refactor: Restructure semantic browser auto-refresh disabling

- Replace hardcoded workspace directory with env variable
- Use functions for better readibility
- Use context manager and `enumerate` for file iteration
- Use `replace` statement to replace old with new

capella/setup/disable_semantic_browser_auto_refresh.py

@@ -18,85 +18,97 @@
     "application": "http://www.eclipse.org/ui/2010/UIModel/application",
     "menu": "http://www.eclipse.org/ui/2010/UIModel/application/ui/menu",
 }
-XPATH_EXPR = (
-    "//persistedState[@key='memento' and"
-    " contains(@value, 'listeningToWorkbenchPageSelectionEvents')]"
-)
-WS = "/home/techuser/workspace"
+XPATH_EXPR = "//persistedState[@key='memento' and contains(@value, 'listeningToWorkbenchPageSelectionEvents')]"
+WORKSPACE_DIR = os.getenv("WORKSPACE_DIR", "/workspace")
 
 logging.basicConfig(level=os.getenv("LOG_LEVEL", "INFO"))
 logger = logging.getLogger(__file__)
 
-# we do something if it is configured like that to keep with defaults
-# and act only, if deviating from defaults has been configured
-if os.getenv("CAPELLA_DISABLE_SEMANTIC_BROWSER_AUTO_REFRESH", "0") != "1":
-    sys.exit(0)
-logger.debug(
-    "Identified that the environment variable"
-    " `CAPELLA_DISABLE_SEMANTIC_BROWSER_AUTO_REFRESH` is set to `1`."
-    " We will disable the auto-refresh of the semantic browser."
-)
-logger.debug("Expecting the workspace to be at: `%s`", WS)
-FILE_PATH = pathlib.Path(
-    f"{WS}/.metadata/.plugins/org.eclipse.e4.workbench/workbench.xmi"
-)
-if not FILE_PATH.is_file():
+
+def check_environment_variable() -> None:
+    if os.getenv(
+        "CAPELLA_DISABLE_SEMANTIC_BROWSER_AUTO_REFRESH", "0"
+    ).lower() in (
+        "1",
+        "true",
+        "t",
+    ):
+        logger.info("The semantic browser auto refresh will not be disabled.")
+        sys.exit(0)
+
     logger.debug(
-        "File not found: `%s`."
-        " Cannot disable auto-refresh of semantic browser.",
-        FILE_PATH,
+        "Identified that the environment variable "
+        "`CAPELLA_DISABLE_SEMANTIC_BROWSER_AUTO_REFRESH` is set to `1`. "
+        "We will disable the auto-refresh of the semantic browser."
     )
-    sys.exit(0)
 
 
-def main() -> None:
-    tree = etree.parse(FILE_PATH)
-    root = tree.getroot()
+def check_for_file_existence(file_path: pathlib.Path) -> None:
+    if not file_path.is_file():
+        logger.debug(
+            "File not found: `%s`. "
+            "Cannot disable auto-refresh of semantic browser.",
+            file_path,
+        )
+        sys.exit(0)
+
+
+def identify_semantic_browser_line_no(file_path: pathlib.Path) -> int:
+    root = etree.parse(file_path).getroot()
     logger.debug(
         "Searching for XPath expression: `%s` in the file `%s`",
         XPATH_EXPR,
-        FILE_PATH,
+        file_path,
     )
     hit_elements = root.xpath(XPATH_EXPR, namespaces=NS_MAP)
     if not hit_elements:
         logger.debug("No elements found. Exiting.")
         sys.exit(0)
-    # runtime lands here, when we found a setting that controls if the semantic
+
+    # Runtime lands here, when we found a setting that controls if the semantic
     # browser should auto-refresh or not
     persisted_state = hit_elements[0]
     parent_element = persisted_state.getparent()
-    if parent_element is None:
-        sys.exit(0)
-    if "elementId" not in parent_element.attrib:
-        sys.exit(0)
-    if "semanticbrowser" not in parent_element.attrib["elementId"].lower():
+    if (
+        parent_element is None
+        or "elementId" not in parent_element.attrib
+        or "semanticbrowser" not in parent_element.attrib["elementId"].lower()
+    ):
         sys.exit(0)
-    # get line number of the element we want to modify
+
     browser_autorefresh_line_no = persisted_state.sourceline
     logger.debug(
         "Found element at line number: `%d`", browser_autorefresh_line_no
     )
-    line_no = 0
-    old = new = None
-    for line in fileinput.input(FILE_PATH, inplace=True):
-        line_no += 1
-        if line_no == browser_autorefresh_line_no:
-            old = "listeningToWorkbenchPageSelectionEvents="1""
-            new = "listeningToWorkbenchPageSelectionEvents="0""
-            if old in line:
+    return browser_autorefresh_line_no
+
+
+def replace_content_of_line(
+    file_path: pathlib.Path, line_no: int, old: str, new: str
+) -> None:
+    with fileinput.input(file_path, inplace=True, backup=".bak") as file:
+        for cur_line_no, line in enumerate(file, start=1):
+            if cur_line_no == line_no:
                 line = line.replace(old, new)
-            else:
-                old = new = None
-        sys.stdout.write(line)
-    fileinput.close()
-    if old is not None:
-        logger.debug(
-            "Replaced `%s` with `%s` in file `%s` at line number %d.",
-            old,
-            new,
-            FILE_PATH,
-            browser_autorefresh_line_no,
-        )
+            sys.stdout.write(line)
+
+
+def main() -> None:
+    check_environment_variable()
+    logger.debug("Expecting the workspace to be at: `%s`", WORKSPACE_DIR)
+    file_path = pathlib.Path(
+        f"{WORKSPACE_DIR}/.metadata/.plugins/org.eclipse.e4.workbench/workbench.xmi"
+    )
+    check_for_file_existence(file_path)
+
+    browser_autorefresh_line_no = identify_semantic_browser_line_no(file_path)
+
+    replace_content_of_line(
+        file_path,
+        browser_autorefresh_line_no,
+        "listeningToWorkbenchPageSelectionEvents="1"",
+        "listeningToWorkbenchPageSelectionEvents="0"",
+    )
 
 
 if __name__ == "__main__":