const {createWorker, createScheduler} = require('tesseract.js');
const fs = require('fs');

const scheduler = createScheduler();
const nWorkers = 4;

async function initialize() {
    for (let i = 0; i < nWorkers; i++) {
        let worker = createWorker({
            cachePath: 'langs',
            langPath: 'langs',
            logger: m => console.log(m)
        });
        await worker.load();
        await worker.loadLanguage('dan-fast');
        await worker.initialize('dan-fast');
        scheduler.addWorker(worker);
    }
    console.log('OCR initialized');
}

async function recognize(imagePath) {
    const filePath = imagePath.split('/').slice(-1).pop();
    const result = await scheduler.addJob('recognize', imagePath);
    const {data} = await scheduler.addJob('getPDF', filePath);
    fs.writeFileSync(`images/ocr-${filePath.replace('.png', '.pdf')}`, Buffer.from(data));
    return result.data.text
}

initialize()
    .then(() => {
        const promises = [];
        for (let i = 0; i < 3; i++) {
            const promise = recognize(`images/page-${i+1}.png`)
            promises.push(promise);
        }

        return Promise.all(promises)
    })
    .then((results) => {
        results.forEach((res) => {
            console.log('-----------');
            console.log(res);
        })
    })
    .then(() => {
        return scheduler.terminate();
    });