Add Unify raster nodata utility processing algorithm

eis_qgis_plugin/processing/algorithms/utilities/unify_raster_nodata.py

@@ -0,0 +1,54 @@
+from qgis.core import (
+    QgsProcessing,
+    QgsProcessingParameterFolderDestination,
+    QgsProcessingParameterMultipleLayers,
+    QgsProcessingParameterNumber,
+)
+
+from eis_qgis_plugin.processing.eis_processing_algorithm import EISProcessingAlgorithm
+
+
+class EISUnifyRasterNodata(EISProcessingAlgorithm):
+    def __init__(self) -> None:
+        super().__init__()
+
+        self._name = "unify_raster_nodata"
+        self._display_name = "Unify raster nodata"
+        self._group = "Utilities"
+        self._group_id = "utilities"
+        self._short_help_string = """
+            Unifies nodata for the input rasters.
+
+            Sets nodata in raster metadata to the specified value and replaces all found old nodata \
+            pixels with new nodata pixels for all rasters. 
+
+            Old nodata values are read from raster metadata. If some raster metadata are incorrect, \
+            fix them first with "Set raster nodata" or "Convert raster nodata" tools.
+        """
+
+    def initAlgorithm(self, config=None):
+        self.alg_parameters = ["input_rasters", "new_nodata", "output_dir"]
+
+        input_raster_param = QgsProcessingParameterMultipleLayers(
+            name=self.alg_parameters[0],
+            description="Input rasters",
+            layerType=QgsProcessing.TypeRaster,
+        )
+        input_raster_param.setHelp("Input rasters with nodata to be unified.")
+        self.addParameter(input_raster_param)
+
+        new_nodata_param = QgsProcessingParameterNumber(
+            name=self.alg_parameters[1],
+            description="New nodata",
+            defaultValue=-9999,
+            type=QgsProcessingParameterNumber.Double,
+        )
+        new_nodata_param.setHelp("New nodata value used for the rasters.")
+        self.addParameter(new_nodata_param)
+
+        output_folder_param = QgsProcessingParameterFolderDestination(
+            name=self.alg_parameters[2],
+            description="Output raster"
+        )
+        output_folder_param.setHelp("Output folder where the unified rasters will be saved.")
+        self.addParameter(output_folder_param)