feat: WA Business Labels support (#407)

* Get all labels
* Get chats by label
* Get labels assigned to chats

Co-authored-by: Pedro S. Lopez <pslamoros@hotmail.com>
Co-authored-by: Pedro Lopez <pedroslopez@me.com>

src/Client.js

@@ -11,7 +11,7 @@ const { WhatsWebURL, DefaultOptions, Events, WAState } = require('./util/Constan
 const { ExposeStore, LoadUtils } = require('./util/Injected');
 const ChatFactory = require('./factories/ChatFactory');
 const ContactFactory = require('./factories/ContactFactory');
-const { ClientInfo, Message, MessageMedia, Contact, Location, GroupNotification } = require('./structures');
+const { ClientInfo, Message, MessageMedia, Contact, Location, GroupNotification , Label } = require('./structures');
 /**
  * Starting point for interacting with the WhatsApp Web API
  * @extends {EventEmitter}
@@ -749,6 +749,63 @@ class Client extends EventEmitter {
         return { gid: createRes.gid, missingParticipants };
     }
 
+    /**
+     * Get all current Labels
+     * @returns {Promise<Array<Label>>}
+     */
+    async getLabels() {
+        const labels = await this.pupPage.evaluate(async () => {
+            return window.WWebJS.getLabels();
+        }); 
+
+        return labels.map(data => new Label(this , data));
+    }
+
+    /**
+     * Get Label instance by ID
+     * @param {string} labelId
+     * @returns {Promise<Label>}
+     */
+    async getLabelById(labelId) {
+        const label = await this.pupPage.evaluate(async (labelId) => {
+            return window.WWebJS.getLabel(labelId);
+        }, labelId); 
+
+        return new Label(this, label);
+    }
+
+    /**
+     * Get all Labels assigned to a chat 
+     * @param {string} chatId
+     * @returns {Promise<Array<Label>>}
+     */
+    async getChatLabels(chatId){
+        const labels = await this.pupPage.evaluate(async (chatId) => {
+            return window.WWebJS.getChatLabels(chatId);
+        }, chatId);
+
+        return labels.map(data => new Label(this, data)); 
+    }
+
+    /**
+     * Get all Chats for a specific Label
+     * @param {string} labelId
+     * @returns {Promise<Array<Chat>>}
+     */
+    async getChatsByLabelId(labelId){
+        const chatIds = await this.pupPage.evaluate(async (labelId) => {
+            const label = window.Store.Label.get(labelId);
+            const labelItems = label.labelItemCollection.models;
+            return labelItems.reduce((result, item) => {
+                if(item.parentType === 'Chat'){  
+                    result.push(item.parentId);
+                }
+                return result;
+            },[]);
+        }, labelId);
+
+        return Promise.all(chatIds.map(id => this.getChatById(id)));
+    }
 }
 
 module.exports = Client;