# -*- coding: utf8 -*-
# Copyright (c) 2019 Niklas Rosenstein
#
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# of this software and associated documentation files (the "Software"), to
# deal in the Software without restriction, including without limitation the
# rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
# sell copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
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# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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# IN THE SOFTWARE.

import dataclasses
import re
import typing as t

import docspec

from pydoc_markdown.contrib.processors.sphinx import generate_sections_markdown
from pydoc_markdown.interfaces import Processor, Resolver


@dataclasses.dataclass
class GoogleProcessor(Processor):
    """
    This class implements the preprocessor for Google and PEP 257 docstrings. It converts
    docstrings formatted in the Google docstyle to Markdown syntax.

    References:

    * https://sphinxcontrib-napoleon.readthedocs.io/en/latest/example_google.html
    * https://www.python.org/dev/peps/pep-0257/

    Example:

    ```
    Attributes:
        module_level_variable1 (int): Module level variables may be documented in
            either the ``Attributes`` section of the module docstring, or in an
            inline docstring immediately following the variable.

            Either form is acceptable, but the two should not be mixed. Choose
            one convention to document module level variables and be consistent
            with it.

    Todo:
        * For module TODOs
        * You have to also use ``sphinx.ext.todo`` extension
    ```

    Renders as:

    Attributes:
        module_level_variable1 (int): Module level variables may be documented in
            either the ``Attributes`` section of the module docstring, or in an
            inline docstring immediately following the variable.

            Either form is acceptable, but the two should not be mixed. Choose
            one convention to document module level variables and be consistent
            with it.

    Todo:
        * For module TODOs
        * You have to also use ``sphinx.ext.todo`` extension

    @doc:fmt:google
    """

    _param_res = [
        re.compile(r"^(?P<param>\S+):\s+(?P<desc>.+)$"),
        re.compile(r"^(?P<param>\S+)\s+\((?P<type>[^)]+)\):\s+(?P<desc>.+)$"),
        re.compile(r"^(?P<param>\S+)\s+--\s+(?P<desc>.+)$"),
        re.compile(r"^(?P<param>\S+)\s+\{\[(?P<type>\S+)\]\}\s+--\s+(?P<desc>.+)$"),
        re.compile(r"^(?P<param>\S+)\s+\{(?P<type>\S+)\}\s+--\s+(?P<desc>.+)$"),
    ]

    _keywords_map = {
        "Args:": "Arguments",
        "Arguments:": "Arguments",
        "Attributes:": "Attributes",
        "Example:": "Example",
        "Examples:": "Examples",
        "Keyword Args:": "Arguments",
        "Keyword Arguments:": "Arguments",
        "Methods:": "Methods",
        "Note:": "Notes",
        "Notes:": "Notes",
        "Other Parameters:": "Arguments",
        "Parameters:": "Arguments",
        "Return:": "Returns",
        "Returns:": "Returns",
        "Raises:": "Raises",
        "References:": "References",
        "See Also:": "See Also",
        "Todo:": "Todo",
        "Warning:": "Warnings",
        "Warnings:": "Warnings",
        "Warns:": "Warns",
        "Yield:": "Yields",
        "Yields:": "Yields",
    }

    def check_docstring_format(self, docstring: str) -> bool:
        for section_name in self._keywords_map:
            if section_name in docstring:
                return True
        return False

    def process(self, modules: t.List[docspec.Module], resolver: t.Optional[Resolver]) -> None:
        docspec.visit(modules, self._process)

    def _process(self, node: docspec.ApiObject):
        if not node.docstring:
            return

        lines = []
        current_lines: t.List[str] = []
        in_codeblock = False
        keyword = None

        def _commit():
            if keyword:
                generate_sections_markdown(lines, {keyword: current_lines})
            else:
                lines.extend(current_lines)
            current_lines.clear()

        for line in node.docstring.content.split("\n"):
            if line.lstrip().startswith("```"):
                in_codeblock = not in_codeblock
                current_lines.append(line)
                continue

            if in_codeblock:
                current_lines.append(line)
                continue

            line = line.strip()
            if line in self._keywords_map:
                _commit()
                keyword = self._keywords_map[line]
                continue

            if keyword is None:
                lines.append(line)
                continue

            for param_re in self._param_res:
                param_match = param_re.match(line)
                if param_match:
                    if "type" in param_match.groupdict():
                        current_lines.append("- `{param}` _{type}_ - {desc}".format(**param_match.groupdict()))
                    else:
                        current_lines.append("- `{param}` - {desc}".format(**param_match.groupdict()))
                    break

            if not param_match:
                current_lines.append("  {line}".format(line=line))

        _commit()
        node.docstring.content = "\n".join(lines)