import * as Express from 'express';

import { DyNTS_createLoadShedMiddleware } from './load-shed.util';
import { DyNTS_MemoryGuard } from '../_services/core/memory-guard.service';

// Az auto-load-shed middleware tesztjei (BFR-OVERSEER-009 maradék): critical-nyomásnál 503,
// esszenciális útvonalon SOHA, ok-nyomásnál átenged.
describe('| DyNTS_createLoadShedMiddleware', (): void => {

  /** Minimál Express req/res/next hármas a middleware meghajtásához. */
  function buildContext(path: string): {
    req: Express.Request; res: Express.Response; next: jasmine.Spy;
    sent: { status?: number; body?: unknown };
  } {
    const sent: { status?: number; body?: unknown } = {};
    const res: Partial<Express.Response> = {
      status: (code: number): Express.Response => { sent.status = code; return res as Express.Response; },
      setHeader: (): Express.Response => res as Express.Response,
      send: (body: unknown): Express.Response => { sent.body = body; return res as Express.Response; },
    };

    return {
      req: { path: path } as Express.Request,
      res: res as Express.Response,
      next: jasmine.createSpy('next'),
      sent: sent,
    };
  }

  it('| critical nyomásnál 503-mal ejti a nem-esszenciális kérést', (): void => {
    spyOn(DyNTS_MemoryGuard.getInstance(), 'shouldShedLoad').and.returnValue(true);
    const middleware: Express.Handler = DyNTS_createLoadShedMiddleware();
    const ctx = buildContext('/api/heavy-operation');

    middleware(ctx.req, ctx.res, ctx.next);

    expect(ctx.sent.status).toBe(503);
    expect(ctx.next).not.toHaveBeenCalled();
  });

  it('| esszenciális útvonalon (health) critical alatt SEM shed-el', (): void => {
    spyOn(DyNTS_MemoryGuard.getInstance(), 'shouldShedLoad').and.returnValue(true);
    const middleware: Express.Handler = DyNTS_createLoadShedMiddleware();
    const ctx = buildContext('/api/server/health');

    middleware(ctx.req, ctx.res, ctx.next);

    expect(ctx.next).toHaveBeenCalled();
    expect(ctx.sent.status).toBeUndefined();
  });

  it('| ok-nyomásnál átengedi a kérést', (): void => {
    spyOn(DyNTS_MemoryGuard.getInstance(), 'shouldShedLoad').and.returnValue(false);
    const middleware: Express.Handler = DyNTS_createLoadShedMiddleware();
    const ctx = buildContext('/api/anything');

    middleware(ctx.req, ctx.res, ctx.next);

    expect(ctx.next).toHaveBeenCalled();
    expect(ctx.sent.status).toBeUndefined();
  });
});