src/application/Context/ApplicationContext.ts
import type { IApplication } from '@/domain/IApplication';
import { OperatingSystem } from '@/domain/OperatingSystem';
import type { ICategoryCollection } from '@/domain/ICategoryCollection';
import { EventSource } from '@/infrastructure/Events/EventSource';
import { assertInRange } from '@/application/Common/Enum';
import { CategoryCollectionState } from './State/CategoryCollectionState';
import type { IApplicationContext, IApplicationContextChangedEvent } from './IApplicationContext';
import type { ICategoryCollectionState } from './State/ICategoryCollectionState';
type StateMachine = Map<OperatingSystem, ICategoryCollectionState>;
export class ApplicationContext implements IApplicationContext {
public readonly contextChanged = new EventSource<IApplicationContextChangedEvent>();
public collection: ICategoryCollection;
public currentOs: OperatingSystem;
public get state(): ICategoryCollectionState {
return this.states[this.collection.os];
}
private readonly states: StateMachine;
public constructor(
public readonly app: IApplication,
initialContext: OperatingSystem,
) {
this.states = initializeStates(app);
this.changeContext(initialContext);
}
public changeContext(os: OperatingSystem): void {
assertInRange(os, OperatingSystem);
if (this.currentOs === os) {
return;
}
const collection = this.app.getCollection(os);
this.collection = collection;
const event: IApplicationContextChangedEvent = {
newState: this.states[os],
oldState: this.states[this.currentOs],
};
this.contextChanged.notify(event);
this.currentOs = os;
}
}
function initializeStates(app: IApplication): StateMachine {
const machine = new Map<OperatingSystem, ICategoryCollectionState>();
for (const collection of app.collections) {
machine[collection.os] = new CategoryCollectionState(collection);
}
return machine;
}