pages/sol.py

import solara 
import geopandas as gpd
import pandas as pd
import solara.lab 
import leafmap.foliumap as leafmap
import os
import tempfile
import io
import datetime as dt

import pystac_client
import planetary_computer
import stackstac
import xrspatial
import rioxarray
import xarray
import numpy as np


##Function to Read ROI
def roi_reader():

    roi_path, set_roi_path = solara.use_state(None)
    roi_error, set_roi_error = solara.use_state(None)

    def on_file(file):

        try: 
            name = file['name']
            suffix = os.path.splitext(name)[1].lower()

            tmp = tempfile.NamedTemporaryFile(delete = False, suffix = suffix)
            tmp.write(file['data'])
            tmp.close()

            set_roi_path(tmp.name)

        except Exception as e:
            set_roi_error(str(e))
            set_roi_path(None)

    #Layout for FileDrop and Date Input
    with solara.Columns(widths = [0.5, 2]):

        solara.FileDrop(
            label = 'Drop Your KML Here!',
            lazy = False,
            on_file = on_file
        )

        with solara.Card(
            title = 'Input Date Range',
            subtitle = 'Please Select Pre Date (Before Deforestation) and Post Date (After Deforestation)- Assumed to be',
            style = {
                'background': "#01144d"
            }
        ):
            with solara.Column(style = {'background': '#ffffff00'}):
            
                with solara.Columns():

                    date_pre = solara.use_reactive(dt.date.today())
                    date_post = solara.use_reactive(dt.date.today())

                    preDate = solara.lab.InputDate(
                        value = date_pre,
                        label = 'Select Pre Date',
                        date_format = "%Y-%m-%d"
                    )

                    postDate = solara.lab.InputDate(
                        value = date_post,
                        label = 'Select Post Date',
                        date_format = "%Y-%m-%d"
                    )
                
                solara.Text(f'selected Date Range is {str(date_pre.value)} to {str(date_post.value)}')

    #Displaying ROI as geoDataFrame and Map
    if roi_path:
        try: 
            roi = gpd.read_file(roi_path)

        except Exception as e:
            solara.Markdown(f'Faied to read fle: {e}')
        
        else:
            solara.Markdown('Uploaded KML Attributes')
            solara.display(roi)

        #Sentinel Extractor

        roi_reprojected = roi.to_crs('EPSG:32755')

        def Sentinel_Extractor(startDate: str, endDate: str, CloudCover: int | float):

            datetime = startDate + '/' + endDate

            catalog = pystac_client.Client.open(
                "https://planetarycomputer.microsoft.com/api/stac/v1",
                modifier = planetary_computer.sign_inplace
            )

            search = catalog.search(
                collections = ['sentinel-2-l2a'],
                intersects = roi.geometry.union_all().__geo_interface__,
                datetime = datetime,
                query = {'eo:cloud_cover': {'lt': CloudCover}}
            )

            items = search.get_all_items()


            stacked = stackstac.stack(items = items,
                                      assets = ['B02', 'B03', 'B04', 'B08', 'B12'],
                                      epsg = 32755,
                                      chunksize = 1024)
            
            stacked_median = stacked.median(dim = 'time', keep_attrs = True)
            stacked_clipped = stacked_median.rio.clip(roi_reprojected.geometry, roi_reprojected.crs)
            stacked_scaled = stacked_clipped * 0.0001

            return stacked_scaled
        
        preImage = Sentinel_Extractor(
            startDate = str(date_pre.value),
            endDate = str(date_pre.value + dt.timedelta(days = 10)),
            CloudCover = 20
        )

        temp_msi = tempfile.NamedTemporaryFile(delete = False, suffix = '.tif')
        temp_save = preImage.rio.write_crs('EPSG:4326')
        temp_save.rio.to_raster(temp_msi.name)


        m = leafmap.Map()
        m.add_basemap('SATELLITE')
        m.add_gdf(roi, zoom_to_layer = True)
        m.add_raster(temp_msi.name, indexes = [3, 2, 1], nodata = np.nan)

        solara.display(m)

def side_bar():
    with solara.Sidebar():

        with solara.Column(align= 'center', style = {'background': '#ffffff00'}, ):
            solara.Markdown('##Steps for User')
        with solara.Column(margin = 2, align = 'stretch', style = {'background': 'red', 
                                                                 'font-size': '14px'}):
            solara.Text('1. Upload Your Region of Interest as KML')

        with solara.Column(margin = 2, align = 'stretch', style = {'background': 'blue', 
                                                                 'font-size': '14px'}):
            solara.Text('2. Select the Date Range')

        with solara.Column(margin = 2, align = 'stretch', style = {'background': 'green', 
                                                                 'font-size': '14px'}):
            solara.Text('2. Visualise the Results Interactively')

def app_bar():
    with solara.AppBar(): 
        with solara.Row():

            with solara.AppBarTitle():
                with solara.Row(style = {
                    'background': '#ffffff00'
                                            },
                                                margin = 0, justify = 'space-evenly', ):
                    
                    logo = solara.Image('Logo black.png', width = '15%')
                    theme_toggler = solara.lab.ThemeToggle()

def main_page():

    title = solara.Markdown('#One End tool for Deforestation Monitoring', 
                    style = {
                        'font-family': 'Century Gothic',
                        'size': '12',
                        'color': '#fee391'
                    })
    subtitle = solara.Text('This Web Application Helps You Monitor the Forest Loss Using NDFI - Spectral Mixture Analysis (N-FINDR)', 
                    style = {
                        'font-family': 'Century Gothic'
                    })
    
    roi_layout = roi_reader()




@solara.component
def Page():
    app_header = app_bar()
    sideBar = side_bar()
    heading = main_page()


Page()