const ee = require('@google/earthengine')



const ndvi = (inputs, callback) => {
    let ndvi
    let vis
    const palette = ['FFFFFF', 'CE7E45', 'DF923D', 'F1B555', 'FCD163', '99B718',
        '74A901', '66A000', '529400', '3E8601', '207401', '056201',
        '004C00', '023B01', '012E01', '011D01', '011301']

    if (inputs.satellite == "SENTINEL") {
        // Map the function over one year of data and take the median.
        // Load Sentinel-2 TOA reflectance data.
        let collection = ee.ImageCollection("COPERNICUS/S2")
            .filterDate(inputs.date[0], inputs.date[1])
            // Pre-filter to get less cloudy granules.
            .filter(ee.Filter.lt('CLOUDY_PIXEL_PERCENTAGE', 20))
            //.map(maskS2clouds)
            .filterBounds(inputs.reg)

        let composite = collection.median()

        ndvi = composite.normalizedDifference(['B8', 'B4'])
        vis = { min: 0, max: 1, palette: palette }

///////////////////////////////CHART_TEST/////////////////////////////////////////////////////

  var geometry = ee.Geometry.Polygon(
        [[[-7.780510647532537, 33.12380141439545],
          [-7.780510647532537, 33.06210458015715],
          [-7.7106444671126155, 33.06210458015715],
          [-7.7106444671126155, 33.12380141439545]]], null, false);

// var mask_agricole = ee.FeatureCollection("users/mahyouh/mask_agricole");


async function to_fr(n,str,str2){

    var ni = n.reduce(ee.Reducer.mean()).reduceRegion({reducer:'mean',geometry: geometry,scale:10,maxPixels: 1e7}).getNumber(str2)
    ni.evaluate(async function(value) {

       console.log(await value)
       fs.appendFile("log_chart.txt",str+","+ await value+",\n", function(err) {
        if(err) {
            return console.log(err);
        }

    });

    });

    }

function to_nd(n){

    var ni = n.reduce(ee.Reducer.mean()).reduceRegion({reducer:'mean',geometry: geometry,scale:10,maxPixels: 1e7}).getNumber("NDVI_median_mean");

    return ni;

}


var years = ee.List.sequence(2003, 2019);
var months = ee.List.sequence(1, 12);

////////////////////////////////////////////////



 ////////// Long term average can be generated directly from the pre-calculated NDVI


var col = ee.ImageCollection("MODIS/006/MYD13Q1")
.filterBounds(geometry);

// select NDVI
var nd = col.select("NDVI");

// scaling factor
var multiply = function(image){
  // multply image
  var img = image.multiply(0.0001);
  return img.set('system:time_start',image.get('system:time_start')) ;
};

// use map function to apply function to all maps
nd = nd.map(multiply);

var monthlymedianNDVI =  ee.ImageCollection.fromImages(
  years.map(function (y) {
    return months.map(function(m) {
    return nd.filter(ee.Filter.calendarRange(y, y, 'year')).filter(ee.Filter.calendarRange(m, m, 'month'))
    .median().set('year', y).set('month', m).set('system:time_start', ee.Date.fromYMD(y, m, 1));
    });
  }).flatten()
);

 /////////////////////////////////////////////////////Median///////////////////////////////////////////////////////////////////
var months1 = ee.List.sequence(9, 12);

var medianMonthlyNDVI =  ee.ImageCollection.fromImages(
  months1.map(function (m) {
    var w = monthlymedianNDVI.filter(ee.Filter.eq('month', m)).reduce(ee.Reducer.median());
    return w.set('month', m)
    .set('system:time_start',ee.Date.fromYMD(2019, m, 1));
    }).flatten()
    );



 var months2 = ee.List.sequence(1, 8);

 var medianMonthlyNDVI1 =  ee.ImageCollection.fromImages(
  months2.map(function (m) {
    var w = monthlymedianNDVI.filter(ee.Filter.eq('month', m)).reduce(ee.Reducer.median());
    return w.set('month', m)
    .set('system:time_start',ee.Date.fromYMD(2020, m, 1));
    }).flatten()
    );


  var Med_sep = medianMonthlyNDVI.filter(ee.Filter.eq('month', 9));
  var Med_Oct = medianMonthlyNDVI.filter(ee.Filter.eq('month', 10));
 var Med_Nov = medianMonthlyNDVI.filter(ee.Filter.eq('month', 11));
var Med_Dec = medianMonthlyNDVI.filter(ee.Filter.eq('month', 12));
 var Med_jan = medianMonthlyNDVI1.filter(ee.Filter.eq('month', 1));
var Med_Fev = medianMonthlyNDVI1.filter(ee.Filter.eq('month', 2));
var Med_Mars = medianMonthlyNDVI1.filter(ee.Filter.eq('month', 3));
 var Med_Avr = medianMonthlyNDVI1.filter(ee.Filter.eq('month', 4));
var Med_Mai = medianMonthlyNDVI1.filter(ee.Filter.eq('month', 5));
var Med_Jun = medianMonthlyNDVI1.filter(ee.Filter.eq('month', 6));
 var Med_jui = medianMonthlyNDVI1.filter(ee.Filter.eq('month', 7));
var Med_Aout = medianMonthlyNDVI1.filter(ee.Filter.eq('month', 8));

var arr = [];

var n_jan = to_nd(Med_jan);

n_jan.evaluate(function(value){
    arr.push(value);

    var n_fev = to_nd(Med_Fev);
    n_fev.evaluate(function(value){
        arr.push(value);

    var n_mars = to_nd(Med_Mars);
    n_mars.evaluate(function(value){

        arr.push(value);
    var n_avril = to_nd(Med_Avr);
    n_avril.evaluate(function(value){

        arr.push(value)

    var n_mai = to_nd(Med_Mai);
    n_mai.evaluate(function(value){

        arr.push(value)

    var n_jun = to_nd(Med_Jun);
    n_jun.evaluate(function(value){

        arr.push(value)

    var n_jui = to_nd(Med_jui);
    n_jui.evaluate(function(value){

        arr.push(value);

        var n_aout = to_nd(Med_Aout);

        n_aout.evaluate(function(value){

            arr.push(value);
            var n_sep = to_nd(Med_sep);
            n_sep.evaluate(function(value){

                arr.push(value);

            var n_oct = to_nd(Med_Oct);
            n_oct.evaluate(function(value){

                arr.push(value);

                var n_nov = to_nd(Med_Nov);

                n_nov.evaluate(function(value){

                    arr.push(value);
                var n_dec = to_nd(Med_Dec);
                n_dec.evaluate(function(value){

                    arr.push(value);

                    console.log(arr)


                               });
                             });
                            });
                           });
                          });
                        });
                       });
                      });
                    });
                   });
                  });
                });