update-wallpapers

#!/usr/bin/env node
const https = require("https");
const fs = require("fs");
const streamTransform = require("stream").Transform;
const path = require("path");

const filenameUrlOffset = 1;
const wallpaperDirArgPosition = 2;

const config = {
  wallpapersDir: ".config/wallpaper",
  wallpaperAPI: "https://www.reddit.com/r/earthporn/top/.json?limit=10&t=month",
};

const wallpapersDir = process.argv[wallpaperDirArgPosition] ?
  process.argv[wallpaperDirArgPosition] : path.join(process.env.HOME, config.wallpapersDir);

const getFilename = (url) => url.substring(url.lastIndexOf("/") + filenameUrlOffset );

const getImageUrls = (data) => JSON.parse(data).data.children.map(post => post.data.url);

function download(url) {
  https.request(url, function(response) {
    const data = new streamTransform();
    let writeError = null;

    response.on("data", function(chunk) {
      data.push(chunk);
    });

    data.pipe(fs.createWriteStream(
      path.join(wallpapersDir, getFilename(url))
    ).on("error", (err) => {
      writeError = err;
    }));

    response.on("end", function(err) {
      writeError ?
        console.log("Error downloading", url, "to", path.join(wallpapersDir, getFilename(url)), ":", writeError.message) :
        console.log("Downloaded", url, "to", path.join(wallpapersDir, getFilename(url)));
    });
  }).end().on("error", (err) => {
    console.log("Error: " + err.message);
  });
}

https.get(config.wallpaperAPI, (resp) => {
  let data = "";

  resp.on("data", (chunk) => {
    data += chunk;
  });

  resp.on("end", () => {
    getImageUrls(data).forEach(download);
  });

}).on("error", (err) => {
  console.log("Error: " + err.message);
});