Renderer/assets/Scripts/engine/hook-manager.ts

import { Hook } from "/Scripts/types/hook"
import { Scene } from "/Scripts/types/scene"


/**
 * The scope that the hook is firing from
 */
export enum HookScope {
    CORE,
    SCRIPT,
    SCENE_CLIENT,
    SCENE_SERVER,
}

/**
 * A hook that is tracked by the manager
 */
interface TrackedHook extends Hook {

    /**
     * The scope that this hook was defined at
     */
    scope: HookScope,

    /**
     * The scene that added the hook
     */
    scene?: TrackedScene,

}

/**
 * A scene being tracked by the manager
 */
interface TrackedScene {

    /**
     * The id assigned to the scene
     */
    sceneId: number,

    /**
     * The scene itself
     */
    scene: Scene,

}

/**
 * Manages hooks for the engine
 */
export class HookManager {

    /**
     * The list of all hooks currently tracked by this manager
     */
    hooks: Array<TrackedHook> = []

    /**
     * A map of a scene to all hooks related to the scene
     */
    sceneHookMap: Record<number,Array<TrackedHook>> = { }

    /**
     * A map of engine signal to the list of hooks that should be called when that signal fires
     */
    signalHookMap: Record<string,Array<TrackedHook>> = { }

    /**
     * The list of all scenes tracked by the manager
     */
    trackedScenes: Array<{ sceneId: number, scene: Scene }> = []

    /**
     * A scene 
     */
    sceneIdIncrementer: number = 0

    /**
     * Registers all hooks in a scene to the hook manager
     * @param scene The scene
     */
    registerScene(scene: Scene, isServerScene: boolean){
        const shouldRegister: boolean = !this.containsScene(scene)
        if(shouldRegister){

            //add to the list of tracked scenes
            const trackedScene: TrackedScene = {
                sceneId: this.sceneIdIncrementer++,
                scene: scene,
            }
            this.trackedScenes.push(trackedScene)

            //load all hooks from the scene
            scene.hooks.forEach((hook: Hook) => {
                this.registerHook(trackedScene,hook,isServerScene)
            })

        }
    }

    /**
     * Deregisters all hooks in a scene from the hook manager
     * @param scene The scene
     */
    deregisterScene(scene: Scene){
        throw new Error("Unsupported Operation!")
    }

    /**
     * Checks if the manager is tracking a given scene
     * @param scene The scene
     * @returns true if it is being tracked already, false otherwise
     */
    containsScene(scene: Scene): boolean {
        this.trackedScenes.forEach(trackedScene => {
            if(trackedScene.scene === scene){
                return true
            }
        })
        return false
    }

    /**
     * Registers a hook
     * @param scene The scene introducing the hook
     * @param hook The hook
     */
    registerHook(scene: TrackedScene, hook: Hook, isServerScene: boolean){
        const trackedHook: TrackedHook = {
            ...hook,
            scope: isServerScene ? HookScope.SCENE_SERVER : HookScope.SCENE_CLIENT,
            scene: scene,
        }
        //add to flat array
        this.hooks.push(trackedHook)
        //add to signal array
        const hookSignal: string = hook.signal
        const signalArray: Array<TrackedHook> = this.signalHookMap?.[hookSignal] ? this.signalHookMap?.[hookSignal] : []
        signalArray.push(trackedHook)
        this.signalHookMap[hookSignal] = signalArray
        //add to scene array
        const sceneArray: Array<TrackedHook> = this.sceneHookMap?.[scene.sceneId] ? this.sceneHookMap?.[scene.sceneId] : []
        sceneArray.push(trackedHook)
        this.sceneHookMap[scene.sceneId] = sceneArray
    }

    /**
     * Deregisters a hook
     * @param scene The scene which introduced the hook
     * @param hook The hook
     */
    deregisterHook(scene: Scene, hook: Hook){
        throw new Error("Supported operation!")
    }

    /**
     * Fires a signal
     * @param signal The signal
     * @param value The value associated with the signal
     */
    fireSignal(signal: string, value: any){
        const hooks: Array<TrackedHook> = this.signalHookMap[signal]
        hooks.forEach(trackedHook => {
            trackedHook.callback(value)
        })
    }

}