#!/usr/bin/env node

// List videos in any YouTube playlist sorted in descending order of views.
// 
// Usage:
//   ytpsort.mjs https://www.youtube.com/playlist?list=listid
//   ytpsort.mjs listid

const ytBaseUrl = "https://www.youtube.com";

const args = process.argv.slice(2);

if (!args[0]) {
    console.error("Playlist URL or ID must be passed");
    process.exit(1);
}

let playlistId = null;

try {
    const url = new URL(args[0]);
    playlistId = url.searchParams.get("list");

    if (!playlistId) {
        console.error("Invalid playlist URL passed");
        process.exit(1);
    }
} catch {
    playlistId = args[0];
}

const body = await fetch("https://www.youtube.com/youtubei/v1/browse?prettyPrint=false", {
    method: "POST",
    headers: {
        "Origin": "https://www.youtube.com"
    },
    body: JSON.stringify({
        "context": {
            "client": {
                "remoteHost": "0.0.0.0",
                "clientName": "WEB",
                "clientVersion": "2.20240702.09.00",
                "originalUrl": `https://www.youtube.com/playlist?list=${playlistId}`,
                "mainAppWebInfo": {
                    "graftUrl": `/playlist?list=${playlistId}`,
                }
            }
        },
        "browseId": `VL${playlistId}`
    })
}).then(res => res.json())

let rawPlaylistItems = null;
try {
    rawPlaylistItems = body.contents.twoColumnBrowseResultsRenderer.tabs[0].tabRenderer.content.sectionListRenderer.contents[0].itemSectionRenderer.contents[0].playlistVideoListRenderer.contents;
} catch {
    console.error("Error accessing JSON response fields: YT response possibly changed?");
    process.exit(1);
}

const viewsRegex = /by .* ((?:\d+,?)+) views .*ago/;

function parseViews(text) {
    return Number.parseInt(text.match(viewsRegex)[1].replaceAll(",", ""));
}

const videos = rawPlaylistItems.map(root => {
    const item = root.playlistVideoRenderer;
    return {
        title: item.title.runs[0].text.slice(0, 70),
        url: `${ytBaseUrl}/watch?v=${item.videoId}`,
        views: parseViews(item.title.accessibility.accessibilityData.label),
    }
});

videos.sort((a, b) => b.views - a.views);

console.table(videos);