# Nick's web site: svg2png filter: convert SVG to PNG using rsvg-convert.
#
# Copyright © 2021 Nick Bowler
#
# 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 3 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, see <https://www.gnu.org/licenses/>.

class SVG2PNG < Nanoc::Filter
    identifier :svg2png
    type :text => :binary

    def run(content, params = {})
        args = ["-o", output_filename]
        params.each do |key, val|
            next if !val

            args << "--#{key.to_s.gsub("_", "-")}"
            if val != true then args << val.to_s end
        end

        dummy, status = Open3.capture2("rsvg-convert", *args,
                                       stdin_data: content)
        raise "rsvg-convert failed" if status != 0
    end
end