#!/usr/bin/env python3
#
#  commands.py
"""
Customised click commands and command groups.

.. versionadded:: 0.8.0
"""
#
#  Copyright © 2020-2021 Dominic Davis-Foster <dominic@davis-foster.co.uk>
#
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#  in the Software without restriction, including without limitation the rights
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#  copies of the Software, and to permit persons to whom the Software is
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#  copies or substantial portions of the Software.
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#  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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#  OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
#  OR OTHER DEALINGS IN THE SOFTWARE.
#
#  MarkdownHelpCommand.parse_args and the docstrings of ContextInheritingGroup
#  based on https://github.com/pallets/click
#  Copyright 2014 Pallets
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#

# stdlib
import difflib
import inspect
from textwrap import indent
from typing import TYPE_CHECKING, Any, Callable, List, Optional, Tuple

# 3rd party
import click
from click.core import iter_params_for_processing
from click.parser import split_opt
from click.utils import make_str
from domdf_python_tools.stringlist import DelimitedList
from domdf_python_tools.words import Plural
from mistletoe import block_token  # type: ignore[import]

# this package
from consolekit.terminal_colours import ColourTrilean, resolve_color_default, strip_ansi
from consolekit.utils import TerminalRenderer

__all__ = (
		"MarkdownHelpCommand",
		"MarkdownHelpGroup",
		"MarkdownHelpMixin",
		"RawHelpCommand",
		"RawHelpGroup",
		"RawHelpMixin",
		"SuggestionGroup",
		"ContextInheritingGroup",
		)

_argument = Plural("argument", "arguments")


class RawHelpMixin:
	"""
	Mixin class for :class:`click.Command` and :class:`click.Group` which leaves the help text unformatted.

	.. seealso:: :class:`~.RawHelpCommand` and :class:`~.RawHelpGroup`

	.. tip:: This can be combined with groups such as :class:`~.SuggestionGroup`.

	.. versionadded:: 0.8.0
	"""

	help: Optional[str]  # noqa: A003  # pylint: disable=redefined-builtin

	def format_help_text(self, ctx: click.Context, formatter: click.formatting.HelpFormatter) -> None:
		"""
		Writes the help text to the formatter if it exists.

		:param ctx:
		:param formatter:
		"""

		if not self.help:
			return

		text = inspect.cleandoc(self.help or '').partition('\x0c')[0]

		if getattr(self, "deprecated", False):
			text = f"(Deprecated) {text}"

		formatter.write('\n')
		formatter.write(indent(text, "  "))
		formatter.write('\n')


class RawHelpCommand(RawHelpMixin, click.Command):  # lgtm [py/conflicting-attributes]
	"""
	Subclass of :class:`click.Command` which leaves the help text unformatted.

	.. versionadded:: 0.8.0
	"""


class RawHelpGroup(RawHelpMixin, click.Group):  # lgtm [py/conflicting-attributes]
	"""
	Subclass of :class:`click.Group` which leaves the help text unformatted.

	.. versionadded:: 0.8.0
	"""


class MarkdownHelpMixin:
	"""
	Mixin class for :class:`click.Command` and :class:`click.Group` which treats the help text as markdown
	and prints a rendered representation.

	.. seealso:: :class:`~.MarkdownHelpCommand` and :class:`~.MarkdownHelpGroup`

	.. tip:: This can be combined with groups such as :class:`~.SuggestionGroup`.

	Tested in Gnome Terminal and Terminator (both libVTE-based), and PyCharm.
	libVTE has the best support.
	PyCharm's support for italics and strikethrough is poor.
	Support on Windows is, as expected, poor.

	Not tested on other terminals, but contributions are welcome to improve support.

	.. versionadded:: 0.8.0
	"""  # noqa: D400

	help: Optional[str]  # noqa: A003  # pylint: disable=redefined-builtin
	no_args_is_help: bool
	_colour: ColourTrilean = None

	if TYPE_CHECKING:

		def get_params(self, ctx: click.Context) -> List[click.Parameter]:
			"""
			Returns the list of parameters for this command in the order they should appear in the help page.

			:param ctx:
			"""

			raise NotImplementedError

		def make_parser(self, ctx: click.Context) -> click.OptionParser:
			"""
			Creates the underlying option parser for this command.

			:param ctx:
			"""

			raise NotImplementedError

	def format_help_text(self, ctx: click.Context, formatter: click.formatting.HelpFormatter) -> None:
		"""
		Writes the help text to the formatter if it exists.

		:param ctx:
		:param formatter:
		"""

		if not self.help:
			return

		text = inspect.cleandoc(self.help or '').partition('\x0c')[0]

		if getattr(self, "deprecated", False):
			text = f"(Deprecated) {text}"

		doc = block_token.Document(text)

		with TerminalRenderer() as renderer:
			rendered_doc = indent(renderer.render(doc).strip(), "  ")

		if resolve_color_default(self._colour) is False:
			# Also remove 'COMBINING LONG STROKE OVERLAY', used for strikethrough.
			rendered_doc = strip_ansi(rendered_doc).replace('̶', '')

		formatter.write('\n')
		formatter.write(rendered_doc)
		formatter.write('\n')


def parse_help_args(obj: MarkdownHelpMixin, ctx: click.Context, args: List[str]) -> List[str]:
	"""
	Helper function for markdown help classes to parse the given arguments
	and modify the context as necessary.

	.. versionadded:: 1.1.0

	:param obj:
	:param ctx:
	:param args:
	"""  # noqa: D400

	# This is necessary to parse any --colour/--no-colour commands before generating the help,
	# to ensure the option is honoured.

	if not args and obj.no_args_is_help and not ctx.resilient_parsing:
		click.echo(ctx.get_help(), color=ctx.color)
		ctx.exit()

	parser = obj.make_parser(ctx)
	opts, args, param_order = parser.parse_args(args=args)

	obj._colour = opts.get("colour", ctx.color)

	for param in iter_params_for_processing(param_order, obj.get_params(ctx)):
		value, args = param.handle_parse_result(ctx, opts, args)

	if args and not ctx.allow_extra_args and not ctx.resilient_parsing:
		args_string = DelimitedList(map(make_str, args))
		ctx.fail(f"Got unexpected extra {_argument(len(args))} ({args_string: })")

	ctx.args = args
	return args


class MarkdownHelpCommand(MarkdownHelpMixin, click.Command):  # lgtm [py/conflicting-attributes]
	"""
	Subclass of :class:`click.Command` which treats the help text as markdown
	and prints a rendered representation.

	Tested in Gnome Terminal and Terminator (both libVTE-based), and PyCharm.
	libVTE has the best support.
	PyCharm's support for italics and strikethrough is poor.
	Support on Windows is, as expected, poor.

	Not tested on other terminals, but contributions are welcome to improve support.

	.. versionadded:: 0.8.0
	"""  # noqa: D400

	def parse_args(self, ctx: click.Context, args: List[str]) -> List[str]:
		"""
		Parse the given arguments and modify the context as necessary.

		:param ctx:
		:param args:
		"""

		return parse_help_args(self, ctx, args)


class MarkdownHelpGroup(MarkdownHelpMixin, click.Group):  # lgtm [py/conflicting-attributes]
	"""
	Subclass of :class:`click.Group` which treats the help text as markdown
	and prints a rendered representation.

	Tested in Gnome Terminal and Terminator (both libVTE-based), and PyCharm.
	libVTE has the best support.
	PyCharm's support for italics and strikethrough is poor.
	Support on Windows is, as expected, poor.

	Not tested on other terminals, but contributions are welcome to improve support.

	.. versionadded:: 0.8.0
	"""  # noqa: D400

	def parse_args(self, ctx: click.Context, args: List[str]) -> List[str]:
		"""
		Parse the given arguments and modify the context as necessary.

		:param ctx:
		:param args:
		"""

		# This is necessary to parse any --colour/--no-colour commands before generating the help,
		# to ensure the option is honoured.

		if not args and self.no_args_is_help and not ctx.resilient_parsing:
			click.echo(ctx.get_help(), color=ctx.color)
			ctx.exit()

		rest = parse_help_args(self, ctx, args)

		if self.chain:
			ctx.protected_args = rest
			ctx.args = []
		elif rest:
			ctx.protected_args, ctx.args = rest[:1], rest[1:]

		return ctx.args


class ContextInheritingGroup(click.Group):
	"""
	Subclass of :class:`click.Group` whose children inherit its :attr:`~click.BaseCommand.context_settings`.

	The group's commands can be given different context settings by passing the
	``context_settings`` keyword argument to :meth:`~.command` and :meth:`~.group` as normal.

	.. versionadded:: 1.1.0

	.. autosummary-widths:: 5/16
	"""

	def command(self, *args, **kwargs) -> Callable[[Callable[..., Any]], click.Command]:
		"""
		A shortcut decorator for declaring and attaching a command to the group.

		This takes the same arguments as :func:`click.command` but
		immediately registers the created command with this instance
		by calling into :meth:`click.Group.add_command`.
		"""

		kwargs.setdefault("context_settings", self.context_settings)
		return super().command(*args, **kwargs)

	def group(self, *args, **kwargs) -> Callable[[Callable[..., Any]], click.Group]:
		"""
		A shortcut decorator for declaring and attaching a group to the group.

		This takes the same arguments as :func:`click.group` but
		immediately registers the created group with this instance
		by calling into :meth:`click.Group.add_command`.
		"""

		kwargs.setdefault("context_settings", self.context_settings)
		return super().group(*args, **kwargs)


class SuggestionGroup(ContextInheritingGroup):
	"""
	Subclass of :class:`click.Group` which suggests the most similar command if the command is not found.

	.. versionadded 0.2.0

	.. versionchanged:: 0.8.0

		Moved to :mod:`consolekit.commands`.

	.. versionchanged:: 1.1.0

		Now inherits from :class:`~.ContextInheritingGroup`
	"""

	def resolve_command(
			self,
			ctx: click.Context,
			args: List[str],
			) -> Tuple[str, click.Command, List[str]]:
		"""
		Resolve the requested command belonging to this group, and print a suggestion if it can't be found.

		:param ctx:
		:param args:

		:return: The name of the matching command,
			the :class:`click.Command` object itself,
			and any remaining arguments.
		"""

		cmd_name = make_str(args[0])
		original_cmd_name = cmd_name

		# Get the command
		cmd = self.get_command(ctx, cmd_name)

		# If we can't find the command but there is a normalization
		# function available, we try with that one.
		if cmd is None and ctx.token_normalize_func is not None:
			cmd_name = ctx.token_normalize_func(cmd_name)
			cmd = self.get_command(ctx, cmd_name)

		# If we don't find the command we want to show an error message
		# to the user that it was not provided.
		# However, there is something else we should do:
		# if the first argument looks like an option we want to kick off parsing again
		# for arguments to resolve things like --help which now should go to the main place.
		if cmd is None and not ctx.resilient_parsing:
			if split_opt(cmd_name)[0]:
				self.parse_args(ctx, ctx.args)

			closest = difflib.get_close_matches(original_cmd_name, self.commands, n=1)
			message = [f"No such command '{original_cmd_name}'."]
			if closest:
				message.append(f"The most similar command is {closest[0]!r}.")
			ctx.fail('\n'.join(message))

		# TODO: cmd here is Optional[click.Command], typeshed says it should be just click.Command
		#  I think typeshed is wrong.
		#  https://github.com/python/typeshed/blob/484c014665cdf071b292dd9630f207c03e111895/third_party/2and3/click/core.pyi#L171
		return cmd_name, cmd, args[1:]  # type: ignore[return-value]
