# $Id: __init__.py 9368 2023-04-28 21:26:36Z milde $
# Author: David Goodger <goodger@python.org>
# Copyright: This module has been placed in the public domain.

"""
This package contains Docutils Writer modules.
"""

__docformat__ = "reStructuredText"

from importlib import import_module

import docutils
from docutils import languages, Component
from docutils.transforms import universal


class Writer(Component):

    """
    Abstract base class for docutils Writers.

    Each writer module or package must export a subclass also called 'Writer'.
    Each writer must support all standard node types listed in
    `docutils.nodes.node_class_names`.

    The `write()` method is the main entry point.
    """

    component_type = "writer"
    config_section = "writers"

    def get_transforms(self):
        return super().get_transforms() + [
            universal.Messages,
            universal.FilterMessages,
            universal.StripClassesAndElements,
        ]

    document = None
    """The document to write (Docutils doctree); set by `write()`."""

    output = None
    """Final translated form of `document`

    (`str` for text, `bytes` for binary formats); set by `translate()`.
    """

    language = None
    """Language module for the document; set by `write()`."""

    destination = None
    """`docutils.io` Output object; where to write the document.

    Set by `write()`.
    """

    def __init__(self):
        self.parts = {}
        """Mapping of document part names to fragments of `self.output`.

        See `Writer.assemble_parts()` below and
        <https://docutils.sourceforge.io/docs/api/publisher.html>.
        """

    def write(self, document, destination):
        """
        Process a document into its final form.

        Translate `document` (a Docutils document tree) into the Writer's
        native format, and write it out to its `destination` (a
        `docutils.io.Output` subclass object).

        Normally not overridden or extended in subclasses.
        """
        self.document = document
        self.language = languages.get_language(document.settings.language_code, document.reporter)
        self.destination = destination
        self.translate()
        return self.destination.write(self.output)

    def translate(self):
        """
        Do final translation of `self.document` into `self.output`.  Called
        from `write`.  Override in subclasses.

        Usually done with a `docutils.nodes.NodeVisitor` subclass, in
        combination with a call to `docutils.nodes.Node.walk()` or
        `docutils.nodes.Node.walkabout()`.  The ``NodeVisitor`` subclass must
        support all standard elements (listed in
        `docutils.nodes.node_class_names`) and possibly non-standard elements
        used by the current Reader as well.
        """
        raise NotImplementedError("subclass must override this method")

    def assemble_parts(self):
        """Assemble the `self.parts` dictionary.  Extend in subclasses.

        See <https://docutils.sourceforge.io/docs/api/publisher.html>.
        """
        self.parts["whole"] = self.output
        self.parts["encoding"] = self.document.settings.output_encoding
        self.parts["errors"] = self.document.settings.output_encoding_error_handler
        self.parts["version"] = docutils.__version__


class UnfilteredWriter(Writer):

    """
    A writer that passes the document tree on unchanged (e.g. a
    serializer.)

    Documents written by UnfilteredWriters are typically reused at a
    later date using a subclass of `readers.ReReader`.
    """

    def get_transforms(self):
        # Do not add any transforms.  When the document is reused
        # later, the then-used writer will add the appropriate
        # transforms.
        return Component.get_transforms(self)


_writer_aliases = {
    "html": "html4css1",  # may change to html5 some day
    "html4": "html4css1",
    "xhtml10": "html4css1",
    "html5": "html5_polyglot",
    "xhtml": "html5_polyglot",
    "s5": "s5_html",
    "latex": "latex2e",
    "xelatex": "xetex",
    "luatex": "xetex",
    "lualatex": "xetex",
    "odf": "odf_odt",
    "odt": "odf_odt",
    "ooffice": "odf_odt",
    "openoffice": "odf_odt",
    "libreoffice": "odf_odt",
    "pprint": "pseudoxml",
    "pformat": "pseudoxml",
    "pdf": "rlpdf",
    "xml": "docutils_xml",
}


def get_writer_class(writer_name):
    """Return the Writer class from the `writer_name` module."""
    name = writer_name.lower()
    name = _writer_aliases.get(name, name)
    try:
        module = import_module("docutils.writers." + name)
    except ImportError:
        try:
            module = import_module(name)
        except ImportError as err:
            raise ImportError(f'Writer "{writer_name}" not found. {err}')
    return module.Writer
