pandoc_latex_tip._main

Complexity

Total Complexity

105

Size/Duplication

Total Lines	969
Duplicated Lines	0 %

Importance

Changes

0

3 Methods

Rating	Name	Duplication	Size	Complexity
A	IconFont.__init__()	0	9	1
C	IconFont.export_icon()	0	126	10
C	IconFont.load_css()	0	52	11

#!/usr/bin/env python

"""
Pandoc filter for adding tip in LaTeX.
"""

from __future__ import annotations

import operator
import pathlib
import re
import sys
import tempfile
from os import path
from typing import Any

import PIL.Image
import PIL.ImageColor
import PIL.ImageDraw
import PIL.ImageFont

import fontTools.ttLib

from panflute import (
    BulletList,
    Code,
    CodeBlock,
    DefinitionList,
    Div,
    Doc,
    Element,
    Figure,
    HorizontalRule,
    Image,
    LineBlock,
    Link,
    MetaInlines,
    MetaList,
    OrderedList,
    Para,
    Plain,
    RawBlock,
    RawInline,
    Span,
    convert_text,
    debug,
    run_filter,
)

import platformdirs

import tinycss2

import yaml


class IconFont:
    """
    Base class that represents web icon font.

    This class has been greatly inspired by the code found
    in https://github.com/Pythonity/icon-font-to-png

    Arguments
    ---------
    css_file
        path to icon font CSS file
    ttf_file
        path to icon font TTF file
    prefix
        new prefix if any
    """

    def __init__(
        self,
        css_file: pathlib.Path,
        ttf_file: pathlib.Path,
        prefix: str | None = None,
    ) -> None:
        self.css_file = css_file
        self.ttf_file = ttf_file
        self.css_icons = self.load_css(prefix)

    def load_css(self, prefix: str | None) -> dict[str, str]:
        """
        Create a dict of all icons available in CSS file.

        Arguments
        ---------
        prefix
            new prefix if any

        Returns
        -------
        dict[str, str]
            sorted icons dict
        """
        # pylint: disable=too-many-locals
        icons = {}
        common = None
        with self.css_file.open() as stream:
            rules = tinycss2.parse_stylesheet(stream.read())
        font = fontTools.ttLib.TTFont(self.ttf_file)
        prelude_regex = re.compile("\\.([^:]*):?:before,?")
        content_regex = re.compile("\\s*content:\\s*([^;]+);")

        # pylint: disable=too-many-nested-blocks
        for rule in rules:
            if rule.type == "qualified-rule":
                prelude = tinycss2.serialize(rule.prelude)
                content = tinycss2.serialize(rule.content)
                prelude_result = prelude_regex.match(prelude)
                content_result = content_regex.match(content)
                if prelude_result and content_result:
                    name = prelude_result.group(1)
                    character = content_result.group(1)[1:-1]
                    for cmap in font["cmap"].tables:
                        if cmap.isUnicode() and ord(character) in cmap.cmap:
                            common = (
                                name
                                if common is None
                                else path.commonprefix((common, name))  # type: ignore
                            )
                            icons[name] = character
                            break

        common = common or ""

        # Remove common prefix
        if prefix:
            icons = {
                prefix + name[len(common) :]: value for name, value in icons.items()
            }

        return dict(sorted(icons.items(), key=operator.itemgetter(0)))

    # pylint: disable=too-many-arguments,too-many-locals,too-many-positional-arguments
    def export_icon(
        self,
        icon: str,
        size: int,
        color: str = "black",
        scale: float | str = "auto",
        filename: str | None = None,
        export_dir: str = "exported",
    ) -> None:
        """
        Export given icon with provided parameters.

        If the desired icon size is less than 150x150 pixels, we will first
        create a 150x150 pixels image and then scale it down, so that
        it's much less likely that the edges of the icon end up cropped.

        Parameters
        ----------
        icon
            valid icon name
        size
            icon size in pixels
        color
            color name or hex value
        scale
            scaling factor between 0 and 1, or 'auto' for automatic scaling
        filename
            name of the output file
        export_dir
            path to export directory
        """
        org_size = size
        size = max(150, size)

        image = PIL.Image.new("RGBA", (size, size), color=(0, 0, 0, 0))
        draw = PIL.ImageDraw.Draw(image)

        scale_factor = 1.0 if scale == "auto" else float(scale)

        font_size = int(size * scale_factor)
        font = PIL.ImageFont.truetype(self.ttf_file, font_size)
        width = draw.textlength(self.css_icons[icon], font=font)
        height = font_size  # always, as long as single-line of text

        # If auto-scaling is enabled, we need to make sure the resulting
        # graphic fits inside the boundary. The values are rounded and may be
        # off by a pixel or two, so we may need to do a few iterations.
        # The use of a decrementing multiplication factor protects us from
        # getting into an infinite loop.
        if scale == "auto":
            iteration = 0
            factor = 1.0

            while True:
                width = draw.textlength(self.css_icons[icon], font=font)

                # Check if the image fits
                dim = max(width, height)
                if dim > size:
                    font = PIL.ImageFont.truetype(
                        self.ttf_file,
                        int(size * size / dim * factor),
                    )
                else:
                    break

                # Adjust the factor every two iterations
                iteration += 1
                if iteration % 2 == 0:
                    factor *= 0.99

        draw.text(
            ((size - width) / 2, (size - height) / 2),
            self.css_icons[icon],
            font=font,
            fill=color,
            anchor="lt",
        )

        # Get bounding box
        bbox = image.getbbox()

        # Create an alpha mask
        image_mask = PIL.Image.new("L", (size, size))
        draw_mask = PIL.ImageDraw.Draw(image_mask)

        # Draw the icon on the mask
        draw_mask.text(
            ((size - width) / 2, (size - height) / 2),
            self.css_icons[icon],
            font=font,
            fill=255,
            anchor="lt",
        )

        # Create a solid color image and apply the mask
        icon_image = PIL.Image.new("RGBA", (size, size), color)
        icon_image.putalpha(image_mask)

        if bbox:
            icon_image = icon_image.crop(bbox)

        border_w = int((size - (bbox[2] - bbox[0])) / 2)
        border_h = int((size - (bbox[3] - bbox[1])) / 2)

        # Create output image
        out_image = PIL.Image.new("RGBA", (size, size), (0, 0, 0, 0))
        out_image.paste(icon_image, (border_w, border_h))

        # If necessary, scale the image to the target size
        if org_size != size:
            out_image = out_image.resize(
                (org_size, org_size),
                PIL.Image.Resampling.LANCZOS,
            )

        # Make sure export directory exists
        if not pathlib.Path(export_dir).exists():
            pathlib.Path(export_dir).mkdir(parents=True)

        # Default filename
        if not filename:
            filename = icon + ".png"

        # Save file
        out_image.save(path.join(export_dir, filename))


def get_core_icons() -> list[dict[str, str]]:
    """
    Get the core icons.

    Returns
    -------
    list[dict[str, str]]
        The core icons.
    """
    return [
        {
            "collection": "fontawesome",
            "CSS": "fontawesome.css",
            "TTF": "fa-solid-900.ttf",
            "prefix": "fa-",
        },
        {
            "collection": "fontawesome",
            "CSS": "fontawesome.css",
            "TTF": "fa-regular-400.ttf",
            "prefix": "far-",
        },
        {
            "collection": "fontawesome",
            "CSS": "brands.css",
            "TTF": "fa-brands-400.ttf",
            "prefix": "fab-",
        },
    ]


def load_icons() -> dict[str, IconFont]:
    """
    Get the icons.

    Returns
    -------
    dict["str", IconFont]
        A dictionnary from icon name to IconFont.
    """
    icons = {}
    for definition in get_core_icons():
        icon_font = IconFont(
            css_file=pathlib.Path(
                sys.prefix,
                "share",
                "pandoc_latex_tip",
                definition["collection"],
                definition["CSS"],
            ),
            ttf_file=pathlib.Path(
                sys.prefix,
                "share",
                "pandoc_latex_tip",
                definition["collection"],
                definition["TTF"],
            ),
            prefix=definition["prefix"],
        )
        icons.update({key: icon_font for key in icon_font.css_icons})

    config_path = pathlib.Path(sys.prefix, "share", "pandoc_latex_tip", "config.yml")
    if config_path.exists():
        with config_path.open(encoding="utf-8") as stream:
            config = yaml.safe_load(stream)
            for definition in config:
                if "collection" not in definition:
                    break
                collection = definition["collection"]
                if "CSS" not in definition:
                    break
                css_file = definition["CSS"]
                if "TTF" not in definition:
                    break
                ttf_file = definition["TTF"]
                if "prefix" not in definition:
                    break
                prefix = definition["prefix"]
                icon_font = IconFont(
                    css_file=pathlib.Path(
                        sys.prefix,
                        "share",
                        "pandoc_latex_tip",
                        collection,
                        css_file,
                    ),
                    ttf_file=pathlib.Path(
                        sys.prefix,
                        "share",
                        "pandoc_latex_tip",
                        collection,
                        ttf_file,
                    ),
                    prefix=prefix,
                )
                icons.update({key: icon_font for key in icon_font.css_icons})

    return icons


def tip(elem: Element, doc: Doc) -> list[Element] | None:
    """
    Apply tip transformation to element.

    Parameters
    ----------
    elem
        The element
    doc
        The original document.

    Returns
    -------
    list[Element] | None
        The additional elements if any.
    """
    # Is it in the right format and is it a Span, Div?
    if doc.format in ("latex", "beamer") and isinstance(
        elem, Span | Div | Code | CodeBlock
    ):
        # Is there a latex-tip-icon attribute?
        if "latex-tip-icon" in elem.attributes or "latex-tip-image" in elem.attributes:
            return add_latex(
                elem,
                latex_code(
                    doc,
                    elem.attributes,
                    {
                        "icon": "latex-tip-icon",
                        "image": "latex-tip-image",
                        "position": "latex-tip-position",
                        "size": "latex-tip-size",
                        "color": "latex-tip-color",
                        "link": "latex-tip-link",
                    },
                ),
            )

        # Get the classes
        classes = set(elem.classes)

        # Loop on all font size definition
        # noinspection PyUnresolvedReferences
        for definition in doc.defined:
            # Are the classes correct?
            if classes >= definition["classes"]:
                return add_latex(elem, definition["latex"])

    return None


def add_latex(elem: Element, latex: str) -> list[Element] | None:
    """
    Add latex code.

    Parameters
    ----------
    elem
        Current element
    latex
        Latex code

    Returns
    -------
    list[Element] | None
        The additional elements if any.
    """
    # pylint: disable=too-many-return-statements
    if bool(latex):
        # Is it a Span or a Code?
        if isinstance(elem, Span | Code):
            return [elem, RawInline(latex, "tex")]
        if isinstance(elem, CodeBlock):
            return [RawBlock(latex, "tex"), elem]
        while elem.content and isinstance(elem.content[0], Div):
            elem = elem.content[0]
        if not elem.content or isinstance(
            elem.content[0],
            HorizontalRule | Figure | RawBlock | DefinitionList | CodeBlock,
        ):
            elem.content.insert(0, RawBlock(latex, "tex"))
            return None
        if isinstance(elem.content[0], Plain | Para):
            elem.content[0].content.insert(1, RawInline(latex, "tex"))
            return None
        if isinstance(elem.content[0], LineBlock):
            elem.content[0].content[0].content.insert(1, RawInline(latex, "tex"))
            return None
        if isinstance(elem.content[0], BulletList | OrderedList):
            elem.content[0].content[0].content[0].content.insert(
                1,
                RawInline(latex, "tex"),
            )
            return None
        debug("[WARNING] pandoc-latex-tip: Bad usage")
    return None


# pylint: disable=too-many-arguments,too-many-locals
def latex_code(doc: Doc, definition: dict[str, Any], keys: dict[str, str]) -> str:
    """
    Get the latex code.

    Parameters
    ----------
    doc
        The original document
    definition
        The defition
    keys
        Key mapping

    Returns
    -------
    str
        The latex code.
    """
    # Get the size
    size = get_size(str(definition.get(keys["size"], "18")))

    # Get the prefixes
    # noinspection PyArgumentEqualDefault
    prefix_odd = get_prefix_odd(str(definition.get(keys["position"], "")))
    prefix_even = get_prefix_even(str(definition.get(keys["position"], "")))

    # Get the icons
    icons = get_icons(doc, definition, keys)

    # Get the images
    images = create_images(doc, icons, size)

    if bool(images):
        # pylint: disable=consider-using-f-string
        return f"""
\\checkoddpage%%
\\ifoddpage%%
{prefix_odd}%%
\\else%%
{prefix_even}%%
\\fi%%
\\marginnote{{{''.join(images)}}}[0pt]\\vspace{{0cm}}%%
"""

    return ""


def get_icons(
    doc: Doc,
    definition: dict[str, Any],
    keys: dict[str, str],
) -> list[dict[str, Any]]:
    """
    Get tge icons.

    Parameters
    ----------
    doc
        The original document
    definition
        The definition
    keys
        Key mapping

    Returns
    -------
    list[dict[str, Any]]
        A list of icon definitions.
    """
    # Get the link
    link = str(definition.get(keys["link"], ""))

    # Get the default color
    color = str(definition.get(keys["color"], "black"))

    # Test the icons definition
    if keys["icon"] in definition:
        icons: list[dict[str, str]] = []
        # pylint: disable=invalid-name
        if isinstance(definition[keys["icon"]], list):
            for icon in definition[keys["icon"]]:
                if isinstance(icon, dict):
                    icon["link"] = icon.get("link", link)
                    if not icon.get("image"):
                        icon["color"] = icon.get("color", color)
                    add_icon(doc, icons, icon)
                else:
                    add_icon(
                        doc,
                        icons,
                        {
                            "name": icon,
                            "color": color,
                            "link": link,
                        },
                    )
        elif definition[keys["icon"]] in doc.icons:
            icons = [
                {
                    "name": definition[keys["icon"]],
                    "color": color,
                    "link": link,
                }
            ]
        elif definition.get(keys["image"]):
            icons = [
                {
                    "image": definition[keys["image"]],
                    "link": link,
                }
            ]
        else:
            icons = []
    elif keys.get("image") and keys.get("image") in definition:
        icons = [
            {
                "image": definition[keys["image"]],
                "link": link,
            }
        ]
    else:
        icons = [
            {
                "name": "fa-exclamation-circle",
                "color": color,
                "link": link,
            }
        ]

    return icons


def add_icon(doc: Doc, icons: list[dict[str, str]], icon: dict[str, str]) -> None:
    """
    Add icon.

    Parameters
    ----------
    doc
        The original document.
    icons
        A list of icon definition
    icon
        A potential new icon
    """
    if "image" in icon:
        icons.append(
            {
                "image": icon["image"],
                "link": icon["link"],
            }
        )
    else:
        if "name" not in icon:
            # Bad formed icon
            debug("[WARNING] pandoc-latex-tip: Bad formed icon")
            return

        # Lower the color
        lower_color = icon["color"].lower()

        # Convert the color to black if unexisting
        # pylint: disable=import-outside-toplevel

        if lower_color not in PIL.ImageColor.colormap:
            debug(
                f"[WARNING] pandoc-latex-tip: {lower_color}"
                " is not a correct color name; using black"
            )
            lower_color = "black"

        # Is the icon correct?
        try:
            # noinspection PyUnresolvedReferences
            if icon["name"] in doc.icons:
                icons.append(
                    {
                        "name": icon["name"],
                        "color": lower_color,
                        "link": icon["link"],
                    }
                )
            else:
                debug(
                    f"[WARNING] pandoc-latex-tip: {icon['name']}"
                    " is not a correct icon name"
                )
        except FileNotFoundError:
            debug("[WARNING] pandoc-latex-tip: error in accessing to icons definition")


# pylint:disable=too-many-return-statements
def get_prefix_odd(position: str) -> str:
    """
    Get the latex prefix.

    Parameters
    ----------
    position
        The icon position

    Returns
    -------
    str
        The latex prefix.
    """
    if position == "right":
        return "\\PandocLatexTipOddRight"
    if position in ("left", ""):
        return "\\PandocLatexTipOddLeft"
    if position == "inner":
        return "\\PandocLatexTipOddInner"
    if position == "outer":
        return "\\PandocLatexTipOddOuter"
    debug(
        f"[WARNING] pandoc-latex-tip: {position}"
        " is not a correct position; using left"
    )
    return "\\PandocLatexTipOddLeft"


def get_prefix_even(position: str) -> str:
    """
    Get the latex prefix.

    Parameters
    ----------
    position
        The icon position

    Returns
    -------
    str
        The latex prefix.
    """
    if position == "right":
        return "\\PandocLatexTipEvenRight"
    if position in ("left", ""):
        return "\\PandocLatexTipEvenLeft"
    if position == "inner":
        return "\\PandocLatexTipEvenInner"
    if position == "outer":
        return "\\PandocLatexTipEvenOuter"
    debug(
        f"[WARNING] pandoc-latex-tip: {position}"
        " is not a correct position; using left"
    )
    return "\\PandocLatexTipEvenLeft"


def get_size(size: str) -> str:
    """
    Get the correct size.

    Parameters
    ----------
    size
        The initial size

    Returns
    -------
    str
        The correct size.
    """
    regex = re.compile("^(?P<length>\\d+(\\.\\d*)?)(pt|mm|cm|in|ex|em|mu|sp)?$")
    if regex.match(size):
        length = float(regex.match(size).group("length"))
        if length <= 0:
            debug("[WARNING] pandoc-latex-tip: size must be greater than 0; using 18")
            return "18"
    else:
        debug(
            "[WARNING] pandoc-latex-tip: size must be a correct LaTeX length; using 18"
        )
        return "18"
    return size


def create_images(doc: Doc, icons: list[dict[str, Any]], size: str) -> list[str]:
    """
    Create the images.

    Parameters
    ----------
    doc
        The original document
    icons
        A list of icon definitions
    size
        The icon size.

    Returns
    -------
    list[str]
        A list of latex code.
    """
    # Generate the LaTeX image code
    images = []

    for icon in icons:
        # Get the image from the App cache folder
        # noinspection PyUnresolvedReferences
        if size.isdigit():
            size += "pt"
        if icon.get("image"):
            image = Image(
                url=str(icon.get("image")),
                attributes={"height": size},
            )
            elem = image if icon["link"] == "" else Link(image, url=icon["link"])
            images.append(
                convert_text(
                    Plain(elem), input_format="panflute", output_format="latex"
                )
            )
        else:
            image_path = path.join(doc.folder, icon["color"], icon["name"] + ".png")

            # Create the image if not existing in the cache
            try:
                if not path.isfile(image_path):
                    # Create the image in the cache
                    # noinspection PyUnresolvedReferences
                    doc.icons[icon["name"]].export_icon(
                        icon["name"],
                        512,
                        color=icon["color"],
                        export_dir=path.join(doc.folder, icon["color"]),
                    )

                # Add the LaTeX image
                image = Image(
                    url=str(image_path),
                    attributes={"height": size},
                )
                elem = image if icon["link"] == "" else Link(image, url=icon["link"])
                images.append(
                    convert_text(
                        Plain(elem), input_format="panflute", output_format="latex"
                    )
                )
            except TypeError:
                debug(
                    f"[WARNING] pandoc-latex-tip: icon name "
                    f"{icon['name']} does not exist"
                )
            except FileNotFoundError:
                debug("[WARNING] pandoc-latex-tip: error in generating image")

    return images


def add_definition(doc: Doc, definition: dict[str, Any]) -> None:
    """
    Add definition to document.

    Parameters
    ----------
    doc
        The original document
    definition
        The definition
    """
    # Get the classes
    classes = definition["classes"]

    # Add a definition if correct
    if bool(classes):
        latex = latex_code(
            doc,
            definition,
            {
                "icon": "icons",
                "position": "position",
                "size": "size",
                "color": "color",
                "link": "link",
            },
        )
        if latex:
            # noinspection PyUnresolvedReferences
            doc.defined.append({"classes": set(classes), "latex": latex})


def prepare(doc: Doc) -> None:
    """
    Prepare the document.

    Parameters
    ----------
    doc
        The original document.
    """
    # Add getIconFont library to doc
    doc.icons = load_icons()

    # Prepare the definitions
    doc.defined = []

    # Prepare the folder
    try:
        # Use user cache dir if possible
        doc.folder = platformdirs.AppDirs(
            "pandoc_latex_tip",
        ).user_cache_dir
        if not pathlib.Path(doc.folder).exists():
            pathlib.Path(doc.folder).mkdir(parents=True)
    except PermissionError:
        # Fallback to a temporary dir
        doc.folder = tempfile.mkdtemp(
            prefix="pandoc_latex_tip_",
            suffix="_cache",
        )

    # Get the meta data
    # noinspection PyUnresolvedReferences
    meta = doc.get_metadata("pandoc-latex-tip")

    if isinstance(meta, list):
        # Loop on all definitions
        for definition in meta:
            # Verify the definition
            if (
                isinstance(definition, dict)
                and "classes" in definition
                and isinstance(definition["classes"], list)
            ):
                add_definition(doc, definition)


def finalize(doc: Doc) -> None:
    """
    Finalize the document.

    Parameters
    ----------
    doc
        The original document
    """
    # Add header-includes if necessary
    if "header-includes" not in doc.metadata:
        doc.metadata["header-includes"] = MetaList()
    # Convert header-includes to MetaList if necessary
    elif not isinstance(doc.metadata["header-includes"], MetaList):
        doc.metadata["header-includes"] = MetaList(doc.metadata["header-includes"])

    doc.metadata["header-includes"].append(
        MetaInlines(RawInline("\\usepackage{graphicx,grffile}", "tex"))
    )
    doc.metadata["header-includes"].append(
        MetaInlines(RawInline("\\usepackage{marginnote}", "tex"))
    )
    doc.metadata["header-includes"].append(
        MetaInlines(RawInline("\\usepackage{etoolbox}", "tex"))
    )
    doc.metadata["header-includes"].append(
        MetaInlines(RawInline("\\usepackage[strict]{changepage}", "tex"))
    )
    doc.metadata["header-includes"].append(
        MetaInlines(
            RawInline(
                r"""
\makeatletter%
\newcommand{\PandocLatexTipOddInner}{\reversemarginpar}%
\newcommand{\PandocLatexTipEvenInner}{\reversemarginpar}%
\newcommand{\PandocLatexTipOddOuter}{\normalmarginpar}%
\newcommand{\PandocLatexTipEvenOuter}{\normalmarginpar}%
\newcommand{\PandocLatexTipOddLeft}{\reversemarginpar}%
\newcommand{\PandocLatexTipOddRight}{\normalmarginpar}%
\if@twoside%
\newcommand{\PandocLatexTipEvenRight}{\reversemarginpar}%
\newcommand{\PandocLatexTipEvenLeft}{\normalmarginpar}%
\else%
\newcommand{\PandocLatexTipEvenRight}{\normalmarginpar}%
\newcommand{\PandocLatexTipEvenLeft}{\reversemarginpar}%
\fi%
\makeatother%
\checkoddpage%
    """,
                "tex",
            )
        )
    )


def main(doc: Doc | None = None) -> Doc:
    """
    Transform the pandoc document.

    Arguments
    ---------
    doc
        The pandoc document

    Returns
    -------
    Doc
        The transformed document
    """
    return run_filter(tip, prepare=prepare, finalize=finalize, doc=doc)


if __name__ == "__main__":
    main()