import { engine } from "/Scripts/engine/engine-init";
import { HookManager, TrackedHook } from "/Scripts/engine/hooks/hook-manager";
import { Hook } from "/Scripts/types/hook";
import { Scene } from "/Scripts/types/scene";


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

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

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

    /**
     * A map of a scene to all hooks related to the scene
     */
    sceneHooks: 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>>

}


/**
 * Loads scenes
 */
export class SceneLoader {


    
    /**
     * The hook manager
     */
    hookManager: HookManager

    /**
     * The list of loaded scenes
     */
    loadedScenes: TrackedScene[]

    /**
     * A record of tracked scene id to tracked scene object
     */
    sceneIdMap: Record<number,TrackedScene>

    /**
     * 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,
                sceneHooks: [],
                signalHookMap: { },
            }
            this.loadedScenes.push(trackedScene)
            this.sceneIdMap[trackedScene.sceneId] = trackedScene

            //load all hooks from the scene
            scene.hooks.forEach((hook: Hook) => {
                engine.hookManager.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.loadedScenes.forEach(trackedScene => {
            if(trackedScene.scene === scene){
                return true
            }
        })
        return false
    }

    /**
     * Gets a tracked scene by its id
     * @param sceneId The tracked scene
     * @returns The tracked scene if it exists, null otherwise
     */
    getScene(sceneId: number){
        return this.sceneIdMap[sceneId]
    }
    
}