From a3ecf5994018c4ab9e9f1f2a1b70f93bb6ee892c Mon Sep 17 00:00:00 2001
From: belthlemar <martin.belthle@rte-france.com>
Date: Wed, 8 Jan 2025 15:54:31 +0100
Subject: [PATCH] fix(matrix): return default matrix when it's empty

---
 .../filesystem/matrix/input_series_matrix.py  |  4 +++
 .../model/filesystem/matrix/matrix.py         | 26 ++++++++++++++++---
 .../filesystem/matrix/test_matrix_node.py     |  5 ++++
 3 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/antarest/study/storage/rawstudy/model/filesystem/matrix/input_series_matrix.py b/antarest/study/storage/rawstudy/model/filesystem/matrix/input_series_matrix.py
index d2ac83c19c..e23cb9842a 100644
--- a/antarest/study/storage/rawstudy/model/filesystem/matrix/input_series_matrix.py
+++ b/antarest/study/storage/rawstudy/model/filesystem/matrix/input_series_matrix.py
@@ -150,3 +150,7 @@ def get_file_content(self) -> OriginalFile:
         else:
             content = self.config.path.read_bytes()
         return OriginalFile(content=content, suffix=suffix, filename=filename)
+
+    @override
+    def get_default_empty_matrix(self) -> t.Optional[npt.NDArray[np.float64]]:
+        return self.default_empty
diff --git a/antarest/study/storage/rawstudy/model/filesystem/matrix/matrix.py b/antarest/study/storage/rawstudy/model/filesystem/matrix/matrix.py
index 7897715f92..3b28f36600 100644
--- a/antarest/study/storage/rawstudy/model/filesystem/matrix/matrix.py
+++ b/antarest/study/storage/rawstudy/model/filesystem/matrix/matrix.py
@@ -16,7 +16,9 @@
 from pathlib import Path
 from typing import List, Optional, Union, cast
 
+import numpy as np
 import pandas as pd
+from numpy import typing as npt
 from typing_extensions import override
 
 from antarest.core.model import JSON
@@ -127,16 +129,25 @@ def load(
         formatted: bool = True,
     ) -> Union[bytes, JSON]:
         file_path, tmp_dir = self._get_real_file_path()
-        if not formatted:
-            if file_path.exists():
-                return file_path.read_bytes()
 
+        if formatted:
+            return self.parse_as_json(file_path)
+
+        if not file_path.exists():
             logger.warning(f"Missing file {self.config.path}")
             if tmp_dir:
                 tmp_dir.cleanup()
             return b""
 
-        return self.parse_as_json(file_path)
+        file_content = file_path.read_bytes()
+        if file_content != b"":
+            return file_content
+
+        # here we should return the default matrix
+        default_matrix = self.get_default_empty_matrix()
+        if not default_matrix:
+            return b""
+        return default_matrix.tobytes()
 
     @abstractmethod
     def parse_as_json(self, file_path: Optional[Path] = None) -> JSON:
@@ -145,6 +156,13 @@ def parse_as_json(self, file_path: Optional[Path] = None) -> JSON:
         """
         raise NotImplementedError()
 
+    @abstractmethod
+    def get_default_empty_matrix(self) -> Optional[npt.NDArray[np.float64]]:
+        """
+        Returns the default matrix to return when the existing one is empty
+        """
+        raise NotImplementedError()
+
     @override
     def dump(
         self,
diff --git a/tests/storage/repository/filesystem/matrix/test_matrix_node.py b/tests/storage/repository/filesystem/matrix/test_matrix_node.py
index 38dce45486..936a54b6ea 100644
--- a/tests/storage/repository/filesystem/matrix/test_matrix_node.py
+++ b/tests/storage/repository/filesystem/matrix/test_matrix_node.py
@@ -14,7 +14,9 @@
 from typing import List, Optional
 from unittest.mock import Mock
 
+import numpy as np
 import pandas as pd  # type: ignore
+from numpy import typing as npt
 
 from antarest.core.model import JSON
 from antarest.study.storage.rawstudy.model.filesystem.config.model import FileStudyTreeConfig
@@ -41,6 +43,9 @@ def __init__(self, context: ContextServer, config: FileStudyTreeConfig) -> None:
     def parse_as_json(self, file_path: Optional[Path] = None) -> JSON:
         return MOCK_MATRIX_JSON
 
+    def get_default_empty_matrix(self) -> Optional[npt.NDArray[np.float64]]:
+        pass
+
     def check_errors(self, data: str, url: Optional[List[str]] = None, raising: bool = False) -> List[str]:
         pass  # not used