Added a more advanced method to locate maindir

Added a more advanced method to locate maindir and filename for usage
with the python scripts.

scripts/python/src/fodt/constants.py

@@ -9,7 +9,7 @@ class ClickOptions():
         '--filename',
         envvar='FODT_FILENAME',
         required=True,
-        help='Name of the FODT file to extract from.'
+        help='Name of the FODT file to extract from. Used in combination with the --maindir option. This can be an absolute path or a relative path. If the filename is an absolute path, the --maindir option is ignored and the filename is used as is. If the filename is a relative path, and not found by concatenating maindir and filename it is searched for relative to the current working directory. If found, maindir is derived from the filename by searching its parent directories for a file main.fodt.'
     )(func)
     keyword_dir = lambda func: click.option(
         '--keyword-dir',
@@ -27,7 +27,7 @@ def decorator(func):
                 required=required,
                 default=default,
                 type=str,
-                help='Directory to save generated files.'
+                help='Directory where the main.fodt file is located. Often used in combination with the --filename option. Defaults to ../../parts (this default is based on that it is likely the user will run the script from the scripts/python directory) The environment variable FODT_MAIN_DIR can also be used to provide this value. If the filename is an absolute path, this option is ignored and maindir is derived from the filename by searching its parent directories for a file main.fodt. If the filename is a relative path, and not found by concatenating maindir and filename it is searched for relative to the current working directory. If found, maindir is derived from the filename by searching its parent directories for a file main.fodt.'
             )(func)
         return decorator
 
@@ -38,6 +38,7 @@ class Directories():
     keywords = "keywords"
     meta = "meta"
     meta_sections = "sections"
+    parts = "parts"
     styles = "styles"
     chapters = "chapters"
     sections = "sections"

scripts/python/src/fodt/helpers.py

@@ -30,6 +30,27 @@ def create_backup_document(filename) -> None:
         backup_file = backupdir / filename.name
         return backup_file
 
+    @staticmethod
+    def derive_maindir_from_filename(filename: str) -> Path:
+        filename = Path(filename)
+        assert filename.is_absolute()
+        # Search parent directories for main.fodt in a directory called "parts"
+        while True:
+            # Check if we have reached the root directory
+            #  filename.parent == filename is True if filename is the root directory
+            if filename.parent == filename:
+                raise FileNotFoundError(f"Could not derive maindir from filename: "
+                      f"Could not find '{FileNames.main_document}' in a directory "
+                      f"called '{Directories.parts}' by searching the parent "
+                      f"directories of filename."
+                )
+                return filename.parent
+            if filename.parent.name == Directories.parts:
+                if (filename.parent / FileNames.main_document).exists():
+                    return filename.parent
+            filename = filename.parent
+        # This should never be reached
+
     @staticmethod
     def get_keyword_dir(keyword_dir: str) -> str:
         if keyword_dir is None:
@@ -75,6 +96,30 @@ def keyword_fodt_file_path(
     def keywords_inverse_map(keyw_list: list[str]) -> dict[str, int]:
         return {keyw_list[i]: i + 1 for i in range(len(keyw_list))}
 
+
+    @staticmethod
+    def locate_maindir_and_filename(
+        maindir: str,
+        filename: str
+    ) -> tuple[Path, Path]:
+        filename = Path(filename)
+        maindir = Path(maindir)  # maindir can be absolute or relative
+        # If filename is an absolute path, ignore maindir
+        if filename.is_absolute():
+            assert filename.exists()
+            maindir = Helpers.derive_maindir_from_filename(filename)
+            return maindir, Path(filename)
+        else:
+            # Try to find filename by concatenating maindir and filename
+            filename = maindir / filename
+            if filename.exists():
+                return maindir, filename
+            # If not found, search for filename relative to the current working directory
+            filename = Path.cwd() / filename
+            if filename.exists():
+                maindir = Helpers.derive_maindir_from_filename(filename)
+                return maindir, filename
+
     @staticmethod
     def read_keyword_order(outputdir: Path, chapter: int, section: int) -> list[str]:
         file = Helpers.keyword_file(outputdir, chapter, section)

scripts/python/src/fodt/remove_span_tags.py

@@ -9,6 +9,7 @@
 import click
 
 from fodt.constants import ClickOptions
+from fodt.helpers import Helpers
 from fodt.xml_helpers import XMLHelper
 
 class RemoveEmptyLinesHandler(xml.sax.handler.ContentHandler):
@@ -346,4 +347,5 @@ def remove_version_span_tags(
 ) -> None:
     """Remove version span tags from all .fodt subdocuments."""
     logging.basicConfig(level=logging.INFO)
+    maindir, filename = Helpers.locate_maindir_and_filename(maindir, filename)
     RemoveSpanTags(maindir, filename, max_files).remove_span_tags()

scripts/python/tests/test_helpers.py

@@ -0,0 +1,88 @@
+import os
+from pathlib import Path
+
+import pytest
+from fodt.constants import Directories, FileNames
+from fodt.helpers import Helpers
+
+class TestLocateMainDir:
+    def test_locate_with_absolute_path_exists(self, tmp_path: Path) -> None:
+        maindir = tmp_path / Directories.parts
+        maindir.mkdir()
+        mainfile = maindir / FileNames.main_document
+        mainfile.touch()
+        filename_dir = maindir / Directories.chapters
+        filename_dir.mkdir()
+        filename = filename_dir / "1.fodt"
+        filename.touch()
+        result_maindir, result_filename = Helpers.locate_maindir_and_filename(
+            str(maindir), str(filename)
+        )
+        assert result_maindir == maindir
+        assert result_filename == filename
+
+    def test_locate_with_absolute_path_exists_no_main(self, tmp_path: Path) -> None:
+        maindir = tmp_path / Directories.parts
+        maindir.mkdir()
+        mainfile = maindir / FileNames.main_document
+        # mainfile.touch()  # Do not create the main file
+        filename_dir = maindir / Directories.chapters
+        filename_dir.mkdir()
+        filename = filename_dir / "1.fodt"
+        filename.touch()
+        with pytest.raises(FileNotFoundError) as excinfo:
+            Helpers.locate_maindir_and_filename(
+                str(maindir), str(filename)
+            )
+        assert (f"Could not find '{FileNames.main_document}' in a directory "
+                f"called '{Directories.parts}'" in str(excinfo.value))
+
+    def test_locate_with_relative_path_in_maindir_exists(self, tmp_path: Path) -> None:
+        maindir = tmp_path / Directories.parts
+        maindir.mkdir()
+        mainfile = maindir / FileNames.main_document
+        mainfile.touch()  # Ensure the main document exists
+        # Change directory to maindir
+        os.chdir(str(maindir))
+        filename_dir = Path(Directories.appendices)
+        filename_dir.mkdir()
+        filename = "A.fodt"
+        filename_path = filename_dir / filename
+        filename_path.touch()  # Create the file within maindir
+        filename_abs_path = maindir / filename_path
+        result_maindir, result_filename = Helpers.locate_maindir_and_filename(
+            str(maindir), str(filename_path)
+        )
+        assert result_maindir == maindir
+        assert result_filename == filename_abs_path
+
+    def test_locate_with_relative_path_not_in_maindir_but_in_cwd(
+            self, tmp_path: Path
+    ):
+        cwd = tmp_path / "cwd"
+        cwd.mkdir()
+        os.chdir(str(cwd))
+        filename = "1.fodt"
+        filename_path = cwd / filename
+        filename_path.touch()  # Create the file in CWD
+        maindir = tmp_path  # Some dummy path that is not the maindir
+        with pytest.raises(FileNotFoundError) as excinfo:
+            Helpers.locate_maindir_and_filename(
+                str(maindir), str(filename_path)
+            )
+        assert excinfo.match(
+            f"Could not find '{FileNames.main_document}' in a directory "
+            f"called '{Directories.parts}' by searching the parent "
+            f"directories of filename."
+        )
+
+    def test_locate_with_absolute_path_not_exists(self, tmp_path: Path):
+        maindir = tmp_path / Directories.parts
+        maindir.mkdir()
+        filename = tmp_path / "nonexistent.fodt"
+        # Do not create the file, simulating a non-existent file scenario
+
+        with pytest.raises(AssertionError):
+            Helpers.locate_maindir_and_filename(
+                str(maindir), str(filename)
+            )