import http from "k6/http";
import crypto from "k6/crypto";
import exec from "k6/execution";
import { check } from "k6";

const baseURL = __ENV.CALLBACK_URL || "http://host.docker.internal:58081";
const secret = __ENV.PROVIDER_CALLBACK_SECRET;
const fixtureText = __ENV.PROVIDER_FIXTURES || `${__ENV.CONVERSATION_ID || ""}|${__ENV.PROVIDER_TASK_REF || ""}`;
const fixtures = fixtureText.split(",").filter(Boolean).map((item) => {
  const [conversationID, taskRef] = item.split("|");
  return { conversationID, taskRef };
});
const smoke = (__ENV.PROFILE || "acceptance").toLowerCase() === "smoke";
const targetRate = Number(__ENV.RATE || (smoke ? 25 : 500));
const duration = __ENV.DURATION || (smoke ? "10s" : "10m");
const duplicateWindow = Number(__ENV.DUPLICATE_WINDOW || (smoke ? 100 : 300000));
const occurredAt = __ENV.OCCURRED_AT || new Date().toISOString();

if (!secret || !fixtures.length || fixtures.some((item) => !item.conversationID || !item.taskRef)) {
  throw new Error("PROVIDER_CALLBACK_SECRET and valid PROVIDER_FIXTURES are required");
}

export const options = {
  scenarios: {
    provider_notifications: {
      executor: "constant-arrival-rate",
      rate: targetRate,
      timeUnit: "1s",
      duration,
      preAllocatedVUs: smoke ? 50 : 600,
      maxVUs: smoke ? 150 : 1500,
      gracefulStop: "30s",
    },
  },
  thresholds: {
    http_req_failed: [smoke ? "rate<0.01" : "rate<0.001"],
    http_req_duration: ["p(95)<200", "p(99)<1000"],
    checks: ["rate>0.999"],
  },
};

function base64URL(value) {
  return value.replace(/=/g, "").replace(/\+/g, "-").replace(/\//g, "_");
}

export default function () {
  const eventNumber = exec.scenario.iterationInTest % duplicateWindow;
  const fixture = fixtures[eventNumber % fixtures.length];
  const body = JSON.stringify({
    provider: "mock",
    event_id: `load-started-${eventNumber}`,
    task_ref: fixture.taskRef,
    conversation_id: fixture.conversationID,
    event_type: "voice_chat.started",
    status: "ACTIVE",
    occurred_at: occurredAt,
  });
  const timestamp = new Date().toISOString().replace(/\.\d{3}Z$/, "Z");
  const digest = crypto.sha256(body, "hex");
  const signature = base64URL(crypto.hmac("sha256", secret, `${timestamp}\n${digest}`, "base64"));
  const response = http.post(`${baseURL}/callbacks/v1/vertc/voice-chat`, body, {
    headers: {
      "Content-Type": "application/json",
      "X-Provider-Timestamp": timestamp,
      "X-Provider-Signature": signature,
    },
    tags: { operation: "provider_callback" },
    timeout: "3s",
  });
  check(response, {
    "callback acknowledged": (item) => item.status === 200,
    "callback response is correlated": (item) => item.status === 200 && item.body.includes('"request_id"'),
  });
}