import { check, sleep } from "k6";
import http from "k6/http";
import exec from "k6/execution";
import { Trend } from "k6/metrics";

function required(name) {
  const value = __ENV[name];

  if (value === undefined || value === "") {
    throw new Error(`${name} is required`);
  }

  return value;
}

function positiveInteger(name) {
  const value = Number(required(name));

  if (!Number.isInteger(value) || value <= 0) {
    throw new Error(`${name} must be a positive integer`);
  }

  return value;
}

function nonNegativeNumber(name) {
  const value = Number(required(name));

  if (!Number.isFinite(value) || value < 0) {
    throw new Error(`${name} must be a non-negative number`);
  }

  return value;
}

const baseUrl = required("BASE_URL").replace(/\/+$/, "");

if (baseUrl !== "http://web:4000") {
  throw new Error("The scale read-only profile is pinned to http://web:4000");
}

const sessionCookie = required("SESSION_COOKIE");
const vus = positiveInteger("VUS");
const duration = required("DURATION");
const thinkSeconds = nonNegativeNumber("THINK_SECONDS");

const viewports = [
  {
    path:
      "/requests?west=22.096886&south=45.034261&east=38.949914&north=55.310025&zoom=5&width=767&height=734&view=split",
    endpoint: "requests_europe",
    heading: "Who needs help?",
  },
  {
    path:
      "/activities?west=22.096886&south=45.034261&east=38.949914&north=55.310025&zoom=5&width=767&height=734&view=split",
    endpoint: "activities_europe",
    heading: "Nearby activities",
  },
  {
    path:
      "/requests?west=-179.9&south=-80&east=179.9&north=80&zoom=1&width=1280&height=720&view=map",
    endpoint: "requests_world",
    heading: "Who needs help?",
  },
  {
    path:
      "/activities?west=-179.9&south=-80&east=179.9&north=80&zoom=1&width=1280&height=720&view=map",
    endpoint: "activities_world",
    heading: "Nearby activities",
  },
];

const endpointDurations = {
  requests_europe: new Trend("wnh_requests_europe_duration", true),
  activities_europe: new Trend("wnh_activities_europe_duration", true),
  requests_world: new Trend("wnh_requests_world_duration", true),
  activities_world: new Trend("wnh_activities_world_duration", true),
};

export const options = {
  scenarios: {
    scale_readonly_http: {
      executor: "constant-vus",
      exec: "scaleReadonlyHttp",
      vus,
      duration,
    },
  },
  thresholds: {
    checks: [{ threshold: "rate==1", abortOnFail: true }],
    http_req_failed: [{ threshold: "rate==0", abortOnFail: true }],
  },
};

export function scaleReadonlyHttp() {
  const viewport = viewports[exec.scenario.iterationInTest % viewports.length];
  const response = http.get(`${baseUrl}${viewport.path}`, {
    redirects: 0,
    tags: {
      endpoint: viewport.endpoint,
      safety_scope: "persistent_local_scale_readonly",
    },
    headers: {
      Cookie: sessionCookie,
      Host: "scale.localhost",
      "X-Forwarded-Host": "scale.localhost",
      "X-Forwarded-Port": "4121",
      "X-Forwarded-Proto": "https",
      "User-Agent": "WhoNeedHelp-persistent-scale-readonly/1",
    },
  });

  endpointDurations[viewport.endpoint].add(response.timings.duration);

  check(response, {
    [`GET ${viewport.endpoint} returned 200`]: (candidate) =>
      candidate.status === 200,
    [`GET ${viewport.endpoint} rendered its loading shell`]: (candidate) =>
      candidate.body.includes(viewport.heading) &&
      candidate.body.includes("Loading results"),
  });

  sleep(thinkSeconds);
}