#!/usr/bin/env python3
# coding=utf-8
#
# Copyright (C) 2005,2007 Aaron Spike, aaron@ekips.org
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
# pylint: disable=ungrouped-imports
"""
Embed images so they are base64 encoded data inside the svg.
"""

from __future__ import unicode_literals

import os

import inkex
from inkex import Image
from inkex.localization import inkex_gettext as _

try:
    import urllib.request as urllib
    import urllib.parse as urlparse
    from base64 import encodebytes
except ImportError:
    # python2 compatibility, remove when python3 only.
    import urllib
    import urlparse
    from base64 import encodestring as encodebytes


class EmbedImage(inkex.EffectExtension):
    """Allow selected image tags to become embeded image tags"""

    def add_arguments(self, pars):
        pars.add_argument(
            "--selectedonly", type=inkex.Boolean, help="embed only selected images"
        )

    def effect(self):
        # if slectedonly is enabled and there is a selection
        # only embed selected images. otherwise embed all images
        if self.options.selectedonly:
            images = self.svg.selection.get(Image)
        else:
            images = self.svg.xpath("//svg:image")

        for node in images:
            self.embed_image(node)

    def embed_image(self, node):
        """Embed the data of the selected Image Tag element"""
        xlink = node.get("xlink:href")
        if xlink is not None and xlink[:5] == "data:":
            # No need, data already embedded
            return
        if xlink is None:
            inkex.errormsg(
                _('Attribute "xlink:href" not set on node {}.'.format(node.get_id()))
            )
            return

        url = urlparse.urlparse(xlink)
        href = urllib.url2pathname(url.path)

        # Look relative to the *temporary* filename instead of the original filename.
        try:
            cwd = os.path.dirname(self.options.input_file)
        except TypeError:
            # input_file was actually stdin, fall back.
            cwd = None

        path = self.absolute_href(href or "", cwd=cwd)

        # Backup directory where we can find the image
        if not os.path.isfile(path):
            path = node.get("sodipodi:absref", path)

        if not os.path.isfile(path):
            inkex.errormsg(
                _('File not found "{}". Unable to embed image.').format(path)
            )
            return

        with open(path, "rb") as handle:
            # Don't read the whole file to check the header
            file_type = get_type(path, handle.read(10))
            handle.seek(0)

            if file_type:
                # Future: Change encodestring to encodebytes when python3 only
                node.set(
                    "xlink:href",
                    "data:{};base64,{}".format(
                        file_type, encodebytes(handle.read()).decode("ascii")
                    ),
                )
                node.pop("sodipodi:absref")
            else:
                inkex.errormsg(
                    _(
                        "%s is not of type image/png, image/jpeg, "
                        "image/bmp, image/gif, image/tiff, or image/x-icon"
                    )
                    % path
                )


def get_type(path, header):
    """Basic magic header checker, returns mime type"""
    for head, mime in (
        (b"\x89PNG", "image/png"),
        (b"\xff\xd8", "image/jpeg"),
        (b"BM", "image/bmp"),
        (b"GIF87a", "image/gif"),
        (b"GIF89a", "image/gif"),
        (b"MM\x00\x2a", "image/tiff"),
        (b"II\x2a\x00", "image/tiff"),
    ):
        if header.startswith(head):
            return mime

    # ico files lack any magic... therefore we check the filename instead
    for ext, mime in (
        # official IANA registered MIME is 'image/vnd.microsoft.icon' tho
        (".ico", "image/x-icon"),
        (".svg", "image/svg+xml"),
    ):
        if path.endswith(ext):
            return mime
    return None


if __name__ == "__main__":
    EmbedImage().run()
