Feature/46 event sub follow (#85)

* Add `FollowEvent` table to DB

* Add `FollowEventHandler` event sub to bot

bot/chat-bot.ts

@@ -17,6 +17,7 @@ import { EventSubWsListener } from '@twurple/eventsub-ws';
 import {
     EventSubChannelBanEvent,
     EventSubChannelCheerEvent,
+    EventSubChannelFollowEvent,
     EventSubChannelModeratorEvent,
     EventSubChannelRedemptionAddEvent,
     EventSubChannelUnbanEvent,
@@ -36,6 +37,7 @@ import {
     BanEventHandler,
     ChannelPointEventHandler,
     CheerEventHandler,
+    FollowerEventHandler,
     ModeratorEventHandler,
     StreamEventHandler,
 } from './event-sub-handlers';
@@ -53,6 +55,7 @@ export default class ChatBot {
         @inject(BanEventHandler) private banEventHandler: BanEventHandler,
         @inject(ChannelPointEventHandler) private channelPointEventHandler: ChannelPointEventHandler,
         @inject(CheerEventHandler) private cheerEventHandler: CheerEventHandler,
+        @inject(FollowerEventHandler) private followerEventHandler: FollowerEventHandler,
         @inject(ModeratorEventHandler) private moderatorEventHandler: ModeratorEventHandler,
         @inject(StreamEventHandler) private streamEventHandler: StreamEventHandler,
         @inject(InjectionTypes.Logger) private logger: winston.Logger,
@@ -129,6 +132,16 @@ export default class ChatBot {
             },
         );
 
+        // Requires that a moderator with permission is part of the subscription
+        // Using the broadcaster as that user
+        this.eventSubWsListener.onChannelFollow(
+            environment.twitchBot.broadcaster.id,
+            environment.twitchBot.broadcaster.id,
+            (event: EventSubChannelFollowEvent): void => {
+                this.followerEventHandler.follow(event);
+            },
+        );
+
         this.eventSubWsListener.onChannelModeratorAdd(
             environment.twitchBot.broadcaster.id,
             (event: EventSubChannelModeratorEvent): void => {

bot/event-sub-handlers/follow-event.handler.ts

@@ -0,0 +1,28 @@
+import { EventSubChannelFollowEvent } from '@twurple/eventsub-base';
+import { inject, injectable } from 'inversify';
+import winston from 'winston';
+import InjectionTypes from '../../dependency-management/types';
+import { FollowEvent, ModeratorEvent } from '../../database';
+
+@injectable()
+export default class FollowerEventHandler {
+    constructor(
+        @inject(InjectionTypes.Logger) private logger: winston.Logger,
+    ) {
+    }
+
+    /**
+     * Records the event of a user being added as a moderator to the channel
+     * @param event Moderator Event
+     */
+    async follow(event: EventSubChannelFollowEvent): Promise<void> {
+        return FollowEvent
+            .follow(event)
+            .catch((reason: any) => {
+                this.logger.error(`Unable to store Follow event in DB >> ${reason}`);
+            })
+            .then(() => {
+                this.logger.info(`User ${event.userDisplayName}: followed ${event.broadcasterDisplayName} on ${(new Date()).toDateString()}`);
+            });
+    }
+}

bot/event-sub-handlers/index.ts

@@ -1,13 +1,15 @@
 import BanEventHandler from './ban-event.handler';
 import ChannelPointEventHandler from './channel-point-event.handler';
 import CheerEventHandler from './cheer-event.handler';
+import FollowerEventHandler from './follow-event.handler';
 import ModeratorEventHandler from './moderator-event.handler';
 import StreamEventHandler from './stream-event.handler';
 
 export {
     BanEventHandler,
     ChannelPointEventHandler,
     CheerEventHandler,
+    FollowerEventHandler,
     ModeratorEventHandler,
     StreamEventHandler,
 };

database/database.ts

@@ -8,6 +8,7 @@ import {
     ChannelPointRedeem,
     CheerEvent,
     DeathCounts,
+    FollowEvent,
     LurkingUsers,
     ModeratorEvent,
     Raiders,
@@ -45,6 +46,7 @@ const pgConfig: SequelizeOptions = {
         ChannelPointRedeem,
         CheerEvent,
         DeathCounts,
+        FollowEvent,
         LurkingUsers,
         ModeratorEvent,
         Raiders,

database/index.ts

@@ -2,6 +2,7 @@ import BanEvent from './models/banEvent.dbo';
 import ChannelPointRedeem from './models/channelPointRedeem.dbo';
 import CheerEvent from './models/cheerEvent.dbo';
 import DeathCounts from './models/deathCountRecord.dbo';
+import FollowEvent from './models/follow-event.dbo';
 import LurkingUsers from './models/lurkingUser.dbo';
 import ModeratorEvent from './models/moderatorEvent.dbo';
 import Raiders from './models/raiders.dbo';
@@ -15,6 +16,7 @@ export {
     ChannelPointRedeem,
     CheerEvent,
     DeathCounts,
+    FollowEvent,
     LurkingUsers,
     ModeratorEvent,
     Raiders,

database/models/follow-event.dbo.ts

@@ -0,0 +1,87 @@
+import { EventSubChannelFollowEvent } from '@twurple/eventsub-base';
+import { Column, DataType, Model, Table } from 'sequelize-typescript';
+
+@Table({
+    // consider placing this in a schema to
+    // cover all Event Sub data
+    // schema: 'EventSubData',
+    tableName: 'FollowEvent',
+    paranoid: true,
+})
+export default class FollowEvent extends Model {
+    /**
+     * The date when the user followed.
+     */
+    @Column({
+        type: DataType.DATE,
+    })
+    followDate: Date;
+
+    /**
+     * The ID of the broadcaster.
+     */
+    @Column({
+        type: DataType.STRING(20),
+    })
+    broadcasterId: string;
+
+    /**
+     * The name of the broadcaster.
+     */
+    @Column({
+        type: DataType.STRING(40),
+    })
+    broadcasterName: string;
+
+    /**
+     * The display name of the broadcaster.
+     */
+    @Column({
+        type: DataType.STRING(40),
+    })
+    broadcasterDisplayName: string;
+
+    /**
+     * The ID of the following user.
+     */
+    @Column({
+        type: DataType.STRING(20),
+    })
+    userId: string;
+
+    /**
+     * The name of the following user.
+     */
+    @Column({
+        type: DataType.STRING(40),
+    })
+    userName: string;
+
+    /**
+     * The display name of the following user.
+     */
+    @Column({
+        type: DataType.STRING(40),
+    })
+    userDisplayName: string;
+
+    /**
+     * Records the event of a user following the specific channel (broadcaster)
+     * @param event Follow Event
+     * @returns Follow Event Record
+     */
+    static async follow(event: EventSubChannelFollowEvent): Promise<FollowEvent> {
+        const record: Partial<FollowEvent> = {
+            followDate: event.followDate,
+            broadcasterId: event.broadcasterId,
+            broadcasterName: event.broadcasterName,
+            broadcasterDisplayName: event.broadcasterDisplayName,
+            userId: event.userId,
+            userName: event.userName,
+            userDisplayName: event.userDisplayName,
+        };
+
+        return this
+            .create(record);
+    }
+}

dependency-management/inversify.config.ts

@@ -53,6 +53,7 @@ import {
     BanEventHandler,
     ChannelPointEventHandler,
     CheerEventHandler,
+    FollowerEventHandler,
     ModeratorEventHandler,
     StreamEventHandler,
 } from '../bot/event-sub-handlers';
@@ -114,6 +115,7 @@ SAContainer.bind<ICommandHandler>(InjectionTypes.CommandHandlers).to(WishListCom
 SAContainer.bind(BanEventHandler).toSelf();
 SAContainer.bind(ChannelPointEventHandler).toSelf();
 SAContainer.bind(CheerEventHandler).toSelf();
+SAContainer.bind(FollowerEventHandler).toSelf();
 SAContainer.bind(ModeratorEventHandler).toSelf();
 SAContainer.bind(StreamEventHandler).toSelf();