From 47cd3280bd7731b6f92b1b81bf4b5bde942b6a71 Mon Sep 17 00:00:00 2001
From: Alexander <me@hywax.space>
Date: Wed, 26 Jun 2024 22:46:02 +0500
Subject: [PATCH] feat: create event broker (#184)

---
 src/lib/game/baseGame.ts                      | 12 ++++++
 src/lib/game/services/broker/brokerService.ts | 42 +++++++++++++++++++
 src/lib/game/services/broker/interface.ts     | 16 +++++++
 src/routes/[lang]/(game)/play/+page.svelte    |  3 +-
 4 files changed, 72 insertions(+), 1 deletion(-)
 create mode 100644 src/lib/game/services/broker/brokerService.ts
 create mode 100644 src/lib/game/services/broker/interface.ts

diff --git a/src/lib/game/baseGame.ts b/src/lib/game/baseGame.ts
index 8901bce7..7af35e9f 100644
--- a/src/lib/game/baseGame.ts
+++ b/src/lib/game/baseGame.ts
@@ -33,6 +33,8 @@ import { PlayerService } from '$lib/game/services/player/playerService'
 import { Raider } from '$lib/game/objects/units/raider'
 import { QuestService } from '$lib/game/services/quest/questService'
 import type { Wagon } from '$lib/game/services/wagon/interface'
+import type { Broker } from '$lib/game/services/broker/interface'
+import { BrokerService } from '$lib/game/services/broker/brokerService'
 
 interface BaseGameOptions {
   isSocketOn?: boolean
@@ -51,6 +53,7 @@ export class BaseGame extends Container implements Game {
   tick: Game['tick'] = 0
   group: Group
 
+  brokerService: Broker
   actionService: ActionService
   eventService: EventService
   tradeService: TradeService
@@ -80,6 +83,7 @@ export class BaseGame extends Container implements Game {
     this.bg = new BackgroundGenerator(this.app)
     this.group = new Group()
 
+    this.brokerService = new BrokerService()
     this.actionService = new ActionService(this)
     this.eventService = new EventService(this)
     this.tradeService = new TradeService(this)
@@ -233,6 +237,14 @@ export class BaseGame extends Container implements Game {
     this.removeChild(...this.children)
   }
 
+  subscribe(event: string, callback: Function) {
+    return this.brokerService.register(event, callback)
+  }
+
+  dispatch<T>(event: string, arg?: T) {
+    this.brokerService.dispatch(event, arg)
+  }
+
   #updateObjects() {
     for (const object of this.children) {
       object.animate()
diff --git a/src/lib/game/services/broker/brokerService.ts b/src/lib/game/services/broker/brokerService.ts
new file mode 100644
index 00000000..fe5e2bb8
--- /dev/null
+++ b/src/lib/game/services/broker/brokerService.ts
@@ -0,0 +1,42 @@
+import type { Broker, Registry, Subscriber } from './interface'
+
+export class BrokerService implements Broker {
+  private subscribers: Subscriber
+  private static nextId = 0
+
+  constructor() {
+    this.subscribers = {}
+  }
+
+  public dispatch<T>(event: string, arg?: T): void {
+    const subscriber = this.subscribers[event]
+
+    if (subscriber === undefined) {
+      return
+    }
+
+    Object.keys(subscriber).forEach((key) => subscriber[key](arg))
+  }
+
+  public register(event: string, callback: Function): Registry {
+    const id = this.getNextId()
+    if (!this.subscribers[event]) {
+      this.subscribers[event] = {}
+    }
+
+    this.subscribers[event][id] = callback
+
+    return {
+      unregister: () => {
+        delete this.subscribers[event][id]
+        if (Object.keys(this.subscribers[event]).length === 0) {
+          delete this.subscribers[event]
+        }
+      },
+    }
+  }
+
+  private getNextId(): number {
+    return BrokerService.nextId++
+  }
+}
diff --git a/src/lib/game/services/broker/interface.ts b/src/lib/game/services/broker/interface.ts
new file mode 100644
index 00000000..429a5e87
--- /dev/null
+++ b/src/lib/game/services/broker/interface.ts
@@ -0,0 +1,16 @@
+export interface Registry {
+  unregister: () => void
+}
+
+export interface Callable {
+  [key: string]: Function
+}
+
+export interface Subscriber {
+  [key: string]: Callable
+}
+
+export interface Broker {
+  dispatch: <T>(event: string, arg?: T) => void
+  register: (event: string, callback: Function) => Registry
+}
diff --git a/src/routes/[lang]/(game)/play/+page.svelte b/src/routes/[lang]/(game)/play/+page.svelte
index 7b421644..225762c6 100644
--- a/src/routes/[lang]/(game)/play/+page.svelte
+++ b/src/routes/[lang]/(game)/play/+page.svelte
@@ -1,10 +1,11 @@
 <script lang='ts'>
-  import { onMount } from 'svelte'
+  import { onMount, setContext } from 'svelte'
   import GameInterface from './GameInterface.svelte'
   import { BaseGame } from '$lib/game/baseGame'
   import { page } from '$app/stores'
 
   const game = new BaseGame({ isSocketOn: true, profileJWT: $page.data.gameProfileJWT })
+  setContext('game', game)
   let gameElement: HTMLElement
 
   const handleVisibilityChange = () => {