1 files changed, 142 insertions, 0 deletions
diff --git a/tools/cru-py/cru/template.py b/tools/cru-py/cru/template.py
new file mode 100644
index 0000000..8e06418
--- /dev/null
+++ b/tools/cru-py/cru/template.py
@@ -0,0 +1,142 @@
+from collections.abc import Iterable, Mapping
+import os
+import os.path
+from string import Template
+
+from ._error import CruException
+
+
+class CruTemplateError(CruException):
+    pass
+
+
+class TemplateFile:
+    def __init__(self, source: str, destination_path: str | None):
+        self._source = source
+        self._destination = destination_path
+        self._template: Template | None = None
+
+    @property
+    def source(self) -> str:
+        return self._source
+
+    @property
+    def destination(self) -> str | None:
+        return self._destination
+
+    @destination.setter
+    def destination(self, value: str | None) -> None:
+        self._destination = value
+
+    @property
+    def template(self) -> Template:
+        if self._template is None:
+            return self.reload_template()
+        return self._template
+
+    def reload_template(self) -> Template:
+        with open(self._source, "r") as f:
+            self._template = Template(f.read())
+        return self._template
+
+    @property
+    def variables(self) -> set[str]:
+        return set(self.template.get_identifiers())
+
+    def generate(self, variables: Mapping[str, str]) -> str:
+        return self.template.substitute(variables)
+
+    def generate_to_destination(self, variables: Mapping[str, str]) -> None:
+        if self._destination is None:
+            raise CruTemplateError("No destination specified for this template.")
+        with open(self._destination, "w") as f:
+            f.write(self.generate(variables))
+
+
+class TemplateDirectory:
+    def __init__(
+        self,
+        source: str,
+        destination: str,
+        exclude: Iterable[str],
+        file_suffix: str = ".template",
+    ):
+        self._files: list[TemplateFile] | None = None
+        self._source = source
+        self._destination = destination
+        self._exclude = [os.path.normpath(p) for p in exclude]
+        self._file_suffix = file_suffix
+
+    @property
+    def files(self) -> list[TemplateFile]:
+        if self._files is None:
+            return self.reload()
+        else:
+            return self._files
+
+    @property
+    def source(self) -> str:
+        return self._source
+
+    @property
+    def destination(self) -> str:
+        return self._destination
+
+    @property
+    def exclude(self) -> list[str]:
+        return self._exclude
+
+    @property
+    def file_suffix(self) -> str:
+        return self._file_suffix
+
+    @staticmethod
+    def _scan_files(
+        root_path: str, exclude: list[str], suffix: str | None
+    ) -> Iterable[str]:
+        for root, _dirs, files in os.walk(root_path):
+            for file in files:
+                if suffix is None or file.endswith(suffix):
+                    path = os.path.join(root, file)
+                    path = os.path.relpath(path, root_path)
+                    if suffix is not None:
+                        path = path[: -len(suffix)]
+                    is_exclude = False
+                    for exclude_path in exclude:
+                        if path.startswith(exclude_path):
+                            is_exclude = True
+                            break
+                    if not is_exclude:
+                        yield path
+
+    def reload(self) -> list[TemplateFile]:
+        if not os.path.isdir(self.source):
+            raise CruTemplateError(
+                f"Source directory {self.source} does not exist or is not a directory."
+            )
+        files = self._scan_files(self.source, self.exclude, self.file_suffix)
+        self._files = [
+            TemplateFile(
+                os.path.join(self._source, file + self.file_suffix),
+                os.path.join(self._destination, file),
+            )
+            for file in files
+        ]
+        return self._files
+
+    @property
+    def variables(self) -> set[str]:
+        s = set()
+        for file in self.files:
+            s.update(file.variables)
+        return s
+
+    def generate_to_destination(self, variables: Mapping[str, str]) -> None:
+        for file in self.files:
+            file.generate_to_destination(variables)
+
+    def extra_files_in_destination(self) -> Iterable[str]:
+        source_files = set(os.path.relpath(f.source, self.source) for f in self.files)
+        for file in self._scan_files(self.destination, self.exclude, None):
+            if file not in source_files:
+                yield file