From 3a571b2c7a1f2841004f70dae7a1219d118a0b1c Mon Sep 17 00:00:00 2001
From: Tulir Asokan <tulir@maunium.net>
Date: Thu, 25 Jun 2020 23:29:16 +0300
Subject: [PATCH] Add command to join groups with invite link

---
 commands.go          | 41 +++++++++++++++++++++++++++++++++++++++--
 whatsapp-ext/chat.go | 28 ++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+), 2 deletions(-)

diff --git a/commands.go b/commands.go
index e40704c..efd82db 100644
--- a/commands.go
+++ b/commands.go
@@ -129,7 +129,7 @@ func (handler *CommandHandler) CommandMux(ce *CommandEvent) {
 		handler.CommandSetPowerLevel(ce)
 	case "logout":
 		handler.CommandLogout(ce)
-	case "login-matrix", "sync", "list", "open", "pm", "invite-link":
+	case "login-matrix", "sync", "list", "open", "pm", "invite-link", "join":
 		if !ce.User.HasSession() {
 			ce.Reply("You are not logged in. Use the `login` command to log into WhatsApp.")
 			return
@@ -151,6 +151,8 @@ func (handler *CommandHandler) CommandMux(ce *CommandEvent) {
 			handler.CommandPM(ce)
 		case "invite-link":
 			handler.CommandInviteLink(ce)
+		case "join":
+			handler.CommandJoin(ce)
 		}
 	default:
 		ce.Reply("Unknown Command")
@@ -208,7 +210,41 @@ func (handler *CommandHandler) CommandInviteLink(ce *CommandEvent) {
 		ce.Reply("Failed to get invite link: %v", err)
 		return
 	}
-	ce.Reply("https://chat.whatsapp.com/%s", link)
+	ce.Reply("%s%s", inviteLinkPrefix, link)
+}
+
+const cmdJoinHelp = `join <invite link> - Join a group chat with an invite link.`
+const inviteLinkPrefix = "https://chat.whatsapp.com/"
+
+func (handler *CommandHandler) CommandJoin(ce *CommandEvent) {
+	if len(ce.Args) == 0 {
+		ce.Reply("**Usage:** `join <invite link>`")
+		return
+	} else if len(ce.Args[0]) <= len(inviteLinkPrefix) || ce.Args[0][:len(inviteLinkPrefix)] != inviteLinkPrefix {
+		ce.Reply("That doesn't look like a WhatsApp invite link")
+		return
+	}
+
+	jid, err := ce.User.Conn.GroupAcceptInviteCode(ce.Args[0][len(inviteLinkPrefix):])
+	if err != nil {
+		ce.Reply("Failed to join group: %v", err)
+		return
+	}
+
+	handler.log.Debugln("%s successfully joined group %s", ce.User.MXID, jid)
+	portal := handler.bridge.GetPortalByJID(database.GroupPortalKey(jid))
+	if len(portal.MXID) > 0 {
+		portal.Sync(ce.User, whatsapp.Contact{Jid: portal.Key.JID})
+		ce.Reply("Successfully joined group \"%s\" and synced portal room", portal.Name)
+	} else {
+		err = portal.CreateMatrixRoom(ce.User)
+		if err != nil {
+			ce.Reply("Failed to create portal room: %v", err)
+			return
+		}
+
+		ce.Reply("Successfully joined group \"%s\" and created portal room", portal.Name)
+	}
 }
 
 const cmdSetPowerLevelHelp = `set-pl [user ID] <power level> - Change the power level in a portal room. Only for bridge admins.`
@@ -470,6 +506,7 @@ func (handler *CommandHandler) CommandHelp(ce *CommandEvent) {
 		cmdPrefix + cmdOpenHelp,
 		cmdPrefix + cmdPMHelp,
 		cmdPrefix + cmdInviteLinkHelp,
+		cmdPrefix + cmdJoinHelp,
 		cmdPrefix + cmdSetPowerLevelHelp,
 		cmdPrefix + cmdDeletePortalHelp,
 		cmdPrefix + cmdDeleteAllPortalsHelp,
diff --git a/whatsapp-ext/chat.go b/whatsapp-ext/chat.go
index d8c96f3..e35ccf0 100644
--- a/whatsapp-ext/chat.go
+++ b/whatsapp-ext/chat.go
@@ -45,6 +45,7 @@ const (
 	ChatActionAnnounce    ChatActionType = "announce"
 	ChatActionPromote     ChatActionType = "promote"
 	ChatActionDemote      ChatActionType = "demote"
+	ChatActionIntroduce   ChatActionType = "introduce"
 )
 
 type ChatUpdateData struct {
@@ -61,12 +62,20 @@ type ChatUpdateData struct {
 		Topic string `json:"desc"`
 		ID    string `json:"descId"`
 		SetAt int64  `json:"descTime"`
+		SetBy string `json:"descOwner"`
 	}
 
 	RemoveTopic struct {
 		ID string `json:"descId"`
 	}
 
+	Introduce struct {
+		CreationTime int64    `json:"creation"`
+		Admins       []string `json:"admins"`
+		SuperAdmins  []string `json:"superadmins"`
+		Regulars     []string `json:"regulars"`
+	}
+
 	Restrict bool
 
 	Announce bool
@@ -98,6 +107,16 @@ func (cud *ChatUpdateData) UnmarshalJSON(data []byte) error {
 
 	var unmarshalTo interface{}
 	switch cud.Action {
+	case ChatActionIntroduce:
+		err = json.Unmarshal(arr[2], &cud.NameChange)
+		if err != nil {
+			return err
+		}
+		err = json.Unmarshal(arr[2], &cud.AddTopic)
+		if err != nil {
+			return err
+		}
+		unmarshalTo = &cud.Introduce
 	case ChatActionNameChange:
 		unmarshalTo = &cud.NameChange
 	case ChatActionAddTopic:
@@ -121,6 +140,15 @@ func (cud *ChatUpdateData) UnmarshalJSON(data []byte) error {
 	for index, jid := range cud.PermissionChange.JIDs {
 		cud.PermissionChange.JIDs[index] = strings.Replace(jid, OldUserSuffix, NewUserSuffix, 1)
 	}
+	for index, jid := range cud.Introduce.SuperAdmins {
+		cud.Introduce.SuperAdmins[index] = strings.Replace(jid, OldUserSuffix, NewUserSuffix, 1)
+	}
+	for index, jid := range cud.Introduce.Admins {
+		cud.Introduce.Admins[index] = strings.Replace(jid, OldUserSuffix, NewUserSuffix, 1)
+	}
+	for index, jid := range cud.Introduce.Regulars {
+		cud.Introduce.Regulars[index] = strings.Replace(jid, OldUserSuffix, NewUserSuffix, 1)
+	}
 	return nil
 }