import Map from '../src/ol/Map.js';
import View from '../src/ol/View.js';
import TileLayer from '../src/ol/layer/Tile.js';
import WebGLPointsLayer from '../src/ol/layer/WebGLPoints.js';
import GeoJSON from '../src/ol/format/GeoJSON.js';
import Vector from '../src/ol/source/Vector.js';
import OSM from '../src/ol/source/OSM.js';

const vectorSource = new Vector({
  url: 'data/geojson/world-cities.geojson',
  format: new GeoJSON()
});

const predefinedStyles = {
  'icons': {
    symbol: {
      symbolType: 'image',
      src: 'data/icon.png',
      size: [18, 28],
      color: 'lightyellow',
      rotateWithView: false,
      offset: [0, 9]
    }
  },
  'triangles': {
    symbol: {
      symbolType: 'triangle',
      size: 18,
      color: [
        ['stretch', ['get', 'population'], 20000, 300000, 0.1, 1.0],
        ['stretch', ['get', 'population'], 20000, 300000, 0.6, 0.3],
        0.6,
        1.0
      ],
      rotateWithView: true
    }
  },
  'circles': {
    symbol: {
      symbolType: 'circle',
      size: ['stretch', ['get', 'population'], 40000, 2000000, 8, 28],
      color: '#006688',
      rotateWithView: false,
      offset: [0, 0],
      opacity: ['stretch', ['get', 'population'], 40000, 2000000, 0.6, 0.92]
    }
  }
};
let literalStyle = predefinedStyles['circles'];
let pointsLayer;

const map = new Map({
  layers: [
    new TileLayer({
      source: new OSM()
    })
  ],
  target: document.getElementById('map'),
  view: new View({
    center: [0, 0],
    zoom: 2
  })
});

const editor = document.getElementById('style-editor');
editor.value = JSON.stringify(literalStyle, null, 2);

function refreshLayer() {
  if (pointsLayer) {
    map.removeLayer(pointsLayer);
  }
  pointsLayer = new WebGLPointsLayer({
    source: vectorSource,
    style: literalStyle
  });
  map.addLayer(pointsLayer);
}

function setStyleStatus(valid) {
  document.getElementById('style-valid').style.display = valid ? 'initial' : 'none';
  document.getElementById('style-invalid').style.display = !valid ? 'initial' : 'none';
}

editor.addEventListener('input', function() {
  const textStyle = editor.value;
  if (JSON.stringify(JSON.parse(textStyle)) === JSON.stringify(literalStyle)) {
    return;
  }

  try {
    literalStyle = JSON.parse(textStyle);
    refreshLayer();
    setStyleStatus(true);
  } catch (e) {
    setStyleStatus(false);
  }
});
refreshLayer();

const select = document.getElementById('style-select');
select.addEventListener('change', function() {
  const style = select.value;
  literalStyle = predefinedStyles[style];
  editor.value = JSON.stringify(literalStyle, null, 2);
  refreshLayer();
});