#!/usr/bin/env node

const fs = require("fs");
const path = require("path");

const DEFAULT_WAIT_MS = 5000;
const MAX_WAIT_MS = 20000;
const NAV_TIMEOUT_MS = 30000;
const EXTRA_CHALLENGE_WAIT_MS = 8000;
const CONTENT_LIMIT = 12000;
const DEFAULT_USER_AGENT =
  "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/136.0.0.0 Safari/537.36";

function fail(message, details) {
  const payload = { error: message };
  if (details) payload.details = details;
  process.stderr.write(`${JSON.stringify(payload)}\n`);
  process.exit(1);
}

function parseWaitTime(raw) {
  const value = Number.parseInt(raw || `${DEFAULT_WAIT_MS}`, 10);
  if (!Number.isFinite(value) || value < 0) return DEFAULT_WAIT_MS;
  return Math.min(value, MAX_WAIT_MS);
}

function parseTarget(rawUrl) {
  if (!rawUrl) {
    fail("Missing URL. Usage: node scripts/playwright-safe.js <URL>");
  }

  let parsed;
  try {
    parsed = new URL(rawUrl);
  } catch (error) {
    fail("Invalid URL.", error.message);
  }

  if (!["http:", "https:"].includes(parsed.protocol)) {
    fail("Only http and https URLs are allowed.");
  }

  return parsed.toString();
}

function ensureParentDir(filePath) {
  if (!filePath) return;
  fs.mkdirSync(path.dirname(filePath), { recursive: true });
}

async function detectChallenge(page) {
  try {
    return await page.evaluate(() => {
      const text = (document.body?.innerText || "").toLowerCase();
      return (
        text.includes("checking your browser") ||
        text.includes("just a moment") ||
        text.includes("verify you are human") ||
        text.includes("press and hold") ||
        document.querySelector('iframe[src*="challenge"]') !== null ||
        document.querySelector('iframe[src*="cloudflare"]') !== null
      );
    });
  } catch {
    return false;
  }
}

async function main() {
  const requestedUrl = parseTarget(process.argv[2]);
  const waitTime = parseWaitTime(process.env.WAIT_TIME);
  const screenshotPath = process.env.SCREENSHOT_PATH || "";
  const saveHtml = process.env.SAVE_HTML === "true";
  const headless = process.env.HEADLESS !== "false";
  const userAgent = process.env.USER_AGENT || DEFAULT_USER_AGENT;
  const startedAt = Date.now();
  let chromium;
  try {
    ({ chromium } = require("playwright"));
  } catch (error) {
    fail(
      "Playwright is not installed for this skill. Run npm install and npx playwright install chromium first.",
      error.message
    );
  }

  let browser;
  try {
    browser = await chromium.launch({
      headless,
      ignoreDefaultArgs: ["--enable-automation"],
      args: [
        "--disable-blink-features=AutomationControlled",
        "--disable-features=IsolateOrigins,site-per-process"
      ]
    });

    const context = await browser.newContext({
      userAgent,
      locale: "en-US",
      viewport: { width: 1440, height: 900 },
      extraHTTPHeaders: {
        "Accept-Language": "en-US,en;q=0.9",
        Accept: "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8"
      }
    });

    await context.addInitScript(() => {
      Object.defineProperty(navigator, "webdriver", {
        get: () => false
      });

      Object.defineProperty(navigator, "languages", {
        get: () => ["en-US", "en"]
      });

      Object.defineProperty(navigator, "plugins", {
        get: () => [1, 2, 3, 4, 5]
      });

      window.chrome = window.chrome || { runtime: {} };

      const originalQuery = window.navigator.permissions?.query?.bind(window.navigator.permissions);
      if (originalQuery) {
        window.navigator.permissions.query = (parameters) => {
          if (parameters?.name === "notifications") {
            return Promise.resolve({ state: Notification.permission });
          }
          return originalQuery(parameters);
        };
      }
    });

    const page = await context.newPage();
    const response = await page.goto(requestedUrl, {
      waitUntil: "domcontentloaded",
      timeout: NAV_TIMEOUT_MS
    });

    await page.waitForTimeout(waitTime);

    let challengeDetected = await detectChallenge(page);
    if (challengeDetected) {
      await page.waitForTimeout(EXTRA_CHALLENGE_WAIT_MS);
      challengeDetected = await detectChallenge(page);
    }

    const extracted = await page.evaluate((contentLimit) => {
      const bodyText = document.body?.innerText || "";
      return {
        finalUrl: window.location.href,
        title: document.title || "",
        content: bodyText.slice(0, contentLimit),
        metaDescription:
          document.querySelector('meta[name="description"]')?.content ||
          document.querySelector('meta[property="og:description"]')?.content ||
          ""
      };
    }, CONTENT_LIMIT);

    const result = {
      requestedUrl,
      finalUrl: extracted.finalUrl,
      title: extracted.title,
      content: extracted.content,
      metaDescription: extracted.metaDescription,
      status: response ? response.status() : null,
      challengeDetected,
      elapsedSeconds: ((Date.now() - startedAt) / 1000).toFixed(2)
    };

    if (screenshotPath) {
      ensureParentDir(screenshotPath);
      await page.screenshot({ path: screenshotPath, fullPage: false, timeout: 10000 });
      result.screenshot = screenshotPath;
    }

    if (saveHtml) {
      const htmlTarget =
        screenshotPath ? screenshotPath.replace(/\.[^.]+$/, ".html") : path.resolve(`page-${Date.now()}.html`);
      ensureParentDir(htmlTarget);
      fs.writeFileSync(htmlTarget, await page.content());
      result.htmlFile = htmlTarget;
    }

    process.stdout.write(`${JSON.stringify(result, null, 2)}\n`);
    await browser.close();
  } catch (error) {
    if (browser) {
      try {
        await browser.close();
      } catch {
        // Ignore close errors after the primary failure.
      }
    }
    fail("Scrape failed.", error.message);
  }
}

main();