const express = require('express');
const { chromium } = require('playwright');
const fs = require('fs');
const path = require('path');

// =========================
// CONFIG
// =========================

const DATA_FILE = 'latest.json';

const DOWNLOAD_DIR = 'downloads';

// Check every 5 minutes
const CHECK_INTERVAL = 5 * 60 * 1000;

const app = express();

const PORT = process.env.PORT || 7860;
// =========================
// CREATE DOWNLOAD FOLDER
// =========================

if (!fs.existsSync(DOWNLOAD_DIR)) {

  fs.mkdirSync(DOWNLOAD_DIR);

}

// =========================
// READ OLD DATA
// =========================

let oldData = {};

if (fs.existsSync(DATA_FILE)) {

  oldData = JSON.parse(
    fs.readFileSync(DATA_FILE, 'utf-8')
  );

}

// =========================
// URLS
// =========================

const urls = [

  {
    name: "Guidelines and Help Files",

    url:
      "https://admissions.jnvuiums.in/ViewAllNews.aspx?type=D&Heading=Guidelines%20and%20Help%20Files%20(Download%20Section)",

    selector:
      "a[href*='DownloadAttachment']"
  },

  {
    name: "News and Events",

    url:
      "https://admissions.jnvuiums.in/ViewAllNews.aspx?type=N&&Heading=News%20and%20Events",

    selector:
      "ul.important_announcement li:nth-of-type(2)"
  },

  {
    name: "Time Table",

    url:
      "https://erp.jnvuiums.in/CollegePortal/General_Inst_Notification.aspx?type=O&&Heading=Examination%20Time%20Table"
  },

  {
    name: "General Instructions and Notification",

    url:
      "https://erp.jnvuiums.in/CollegePortal/General_Inst_Notification.aspx?type=G&&Heading=General%20Instructions%20and%20Notification"
  }

];

// =========================
// MAIN FUNCTION
// =========================

async function startChecking() {

  const browser = await chromium.launch({

    headless: true,

    args: [
      '--no-sandbox',
      '--disable-setuid-sandbox'
    ]

  });

  const context = await browser.newContext({

    acceptDownloads: true

  });

  const page = await context.newPage();

  // =========================
  // SCRAPE FUNCTION
  // =========================

  async function scrapeItem(item) {

    console.log("\n==============================");

    console.log("CHECKING:", item.name);

    console.log("==============================\n");

    await page.goto(item.url, {

      waitUntil: 'networkidle'

    });

    await page.waitForTimeout(3000);

    // =========================
    // NEWS SECTION
    // =========================

    if (item.name === "News and Events") {

      await page.waitForSelector(item.selector);

      const latestText = await page
        .locator(item.selector)
        .innerText();

      console.log("LATEST NEWS:\n");

      console.log(latestText);

      const oldTitle =
        oldData[item.name]?.title;

      if (oldTitle !== latestText) {

        console.log("\n🔥 NEW NEWS UPDATE FOUND 🔥");

        console.log("\nOLD :");

        console.log(oldTitle || "No old data");

        console.log("\nNEW :");

        console.log(latestText);

        oldData[item.name] = {

          title: latestText

        };

      }

      else {

        console.log("\n✅ NO NEW NEWS UPDATE");

      }

      return;

    }

    // =========================
    // GUIDELINES SECTION
    // =========================

    if (item.name === "Guidelines and Help Files") {

      const element = page
        .locator(item.selector)
        .first();

      const title = await element.innerText();

      console.log("TITLE :\n");

      console.log(title);

      const oldTitle =
        oldData[item.name]?.title;

      if (oldTitle !== title) {

        console.log("\n🔥 NEW UPDATE FOUND 🔥");

        console.log("\nOLD :");

        console.log(oldTitle || "No old data");

        console.log("\nNEW :");

        console.log(title);

        const [ download ] = await Promise.all([

          page.waitForEvent('download'),

          element.click()

        ]);

        const fileName =
          download.suggestedFilename();

        const savePath = path.join(

          DOWNLOAD_DIR,

          fileName

        );

        await download.saveAs(savePath);

        console.log("\n✅ PDF DOWNLOADED");

        console.log("📁 SAVED:");

        console.log(savePath);

        oldData[item.name] = {

          title: title

        };

      }

      else {

        console.log("\n✅ NO NEW UPDATE");

      }

      return;

    }

    // =========================
    // TIME TABLE + NOTIFICATION
    // =========================

    const row = page.locator(
      '#ctl00_ContentPlaceHolder1_GridData tr'
    ).nth(1);

    const title = await row
      .locator('td')
      .nth(1)
      .innerText();

    const element = row.locator(
      'a[id*="LnkBtnDownload"]'
    );

    console.log("TITLE :\n");

    console.log(title);

    const oldTitle =
      oldData[item.name]?.title;

    if (oldTitle !== title) {

      console.log("\n🔥 NEW UPDATE FOUND 🔥");

      console.log("\nOLD :");

      console.log(oldTitle || "No old data");

      console.log("\nNEW :");

      console.log(title);

      const [ download ] = await Promise.all([

        page.waitForEvent('download'),

        element.click()

      ]);

      const fileName =
        download.suggestedFilename();

      const savePath = path.join(

        DOWNLOAD_DIR,

        fileName

      );

      await download.saveAs(savePath);

      console.log("\n✅ PDF DOWNLOADED");

      console.log("📁 SAVED:");

      console.log(savePath);

      oldData[item.name] = {

        title: title

      };

    }

    else {

      console.log("\n✅ NO NEW UPDATE");

    }

  }

  // =========================
  // LOOP ALL URLS
  // =========================

  for (const item of urls) {

    try {

      await scrapeItem(item);

    }

    catch (err) {

      console.log("\n❌ ERROR IN:", item.name);

      console.log(err.message);

    }

  }

  // =========================
  // SAVE JSON
  // =========================

  fs.writeFileSync(

    DATA_FILE,

    JSON.stringify(oldData, null, 2)

  );

  console.log("\n==============================");

  console.log("✅ ALL CHECK COMPLETE");

  console.log("==============================\n");

  await browser.close();

}

// =========================
// FIRST RUN
// =========================

startChecking();

// =========================
// AUTO CHECK EVERY 5 MIN
// =========================

setInterval(async () => {

  console.log("\n⏳ CHECKING AGAIN...\n");

  await startChecking();

}, CHECK_INTERVAL);

// =========================
// EXPRESS SERVER
// =========================

app.get('/', (req, res) => {

  res.send('JNVU Monitor Running ✅');

});

app.listen(PORT, () => {

  console.log(`Server running on port ${PORT}`);

});