Files
symconf/symconf/matching.py

268 lines
9.6 KiB
Python

"""
Generic combinatorial name-matching subsystem
Config files are expected to have names matching the following spec:
.. code-block:: sh
<style>-<scheme>.<config_pathname>
- ``config_pathname``: refers to a concrete filename, typically that which is
expected by the target app (e.g., ``kitty.conf``). In the context of
``config_map`` in the registry, however, it merely serves as an identifier,
as it can be mapped onto any path.
- ``scheme``: indicates the lightness mode ("light" or "dark")
- ``style``: general identifier capturing the stylizations applied to the
config file. This is typically of the form ``<variant>-<palette>``, i.e.,
including a reference to a particular color palette.
For example
.. code-block:: sh
soft-gruvbox-dark.kitty.conf
gets mapped to
.. code-block:: sh
style -> "soft-gruvbox"
scheme -> "dark"
pathname -> "kitty.conf"
"""
from pathlib import Path
from symconf import util
class FilePart:
def __init__(self, path: str | Path) -> None:
self.path = util.absolute_path(path)
self.pathname = self.path.name
parts = str(self.pathname).split(".")
if len(parts) < 2:
raise ValueError(
f'Filename "{self.pathname}" incorrectly formatted, ignoring'
)
self.theme = parts[0]
self.conf = ".".join(parts[1:])
theme_split = self.theme.split("-")
self.scheme = theme_split[-1]
self.style = "-".join(theme_split[:-1])
self.index = -1
def set_index(self, idx: int) -> None:
self.index = idx
class Matcher:
def get_file_parts(
self,
paths: list[str | Path],
) -> list[FilePart]:
"""
Split pathnames into parts for matching.
Pathnames should be of the format
.. code-block:: sh
<style>-<scheme>.<config_pathname>
where ``style`` is typically itself of the form
``<variant>-<palette>``.
"""
file_parts = []
for path in paths:
try:
config_file = FilePart(path)
file_parts.append(config_file)
except ValueError:
print(f'Filename "{path}" incorrectly formatted, ignoring')
return file_parts
def prefix_order(
self,
scheme: str,
style: str,
strict: bool = False,
) -> list[tuple[str, str]]:
"""
Determine the order of concrete config pathname parts to match, given
the ``scheme`` and ``style`` inputs.
There is a unique preferred match order when ``style``, ``scheme``,
both, or none are ``any``. In general, when ``any`` is provided for a
given factor, it is best matched by a config file that expresses
indifference under that factor.
"""
# explicit cases are the most easily managed here, even if a little
# redundant
if strict:
theme_order = [
(style, scheme),
]
else:
# inverse order of match relaxation; intention being to overwrite
# with results from increasingly relevant groups given the
# conditions
if style == "any" and scheme == "any":
# prefer both be "none", with preference for specific scheme
theme_order = [
(style, scheme),
(style, "none"),
("none", scheme),
("none", "none"),
]
elif style == "any":
# prefer style to be "none", then specific, then relax specific
# scheme to "none"
theme_order = [
(style, "none"),
("none", "none"),
(style, scheme),
("none", scheme),
]
elif scheme == "any":
# prefer scheme to be "none", then specific, then relax
# specific style to "none"
theme_order = [
("none", scheme),
("none", "none"),
(style, scheme),
(style, "none"),
]
else:
# neither component is any; prefer most specific
theme_order = [
("none", "none"),
("none", scheme),
(style, "none"),
(style, scheme),
]
return theme_order
def match_paths(
self,
paths: list[str | Path],
prefix_order: list[tuple[str, str]],
) -> list[FilePart]:
"""
Find and return FilePart matches according to the provided prefix
order.
The prefix order specifies all valid style-scheme combos that can be
considered as "consistent" with some user input (and is computed
external to this method). For example, it could be
.. code-block:: python
[("none", "none")("none", "dark")]
indicating that either ``none-none.<config>`` or ``none-dark.<config>``
would be considered matching pathnames, with the latter being
preferred.
This method exists because we need a way to allow any of the combos in
the prefix order to match the candidate files. We don't know a priori
how good of a match will be available, so we consider each file for
each of the prefixes, and take the latest/best match for each unique
config pathname (allowing for a "soft" match).
.. admonition:: Checking for matches
When thinking about how best to structure this method, it initially
felt like indexing factors of the FileParts would make the most
sense, preventing the inner loop that needs to inspect each
FilePart for each element of the prefix order. But indexing the
file parts and checking against prefixes isn't so straightforward,
as we'd still need to check matches by factor. For instance, if we
index by style-scheme, either are allowed to be "any," so we'd need
to check for the 4 valid combos and join the matching lists. If we
index by both factors individually, we may have several files
associated with a given key, and then need to coordinate the checks
across both to ensure they belong to the same file.
In any case, you should be able to do this in a way that's a bit
more efficient, but the loop and the simple conditionals is just
much simpler to follow. We're also talking about at most 10s of
files, so it really doesn't matter.
Parameters:
pathnames:
scheme:
style:
prefix_order:
strict:
"""
file_parts = self.get_file_parts(paths)
ordered_matches = []
for i, (style_prefix, scheme_prefix) in enumerate(prefix_order):
for fp in file_parts:
style_match = style_prefix == fp.style or style_prefix == "any"
scheme_match = (
scheme_prefix == fp.scheme or scheme_prefix == "any"
)
if style_match and scheme_match:
fp.set_index(i + 1)
ordered_matches.append(fp)
return ordered_matches
def relaxed_match(self, match_list: list[FilePart]) -> list[FilePart]:
"""
Isolate the best match in a match list and find its relaxed variants.
This method allows us to use the ``match_paths()`` method for matching
templates rather than direct user config files. In the latter case, we
want to symlink the single best config file match for each stem, across
all stems with matching prefixes (e.g., ``none-dark.config.a`` and
``solarized-dark.config.b`` have two separate stems with prefixes that
could match ``scheme=dark, style=any`` query). We can find these files
by just indexing the ``match_path`` outputs (i.e., all matches) by
config pathname and taking the one that appears latest (under the
prefix order) for each unique value.
In the template matching case, we want only a single best file match,
period (there's really no notion of "config stems," it's just the
prefixes). Once that match has been found, we can then "relax" either
the scheme or style (or both) to ``none``, and if the corresponding
files exist, we use those as parts of the template keys. For example,
if we match ``solarized-dark.toml``, we would also consider the values
in ``none-dark.toml`` if available. The TOML values that are defined in
the most specific (i.e., better under the prefix order) match are
loaded "on top of" those less specific matches, overwriting keys when
there's a conflict. ``none-dark.toml``, for instance, might define a
general dark scheme background color, but a more specific definition in
``solarized-dark.toml`` would take precedent. These TOML files would be
stacked before using the resulting dictionary to populate config
templates.
"""
if not match_list:
return []
relaxed_map = {}
match = match_list[-1]
for fp in match_list:
style_match = fp.style == match.style or fp.style == "none"
scheme_match = fp.scheme == match.scheme or fp.scheme == "none"
if style_match and scheme_match:
relaxed_map[fp.pathname] = fp
return list(relaxed_map.values())