text: import argparse
  import contextlib
  import functools
  import logging
  import os
  import re
  import subprocess
  import time
  import unicodedata
  from typing import Any
  from typing import Collection
  from typing import Dict
  from typing import List
  from typing import MutableMapping
  from typing import Sequence
  from typing import Set
  from typing import Tuple
  
  from identify.identify import tags_from_path
  
  from pre_commit import color
  from pre_commit import git
  from pre_commit import output
  from pre_commit.clientlib import load_config
  from pre_commit.hook import Hook
  from pre_commit.languages.all import languages
  from pre_commit.repository import all_hooks
  from pre_commit.repository import install_hook_envs
  from pre_commit.staged_files_only import staged_files_only
  from pre_commit.store import Store
  from pre_commit.util import cmd_output_b
  
  
  logger = logging.getLogger('pre_commit')
  
  
  def _len_cjk(msg: str) -> int:
      widths = {'A': 1, 'F': 2, 'H': 1, 'N': 1, 'Na': 1, 'W': 2}
      return sum(widths[unicodedata.east_asian_width(c)] for c in msg)
  
  
  def _start_msg(*, start: str, cols: int, end_len: int) -> str:
      dots = '.' * (cols - _len_cjk(start) - end_len - 1)
      return f'{start}{dots}'
  
  
  def _full_msg(
          *,
          start: str,
          cols: int,
          end_msg: str,
          end_color: str,
          use_color: bool,
          postfix: str = '',
  ) -> str:
      dots = '.' * (cols - _len_cjk(start) - len(postfix) - len(end_msg) - 1)
      end = color.format_color(end_msg, end_color, use_color)
      return f'{start}{dots}{postfix}{end}\n'
  
  
  def filter_by_include_exclude(
          names: Collection[str],
          include: str,
          exclude: str,
  ) -> List[str]:
      include_re, exclude_re = re.compile(include), re.compile(exclude)
      return [
          filename for filename in names
          if include_re.search(filename)
          if not exclude_re.search(filename)
      ]
  
  
  class Classifier:
      def __init__(self, filenames: Collection[str]) -> None:
          self.filenames = [f for f in filenames if os.path.lexists(f)]
  
      @functools.lru_cache(maxsize=None)
      def _types_for_file(self, filename: str) -> Set[str]:
          return tags_from_path(filename)
  
      def by_types(
              self,
              names: Sequence[str],
              types: Collection[str],
              types_or: Collection[str],
              exclude_types: Collection[str],
      ) -> List[str]:
          types = frozenset(types)
          types_or = frozenset(types_or)
          exclude_types = frozenset(exclude_types)
          ret = []
          for filename in names:
              tags = self._types_for_file(filename)
              if tags >= types and tags & types_or and not tags & exclude_types:
                  ret.append(filename)
          return ret
  
      def filenames_for_hook(self, hook: Hook) -> Tuple[str, ...]:
          names = self.filenames
          names = filter_by_include_exclude(names, hook.files, hook.exclude)
          names = self.by_types(
              names,
              hook.types,
              hook.types_or,
              hook.exclude_types,
          )
          return tuple(names)
  
      @classmethod
      def from_config(
              cls,
              filenames: Collection[str],
              include: str,
              exclude: str,
      ) -> 'Classifier':
          # on windows we normalize all filenames to use forward slashes
          # this makes it easier to filter using the `files:` regex
          # this also makes improperly quoted shell-based hooks work better
          # see #1173
          if os.altsep == '/' and os.sep == '\\':
              filenames = [f.replace(os.sep, os.altsep) for f in filenames]
          filenames = filter_by_include_exclude(filenames, include, exclude)
          return Classifier(filenames)
  
  
  def _get_skips(environ: MutableMapping[str, str]) -> Set[str]:
      skips = environ.get('SKIP', '')
      return {skip.strip() for skip in skips.split(',') if skip.strip()}
  
  
  SKIPPED = 'Skipped'
  NO_FILES = '(no files to check)'
  
  
  def _subtle_line(s: str, use_color: bool) -> None:
      output.write_line(color.format_color(s, color.SUBTLE, use_color))
  
  
  def _run_single_hook(
          classifier: Classifier,
          hook: Hook,
          skips: Set[str],
          cols: int,
          diff_before: bytes,
          verbose: bool,
          use_color: bool,
  ) -> Tuple[bool, bytes]:
      filenames = classifier.filenames_for_hook(hook)
  
      if hook.id in skips or hook.alias in skips:
          output.write(
              _full_msg(
                  start=hook.name,
                  end_msg=SKIPPED,
                  end_color=color.YELLOW,
                  use_color=use_color,
                  cols=cols,
              ),
          )
          duration = None
          retcode = 0
          diff_after = diff_before
          files_modified = False
          out = b''
      elif not filenames and not hook.always_run:
          output.write(
              _full_msg(
                  start=hook.name,
                  postfix=NO_FILES,
                  end_msg=SKIPPED,
                  end_color=color.TURQUOISE,
                  use_color=use_color,
                  cols=cols,
              ),
          )
          duration = None
          retcode = 0
          diff_after = diff_before
          files_modified = False
          out = b''
      else:
          # print hook and dots first in case the hook takes a while to run
          output.write(_start_msg(start=hook.name, end_len=6, cols=cols))
  
          if not hook.pass_filenames:
              filenames = ()
          time_before = time.time()
          language = languages[hook.language]
          retcode, out = language.run_hook(hook, filenames, use_color)
          duration = round(time.time() - time_before, 2) or 0
          diff_after = _get_diff()
  
          # if the hook makes changes, fail the commit
          files_modified = diff_before != diff_after
  
          if retcode or files_modified:
              print_color = color.RED
              status = 'Failed'
          else:
              print_color = color.GREEN
              status = 'Passed'
  
          output.write_line(color.format_color(status, print_color, use_color))
  
      if verbose or hook.verbose or retcode or files_modified:
          _subtle_line(f'- hook id: {hook.id}', use_color)
  
          if (verbose or hook.verbose) and duration is not None:
              _subtle_line(f'- duration: {duration}s', use_color)
  
          if retcode:
              _subtle_line(f'- exit code: {retcode}', use_color)
  
          # Print a message if failing due to file modifications
          if files_modified:
              _subtle_line('- files were modified by this hook', use_color)
  
          if out.strip():
              output.write_line()
              output.write_line_b(out.strip(), logfile_name=hook.log_file)
              output.write_line()
  
      return files_modified or bool(retcode), diff_after
  
  
  def _compute_cols(hooks: Sequence[Hook]) -> int:
      """Compute the number of columns to display hook messages.  The widest
      that will be displayed is in the no files skipped case:
  
          Hook name...(no files to check) Skipped
      """
      if hooks:
          name_len = max(_len_cjk(hook.name) for hook in hooks)
      else:
          name_len = 0
  
      cols = name_len + 3 + len(NO_FILES) + 1 + len(SKIPPED)
      return max(cols, 80)
  
  
  def _all_filenames(args: argparse.Namespace) -> Collection[str]:
      # these hooks do not operate on files
      if args.hook_stage in {'post-checkout', 'post-commit'}:
          return ()
      elif args.hook_stage in {'prepare-commit-msg', 'commit-msg'}:
          return (args.commit_msg_filename,)
      elif args.from_ref and args.to_ref:
          return git.get_changed_files(args.from_ref, args.to_ref)
      elif args.files:
          return args.files
      elif args.all_files:
          return git.get_all_files()
      elif git.is_in_merge_conflict():
          return git.get_conflicted_files()
      else:
          return git.get_staged_files()
  
  
  def _get_diff() -> bytes:
      _, out, _ = cmd_output_b('git', 'diff', '--no-ext-diff', retcode=None)
      return out
  
  
  def _run_hooks(
          config: Dict[str, Any],
          hooks: Sequence[Hook],
          args: argparse.Namespace,
          environ: MutableMapping[str, str],
  ) -> int:
      """Actually run the hooks."""
      skips = _get_skips(environ)
      cols = _compute_cols(hooks)
      classifier = Classifier.from_config(
          _all_filenames(args), config['files'], config['exclude'],
      )
      retval = 0
      prior_diff = _get_diff()
      for hook in hooks:
          current_retval, prior_diff = _run_single_hook(
              classifier, hook, skips, cols, prior_diff,
              verbose=args.verbose, use_color=args.color,
          )
          retval |= current_retval
          if retval and config['fail_fast']:
              break
      if retval and args.show_diff_on_failure and prior_diff:
          if args.all_files:
              output.write_line(
                  'pre-commit hook(s) made changes.\n'
                  'If you are seeing this message in CI, '
                  'reproduce locally with: `pre-commit run --all-files`.\n'
                  'To run `pre-commit` as part of git workflow, use '
                  '`pre-commit install`.',
              )
          output.write_line('All changes made by hooks:')
          # args.color is a boolean.
          # See user_color function in color.py
          git_color_opt = 'always' if args.color else 'never'
          subprocess.call((
              'git', '--no-pager', 'diff', '--no-ext-diff',
              f'--color={git_color_opt}',
          ))
  
      return retval
  
  
  def _has_unmerged_paths() -> bool:
      _, stdout, _ = cmd_output_b('git', 'ls-files', '--unmerged')
      return bool(stdout.strip())
  
  
  def _has_unstaged_config(config_file: str) -> bool:
      retcode, _, _ = cmd_output_b(
          'git', 'diff', '--no-ext-diff', '--exit-code', config_file,
          retcode=None,
      )
      # be explicit, other git errors don't mean it has an unstaged config.
      return retcode == 1
  
  
  def run(
          config_file: str,
          store: Store,
          args: argparse.Namespace,
          environ: MutableMapping[str, str] = os.environ,
  ) -> int:
      stash = not args.all_files and not args.files
  
      # Check if we have unresolved merge conflict files and fail fast.
      if _has_unmerged_paths():
          logger.error('Unmerged files.  Resolve before committing.')
          return 1
      if bool(args.from_ref) != bool(args.to_ref):
          logger.error('Specify both --from-ref and --to-ref.')
          return 1
      if stash and _has_unstaged_config(config_file):
          logger.error(
              f'Your pre-commit configuration is unstaged.\n'
              f'`git add {config_file}` to fix this.',
          )
          return 1
      if (
              args.hook_stage in {'prepare-commit-msg', 'commit-msg'} and
              not args.commit_msg_filename
      ):
          logger.error(
              f'`--commit-msg-filename` is required for '
              f'`--hook-stage {args.hook_stage}`',
          )
          return 1
      # prevent recursive post-checkout hooks (#1418)
      if (
              args.hook_stage == 'post-checkout' and
              environ.get('_PRE_COMMIT_SKIP_POST_CHECKOUT')
      ):
          return 0
  
      # Expose from-ref / to-ref as environment variables for hooks to consume
      if args.from_ref and args.to_ref:
          # legacy names
          environ['PRE_COMMIT_ORIGIN'] = args.from_ref
          environ['PRE_COMMIT_SOURCE'] = args.to_ref
          # new names
          environ['PRE_COMMIT_FROM_REF'] = args.from_ref
          environ['PRE_COMMIT_TO_REF'] = args.to_ref
  
      if args.remote_name and args.remote_url:
          environ['PRE_COMMIT_REMOTE_NAME'] = args.remote_name
          environ['PRE_COMMIT_REMOTE_URL'] = args.remote_url
  
      if args.checkout_type:
          environ['PRE_COMMIT_CHECKOUT_TYPE'] = args.checkout_type
  
      # Set pre_commit flag
      environ['PRE_COMMIT'] = '1'
  
      with contextlib.ExitStack() as exit_stack:
          if stash:
              exit_stack.enter_context(staged_files_only(store.directory))
  
          config = load_config(config_file)
          hooks = [
              hook
              for hook in all_hooks(config, store)
              if not args.hook or hook.id == args.hook or hook.alias == args.hook
              if args.hook_stage in hook.stages
          ]
  
          if args.hook and not hooks:
              output.write_line(
                  f'No hook with id `{args.hook}` in stage `{args.hook_stage}`',
              )
              return 1
  
          install_hook_envs(hooks, store)
  
          return _run_hooks(config, hooks, args, environ)
  
      # https://github.com/python/mypy/issues/7726
      raise AssertionError('unreachable')
  