'use strict';

/* global Plotly:true */

var fs = require('fs');
var gui = require('nw.gui');

var MOCK = '../../plotly/plotly.js/test/image/mocks/gl2d_marker_line_width.json';
var FORMATS = ['svg', 'jpeg', 'png'];
var BASE_FILENAME = 'out';

FORMATS.forEach(generateOne);

function generateOne(format) {
  var imageOptions = { format: format, imageDataOnly: true };
  var outPath = BASE_FILENAME + '.' + format;
  var div = document.createElement('div');

  fs.readFile(MOCK, 'utf-8', function(err, raw) {
    if(err) throw err;

    var fig = JSON.parse(raw);

    Plotly.plot(div, fig)
      .then(toImage)
      .then(decodeImage)
      .then(saveToFile)
      .then(quit);
  });

  function toImage(gd) {
    return Plotly.toImage(gd, imageOptions);
  }

  function decodeImage(img) {
    return new Promise(function(resolve) {

      switch(imageOptions.format) {
        case 'png':
        case 'jpeg':
          img = new Buffer(img, 'base64');
          break;
        case 'svg':
          break;
      }

      resolve(img);
    });
  }

  function saveToFile(img) {
    return new Promise(function(resolve, reject) {
      fs.writeFile(outPath, img, function(err) {
        if(err) reject(err);
        resolve(outPath);
      });
    });
  }

  function quit() {
    log('generated ' + outPath)
    gui.App.quit();
  }
}

function log(msg) {
  process.stdout.write(msg + '\n');
}