from qgis.core import QgsRasterLayer, QgsVectorLayer, QgsProject
from qgis.analysis import QgsRasterCalculatorEntry, QgsRasterCalculator

# Define the paths to your raster and shapefile
raster_path = 'D:/PHD/výučba/Python/cvičenia/dmr100m.tif'
shapefile_path = 'D:/PHD/výučba/Python/cvičenia/vrstvy_python/ke-kraj.shp'

# Load the raster and shapefile layers
raster_layer = QgsRasterLayer(raster_path, 'Raster')
shapefile_layer = QgsVectorLayer(shapefile_path, 'Shapefile', 'ogr')

# Check if the layers are loaded successfully
if not raster_layer.isValid() or not shapefile_layer.isValid():
    print('Failed to load the layers.')
    exit()

# Set the extent of the raster layer to match the shapefile layer
QgsProject.instance().addMapLayer(raster_layer)
raster_layer.setExtent(shapefile_layer.extent())

# Create an output path for the clipped raster
output_path = 'D:/PHD/výučba/Python/cvičenia/dmr100m_clip.tif'

# Set up the raster calculator expression
entries = []
raster = QgsRasterCalculatorEntry()
raster.ref = 'raster@1'
raster.raster = raster_layer
raster.bandNumber = 1
entries.append(raster)

# Set up the raster calculator parameters
calc = QgsRasterCalculator('raster@1', output_path, 'GTiff', raster_layer.extent(), raster_layer.width(), raster_layer.height(), entries)
calc.processCalculation()

# Check if the clipping was successful
if calc.lastError() != QgsRasterCalculator.NoError:
    print('Failed to clip the raster.')
else:
    print('Raster clipped successfully. Output saved at:', output_path)