wienvonoben.js

const httpclient = require('ringo/httpclient');
const files = require('ringo/utils/files');
const fs = require('fs');
const {command} = require('ringo/subprocess');
const {toot} = require('mastodon-api');

// wien
/*
const left=16.18;
const bottom=48.11;
const right=16.58;
const top=48.33;
*/

// narrow wien
const left = 16.2289;
const bottom = 48.1095;
const right = 16.499;
const top = 48.2596;

const zoom = 20;
const tileWidth = 4;

const sendBasemapToo = false;

const mastodonConfig = {
   accessToken: 'XXXXXXXXX',
   statusUrl: 'https://botsin.space/api/v1/statuses',
   mediaUrl: 'https://botsin.space/api/v1/media'
};

function long2tile(lon, zoom) {
   return (Math.floor((lon+180)/360*Math.pow(2,zoom)));
}
function lat2tile(lat, zoom)  {
   return (Math.floor((1-Math.log(Math.tan(lat*Math.PI/180) + 1/Math.cos(lat*Math.PI/180))/Math.PI)/2 *Math.pow(2,zoom)));
}
function tile2long(x, zoom) {
   return (x/Math.pow(2,zoom)*360-180);
}
function tile2lat(y, zoom) {
   var n= Math.PI-2*Math.PI*y/Math.pow(2,zoom);
   return (180/Math.PI*Math.atan(0.5*(Math.exp(n)-Math.exp(-n))));
}

function getRandom(min, max) {
   return Math.random() * (max - min) + min;
}

function convertCoordinates(tileCoords) {
   const lat = tile2lat(tileCoords[1], zoom);
   const lon = tile2long(tileCoords[0], zoom);
   const x = (lon * 20037508.34) / 180;
   let y = Math.log(Math.tan(((90 + lat) * Math.PI) / 360)) / (Math.PI / 180);
   y = (y * 20037508.34) / 180;
   return [x, y];
 }

function getTilesToCombine() {
   const lon = getRandom(left, right);
   const lat = getRandom(bottom, top);
   const xTile = long2tile(lon, zoom)
   const yTile = lat2tile(lat, zoom);
   let combineTiles = [];
   for (let y=0;y<tileWidth;y++) {
      for (let x=0;x<tileWidth;x++) {
         combineTiles.push([
            xTile+x, yTile+y
         ])
      }
   }
   return combineTiles;
}

function getTileImages(combineTiles, mapType, imageType) {
   return combineTiles.map(function(tileCoords) {
      const tileUrl = `https://maps.wien.gv.at/basemap/${mapType}/normal/google3857/${zoom}/${tileCoords[1]}/${tileCoords[0]}.${imageType}`;
      console.log('retrieving', tileUrl)
      const exchange = httpclient.request({
         method: 'GET',
         url: tileUrl
      });
      if (exchange.status !== 200) {
         throw 'error retrieving tile ' + exchange.status;
      }
      const tempFile = files.createTempFile('satellite-bot', '.jpeg');
      fs.write(tempFile, exchange.contentBytes);
      return tempFile;
   });
}

function combineImages(imagePaths) {
   const combinedTempFile = files.createTempFile('combined-satellite-bot', '.jpeg');
   let args = [
      'gm', 'montage',
      '-geometry', '256x256',
      '-tile', tileWidth + 'x' + tileWidth,
   ].concat(imagePaths).concat([combinedTempFile]);
   command.apply(command, args);
   imagePaths.forEach(function(path) {
      fs.remove(path);
   })
   return combinedTempFile;
}

function main() {
   const combineTiles = getTilesToCombine();

   const satImagePaths = getTileImages(combineTiles, 'bmaporthofoto30cm', 'jpeg');
   const satCombinedImage = combineImages(satImagePaths);
   const mediaPaths = [satCombinedImage]
   if (sendBasemapToo) {
      const baseImagePaths = getTileImages(combineTiles, 'geolandbasemap', 'png');
      const baseCombinedImage = combineImages(baseImagePaths);
      mediaPaths.push(baseCombinedImage);
   }
   const centerIdx = tileWidth * (tileWidth/2) + (tileWidth/2);
   const centerTile = JSON.parse(JSON.stringify(combineTiles[centerIdx]));
   const centerTileCoords = JSON.stringify(convertCoordinates(centerTile));
   const url = `https://basemap.at/bmapp/#{%22center%22:${centerTileCoords},%22zoom%22:${zoom},%22rotation%22:0,%22layers%22:%221000000000%22}`;
   const satToot = toot(mastodonConfig, url, mediaPaths);
   mediaPaths.forEach(function(path) {
      fs.remove(path);
   });
   console.log('sat toot result', JSON.stringify(satToot));
}

main();