# -*- coding: utf8 -*-
# Copyright (c) 2019 Niklas Rosenstein
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# 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:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# 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
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.

import dataclasses
import re
import typing as t

import docspec

from pydoc_markdown.interfaces import Processor, Resolver

# TODO @NiklasRosenstein Figure out a way to mark text linking to other
#     objects so that they can be properly handled by the renderer.


@dataclasses.dataclass
class PydocmdProcessor(Processor):
    """
    The Pydoc-Markdown processor for Markdown docstrings. This processor parses docstrings
    formatted like the examples below and turns them into proper Markdown markup.

    Examples:

    ```
    # Arguments

    arg1 (int): The first argument.
    kwargs (dict): Keyword arguments.

    # Raises
    RuntimeError: If something bad happens.
    ValueError: If an invalid argument is specified.

    # Returns
    A value.
    ```

    Renders as:

    # Arguments

    arg1 (int): The first argument.
    kwargs (dict): Keyword arguments.

    # Raises
    RuntimeError: If something bad happens.
    ValueError: If an invalid argument is specified.

    # Returns
    A value.

    @doc:fmt:pydocmd
    """

    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 = []
        codeblock_opened = False
        current_section = None
        for line in node.docstring.content.split("\n"):
            if line.startswith("```"):
                codeblock_opened = not codeblock_opened
            if not codeblock_opened:
                line, current_section = self._preprocess_line(line, current_section)
            lines.append(line)
        node.docstring.content = "\n".join(lines)

    def _preprocess_line(self, line, current_section):
        match = re.match(r"# (.*)$", line)
        if match:
            current_section = match.group(1).strip().lower()
            line = re.sub(r"# (.*)$", r"__\1__\n", line)

        if current_section in ("arguments", "parameters"):
            style: t.Optional[str] = r"- __\1__:\3"
        elif current_section in ("attributes", "members", "raises"):
            style = r"- `\1`:\3"
        elif current_section in ("returns",):
            style = r"`\1`:\3"
        else:
            style = None
        if style:
            #                  | ident  | types     | doc
            line = re.sub(r"\s*([^\\:]+)(\s*\(.+\))?:(.*)$", style, line)

        # Rewrite the argument type in the parentheses.
        if current_section in ("arguments", "parameters"):

            def sub(m):
                return "__{}__ (`{}`):".format(m.group(1), m.group(2))

            line = re.sub(r"__(\w+)\s*\((.*?)\)__:", sub, line)

        return line, current_section