#!/usr/bin/env python3
#
#  issues.py
"""
Roles and nodes for GitHub issues and Pull Requests.
"""
#
#  Copyright © 2020-2021 Dominic Davis-Foster <dominic@davis-foster.co.uk>
#
#  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.
#
#  Based on pyspecific.py from the Python documentation.
#  Copyright 2008-2014 by Georg Brandl.
#  Licensed under the PSF License 2.0
#
#  Parts of the docstrings based on https://docutils.sourceforge.io/docs/howto/rst-roles.html
#

# stdlib
import warnings
import xml.sax.saxutils
from typing import Any, Dict, List, Optional, Tuple, Union

# 3rd party
import requests  # nodep
from apeye.url import URL
from bs4 import BeautifulSoup  # type: ignore[import-untyped]
from docutils import nodes
from docutils.nodes import system_message
from docutils.parsers.rst.states import Inliner
from sphinx.util.nodes import split_explicit_title
from sphinx.writers.html5 import HTML5Translator
from sphinx.writers.latex import LaTeXTranslator

# this package
from sphinx_toolbox.cache import cache
from sphinx_toolbox.utils import make_github_url

__all__ = (
		"IssueNode",
		"IssueNodeWithName",
		"issue_role",
		"pull_role",
		"visit_issue_node",
		"depart_issue_node",
		"get_issue_title",
		)


class IssueNode(nodes.reference):
	"""
	Docutils Node to represent a link to a GitHub *Issue* or *Pull Request*.

	:param issue_number: The number of the issue or pull request.
	:param refuri: The URL of the issue / pull request on GitHub.
	"""

	has_tooltip: bool
	issue_number: int
	issue_url: str

	def __init__(
			self,
			issue_number: Union[str, int],
			refuri: Union[str, URL],
			**kwargs,
			):
		self.has_tooltip = False
		self.issue_number = int(issue_number)
		self.issue_url = str(refuri)

		source = f"#{issue_number}"
		super().__init__(source, source, refuri=self.issue_url)

	@property
	def _copy_kwargs(self):  # pragma: no cover  # noqa: MAN002
		return {"issue_number": self.issue_number, "refuri": self.issue_url}

	def copy(self) -> "IssueNode":  # pragma: no cover
		"""
		Return a copy of the :class:`sphinx_toolbox.github.issues.IssueNode`.
		"""

		# This was required to stop some breakage, but it doesn't seem to run during the tests.
		obj = self.__class__(**self._copy_kwargs)
		obj.document = self.document
		obj.has_tooltip = self.has_tooltip
		obj.line = self.line
		return obj


class IssueNodeWithName(IssueNode):
	"""
	Docutils Node to represent a link to a GitHub *Issue* or *Pull Request*, with the repository name shown.

	.. versionadded:: 2.4.0

	:param repo_name: The full name of the repository, in the form ``owner/name``.
	:param issue_number: The number of the issue or pull request.
	:param refuri: The URL of the issue / pull request on GitHub.
	"""

	repo_name: str

	def __init__(
			self,
			repo_name: str,
			issue_number: Union[str, int],
			refuri: Union[str, URL],
			**kwargs,
			):
		self.has_tooltip = False
		self.issue_number = int(issue_number)
		self.issue_url = str(refuri)
		self.repo_name = str(repo_name)

		source = f"{repo_name}#{issue_number}"
		nodes.reference.__init__(self, source, source, refuri=self.issue_url)

	@property
	def _copy_kwargs(self) -> Dict[str, Any]:  # pragma: no cover
		return {"repo_name": self.repo_name, "issue_number": self.issue_number, "refuri": self.issue_url}


def issue_role(
		name: str,
		rawtext: str,
		text: str,
		lineno: int,
		inliner: Inliner,
		options: Dict[str, Any] = {},
		content: List[str] = []
		) -> Tuple[List[IssueNode], List[system_message]]:
	"""
	Adds a link to the given issue on GitHub.

	:param name: The local name of the interpreted role, the role name actually used in the document.
	:param rawtext: A string containing the entire interpreted text input, including the role and markup.
	:param text: The interpreted text content.
	:param lineno: The line number where the interpreted text begins.
	:param inliner: The :class:`docutils.parsers.rst.states.Inliner` object that called :func:`~.issue_role`.
		It contains the several attributes useful for error reporting and document tree access.
	:param options: A dictionary of directive options for customization (from the ``role`` directive),
		to be interpreted by the function.
		Used for additional attributes for the generated elements and other functionality.
	:param content: A list of strings, the directive content for customization (from the ``role`` directive).
		To be interpreted by the function.

	:return: A list containing the created node, and a list containing any messages generated during the function.

	.. latex:clearpage::
	"""

	has_t, issue_number, repository = split_explicit_title(text)
	issue_number = nodes.unescape(issue_number)

	messages: List[system_message] = []
	refnode: IssueNode

	if has_t:
		repository_parts = nodes.unescape(repository).split('/')
		if len(repository_parts) != 2:
			warning_message = inliner.document.reporter.warning(
					f"Invalid repository '{repository}' for issue #{issue_number}.",
					)
			messages.append(warning_message)

		else:
			refnode = IssueNodeWithName(
					repo_name=repository,
					issue_number=issue_number,
					refuri=make_github_url(*repository_parts) / "issues" / str(int(issue_number)),
					)
			return [refnode], messages

	issues_url = inliner.document.settings.env.app.config.github_issues_url
	refnode = IssueNode(issue_number=issue_number, refuri=issues_url / str(int(issue_number)))

	return [refnode], messages


def pull_role(
		name: str,
		rawtext: str,
		text: str,
		lineno: int,
		inliner: Inliner,
		options: Dict[str, Any] = {},
		content: List[str] = []
		) -> Tuple[List[IssueNode], List[system_message]]:
	"""
	Adds a link to the given pulll request on GitHub.

	:param name: The local name of the interpreted role, the role name actually used in the document.
	:param rawtext: A string containing the entire interpreted text input, including the role and markup.
	:param text: The interpreted text content.
	:param lineno: The line number where the interpreted text begins.
	:param inliner: The :class:`docutils.parsers.rst.states.Inliner` object that called :func:`~.pull_role`.
		It contains the several attributes useful for error reporting and document tree access.
	:param options: A dictionary of directive options for customization (from the ``role`` directive),
		to be interpreted by the function.
		Used for additional attributes for the generated elements and other functionality.
	:param content: A list of strings, the directive content for customization (from the ``role`` directive).
		To be interpreted by the function.

	:return: A list containing the created node, and a list containing any messages generated during the function.
	"""

	has_t, issue_number, repository = split_explicit_title(text)
	issue_number = nodes.unescape(issue_number)

	messages: List[system_message] = []
	refnode: IssueNode

	if has_t:
		repository_parts = nodes.unescape(repository).split('/')
		if len(repository_parts) != 2:
			warning_message = inliner.document.reporter.warning(
					f"Invalid repository '{repository}' for pull request #{issue_number}."
					)
			messages.append(warning_message)

		else:
			refnode = IssueNodeWithName(
					repo_name=repository,
					issue_number=issue_number,
					refuri=make_github_url(*repository_parts) / "pull" / str(int(issue_number)),
					)
			return [refnode], messages

	pull_url = inliner.document.settings.env.app.config.github_pull_url
	refnode = IssueNode(issue_number=issue_number, refuri=pull_url / str(int(issue_number)))

	return [refnode], messages


def visit_issue_node(translator: HTML5Translator, node: IssueNode) -> None:
	"""
	Visit an :class:`~.IssueNode`.

	If the node points to a valid issue / pull request,
	add a tooltip giving the title of the issue / pull request and a hyperlink to the page on GitHub.

	:param translator:
	:param node: The node being visited.
	"""

	issue_title = get_issue_title(node.issue_url)

	if issue_title:
		node.has_tooltip = True
		translator.body.append(f'<abbr title="{issue_title}">')
		translator.visit_reference(node)
	else:
		warnings.warn(f"Issue/Pull Request #{node.issue_number} not found.")


def depart_issue_node(translator: HTML5Translator, node: IssueNode) -> None:
	"""
	Depart an :class:`~.IssueNode`.

	:param translator:
	:param node: The node being visited.
	"""

	if node.has_tooltip:
		translator.depart_reference(node)
		translator.body.append("</abbr>")


def _visit_issue_node_latex(translator: LaTeXTranslator, node: IssueNode) -> None:
	"""
	Visit an :class:`~.IssueNode`.

	If the node points to a valid issue / pull request,
	add a tooltip giving the title of the issue / pull request and a hyperlink to the page on GitHub.

	:param translator:
	:param node: The node being visited.
	"""

	node.children = node.children[:1]
	translator.visit_reference(node)


def _depart_issue_node_latex(translator: LaTeXTranslator, node: IssueNode) -> None:
	"""
	Depart an :class:`~.IssueNode`.

	:param translator:
	:param node: The node being visited.
	"""

	translator.depart_reference(node)


def get_issue_title(issue_url: str) -> Optional[str]:
	"""
	Returns the title of the issue with the given url,
	or :py:obj:`None` if the issue isn't found.

	:param issue_url:
	"""  # noqa: D400

	try:
		r = cache.session.get(issue_url, timeout=30)
	except requests.exceptions.RequestException:
		return None

	if r.status_code == 200:
		soup = BeautifulSoup(r.content, "html5lib")
		try:
			content = soup.find_all("span", attrs={"class": "js-issue-title"})[0].text
		except IndexError:
			# As of 13 Jan 2023 GitHub seems to use a bidirectional text tag instead
			content = soup.find_all("bdi", attrs={"class": "js-issue-title"})[0].text

		content = xml.sax.saxutils.escape(content).replace('"', "&quot;")
		return content.strip()

	return None
