//Access in the Google Earth Engine code editor: https://code.earthengine.google.com/?accept_repo=users/tatiana/SeteSetembro

////////////////////////////////////////////////////////
//                                                    //
//         SCRIPT4: VEGETATION LOSS AND GAIN MAP      //
//                                                    //
////////////////////////////////////////////////////////


////////////////////////////////////////////////////////
//ENTRER LES DATES ET DATATAKE DES DEUX IMAGES A COMPARER

//Image 1
var datefrom1 = '2019-09-10'   //ENTER DATE
var dateto1 = '2019-09-11'     //ENTER DATE (must be datefrom + at least 1)
var datatake1 = '20190910'     //ENTER DATATAKE ('YYYYMMDD')

//Image 2
var datefrom2 = '2019-09-20'   //ENTER DATE
var dateto2 = '2019-09-21'     //ENTER DATE (must be datefrom + at least 1)
var datatake2 = '20190920'     //ENTER DATATAKE ('YYYYMMDD')

//Export name
var nameExp = datatake2;

////////////////////////////////////////////////////////
//PARAMETRES DU SITE
//Géométrie du site
var studySite = ee.Geometry.Polygon(
  [[[-61.4417, -10.7464],
    [-61.4383, -11.2584],
    [-60.8973, -11.2551],
    [-60.9098, -10.7198]]]);

//Polygone de la terre indigène Sete de Setembro
//Source: "WCMC/WDPA/current/polygons").filterMetadata('NAME','equals','Sete de Setembro')
var protectedArea = ee.FeatureCollection([ee.Geometry.Polygon(
  [[[-61.430890367207255,-10.751891444900613],
[-61.42519163574619,-11.11447884042015], 
[-61.37005491417673,-11.114298205538441],
[-61.31491808398053,-11.114117608447993],
[-61.31458365364846,-11.249759040437475],
[-61.23209698577483,-11.249121383106058],
[-61.149610266132704,-11.248483719229005], 
[-61.09324164199908,-11.175238503746515],
[-61.036873050995155,-11.101993360397458],
[-60.98050448006274,-11.028748124678014],
[-60.92413582759241,-10.955502938986513],
[-60.92913000110267,-10.738589998072223],
[-60.99185011285132,-10.740252698436697],
[-61.05457014507297,-10.741915331211235],
[-61.11729013718773,-10.743578015404607],
[-61.180010217902435,-10.745240724477434],
[-61.24273024957612,-10.746903404731825],
[-61.30545027262106,-10.748566097570336],
[-61.368170327808194,-10.750228766894775],
[-61.430890367207255,-10.751891444900613]]])]);

// Centrer sur la zone d'exportation
Map.centerObject(studySite,10);


////////////////////////////////////////////////////////
//SELECTION ET IMPORTATION DES IMAGES SENTINEL-2

//First image
var img1 = ee.ImageCollection('COPERNICUS/S2')
  .filterBounds(studySite)
  .filterDate(datefrom1,dateto1);

//Caractéristiques de l'image
var meanClouds1 = img1.aggregate_mean('CLOUDY_PIXEL_PERCENTAGE').getInfo();

//Cliper sur la zone d'exportation pour chaque image de la collection  
var img1 = img1.map(function(image){return image.clip(studySite)})
// Créer une image unique à partir de la sélection
  .mean();


//Second image
var img2 = ee.ImageCollection('COPERNICUS/S2')
  .filterBounds(studySite)
  .filterDate(datefrom2,dateto2);

//Caractéristiques de l'image
var meanClouds2 = img2.aggregate_mean('CLOUDY_PIXEL_PERCENTAGE').getInfo();

//Cliper sur la zone d'exportation pour chaque image de la collection  
var img2 = img2.map(function(image){return image.clip(studySite)})
// Créer une image unique à partir de la sélection
  .mean();

print('First image:',datatake1);
print('Mean cloud cover percentage for the first image: ',meanClouds1);
print('Second image:',datatake2);
print('Mean cloud cover percentage for the second image: ',meanClouds2);

//Affichage de l'image
//Paramètres d'affichage pour les image en vraies couleurs
var B432 = {              
  bands: ['B4','B3','B2'],
  min: 200,
  max: 6200,
  gamma: 1.8
};

////////////////////////////////////////////////////////
//SELECTION ET IMPORTATION DES IMAGES ISSUES DE LA CLASSIFICATION
//Automatic variables
var ClassifName1 = datatake1+'_compared';
var ClassifName2 = datatake2+'_classifiedStorage';
var Classif1 = ee.Image('users/tatiana/'+ClassifName1);
var Classif2 = ee.Image('users/tatiana/'+ClassifName2);

//Paramètres d'affichage storage
var visStorage = {              
  bands: ['all'],
  palette: ['ffffff','89d4a4','deb37d'],
  min: 0,
  max: 2,
};

//Paramètres d'affichage pour la comparaison
var visClassif = {              
  bands: ['all'],
  palette: ['ffffff','89d4a4','deb37d','37934f','ff8d3d','ff0000'],
  min: 0,
  max: 5,
};

//Afficher les images
Map.addLayer(img1, B432, 'Image 1',true);
Map.addLayer(Classif1, visClassif, 'Image1_compared',false);
Map.addLayer(img2, B432, 'Image 2',true);
Map.addLayer(Classif2, visStorage, 'Image2_classifiedStorage',false);


////////////////////////////////////////////////////////
//COMPARAISON DES IMAGES

var classifx10 = Classif1.multiply(10);
var comparison = classifx10.subtract(Classif2);

var addBMVegetation = function(image) {
  var img = image.select('all');
  var values = img.expression(
    'V1 + V2 + V3 + V4', {
      'V1': img.gte(-1).and(img.lt(0)),
      'V2': img.gte(9).and(img.lt(11)),
      'V3': img.gte(29).and(img.lt(30)),
      'V4': img.gte(39).and(img.lt(40)),
}).eq(1).rename('comparisonVegetation');
  return image.addBands(values);
};

var addBMBare = function(image) {
  var img = image.select('all');
  var values = img.expression(
    'V1 + V2 + V3 + V4', {
      'V1': img.gte(-2).and(img.lt(-1)),
      'V2': img.gte(20).and(img.lt(21)),
      'V3': img.gte(18).and(img.lt(19)),
      'V4': img.gte(28).and(img.lt(29)),
}).eq(1).multiply(2).rename('comparisonBare');
  return image.addBands(values);
};

var addBMNewVegetation = function(image) {
  var img = image.select('all');
  var values = img.expression(
    'V1 + V2 + V3', {
      'V1': img.gte(19).and(img.lt(20)),
      'V2': img.gte(30).and(img.lt(31)),
      'V3': img.gte(49).and(img.lt(50)),
}).eq(1).multiply(3).rename('comparisonNewVegetation');
  return image.addBands(values);
};

var addBMNewBare = function(image) {
  var img = image.select('all');
  var values = img.expression(
    'V1 + V2', {
      'V1': img.gte(8).and(img.lt(9)),
      'V2': img.gte(40).and(img.lt(41)),
}).eq(1).multiply(4).rename('comparisonNewBare');
  return image.addBands(values);
};

var addBMDeforestation = function(image) {
  var img = image.select('all');
  var values = img.expression(
    'V1 + V2 + V3', {
      'V1': img.gte(38).and(img.lt(39)),
      'V2': img.gte(50).and(img.lt(51)),
      'V3': img.gte(48).and(img.lt(49)),
}).eq(1).multiply(5).rename('comparisonDeforestation');
  return image.addBands(values);
};

var comparison = addBMVegetation(comparison);
var comparison = addBMBare(comparison);
var comparison = addBMNewVegetation(comparison);
var comparison = addBMNewBare(comparison);
var comparison = addBMDeforestation(comparison);

var comparisonVG = comparison.select('comparisonVegetation');
var comparisonB = comparison.select('comparisonBare');
var comparisonNVG = comparison.select('comparisonNewVegetation');
var comparisonNB = comparison.select('comparisonNewBare');
var comparisonDF = comparison.select('comparisonDeforestation');

var comparisonAll = comparisonVG.add(comparisonB).add(comparisonNVG).add(comparisonNB).add(comparisonDF).rename('all').byte();

//Masking
var mask = comparisonAll.gte(0).and(comparisonAll.lt(2)).not();
var comparisonAllMasked = comparisonAll.updateMask(mask);

Map.addLayer(comparisonAll, visClassif, 'Export image',false);
Map.addLayer(comparisonAllMasked, visClassif, 'New classification',true);


///////////////////////////////////////////////////
//EXPORT IMAGES

//Current date and time
var datetime = new Date(); 
var datetime =  datetime.getFullYear() + ""
                + ("0" + (datetime.getMonth() + 1)).slice(-2) + ""
                + ("0" + datetime.getDate()).slice(-2) + "_"  
                + ("0" + datetime.getHours()).slice(-2) + ""
                + ("0" + datetime.getMinutes()).slice(-2);
                
//Export
Export.image.toDrive({
  image: comparisonAll,
  description: nameExp+'_comparedW'+datatake1+'_'+datetime,
  folder: 'GEEexportCompared',
  scale: 30,
  region: studySite,
  fileFormat: 'GeoTIFF'});

  
Export.image.toAsset({
  image: comparisonAll,
  description: nameExp+'_compared',
  scale: 30,
  region: studySite});