const { Builder, Browser, By, until } = require('selenium-webdriver');
const { Options } = require('selenium-webdriver/chrome');
const path = require('path');
const fs = require('fs');

// Taken from: <https://stackoverflow.com/a/70040209>; feel free to make a better implementation, if you want to!
async function checkFileExist(path, timeout = 2000)
{
    let totalTime = 0; 
    let checkTime = timeout / 10;

    return await new Promise((resolve, reject) => {
        const timer = setInterval(function() {
            totalTime += checkTime;
            let fileExists = fs.existsSync(path);
            if (fileExists || totalTime >= timeout) {
                clearInterval(timer);
                resolve(fileExists);
            }
        }, checkTime);
    });
}

(async function exportElixFormsModule() {
    // Override with environment variables, if they exist
    const username = process.env.ELIXFORMS_USERNAME || null;
    const password = process.env.ELIXFORMS_PASSWORD || null;
    const moduleName = process.env.ELIXFORMS_MODULE_TAG || null;
    // Validate that all required environment variables are set
    if (!username || !password || !moduleName) {
        console.error('Please set ELIXFORMS_USERNAME, ELIXFORMS_PASSWORD, and ELIXFORMS_MODULE_TAG using one of:\n- an .env file in the project root\n- specify an .env file with `npx env-cmd --file <.env_path> -- <command>`\n- pass them as environment variables');
        process.exit(1);
    }

    const downloadDir = path.resolve(__dirname, 'downloads');

    // Configure Chrome options
    let options = new Options();
    options.setUserPreferences({
        'download.default_directory': downloadDir, // Set download folder
        'download.prompt_for_download': false,     // No prompt
        'download.directory_upgrade': true,
        'safebrowsing.enabled': true               // Avoid blocking
    });
    options.addArguments("--headless");

    let driver = await new Builder()
        .forBrowser(Browser.CHROME)
        .setChromeOptions(options)
        .build();

    const originalWindow = await driver.getWindowHandle();

    // Implicit timeouts
    await driver.manage().setTimeouts({ implicit: 3000 });

    console.log(`Starting export for module: ${moduleName}`);

    // Cleanup download directory before starting
    if (!fs.existsSync(downloadDir)) {
        console.log(`Creating download directory: ${downloadDir}`);
        fs.mkdirSync(downloadDir);
    } else {
        console.log(`Cleaning up download directory: ${downloadDir}`);
        fs.readdirSync(downloadDir).forEach(file => {
            fs.unlinkSync(path.join(downloadDir, file));
        });
    }

    console.log(`Navigating to login page...`);

    await driver.get('https://console-unipr.elixforms.it/backoffice/');

    console.log(`Logging in with username: ${username}`);

    await driver
        .findElement(By.id('username'))
        .sendKeys(username); // 'Automation_User'

    await driver
        .findElement(By.id('password'))
        .sendKeys(password); // 'n_HH9shL#VPeiiT^%;:t5/,jY'

    await driver
        .findElement(By.name('INSERT_BTN00000'))
        .click();

    console.log(`Waiting for "Benvenuto" (quit if not found, likely login failed)`);

    await driver
        .wait(until.elementLocated(By.id('title_0')), 10000)
        .catch(() => {
            console.error('Login failed or "Benvenuto" not found');
            driver.quit();
            process.exit(1);
        });

    console.log(`Navigating to module export page...`);

    await driver
        .navigate()
        .to('https://console-unipr.elixforms.it/rwe2/admin_console.jsp');

    let moduleSearchTextbox = await driver.findElement(By.id('TITLE__TAG__CATTAG'));
    await moduleSearchTextbox.clear();
    await moduleSearchTextbox.sendKeys(moduleName);
    await moduleSearchTextbox.sendKeys('\n');

    console.log(`Waiting for search results...`);

    // Needed to wait for the search results to load before clicking the export button
    await driver.sleep(2000);

    console.log(`Clicking export button for module: ${moduleName}`);

    await driver
        .findElement(By.xpath('//div[contains(@class, "item")][1]'))
        .findElement(By.xpath('.//input[starts-with(@name, "INSERT_BTN_USER_")]'))
        .click()

    console.log(`Clicking "Esporta il modulo" link...`);

    await driver
        .findElement(By.linkText('Esporta il modulo'))
        .click();


    console.log(`Waiting for the new tab to finish loading content...`);

    await driver.wait(async () => (await driver.getAllWindowHandles()).length === 2, 5000);
    const windows = await driver.getAllWindowHandles();
    windows.forEach(async handle => {
        if (handle !== originalWindow) {
            await driver.switchTo().window(handle);
        }
    });

    let moduleProtocol = await driver.findElement(By.id('moduleProtocol'));
    if (!await moduleProtocol.isSelected()) {
        await moduleProtocol.click();
    }

    let moduleId = await driver.findElement(By.id('moduleId')).getAttribute('value');
    let moduleFilename ="elxforms_" + moduleId + ".elx";

    await driver
        .findElement(By.id('download'))
        .click();

    let downloadLink = await driver.wait(until.elementLocated(By.linkText('Scarica il modulo')));
    let href = await downloadLink.getAttribute('href');

    console.log(`Found download link: ${href}; clicking to download the module as ${moduleFilename}...`);

    await downloadLink.click();

    console.log(`Waiting for the file to be downloaded to ${downloadDir}...`);

    let downloadedFilePath = path.join(downloadDir, moduleFilename);
    await checkFileExist(downloadedFilePath, 5000);

    console.log(`File downloaded!`);

    await driver.quit();

    return downloadedFilePath;
})();