#!/bin/sed -rf
#
# Written in 2016 by Sergei Eremenko <https://github.com/SmartFinn>
#
# To the extent possible under law, the author(s) have dedicated all copyright
# and related and neighboring rights to this software to the public domain
# worldwide. This software is distributed without any warranty.
#
# You should have received a copy of the CC0 Public Domain Dedication along
# with this software. If not, see
# <http://creativecommons.org/publicdomain/zero/1.0/>.
#
# Description:
#  This script removes unused attributes and removes attributes with default
#  values from elements.
#  Details https://www.w3.org/TR/SVG/attindex.html
#
# Get defaults from Inkscape:
#	sed -e '/^$/d' -e '/NO.DEFAULT/d' -e 's/"//g' \
#		/usr/share/inkscape/attributes/css_defaults \
#		| awk -F" - " '{printf "s/[ ]%s=\"%s\"//gI\n", $1,$2}'
#
# Usage:
#  sed -r -i -f _clean_attrs.sed FILE...

# remove unused attributes
s/[ ]aria-label="[^"]*"//gI

# delete default ids
s/[ ]id="circle[0-9-]*"//gI
s/[ ]id="ellipse[0-9-]*"//gI
s/[ ]id="defs[0-9-]*"//gI
s/[ ]id="g[0-9-]*"//gI
s/[ ]id="path[0-9-]*"//gI
s/[ ]id="line[0-9-]*"//gI
s/[ ]id="polygon[0-9-]*"//gI
s/[ ]id="rect[0-9-]*"//gI
s/[ ]id="svg[0-9-]*"//gI
s/[ ]id="layer[0-9-]*"//gI
s/[ ]id="stop[0-9-]*"//gI
s/[ ]id="image[0-9-]*"//gI
s/[ ]id="desc[0-9-]*"//gI
s/[ ]id="grid[0-9-]*"//gI
s/[ ]id="guide[0-9-]*"//gI
s/[ ]id="title[0-9-]*"//gI
s/[ ]id="text[0-9-]*"//gI
s/[ ]id="use[0-9-]*"//gI
s/[ ]id="metadata[0-9-]*"//gI
s/[ ]id="flowRoot[0-9-]*"//gI
s/[ ]id="flowRegion[0-9-]*"//gI
s/[ ]id="flowPara[0-9-]*"//gI

# properties in a style attribute has higher priority
/style=/ {
	/fill:[^;"]/ s/[ ]fill="[^"]+"//gI
	/fill-opacity:[^;"]/ s/[ ]fill-opacity="[^"]+"//gI
	/fill-rule:[^;"]/ s/[ ]fill-rule="[^"]+"//gI
	/[^-]opacity:[^;"]/ s/[ ]opacity="[^"]+"//gI
}

# remove attributes with default values
s/[ ]alignment-baseline="auto"//gI
s/[ ]backface-visibility="visible"//gI
s/[ ]baseline-shift="baseline"//gI
s/[ ]clip="auto"//gI
s/[ ]clip-path="none"//gI
s/[ ]clip-rule="nonzero"//gI
s/[ ]color-interpolation="sRGB"//gI
s/[ ]color-interpolation-filters="linearRGB"//gI
s/[ ]color-profile="auto"//gI
s/[ ]color-rendering="auto"//gI
s/[ ]cursor="auto"//gI
s/[ ]direction="ltr"//gI
s/[ ]display="inline"//gI
s/[ ]dominant-baseline="auto"//gI
s/[ ]enable-background="accumulate"//gI
s/[ ]fill="black"//gI
s/[ ]fill-opacity="1"//gI
s/[ ]fill-rule="nonzero"//gI
s/[ ]filter="none"//gI
s/[ ]flood-color="black"//gI
s/[ ]flood-opacity="1"//gI
s/[ ]font-feature-settings="normal"//gI
s/[ ]font-size="medium"//gI
s/[ ]font-size-adjust="none"//gI
s/[ ]font-stretch="normal"//gI
s/[ ]font-style="normal"//gI
s/[ ]font-variant="normal"//gI
s/[ ]font-variant-alternates="normal"//gI
s/[ ]font-variant-caps="normal"//gI
s/[ ]font-variant-east-asian="normal"//gI
s/[ ]font-variant-ligatures="normal"//gI
s/[ ]font-variant-numeric="normal"//gI
s/[ ]font-variant-position="normal"//gI
s/[ ]font-variation-settings="normal"//gI
s/[ ]font-weight="normal"//gI
s/[ ]glyph-orientation-horizontal="0deg"//gI
s/[ ]glyph-orientation-vertical="auto"//gI
s/[ ]image-rendering="auto"//gI
s/[ ]inline-size="0"//gI
s/[ ]isolation="auto"//gI
s/[ ]kerning="auto"//gI
s/[ ]letter-spacing="normal"//gI
s/[ ]lighting-color="white"//gI
s/[ ]marker="none"//gI
s/[ ]marker-end="none"//gI
s/[ ]marker-mid="none"//gI
s/[ ]marker-start="none"//gI
s/[ ]mask="none"//gI
s/[ ]mix-blend-mode="normal"//gI
s/[ ]opacity="1"//gI
s/[ ]overflow="hidden"//gI
s/[ ]paint-order="normal"//gI
s/[ ]perspective="none"//gI
s/[ ]pointer-events="visiblePainted"//gI
s/[ ]shape-inside="auto"//gI
s/[ ]shape-margin="0"//gI
s/[ ]shape-outside="auto"//gI
s/[ ]shape-padding="(0|none)"//gI
s/[ ]shape-rendering="auto"//gI
s/[ ]shape-subtract="auto"//gI
s/[ ]solid-color="#000000"//gI
s/[ ]solid-opacity="1"//gI
s/[ ]stop-color="black"//gI
s/[ ]stop-opacity="1"//gI
s/[ ]stroke="none"//gI
s/[ ]stroke-dasharray="none"//gI
s/[ ]stroke-dashoffset="0"//gI
s/[ ]stroke-linecap="butt"//gI
s/[ ]stroke-linejoin="miter"//gI
s/[ ]stroke-miterlimit="4"//gI
s/[ ]stroke-opacity="1"//gI
s/[ ]stroke-width="1"//gI
s/[ ]text-align="start"//gI
s/[ ]text-anchor="start"//gI
s/[ ]text-decoration-line="none"//gI
s/[ ]text-decoration-style="solid"//gI
s/[ ]text-indent="0"//gI
s/[ ]text-orientation="mixed"//gI
s/[ ]text-rendering="auto"//gI
s/[ ]text-transform="none"//gI
s/[ ]transform="none"//gI
s/[ ]transform-style="flat"//gI
s/[ ]unicode-bidi="normal"//gI
s/[ ]vector-effect="none"//gI
s/[ ]visibility="visible"//gI
s/[ ]white-space="normal"//gI
s/[ ]word-spacing="normal"//gI
s/[ ]writing-mode="lr-tb"//gI

# round decimal expansion to zero in x=, y=, rx=, ry= attributes
s/([ ]x|y|ry|rx)="[0-9.]+e-[0-9]+"/\1="0"/gI
s/([ ]x|y|ry|rx)="[0-9]?.00[0-9]+"/\1="0"/gI

# delete attributes with nonsense values
s/[ ]fill-opacity="[1-9][0-9.]*"//gI
s/[ ]fill="(#000|#000000|black)"//gI
s/[ ]flood-color="(#000|#000000|black)"//gI
s/[ ]flood-opacity="[1-9][0-9.]*"//gI
s/[ ]opacity="[1-9][0-9.]*"//gI
s/[ ]stroke-opacity="[1-9][0-9.]*"//gI

# delete nonsense values for rounded corners of rectangles
/<rect/ {
	s/[ ](ry|rx)="(0|0?.0[0-9]+)"//gI
}

# delete 'stroke- *' properties if an object doesn't have a stroke
/stroke[:=]/! {
	s/[ ]stroke-width="[^"]+"//gI
	s/[ ]stroke-linecap="[^"]+"//gI
	s/[ ]stroke-linejoin="[^"]+"//gI
	s/[ ]stroke-miterlimit="[^"]+"//gI
	s/[ ]stroke-dasharray="[^"]+"//gI
	s/[ ]stroke-dashoffset="[^"]+"//gI
	s/[ ]stroke-opacity="[^"]+"//gI
}

# delete unused properties from non-container elements
/<(a|defs|glyph|g|marker|mask|missing-glyph|pattern|svg|switch|symbol|use)/! {
	s/[ ]enable-background="[^"]+"//gI
}

# delete useless properties from elements
# https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/fill-rule
/<(altGlyph|path|polygon|polyline|text|textPath|tref|tspan)/! {
	s/[ ]fill-rule="[^"]+"//gI
}

# delete 'clip-rule' properties if an object doesn't have a clip-path
/clip-path[:=]/! {
	s/[ ]clip-rule="[^"]+"//gI
}