telegram-channel-dl.js

telegram-channel-dl.js

// download 


let counter = 0;
let prefix = "TamilFreakers";
const LAST_INDEX = 1210; // get the message Id of last message (right click on the latest post, "copy message link".. this should have latest message id")
let messages = Array(LAST_INDEX).fill(0).map((x, i) => `message${i + 1}`).reverse();
let textContents = [];
let htmlContents = [];


const sleep = (delay) => new Promise(res => setTimeout(res, delay));

let obj = {};
//messages = messages.slice(0, 370);
const start = async () => {
    await messages.reduce(async (memo, message) => {
        await memo;
        try {
            let id = `#${message}`;
            let el = document.querySelector(id);
            if (el) {
                const { content, rawContent } = getElementContent(el);
                if (!obj[id]) {
                    await sleep(500);
                    obj[message] = { content };
                    console.log(message);
                    await copyTextToArray(id);
                    //await downloadElementAsCanvas(id);
                    //await downloadElementAsTxt(id);
                    console.log(`processing ${id}`);
                } else {
                    console.log("ID Already present , ", id);
                }
            }
        } catch (err) {
            console.log("ERROR : ", err);
        }
    }, undefined);
    console.log("COMPLETED ")
}

const getElementContent = (el) => {
    const divEl = el.querySelectorAll('.message-date-group div');
    return {
        rawContent: divEl?.innerText,
        content: divEl?.innerText?.replaceAll("\n", " ")
    }
}


const downloadElementAsCanvas = async (id) => {
    let el = document.querySelector(id);
    if (el) {
        el.scrollIntoView();
        await sleep(2500);
        html2canvas(el.querySelector('.message-content-wrapper .message-content')).then(canvas => {
            var link = document.createElement('a');
            let filename = id.replace("#", '');
            link.download = `${prefix}-${filename}.png`;
            link.href = canvas.toDataURL()
            link.click();
        });
    }
}

const downloadElementAsTxt = async (id) => {
    let el = document.querySelector(id);
    if (el) {
        el.scrollIntoView();
    }
    let text = document.querySelector(id).innerText;
    var element = document.createElement('a');
    element.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(text));
    let filename = id.replace("#", '');
    element.setAttribute('download', `${prefix}-${filename}.txt`);

    element.style.display = 'none';
    document.body.appendChild(element);

    element.click();

    document.body.removeChild(element);
}

const copyTextToArray = async (id) => {
    const el = document.querySelector(id);
    let text = el.innerText;
    let html = el.innerHTML;
    if (el) {
        el.scrollIntoView();
        await sleep(500);
    }
    textContents.push(text);
    htmlContents.push(html);
    const num = parseInt(id.replace("#message", ""));
    if (num % 100 == 0) {
        console.log(textContents);
        await downloadTextAsFile(textContents, num, prefix, true);
        await downloadTextAsFile(htmlContents, num, prefix, false);
        textContents = [];
        htmlContents = [];
    }
    return true;
}

const downloadTextAsFile = async (text, num, prefix, isText) => {
    const isTextStr = isText ? "text": "html";
    var element = document.createElement('a');
    element.setAttribute('href', 'data:text/plain;charset=utf-8,' + encodeURIComponent(text));
    element.setAttribute('download', `${prefix}-${num}-${isTextStr}.txt`);
    element.style.display = 'none';
    document.body.appendChild(element);
    element.click();
    document.body.removeChild(element);
    await sleep(500);
    console.log(`Downloaded ${prefix}-${num}-${isTextStr}.txt`);
    return;
}

start();