From 9d9723d137914a02d089599af839e11ddbbea0a1 Mon Sep 17 00:00:00 2001
From: Franck Royer <franck@royer.one>
Date: Wed, 6 Oct 2021 14:51:45 +1100
Subject: [PATCH] Instantiate chat from community

---
 packages/status-communities/src/chat.ts       |  1 +
 packages/status-communities/src/community.ts  | 34 ++++++++++++++++
 .../src/wire/community_chat.ts                | 39 +++++++++++++++++++
 3 files changed, 74 insertions(+)

diff --git a/packages/status-communities/src/chat.ts b/packages/status-communities/src/chat.ts
index 95457c87..54ee5da2 100644
--- a/packages/status-communities/src/chat.ts
+++ b/packages/status-communities/src/chat.ts
@@ -13,6 +13,7 @@ export class Chat {
 
   /**
    * Create a public chat room.
+   * [[Community.instantiateChat]] MUST be used for chats belonging to a community.
    */
   public static async create(id: string): Promise<Chat> {
     const symKey = await createSymKeyFromPassword(id);
diff --git a/packages/status-communities/src/community.ts b/packages/status-communities/src/community.ts
index 7801d8d3..4e616804 100644
--- a/packages/status-communities/src/community.ts
+++ b/packages/status-communities/src/community.ts
@@ -1,7 +1,9 @@
 import debug from "debug";
 import { Waku } from "js-waku";
 
+import { Chat } from "./chat";
 import { bufToHex, hexToBuf } from "./utils";
+import { CommunityChat } from "./wire/community_chat";
 import { CommunityDescription } from "./wire/community_description";
 
 const dbg = debug("communities:community");
@@ -25,6 +27,7 @@ export class Community {
    *
    * @param publicKey The community's public key in hex format.
    * Can be found in the community's invite link: https://join.status.im/c/<public key>
+   * @param waku The Waku instance, used to retrieve Community information from the network.
    */
   public async instantiateCommunity(
     publicKey: string,
@@ -58,4 +61,35 @@ export class Community {
 
     this.description = desc;
   }
+
+  /**
+   * Instantiate [[Chat]] object based on the passed chat name.
+   * The Chat MUST already be part of the Community and the name MUST be exact (including casing).
+   *
+   * @throws string If the Community Description is unavailable or the chat is not found;
+   */
+  public async instantiateChat(chatName: string): Promise<Chat> {
+    if (!this.description) {
+      await this.refreshCommunityDescription();
+      if (!this.description)
+        throw "Failed to retrieve community description, cannot instantiate chat";
+    }
+
+    let communityChat: CommunityChat | undefined;
+    let chatId: string | undefined;
+
+    this.description.chats.forEach((_chat, _id) => {
+      if (chatId) return;
+
+      if (_chat.identity?.displayName === chatName) {
+        chatId = _id;
+        communityChat = _chat;
+      }
+    });
+
+    if (!communityChat || !chatId)
+      throw `Failed to retrieve community community chat with name ${chatName}`;
+
+    return Chat.create(chatId);
+  }
 }
diff --git a/packages/status-communities/src/wire/community_chat.ts b/packages/status-communities/src/wire/community_chat.ts
index 9cf04c97..915dfd5b 100644
--- a/packages/status-communities/src/wire/community_chat.ts
+++ b/packages/status-communities/src/wire/community_chat.ts
@@ -1,10 +1,20 @@
 import { Reader } from "protobufjs";
 
+import { ChatIdentity } from "../proto/communities/v1/chat_identity";
 import * as proto from "../proto/communities/v1/communities";
+import {
+  CommunityMember,
+  CommunityPermissions,
+} from "../proto/communities/v1/communities";
 
 export class CommunityChat {
   public constructor(public proto: proto.CommunityChat) {}
 
+  /**
+   * Decode the payload as CommunityChat message.
+   *
+   * @throws
+   */
   static decode(bytes: Uint8Array): CommunityChat {
     const protoBuf = proto.CommunityChat.decode(Reader.create(bytes));
 
@@ -14,4 +24,33 @@ export class CommunityChat {
   encode(): Uint8Array {
     return proto.CommunityChat.encode(this.proto).finish();
   }
+
+  // TODO: check and document what is the key of the returned Map;
+  public get members(): Map<string, CommunityMember> {
+    const map = new Map();
+
+    for (const key of Object.keys(this.proto.members)) {
+      map.set(key, this.proto.members[key]);
+    }
+
+    return map;
+  }
+
+  public get permissions(): CommunityPermissions | undefined {
+    return this.proto.permissions;
+  }
+
+  public get identity(): ChatIdentity | undefined {
+    return this.proto.identity;
+  }
+
+  // TODO: Document this
+  public get categoryId(): string | undefined {
+    return this.proto.categoryId;
+  }
+
+  // TODO: Document this
+  public get position(): number | undefined {
+    return this.proto.position;
+  }
 }