import path from 'path';
import fs from 'fs';
import puppeteer from 'puppeteer';
import packageJson from '../package.json' with { type: 'json' };

const exampleName = process.argv[2];
const examplePath = path.resolve('test', 'examples');

const browser = await puppeteer.launch({headless: exampleName === 'all'});

const page = await browser.newPage();
// set viewport and double deviceScaleFactor to get a closer shot of the map
await page.setViewport({
    width: 600,
    height: 250,
    deviceScaleFactor: 2
});

async function createImage(exampleName) {
    // get the example contents
    const html = fs.readFileSync(path.resolve(examplePath, `${exampleName}.html`), 'utf-8');

    await page.setContent(html.replaceAll('../../dist', `https://unpkg.com/maplibre-gl@${packageJson.version}/dist`));

    // Wait for map to load, then wait two more seconds for images, etc. to load.
    try {
        await page.waitForFunction('map.loaded()');
        // Wait for 5 seconds on 3d model examples, since this takes longer to load.
        const waitTime = exampleName.includes('3d-model') ? 5000 : 1500;
        console.log(`waiting for ${waitTime} ms`);
        await new Promise(resolve => setTimeout(resolve, waitTime));
    } catch (err) {
        // map.loaded() does not evaluate to true within 3 seconds, it's probably an animated example.
        // In this case we take the screenshot immediately.
        console.log(`Timed out waiting for map load on ${exampleName}.`);
    }

    await page
        .screenshot({
            path: `./docs/assets/examples/${exampleName}.png`,
            type: 'png',
            clip: {
                x: 0,
                y: 0,
                width: 600,
                height: 250
            }
        })
        .then(() => console.log(`Created ./docs/assets/examples/${exampleName}.png`))
        .catch((err) => {
            console.log(err);
        });
}

if (exampleName === 'all') {
    const allFiles = fs.readdirSync(examplePath).filter(f => f.endsWith('html'));
    console.log(`Generating ${allFiles.length} images.`);
    for (const file of allFiles) {
        await createImage(file);
    }
} else if (exampleName) {
    await createImage(exampleName);
} else {
    throw new Error(
        '\n  Usage: npm run generate-images <file-name|all>\nExample: npm run generate-images 3d-buildings'
    );
}

await browser.close();