po2yaml

#!/usr/bin/env ruby
#
# po2yaml, for converting gettext .po to the RoR translation YAML
#
# Developed from scripts found in http://git.openstreetmap.org/rails.git/tree/HEAD:/script/locale
#
# Usage:
#  - To create a language's yaml from a given po file
#    po2yaml de.po de.yml
#
#
# Copyright (C) 2012 Leandro Regueiro <leandro.regueiro AT gmail DOT com>
# Copyright (C) 2009 Thomas Wood
# Copyright (C) 2009 Tom Hughes
#
# 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.

require "yaml"


def add_translation(hash, keys, value)
    key = keys.shift
    if keys.empty?
        hash[key] = value
    else
        unless hash.has_key? key
            hash[key] = {}
        end
        add_translation(hash[key], keys, value)
    end
    hash
end


def po2hash(f)
    trs = {}
    path = []
    msgstr = ''
    f.each_line { |line|
        line.strip!
        if line[0..8] == 'msgctxt "'
            path = line[9..-2].split(':')
        elsif line[0..7] == 'msgstr "'
            # TODO convert escaped characters
            msgstr = line[8..-2]
        end

        if !path.empty? and !msgstr.empty?
            add_translation(trs, path, msgstr)
            path = []
            msgstr = ''
        end
    }
    trs
end


def generate_yaml(filename, outfilename)
    if File.exists? filename
        pofile = File.open(filename, "r")
        # The following line expects the files to be named like "de.po" and therefore the language code can be recovered by substracting the '.po' suffix
        # TODO refactor in order to extract the language code when the file is not just named like "LANG.po", but like "SOMETHING.LANG.po"
        # TODO refactor in order to request the language code in case it can't be extracted from the filename
        langcode = File.basename(filename, '.po')
        tr = {langcode => po2hash(pofile)}
        outfile = File.new(outfilename, "w")
        outfile.puts(tr.to_yaml)
        outfile.close()
    else
        $stderr.puts("\nError: Specified PO file \"#{filename}\" does not exist.\n\n")
    end
end


def print_usage()
    puts("\nUsage:\n")
    puts("  - To create a language's yaml from a given po file\n")
    puts("    po2yaml de.po de.yml\n\n")
end



if ARGV.size == 2
    generate_yaml(ARGV[0], ARGV[1])
    exit
end

print_usage()