airship-server/src/modules/apiServer/infrastructure/MultyRequestHandler.ts

Airship is a framework for Node.JS & TypeScript that helps you to write big, scalable and maintainable API servers.

import {BaseRequestHandler} from "../domain/BaseRequestHandler";
import {ASResponse} from "../domain/entity/ASResponse";
import {ASRequest, ASRequestType} from "../domain/entity/ASRequest";
import { Wrapper } from "../../codeGen/infrastructure/Utils";

export type HandlerFunction = (request: ASRequest) => ASResponse

export type MultiRequestHandlerType = Wrapper<typeof MultiRequestHandler>

export abstract class MultiRequestHandler extends BaseRequestHandler {

    private static handlers: Map<Function, Map<ASRequestType, HandlerFunction>> = new Map()

    public async handle(request: ASRequest): Promise<ASResponse> {
        let classHandlers = MultiRequestHandler.handlers.get(this.constructor)

        if (!classHandlers || !classHandlers.has(request.constructor as any))
            throw new Error('Cant find request for request: ' + request.constructor.name)

        return classHandlers.get(request.constructor as any)!(request)
    }

    public supports(request: ASRequest): boolean {
        return (
            MultiRequestHandler.handlers.has(this.constructor) &&
            MultiRequestHandler.handlers.get(this.constructor)!.has(request.constructor as any)
        )
    }

    public addHandler(request: ASRequestType, handlerClass: () => MultiRequestHandlerType, handlerFunction: HandlerFunction) {
        if (!MultiRequestHandler.handlers.has(handlerClass))
            MultiRequestHandler.handlers.set(handlerClass, new Map())

        MultiRequestHandler.handlers.get(handlerClass)!.set(request, handlerFunction)
    }
}

export function handles<T extends MultiRequestHandler>(request: ASRequestType) {
    return (target: T, propertyKey: string) => {
        let handler = (target as any)[propertyKey] as HandlerFunction

        target.addHandler(request, target.constructor as any, handler)
    }
}