			evt.Unlink = &types.GroupLinkChange{
+				Type:         types.GroupLinkChangeType(cag.String("unlink_type")),
+				UnlinkReason: types.GroupUnlinkReason(cag.String("unlink_reason")),
+			}
+			groupNode, ok := child.GetOptionalChildByTag("group")
+			if !ok {
+				return nil, &ElementMissingError{Tag: "group", In: "group unlink"}
+			}
+			var err error
+			evt.Unlink.Group, err = parseGroupLinkTargetNode(&groupNode)
+			if err != nil {
+				return nil, fmt.Errorf("failed to parse group unlink node in group change: %w", err)
+			}
+		default:
+			evt.UnknownChanges = append(evt.UnknownChanges, &child)
+		}
+		if !cag.OK() {
+			return nil, fmt.Errorf("group change %s element doesn't contain required attributes: %w", child.Tag, cag.Error())
+		}
+	}
+	return &evt, nil
+}
+
+func (cli *Client) updateGroupParticipantCache(evt *events.GroupInfo) {
+	if len(evt.Join) == 0 && len(evt.Leave) == 0 {
+		return
+	}
+	cli.groupParticipantsCacheLock.Lock()
+	defer cli.groupParticipantsCacheLock.Unlock()
+	cached, ok := cli.groupParticipantsCache[evt.JID]
+	if !ok {
+		return
+	}
+Outer:
+	for _, jid := range evt.Join {
+		for _, existingJID := range cached {
+			if jid == existingJID {
+				continue Outer
+			}
+		}
+		cached = append(cached, jid)
+	}
+	for _, jid := range evt.Leave {
+		for i, existingJID := range cached {
+			if existingJID == jid {
+				cached[i] = cached[len(cached)-1]
+				cached = cached[:len(cached)-1]
+				break
+			}
+		}
+	}
+	cli.groupParticipantsCache[evt.JID] = cached
+}
+
+func (cli *Client) parseGroupNotification(node *waBinary.Node) (interface{}, error) {
+	children := node.GetChildren()
+	if len(children) == 1 && children[0].Tag == "create" {
+		return cli.parseGroupCreate(&children[0])
+	} else {
+		groupChange, err := cli.parseGroupChange(node)
+		if err != nil {
+			return nil, err
+		}
+		cli.updateGroupParticipantCache(groupChange)
+		return groupChange, nil
+	}
+}