text: # Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
  # For details: https://github.com/PyCQA/pylint/blob/main/LICENSE
  # Copyright (c) https://github.com/PyCQA/pylint/blob/main/CONTRIBUTORS.txt
  
  from __future__ import annotations
  
  import linecache
  from typing import TYPE_CHECKING
  
  from astroid import nodes
  
  from pylint import checkers
  from pylint.checkers.utils import only_required_for_messages
  from pylint.interfaces import HIGH
  
  if TYPE_CHECKING:
      from pylint.lint import PyLinter
  
  
  class DocStringStyleChecker(checkers.BaseChecker):
      """Checks format of docstrings based on PEP 0257."""
  
      name = "docstyle"
  
      msgs = {
          "C0198": (
              'Bad docstring quotes in %s, expected """, given %s',
              "bad-docstring-quotes",
              "Used when a docstring does not have triple double quotes.",
          ),
          "C0199": (
              "First line empty in %s docstring",
              "docstring-first-line-empty",
              "Used when a blank line is found at the beginning of a docstring.",
          ),
      }
  
      @only_required_for_messages("docstring-first-line-empty", "bad-docstring-quotes")
      def visit_module(self, node: nodes.Module) -> None:
          self._check_docstring("module", node)
  
      def visit_classdef(self, node: nodes.ClassDef) -> None:
          self._check_docstring("class", node)
  
      def visit_functiondef(self, node: nodes.FunctionDef) -> None:
          ftype = "method" if node.is_method() else "function"
          self._check_docstring(ftype, node)
  
      visit_asyncfunctiondef = visit_functiondef
  
      def _check_docstring(self, node_type, node):
          docstring = node.doc_node.value if node.doc_node else None
          if docstring and docstring[0] == "\n":
              self.add_message(
                  "docstring-first-line-empty",
                  node=node,
                  args=(node_type,),
                  confidence=HIGH,
              )
  
          # Use "linecache", instead of node.as_string(), because the latter
          # looses the original form of the docstrings.
  
          if docstring:
              lineno = node.fromlineno + 1
              line = linecache.getline(node.root().file, lineno).lstrip()
              if line and line.find('"""') == 0:
                  return
              if line and "'''" in line:
                  quotes = "'''"
              elif line and line[0] == '"':
                  quotes = '"'
              elif line and line[0] == "'":
                  quotes = "'"
              else:
                  quotes = False
              if quotes:
                  self.add_message(
                      "bad-docstring-quotes",
                      node=node,
                      args=(node_type, quotes),
                      confidence=HIGH,
                  )
  
  
  def register(linter: PyLinter) -> None:
      linter.register_checker(DocStringStyleChecker(linter))
  