const { chromium } = require('playwright');

const TARGET_URL = process.env.TARGET_URL || 'http://127.0.0.1:8001';
const OLLAMA_HOST = process.env.OLLAMA_HOST || 'http://192.168.254.115:11434';
const SERVER_ID = process.env.TEST_SERVER_ID || 'srv_e2e_cache';
const SERVER_NAME = process.env.TEST_SERVER_NAME || 'E2E Cache Server';
const QUIET_WINDOW_MS = Number(process.env.QUIET_WINDOW_MS || 1500);
const CACHE_WAIT_TIMEOUT_MS = Number(process.env.CACHE_WAIT_TIMEOUT_MS || 20000);

function sleep(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

async function waitForCache(page) {
  await page.waitForFunction(
    (serverId) => {
      return ['health', 'models', 'running'].every((suffix) => {
        return Boolean(localStorage.getItem(`llm_monitor_${suffix}_${serverId}`));
      });
    },
    SERVER_ID,
    { timeout: CACHE_WAIT_TIMEOUT_MS }
  );
}

async function configureServer(page) {
  await page.addInitScript(
    ({ serverId, serverName, host }) => {
      localStorage.setItem(
        'llm_monitor_servers',
        JSON.stringify([
          {
            id: serverId,
            name: serverName,
            host
          }
        ])
      );
      localStorage.setItem('llm_monitor_active_server', serverId);
    },
    {
      serverId: SERVER_ID,
      serverName: SERVER_NAME,
      host: OLLAMA_HOST
    }
  );
}

async function main() {
  const browser = await chromium.launch({ headless: true });
  const context = await browser.newContext({ serviceWorkers: 'block' });
  const page = await context.newPage();
  const apiRequests = [];

  context.on('request', (request) => {
    const url = new URL(request.url());
    if (url.pathname.startsWith('/api/v1/')) {
      apiRequests.push(url.pathname + url.search);
    }
  });

  page.on('console', (msg) => console.log(`[console:${msg.type()}] ${msg.text()}`));
  page.on('pageerror', (error) => console.log(`[pageerror] ${error.message}`));

  const resetApiRequests = () => {
    apiRequests.length = 0;
  };

  const expectNoApiRequests = async (label) => {
    await sleep(QUIET_WINDOW_MS);
    if (apiRequests.length > 0) {
      throw new Error(`${label}: expected no API requests, got ${apiRequests.length} -> ${apiRequests.join(', ')}`);
    }
    console.log(`PASS ${label}: no API requests during ${QUIET_WINDOW_MS}ms quiet window`);
  };

  try {
    await configureServer(page);

    console.log(`Opening first page at ${TARGET_URL}/models-running?server=${SERVER_ID}`);
    await page.goto(`${TARGET_URL}/models-running?server=${SERVER_ID}`, { waitUntil: 'domcontentloaded' });
    await waitForCache(page);

    if (apiRequests.length === 0) {
      throw new Error('Initial page load did not perform any API requests, cache warmup could not be verified');
    }

    console.log(`PASS initial load warmed cache with ${apiRequests.length} API requests`);

    resetApiRequests();
    await page.goto(`${TARGET_URL}/models-available?server=${SERVER_ID}`, { waitUntil: 'domcontentloaded' });
    await expectNoApiRequests('navigate running -> available');

    resetApiRequests();
    await page.goto(`${TARGET_URL}/models-running?server=${SERVER_ID}`, { waitUntil: 'domcontentloaded' });
    await expectNoApiRequests('navigate available -> running');

    resetApiRequests();
    await page.goto(`${TARGET_URL}/models-available?server=${SERVER_ID}`, { waitUntil: 'domcontentloaded' });
    await expectNoApiRequests('navigate running -> available again');

    console.log('PASS cache-first navigation test completed successfully');
  } finally {
    await context.close();
    await browser.close();
  }
}

main().catch((error) => {
  console.error(`FAIL ${error.message}`);
  process.exitCode = 1;
});