Add export function to REST API

docs/tut.restapi.rst

@@ -16,6 +16,8 @@ and is implemented in the class :class:`~epyt_flow.rest_api.server.RestApiServic
 +-----------+-------------------------------------------------------+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------+
 | DELETE    | /scenario/{scenario_id}                               | :class:`~epyt_flow.rest_api.scenario_handler.ScenarioRemoveHandler`                      | Deletes a scenario.                                                                                 |
 +-----------+-------------------------------------------------------+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------+
+| GET       | /scenario/{scenario_id}/export                        |  :class:`~epyt_flow.rest_api.scenario_handler.ScenarioExportHandler`                     | Exports a given scenario to an .inp and (optionally) .msx file.                                     |
++-----------+-------------------------------------------------------+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------+
 | GET       | /scenario/{scenario_id}/topology                      | :class:`~epyt_flow.rest_api.scenario_handler.ScenarioTopologyHandler`                    | Gets the topology of a given scenario.                                                              |
 +-----------+-------------------------------------------------------+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------+
 | GET       | /scenario/{scenario_id}/scenario_config               | :class:`~epyt_flow.rest_api.scenario_handler.ScenarioConfigHandler`                      | Gets the entire configuration/specification of a given scenario.                                    |

epyt_flow/rest_api/scenario_handler.py

@@ -2,10 +2,12 @@
 This module provides all handlers for requests concerning scenarios.
 """
 import warnings
+import os
 import falcon
 
 from .base_handler import BaseHandler
 from .res_manager import ResourceManager
+from ..utils import get_temp_folder, pack_zip_archive
 from .scada_data_handler import ScadaDataManager
 from ..simulation import ScenarioSimulator, Leakage, SensorConfig, SensorFault
 
@@ -69,6 +71,78 @@ def on_delete(self, _, resp: falcon.Response, scenario_id: str) -> None:
             resp.status = falcon.HTTP_INTERNAL_SERVER_ERROR
 
 
+class ScenarioExportHandler(ScenarioBaseHandler):
+    """
+    Class for handling GET requests for exporting a given scenario to EPANET files
+    -- i.e. .inp and (otpionally) .msx files.
+    """
+    def __create_temp_file_path(self, scenario_id: str, file_ext: str) -> None:
+        """
+        Returns a path to a temporary file for storing the scenario.
+
+        Parameters
+        ----------
+        scenario_id : `str`
+            UUID of the scenario.
+        file_ext : `str`
+            File extension.
+        """
+        return os.path.join(get_temp_folder(), f"{scenario_id}.{file_ext}")
+
+    def __send_temp_file(self, resp: falcon.Response, tmp_file: str,
+                         content_type: str = "application/octet-stream") -> None:
+        """
+        Sends a given file (`tmp_file`) to the the client.
+
+        Parameters
+        ----------
+        resp : `falcon.Response`
+            Response instance.
+        tmp_file : `str`
+            Path to the temporary file to be send.
+        """
+        resp.status = falcon.HTTP_200
+        resp.content_type = content_type
+        with open(tmp_file, 'rb') as f:
+            resp.text = f.read()
+
+    def on_get(self, _, resp: falcon.Response, scenario_id: str) -> None:
+        """
+        Exports a given scenario to an .inp and (optionally) .msx file.
+
+        Parameters
+        ----------
+        resp : `falcon.Response`
+            Response instance.
+        scenario_id : `str`
+            UUID of the scenario.
+        """
+        try:
+            if self.scenario_mgr.validate_uuid(scenario_id) is False:
+                self.send_invalid_resource_id_error(resp)
+                return
+
+            my_scenario = self.scenario_mgr.get(scenario_id)
+
+            f_inp_out = self.__create_temp_file_path(scenario_id, "inp")
+            f_msx_out = self.__create_temp_file_path(scenario_id, "msx")
+            my_scenario.save_to_epanet_file(f_inp_out, f_msx_out)
+
+            if os.path.isfile(f_msx_out):
+                f_out = self.__create_temp_file_path(scenario_id, "zip")
+                pack_zip_archive([f_inp_out, f_msx_out], f_out)
+
+                self.__send_temp_file(resp, f_out)
+                os.remove(f_out)
+                os.remove(f_msx_out)
+            else:
+                self.__send_temp_file(resp, f_inp_out)
+            os.remove(f_inp_out)
+        except Exception as ex:
+            warnings.warn(str(ex))
+            resp.status = falcon.HTTP_INTERNAL_SERVER_ERROR
+
+
 class ScenarioConfigHandler(ScenarioBaseHandler):
     """
     Class for handling a GET request for getting the scenario configuration of a given scenario.

epyt_flow/rest_api/server.py

@@ -8,7 +8,7 @@
     ScenarioGeneralParamsHandler, ScenarioSensorConfigHandler, ScenarioSimulationHandler, \
     ScenarioTopologyHandler, ScenarioConfigHandler, ScenarioLeakageHandler, \
     ScenarioBasicQualitySimulationHandler, ScenarioAdvancedQualitySimulationHandler, \
-    ScenarioNodeDemandPatternHandler, ScenarioSensorFaultHandler
+    ScenarioNodeDemandPatternHandler, ScenarioSensorFaultHandler, ScenarioExportHandler
 from .scada_data_handler import ScadaDataManager, ScadaDataSensorConfigHandler, \
     ScadaDataPressuresHandler, ScadaDataDemandsHandler, ScadaDataFlowsHandler, \
     ScadaDataLinksQualityHandler, ScadaDataNodesQualityHandler, ScadaDataRemoveHandler, \
@@ -40,6 +40,8 @@ def __init__(self, port: int = 8080):
                            ScenarioNewHandler(self.scenario_mgr))
         self.app.add_route("/scenario/{scenario_id}",
                            ScenarioRemoveHandler(self.scenario_mgr))
+        self.app.add_route("/scenario/{scenario_id}/export",
+                           ScenarioExportHandler(self.scenario_mgr))
         self.app.add_route("/scenario/{scenario_id}/topology",
                            ScenarioTopologyHandler(self.scenario_mgr))
         self.app.add_route("/scenario/{scenario_id}/scenario_config",

epyt_flow/utils.py

@@ -234,6 +234,22 @@ def create_path_if_not_exist(path_in: str) -> None:
     Path(path_in).mkdir(parents=True, exist_ok=True)
 
 
+def pack_zip_archive(f_in: list[str], f_out: str) -> None:
+    """
+    Compresses a given list of files into a .zip archive.
+
+    Parameters
+    ----------
+    f_in : `list[str]`
+        List of files to be compressed into the .zip archive.
+    f_out : `str`
+        Path to the final .zip file.
+    """
+    with zipfile.ZipFile(f_out, "w") as f_zip_out:
+        for f_cur_in in f_in:
+            f_zip_out.write(f_cur_in, compress_type=zipfile.ZIP_DEFLATED)
+
+
 def unpack_zip_archive(f_in: str, folder_out: str) -> None:
     """
     Unpacks a .zip archive.