style.py

# Copyright 2015 Google Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Python formatting style settings."""

import os
import re
import sys
import textwrap
from configparser import ConfigParser

from yapf.yapflib import errors

if sys.version_info >= (3, 11):
  import tomllib
else:
  import tomli as tomllib


class StyleConfigError(errors.YapfError):
  """Raised when there's a problem reading the style configuration."""
  pass


def Get(setting_name):
  """Get a style setting."""
  return _style[setting_name]


def GetOrDefault(setting_name, default_value):
  """Get a style setting or default value if the setting does not exist."""
  return _style.get(setting_name, default_value)


def Help():
  """Return dict mapping style names to help strings."""
  return _STYLE_HELP


def SetGlobalStyle(style):
  """Set a style dict."""
  global _style
  global _GLOBAL_STYLE_FACTORY
  factory = _GetStyleFactory(style)
  if factory:
    _GLOBAL_STYLE_FACTORY = factory
  _style = style


_STYLE_HELP = dict(
    # BASED_ON_STYLE='Which predefined style this style is based on',
    ALIGN_CLOSING_BRACKET_WITH_VISUAL_INDENT=textwrap.dedent("""\
      Align closing bracket with visual indentation.
    """),
    ALLOW_MULTILINE_DICTIONARY_KEYS=textwrap.dedent("""\
      Allow dictionary keys to exist on multiple lines. For example:

        x = {
            ('this is the first element of a tuple',
             'this is the second element of a tuple'):
                 value,
        }
    """),
    ALLOW_MULTILINE_LAMBDAS=textwrap.dedent("""\
      Allow lambdas to be formatted on more than one line.
    """),
    ALLOW_SPLIT_BEFORE_DEFAULT_OR_NAMED_ASSIGNS=textwrap.dedent("""\
      Allow splitting before a default / named assignment in an argument list.
    """),
    ALLOW_SPLIT_BEFORE_DICT_VALUE=textwrap.dedent("""\
      Allow splits before the dictionary value.
    """),
    ARITHMETIC_PRECEDENCE_INDICATION=textwrap.dedent("""\
      Let spacing indicate operator precedence. For example:

        a = 1 * 2 + 3 / 4
        b = 1 / 2 - 3 * 4
        c = (1 + 2) * (3 - 4)
        d = (1 - 2) / (3 + 4)
        e = 1 * 2 - 3
        f = 1 + 2 + 3 + 4

    will be formatted as follows to indicate precedence:

        a = 1*2 + 3/4
        b = 1/2 - 3*4
        c = (1+2) * (3-4)
        d = (1-2) / (3+4)
        e = 1*2 - 3
        f = 1 + 2 + 3 + 4

    """),
    BLANK_LINE_BEFORE_CLASS_DOCSTRING=textwrap.dedent("""\
      Insert a blank line before a class-level docstring.
    """),
    BLANK_LINE_BEFORE_MODULE_DOCSTRING=textwrap.dedent("""\
      Insert a blank line before a module docstring.
    """),
    BLANK_LINE_BEFORE_NESTED_CLASS_OR_DEF=textwrap.dedent("""\
      Insert a blank line before a 'def' or 'class' immediately nested
      within another 'def' or 'class'. For example:

        class Foo:
                           # <------ this blank line
          def method():
            pass
    """),
    BLANK_LINES_AROUND_TOP_LEVEL_DEFINITION=textwrap.dedent("""\
      Number of blank lines surrounding top-level function and class
      definitions.
    """),
    BLANK_LINES_BETWEEN_TOP_LEVEL_IMPORTS_AND_VARIABLES=textwrap.dedent("""\
      Number of blank lines between top-level imports and variable
      definitions.
    """),
    COALESCE_BRACKETS=textwrap.dedent("""\
      Do not split consecutive brackets. Only relevant when
      dedent_closing_brackets is set. For example:

         call_func_that_takes_a_dict(
             {
                 'key1': 'value1',
                 'key2': 'value2',
             }
         )

      would reformat to:

         call_func_that_takes_a_dict({
             'key1': 'value1',
             'key2': 'value2',
         })
    """),
    COLUMN_LIMIT=textwrap.dedent("""\
      The column limit.
    """),
    CONTINUATION_ALIGN_STYLE=textwrap.dedent("""\
      The style for continuation alignment. Possible values are:

      - SPACE: Use spaces for continuation alignment. This is default behavior.
      - FIXED: Use fixed number (CONTINUATION_INDENT_WIDTH) of columns
        (ie: CONTINUATION_INDENT_WIDTH/INDENT_WIDTH tabs or
        CONTINUATION_INDENT_WIDTH spaces) for continuation alignment.
      - VALIGN-RIGHT: Vertically align continuation lines to multiple of
        INDENT_WIDTH columns. Slightly right (one tab or a few spaces) if
        cannot vertically align continuation lines with indent characters.
    """),
    CONTINUATION_INDENT_WIDTH=textwrap.dedent("""\
      Indent width used for line continuations.
    """),
    DEDENT_CLOSING_BRACKETS=textwrap.dedent("""\
      Put closing brackets on a separate line, dedented, if the bracketed
      expression can't fit in a single line. Applies to all kinds of brackets,
      including function definitions and calls. For example:

        config = {
            'key1': 'value1',
            'key2': 'value2',
        }        # <--- this bracket is dedented and on a separate line

        time_series = self.remote_client.query_entity_counters(
            entity='dev3246.region1',
            key='dns.query_latency_tcp',
            transform=Transformation.AVERAGE(window=timedelta(seconds=60)),
            start_ts=now()-timedelta(days=3),
            end_ts=now(),
        )        # <--- this bracket is dedented and on a separate line
    """),
    DISABLE_ENDING_COMMA_HEURISTIC=textwrap.dedent("""\
      Disable the heuristic which places each list element on a separate line
      if the list is comma-terminated.

      Note: The behavior of this flag changed in v0.40.3.  Before, if this flag
      was true, we would split lists that contained a trailing comma or a
      comment.  Now, we have a separate flag, `DISABLE_SPLIT_LIT_WITH_COMMENT`,
      that controls splitting when a list contains a comment.  To get the old
      behavior, set both flags to true.  More information in CHANGELOG.md.
    """),
    DISABLE_SPLIT_LIST_WITH_COMMENT=textwrap.dedent("""
      Don't put every element on a new line within a list that contains
      interstitial comments.
    """),
    EACH_DICT_ENTRY_ON_SEPARATE_LINE=textwrap.dedent("""\
      Place each dictionary entry onto its own line.
    """),
    FORCE_MULTILINE_DICT=textwrap.dedent("""\
      Require multiline dictionary even if it would normally fit on one line.
      For example:

        config = {
            'key1': 'value1'
        }
    """),
    I18N_COMMENT=textwrap.dedent("""\
      The regex for an i18n comment. The presence of this comment stops
      reformatting of that line, because the comments are required to be
      next to the string they translate.
    """),
    I18N_FUNCTION_CALL=textwrap.dedent("""\
      The i18n function call names. The presence of this function stops
      reformattting on that line, because the string it has cannot be moved
      away from the i18n comment.
    """),
    INDENT_CLOSING_BRACKETS=textwrap.dedent("""\
      Put closing brackets on a separate line, indented, if the bracketed
      expression can't fit in a single line. Applies to all kinds of brackets,
      including function definitions and calls. For example:

        config = {
            'key1': 'value1',
            'key2': 'value2',
            }        # <--- this bracket is indented and on a separate line

        time_series = self.remote_client.query_entity_counters(
            entity='dev3246.region1',
            key='dns.query_latency_tcp',
            transform=Transformation.AVERAGE(window=timedelta(seconds=60)),
            start_ts=now()-timedelta(days=3),
            end_ts=now(),
            )        # <--- this bracket is indented and on a separate line
    """),
    INDENT_DICTIONARY_VALUE=textwrap.dedent("""\
      Indent the dictionary value if it cannot fit on the same line as the
      dictionary key. For example:

        config = {
            'key1':
                'value1',
            'key2': value1 +
                    value2,
        }
    """),
    INDENT_BLANK_LINES=textwrap.dedent("""\
      Indent blank lines.
    """),
    INDENT_WIDTH=textwrap.dedent("""\
      The number of columns to use for indentation.
    """),
    JOIN_MULTIPLE_LINES=textwrap.dedent("""\
      Join short lines into one line. E.g., single line 'if' statements.
    """),
    NO_SPACES_AROUND_SELECTED_BINARY_OPERATORS=textwrap.dedent("""\
      Do not include spaces around selected binary operators. For example:

        1 + 2 * 3 - 4 / 5

      will be formatted as follows when configured with "*,/":

        1 + 2*3 - 4/5
    """),
    SPACE_BETWEEN_ENDING_COMMA_AND_CLOSING_BRACKET=textwrap.dedent("""\
      Insert a space between the ending comma and closing bracket of a list,
      etc.
    """),
    SPACE_INSIDE_BRACKETS=textwrap.dedent("""\
      Use spaces inside brackets, braces, and parentheses.  For example:

        method_call( 1 )
        my_dict[ 3 ][ 1 ][ get_index( *args, **kwargs ) ]
        my_set = { 1, 2, 3 }
    """),
    SPACES_AROUND_DEFAULT_OR_NAMED_ASSIGN=textwrap.dedent("""\
      Use spaces around default or named assigns.
    """),
    SPACES_AROUND_DICT_DELIMITERS=textwrap.dedent("""\
      Adds a space after the opening '{' and before the ending '}' dict
      delimiters.

        {1: 2}

      will be formatted as:

        { 1: 2 }
    """),
    SPACES_AROUND_LIST_DELIMITERS=textwrap.dedent("""\
      Adds a space after the opening '[' and before the ending ']' list
      delimiters.

        [1, 2]

      will be formatted as:

        [ 1, 2 ]
    """),
    SPACES_AROUND_POWER_OPERATOR=textwrap.dedent("""\
      Use spaces around the power operator.
    """),
    SPACES_AROUND_SUBSCRIPT_COLON=textwrap.dedent("""\
      Use spaces around the subscript / slice operator.  For example:

        my_list[1 : 10 : 2]
    """),
    SPACES_AROUND_TUPLE_DELIMITERS=textwrap.dedent("""\
      Adds a space after the opening '(' and before the ending ')' tuple
      delimiters.

        (1, 2, 3)

      will be formatted as:

        ( 1, 2, 3 )
    """),
    SPACES_BEFORE_COMMENT=textwrap.dedent("""\
      The number of spaces required before a trailing comment.
      This can be a single value (representing the number of spaces
      before each trailing comment) or list of values (representing
      alignment column values; trailing comments within a block will
      be aligned to the first column value that is greater than the maximum
      line length within the block). For example:

      With spaces_before_comment=5:

        1 + 1 # Adding values

      will be formatted as:

        1 + 1     # Adding values <-- 5 spaces between the end of the
                  # statement and comment

      With spaces_before_comment=15, 20:

        1 + 1 # Adding values
        two + two # More adding

        longer_statement # This is a longer statement
        short # This is a shorter statement

        a_very_long_statement_that_extends_beyond_the_final_column # Comment
        short # This is a shorter statement

      will be formatted as:

        1 + 1          # Adding values <-- end of line comments in block
                       # aligned to col 15
        two + two      # More adding

        longer_statement    # This is a longer statement <-- end of line
                            # comments in block aligned to col 20
        short               # This is a shorter statement

        a_very_long_statement_that_extends_beyond_the_final_column  # Comment <-- the end of line comments are aligned based on the line length
        short                                                       # This is a shorter statement

    """),  # noqa
    SPLIT_ALL_COMMA_SEPARATED_VALUES=textwrap.dedent("""\
      Split before arguments.
    """),
    SPLIT_ALL_TOP_LEVEL_COMMA_SEPARATED_VALUES=textwrap.dedent("""\
      Split before arguments, but do not split all subexpressions recursively
      (unless needed).
    """),
    SPLIT_ARGUMENTS_WHEN_COMMA_TERMINATED=textwrap.dedent("""\
      Split before arguments if the argument list is terminated by a
      comma.
    """),
    SPLIT_BEFORE_ARITHMETIC_OPERATOR=textwrap.dedent("""\
      Set to True to prefer splitting before '+', '-', '*', '/', '//', or '@'
      rather than after.
    """),
    SPLIT_BEFORE_BITWISE_OPERATOR=textwrap.dedent("""\
      Set to True to prefer splitting before '&', '|' or '^' rather than
      after.
    """),
    SPLIT_BEFORE_CLOSING_BRACKET=textwrap.dedent("""\
      Split before the closing bracket if a list or dict literal doesn't fit on
      a single line.
    """),
    SPLIT_BEFORE_DICT_SET_GENERATOR=textwrap.dedent("""\
      Split before a dictionary or set generator (comp_for). For example, note
      the split before the 'for':

        foo = {
            variable: 'Hello world, have a nice day!'
            for variable in bar if variable != 42
        }
    """),
    SPLIT_BEFORE_DOT=textwrap.dedent("""\
      Split before the '.' if we need to split a longer expression:

        foo = ('This is a really long string: {}, {}, {}, {}'.format(a, b, c, d))

      would reformat to something like:

        foo = ('This is a really long string: {}, {}, {}, {}'
               .format(a, b, c, d))
    """),  # noqa
    SPLIT_BEFORE_EXPRESSION_AFTER_OPENING_PAREN=textwrap.dedent("""\
      Split after the opening paren which surrounds an expression if it doesn't
      fit on a single line.
    """),
    SPLIT_BEFORE_FIRST_ARGUMENT=textwrap.dedent("""\
      If an argument / parameter list is going to be split, then split before
      the first argument.
    """),
    SPLIT_BEFORE_LOGICAL_OPERATOR=textwrap.dedent("""\
      Set to True to prefer splitting before 'and' or 'or' rather than
      after.
    """),
    SPLIT_BEFORE_NAMED_ASSIGNS=textwrap.dedent("""\
      Split named assignments onto individual lines.
    """),
    SPLIT_COMPLEX_COMPREHENSION=textwrap.dedent("""\
      Set to True to split list comprehensions and generators that have
      non-trivial expressions and multiple clauses before each of these
      clauses. For example:

        result = [
            a_long_var + 100 for a_long_var in xrange(1000)
            if a_long_var % 10]

      would reformat to something like:

        result = [
            a_long_var + 100
            for a_long_var in xrange(1000)
            if a_long_var % 10]
    """),
    SPLIT_PENALTY_AFTER_OPENING_BRACKET=textwrap.dedent("""\
      The penalty for splitting right after the opening bracket.
    """),
    SPLIT_PENALTY_AFTER_UNARY_OPERATOR=textwrap.dedent("""\
      The penalty for splitting the line after a unary operator.
    """),
    SPLIT_PENALTY_ARITHMETIC_OPERATOR=textwrap.dedent("""\
      The penalty of splitting the line around the '+', '-', '*', '/', '//',
      `%`, and '@' operators.
    """),
    SPLIT_PENALTY_BEFORE_IF_EXPR=textwrap.dedent("""\
      The penalty for splitting right before an if expression.
    """),
    SPLIT_PENALTY_BITWISE_OPERATOR=textwrap.dedent("""\
      The penalty of splitting the line around the '&', '|', and '^' operators.
    """),
    SPLIT_PENALTY_COMPREHENSION=textwrap.dedent("""\
      The penalty for splitting a list comprehension or generator
      expression.
    """),
    SPLIT_PENALTY_EXCESS_CHARACTER=textwrap.dedent("""\
      The penalty for characters over the column limit.
    """),
    SPLIT_PENALTY_FOR_ADDED_LINE_SPLIT=textwrap.dedent("""\
      The penalty incurred by adding a line split to the logical line. The
      more line splits added the higher the penalty.
    """),
    SPLIT_PENALTY_IMPORT_NAMES=textwrap.dedent("""\
      The penalty of splitting a list of "import as" names. For example:

        from a_very_long_or_indented_module_name_yada_yad import (long_argument_1,
                                                                  long_argument_2,
                                                                  long_argument_3)

      would reformat to something like:

        from a_very_long_or_indented_module_name_yada_yad import (
            long_argument_1, long_argument_2, long_argument_3)
    """),  # noqa
    SPLIT_PENALTY_LOGICAL_OPERATOR=textwrap.dedent("""\
      The penalty of splitting the line around the 'and' and 'or' operators.
    """),
    USE_TABS=textwrap.dedent("""\
      Use the Tab character for indentation.
    """),
)


def CreatePEP8Style():
  """Create the PEP8 formatting style."""
  return dict(
      ALIGN_CLOSING_BRACKET_WITH_VISUAL_INDENT=True,
      ALLOW_MULTILINE_DICTIONARY_KEYS=False,
      ALLOW_MULTILINE_LAMBDAS=False,
      ALLOW_SPLIT_BEFORE_DEFAULT_OR_NAMED_ASSIGNS=True,
      ALLOW_SPLIT_BEFORE_DICT_VALUE=True,
      ARITHMETIC_PRECEDENCE_INDICATION=False,
      BLANK_LINE_BEFORE_CLASS_DOCSTRING=False,
      BLANK_LINE_BEFORE_MODULE_DOCSTRING=False,
      BLANK_LINE_BEFORE_NESTED_CLASS_OR_DEF=True,
      BLANK_LINES_AROUND_TOP_LEVEL_DEFINITION=2,
      BLANK_LINES_BETWEEN_TOP_LEVEL_IMPORTS_AND_VARIABLES=1,
      COALESCE_BRACKETS=False,
      COLUMN_LIMIT=79,
      CONTINUATION_ALIGN_STYLE='SPACE',
      CONTINUATION_INDENT_WIDTH=4,
      DEDENT_CLOSING_BRACKETS=False,
      DISABLE_ENDING_COMMA_HEURISTIC=False,
      DISABLE_SPLIT_LIST_WITH_COMMENT=False,
      EACH_DICT_ENTRY_ON_SEPARATE_LINE=True,
      FORCE_MULTILINE_DICT=False,
      I18N_COMMENT='',
      I18N_FUNCTION_CALL='',
      INDENT_CLOSING_BRACKETS=False,
      INDENT_DICTIONARY_VALUE=False,
      INDENT_WIDTH=4,
      INDENT_BLANK_LINES=False,
      JOIN_MULTIPLE_LINES=True,
      NO_SPACES_AROUND_SELECTED_BINARY_OPERATORS=set(),
      SPACE_BETWEEN_ENDING_COMMA_AND_CLOSING_BRACKET=True,
      SPACE_INSIDE_BRACKETS=False,
      SPACES_AROUND_DEFAULT_OR_NAMED_ASSIGN=False,
      SPACES_AROUND_DICT_DELIMITERS=False,
      SPACES_AROUND_LIST_DELIMITERS=False,
      SPACES_AROUND_POWER_OPERATOR=False,
      SPACES_AROUND_SUBSCRIPT_COLON=False,
      SPACES_AROUND_TUPLE_DELIMITERS=False,
      SPACES_BEFORE_COMMENT=2,
      SPLIT_ALL_COMMA_SEPARATED_VALUES=False,
      SPLIT_ALL_TOP_LEVEL_COMMA_SEPARATED_VALUES=False,
      SPLIT_ARGUMENTS_WHEN_COMMA_TERMINATED=False,
      SPLIT_BEFORE_ARITHMETIC_OPERATOR=False,
      SPLIT_BEFORE_BITWISE_OPERATOR=True,
      SPLIT_BEFORE_CLOSING_BRACKET=True,
      SPLIT_BEFORE_DICT_SET_GENERATOR=True,
      SPLIT_BEFORE_DOT=False,
      SPLIT_BEFORE_EXPRESSION_AFTER_OPENING_PAREN=False,
      SPLIT_BEFORE_FIRST_ARGUMENT=False,
      SPLIT_BEFORE_LOGICAL_OPERATOR=True,
      SPLIT_BEFORE_NAMED_ASSIGNS=True,
      SPLIT_COMPLEX_COMPREHENSION=False,
      SPLIT_PENALTY_AFTER_OPENING_BRACKET=300,
      SPLIT_PENALTY_AFTER_UNARY_OPERATOR=10000,
      SPLIT_PENALTY_ARITHMETIC_OPERATOR=300,
      SPLIT_PENALTY_BEFORE_IF_EXPR=0,
      SPLIT_PENALTY_BITWISE_OPERATOR=300,
      SPLIT_PENALTY_COMPREHENSION=80,
      SPLIT_PENALTY_EXCESS_CHARACTER=7000,
      SPLIT_PENALTY_FOR_ADDED_LINE_SPLIT=30,
      SPLIT_PENALTY_IMPORT_NAMES=0,
      SPLIT_PENALTY_LOGICAL_OPERATOR=300,
      USE_TABS=False,
  )


def CreateGoogleStyle():
  """Create the Google formatting style."""
  style = CreatePEP8Style()
  style['ALIGN_CLOSING_BRACKET_WITH_VISUAL_INDENT'] = False
  style['COLUMN_LIMIT'] = 80
  style['INDENT_DICTIONARY_VALUE'] = True
  style['INDENT_WIDTH'] = 4
  style['I18N_COMMENT'] = r'#\..*'
  style['I18N_FUNCTION_CALL'] = ['N_', '_']
  style['JOIN_MULTIPLE_LINES'] = False
  style['SPACE_BETWEEN_ENDING_COMMA_AND_CLOSING_BRACKET'] = False
  style['SPLIT_BEFORE_BITWISE_OPERATOR'] = False
  style['SPLIT_BEFORE_DICT_SET_GENERATOR'] = False
  style['SPLIT_BEFORE_LOGICAL_OPERATOR'] = False
  style['SPLIT_COMPLEX_COMPREHENSION'] = True
  style['SPLIT_PENALTY_COMPREHENSION'] = 2100
  return style


def CreateYapfStyle():
  """Create the YAPF formatting style."""
  style = CreateGoogleStyle()
  style['ALLOW_MULTILINE_DICTIONARY_KEYS'] = True
  style['ALLOW_SPLIT_BEFORE_DEFAULT_OR_NAMED_ASSIGNS'] = False
  style['INDENT_WIDTH'] = 2
  style['SPLIT_BEFORE_BITWISE_OPERATOR'] = True
  style['SPLIT_BEFORE_DOT'] = True
  style['SPLIT_BEFORE_EXPRESSION_AFTER_OPENING_PAREN'] = True
  return style


def CreateFacebookStyle():
  """Create the Facebook formatting style."""
  style = CreatePEP8Style()
  style['ALIGN_CLOSING_BRACKET_WITH_VISUAL_INDENT'] = False
  style['BLANK_LINE_BEFORE_NESTED_CLASS_OR_DEF'] = False
  style['COLUMN_LIMIT'] = 80
  style['DEDENT_CLOSING_BRACKETS'] = True
  style['INDENT_CLOSING_BRACKETS'] = False
  style['INDENT_DICTIONARY_VALUE'] = True
  style['JOIN_MULTIPLE_LINES'] = False
  style['SPACES_BEFORE_COMMENT'] = 2
  style['SPLIT_PENALTY_AFTER_OPENING_BRACKET'] = 0
  style['SPLIT_PENALTY_BEFORE_IF_EXPR'] = 30
  style['SPLIT_PENALTY_FOR_ADDED_LINE_SPLIT'] = 30
  style['SPLIT_BEFORE_BITWISE_OPERATOR'] = False
  style['SPLIT_BEFORE_LOGICAL_OPERATOR'] = False
  return style


_STYLE_NAME_TO_FACTORY = dict(
    facebook=CreateFacebookStyle,
    google=CreateGoogleStyle,
    pep8=CreatePEP8Style,
    yapf=CreateYapfStyle,
)

_DEFAULT_STYLE_TO_FACTORY = [
    (CreateFacebookStyle(), CreateFacebookStyle),
    (CreateGoogleStyle(), CreateGoogleStyle),
    (CreatePEP8Style(), CreatePEP8Style),
    (CreateYapfStyle(), CreateYapfStyle),
]


def _GetStyleFactory(style):
  for def_style, factory in _DEFAULT_STYLE_TO_FACTORY:
    if style == def_style:
      return factory
  return None


def _ContinuationAlignStyleStringConverter(s):
  """Option value converter for a continuation align style string."""
  accepted_styles = ('SPACE', 'FIXED', 'VALIGN-RIGHT')
  if s:
    r = s.strip('"\'').replace('_', '-').upper()
    if r not in accepted_styles:
      raise ValueError('unknown continuation align style: %r' % (s,))
  else:
    r = accepted_styles[0]
  return r


def _StringListConverter(s):
  """Option value converter for a comma-separated list of strings."""
  return [part.strip() for part in s.split(',')]


def _StringSetConverter(s):
  """Option value converter for a comma-separated set of strings."""
  if len(s) > 2 and s[0] in '"\'':
    s = s[1:-1]
  return {part.strip() for part in s.split(',')}


def _BoolConverter(s):
  """Option value converter for a boolean."""
  return ConfigParser.BOOLEAN_STATES[s.lower()]


def _IntListConverter(s):
  """Option value converter for a comma-separated list of integers."""
  s = s.strip()
  if s.startswith('[') and s.endswith(']'):
    s = s[1:-1]

  return [int(part.strip()) for part in s.split(',') if part.strip()]


def _IntOrIntListConverter(s):
  """Option value converter for an integer or list of integers."""
  if len(s) > 2 and s[0] in '"\'':
    s = s[1:-1]
  return _IntListConverter(s) if ',' in s else int(s)


# Different style options need to have their values interpreted differently when
# read from the config file. This dict maps an option name to a "converter"
# function that accepts the string read for the option's value from the file and
# returns it wrapper in actual Python type that's going to be meaningful to
# yapf.
#
# Note: this dict has to map all the supported style options.
_STYLE_OPTION_VALUE_CONVERTER = dict(
    ALIGN_CLOSING_BRACKET_WITH_VISUAL_INDENT=_BoolConverter,
    ALLOW_MULTILINE_DICTIONARY_KEYS=_BoolConverter,
    ALLOW_MULTILINE_LAMBDAS=_BoolConverter,
    ALLOW_SPLIT_BEFORE_DEFAULT_OR_NAMED_ASSIGNS=_BoolConverter,
    ALLOW_SPLIT_BEFORE_DICT_VALUE=_BoolConverter,
    ARITHMETIC_PRECEDENCE_INDICATION=_BoolConverter,
    BLANK_LINE_BEFORE_CLASS_DOCSTRING=_BoolConverter,
    BLANK_LINE_BEFORE_MODULE_DOCSTRING=_BoolConverter,
    BLANK_LINE_BEFORE_NESTED_CLASS_OR_DEF=_BoolConverter,
    BLANK_LINES_AROUND_TOP_LEVEL_DEFINITION=int,
    BLANK_LINES_BETWEEN_TOP_LEVEL_IMPORTS_AND_VARIABLES=int,
    COALESCE_BRACKETS=_BoolConverter,
    COLUMN_LIMIT=int,
    CONTINUATION_ALIGN_STYLE=_ContinuationAlignStyleStringConverter,
    CONTINUATION_INDENT_WIDTH=int,
    DEDENT_CLOSING_BRACKETS=_BoolConverter,
    DISABLE_ENDING_COMMA_HEURISTIC=_BoolConverter,
    DISABLE_SPLIT_LIST_WITH_COMMENT=_BoolConverter,
    EACH_DICT_ENTRY_ON_SEPARATE_LINE=_BoolConverter,
    FORCE_MULTILINE_DICT=_BoolConverter,
    I18N_COMMENT=str,
    I18N_FUNCTION_CALL=_StringListConverter,
    INDENT_BLANK_LINES=_BoolConverter,
    INDENT_CLOSING_BRACKETS=_BoolConverter,
    INDENT_DICTIONARY_VALUE=_BoolConverter,
    INDENT_WIDTH=int,
    JOIN_MULTIPLE_LINES=_BoolConverter,
    NO_SPACES_AROUND_SELECTED_BINARY_OPERATORS=_StringSetConverter,
    SPACE_BETWEEN_ENDING_COMMA_AND_CLOSING_BRACKET=_BoolConverter,
    SPACE_INSIDE_BRACKETS=_BoolConverter,
    SPACES_AROUND_DEFAULT_OR_NAMED_ASSIGN=_BoolConverter,
    SPACES_AROUND_DICT_DELIMITERS=_BoolConverter,
    SPACES_AROUND_LIST_DELIMITERS=_BoolConverter,
    SPACES_AROUND_POWER_OPERATOR=_BoolConverter,
    SPACES_AROUND_SUBSCRIPT_COLON=_BoolConverter,
    SPACES_AROUND_TUPLE_DELIMITERS=_BoolConverter,
    SPACES_BEFORE_COMMENT=_IntOrIntListConverter,
    SPLIT_ALL_COMMA_SEPARATED_VALUES=_BoolConverter,
    SPLIT_ALL_TOP_LEVEL_COMMA_SEPARATED_VALUES=_BoolConverter,
    SPLIT_ARGUMENTS_WHEN_COMMA_TERMINATED=_BoolConverter,
    SPLIT_BEFORE_ARITHMETIC_OPERATOR=_BoolConverter,
    SPLIT_BEFORE_BITWISE_OPERATOR=_BoolConverter,
    SPLIT_BEFORE_CLOSING_BRACKET=_BoolConverter,
    SPLIT_BEFORE_DICT_SET_GENERATOR=_BoolConverter,
    SPLIT_BEFORE_DOT=_BoolConverter,
    SPLIT_BEFORE_EXPRESSION_AFTER_OPENING_PAREN=_BoolConverter,
    SPLIT_BEFORE_FIRST_ARGUMENT=_BoolConverter,
    SPLIT_BEFORE_LOGICAL_OPERATOR=_BoolConverter,
    SPLIT_BEFORE_NAMED_ASSIGNS=_BoolConverter,
    SPLIT_COMPLEX_COMPREHENSION=_BoolConverter,
    SPLIT_PENALTY_AFTER_OPENING_BRACKET=int,
    SPLIT_PENALTY_AFTER_UNARY_OPERATOR=int,
    SPLIT_PENALTY_ARITHMETIC_OPERATOR=int,
    SPLIT_PENALTY_BEFORE_IF_EXPR=int,
    SPLIT_PENALTY_BITWISE_OPERATOR=int,
    SPLIT_PENALTY_COMPREHENSION=int,
    SPLIT_PENALTY_EXCESS_CHARACTER=int,
    SPLIT_PENALTY_FOR_ADDED_LINE_SPLIT=int,
    SPLIT_PENALTY_IMPORT_NAMES=int,
    SPLIT_PENALTY_LOGICAL_OPERATOR=int,
    USE_TABS=_BoolConverter,
)


def CreateStyleFromConfig(style_config):
  """Create a style dict from the given config.

  Arguments:
    style_config: either a style name or a file name. The file is expected to
      contain settings. It can have a special BASED_ON_STYLE setting naming the
      style which it derives from. If no such setting is found, it derives from
      the default style. When style_config is None, the _GLOBAL_STYLE_FACTORY
      config is created.

  Returns:
    A style dict.

  Raises:
    StyleConfigError: if an unknown style option was encountered.
  """

  def GlobalStyles():
    for style, _ in _DEFAULT_STYLE_TO_FACTORY:
      yield style

  def_style = False
  if style_config is None:
    for style in GlobalStyles():
      if _style == style:
        def_style = True
        break
    if not def_style:
      return _style
    return _GLOBAL_STYLE_FACTORY()

  if isinstance(style_config, dict):
    config = _CreateConfigParserFromConfigDict(style_config)
  elif isinstance(style_config, str):
    style_factory = _STYLE_NAME_TO_FACTORY.get(style_config.lower())
    if style_factory is not None:
      return style_factory()
    if style_config.startswith('{'):
      # Most likely a style specification from the command line.
      config = _CreateConfigParserFromConfigString(style_config)
    else:
      # Unknown config name: assume it's a file name then.
      config = _CreateConfigParserFromConfigFile(style_config)
  return _CreateStyleFromConfigParser(config)


def _CreateConfigParserFromConfigDict(config_dict):
  config = ConfigParser()
  config.add_section('style')
  for key, value in config_dict.items():
    config.set('style', key, str(value))
  return config


def _CreateConfigParserFromConfigString(config_string):
  """Given a config string from the command line, return a config parser."""
  if config_string[0] != '{' or config_string[-1] != '}':
    raise StyleConfigError(
        "Invalid style dict syntax: '{}'.".format(config_string))
  config = ConfigParser()
  config.add_section('style')
  for key, value, _ in re.findall(
      r'([a-zA-Z0-9_]+)\s*[:=]\s*'
      r'(?:'
      r'((?P<quote>[\'"]).*?(?P=quote)|'
      r'[a-zA-Z0-9_]+)'
      r')', config_string):  # yapf: disable
    config.set('style', key, value)
  return config


def _CreateConfigParserFromConfigFile(config_filename):
  """Read the file and return a ConfigParser object."""
  if not os.path.exists(config_filename):
    # Provide a more meaningful error here.
    raise StyleConfigError(
        '"{0}" is not a valid style or file path'.format(config_filename))
  config = ConfigParser()

  if config_filename.endswith(PYPROJECT_TOML):
    with open(config_filename, 'rb') as style_file:
      pyproject_toml = tomllib.load(style_file)
      style_dict = pyproject_toml.get('tool', {}).get('yapf', None)
      if style_dict is None:
        raise StyleConfigError(
            'Unable to find section [tool.yapf] in {0}'.format(config_filename))
      config.add_section('style')
      for k, v in style_dict.items():
        config.set('style', k, str(v))
      return config

  with open(config_filename) as style_file:
    config.read_file(style_file)

    if config_filename.endswith(SETUP_CONFIG):
      if not config.has_section('yapf'):
        raise StyleConfigError(
            'Unable to find section [yapf] in {0}'.format(config_filename))
      return config

    if config_filename.endswith(LOCAL_STYLE):
      if not config.has_section('style'):
        raise StyleConfigError(
            'Unable to find section [style] in {0}'.format(config_filename))
      return config

    if not config.has_section('style'):
      raise StyleConfigError(
          'Unable to find section [style] in {0}'.format(config_filename))
    return config


def _CreateStyleFromConfigParser(config):
  """Create a style dict from a configuration file.

  Arguments:
    config: a ConfigParser object.

  Returns:
    A style dict.

  Raises:
    StyleConfigError: if an unknown style option was encountered.
  """
  # Initialize the base style.
  section = 'yapf' if config.has_section('yapf') else 'style'
  if config.has_option('style', 'based_on_style'):
    based_on = config.get('style', 'based_on_style').lower()
    base_style = _STYLE_NAME_TO_FACTORY[based_on]()
  elif config.has_option('yapf', 'based_on_style'):
    based_on = config.get('yapf', 'based_on_style').lower()
    base_style = _STYLE_NAME_TO_FACTORY[based_on]()
  else:
    base_style = _GLOBAL_STYLE_FACTORY()

  # Read all options specified in the file and update the style.
  for option, value in config.items(section):
    if option.lower() == 'based_on_style':
      # Now skip this one - we've already handled it and it's not one of the
      # recognized style options.
      continue
    option = option.upper()
    if option not in _STYLE_OPTION_VALUE_CONVERTER:
      raise StyleConfigError('Unknown style option "{0}"'.format(option))
    try:
      base_style[option] = _STYLE_OPTION_VALUE_CONVERTER[option](value)
    except ValueError:
      raise StyleConfigError("'{}' is not a valid setting for {}.".format(
          value, option))
  return base_style


# The default style - used if yapf is not invoked without specifically
# requesting a formatting style.
DEFAULT_STYLE = 'pep8'
DEFAULT_STYLE_FACTORY = CreatePEP8Style
_GLOBAL_STYLE_FACTORY = CreatePEP8Style

# The name of the file to use for global style definition.
GLOBAL_STYLE = (
    os.path.join(
        os.getenv('XDG_CONFIG_HOME') or os.path.expanduser('~/.config'), 'yapf',
        'style'))

# The name of the file to use for directory-local style definition.
LOCAL_STYLE = '.style.yapf'

# Alternative place for directory-local style definition. Style should be
# specified in the '[yapf]' section.
SETUP_CONFIG = 'setup.cfg'

# Style definition by local pyproject.toml file. Style should be specified
# in the '[tool.yapf]' section.
PYPROJECT_TOML = 'pyproject.toml'

# TODO(eliben): For now we're preserving the global presence of a style dict.
# Refactor this so that the style is passed around through yapf rather than
# being global.
_style = None
SetGlobalStyle(_GLOBAL_STYLE_FACTORY())