pdfmetadata

#!/usr/bin/env ruby

=begin

= Info
    Prints out the metadata contained in a PDF document.

= License
    Copyright (C) 2019  Guillaume Delugré.

    Origami is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    Origami 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 Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public License
    along with Origami.  If not, see <http://www.gnu.org/licenses/>.

=end

begin
    require 'origami'
rescue LoadError
    $: << File.join(__dir__, '../lib')
    require 'origami'
end
include Origami

require 'colorize'
require 'optparse'
require 'json'

class OptParser
    BANNER = <<USAGE
Usage: #{$0} [<PDF-file>] [-i] [-x]
Prints out the metadata contained in a PDF document.
Bug reports or feature requests at: http://github.com/gdelugre/origami

Options:
USAGE

    def self.parser(options)
        OptionParser.new do |opts|
            opts.banner = BANNER

            opts.on("-i", "--info", "Extracts document info metadata") do
                options[:doc_info] = true
            end

            opts.on("-x", "--xmp", "Extracts XMP document metadata stream") do
                options[:doc_stream] = true
            end

            opts.on("-f", "--format [FORMAT]", %i{text json}, "Output format ('text', 'json')") do |format|
                options[:output_format] = format
            end

            opts.on("-n", "--no-color", "Turn off colorized output.") do
                options[:disable_colors] = true
            end

            opts.on_tail("-h", "--help", "Show this message") do
                puts opts
                exit
            end
        end
    end

    def self.parse(args)
        options =
        {
            output_format: :text,
            disable_colors: false
        }

        self.parser(options).parse!(args)

        options
    end
end

def print_section(name, elements)
    puts "[*] #{name}:".magenta

    elements.each_pair do |name, item|
        print name.ljust(20, ' ').green
        puts ": #{item}"
    end
end

begin
    @options = OptParser.parse(ARGV)

    unless @options[:doc_info] or @options[:doc_stream]
        @options[:doc_info] = @options[:doc_stream] = true
    end

    String.disable_colorization @options[:disable_colors]

    target = (ARGV.empty?) ? STDIN : ARGV.shift
    params =
    {
        verbosity: Parser::VERBOSE_QUIET,
        lazy: true
    }

    pdf = PDF.read(target, params)
    result = {}

    if @options[:doc_info] and pdf.document_info?
        result[:document_info] = pdf.document_info.map {|k,v| 
            key = k.value.to_s
            obj = v.solve
            str_value = obj.respond_to?(:to_utf8) ? obj.to_utf8 : obj.value.to_s

            [ key, str_value ]
        }.to_h
    end

    if @options[:doc_stream] and pdf.metadata?
        result[:xmp_metadata] = pdf.metadata
    end


    if @options[:output_format] == :text
        print_section("Document information dictionary", result[:document_info]) if result.key?(:document_info)
        
        if result.key?(:xmp_metadata)
            puts if result.key?(:document_info)
            print_section("Metadata stream", result[:xmp_metadata])
        end
    elsif @options[:output_format] == :json
        puts JSON.pretty_generate(result)
    end

rescue
    puts $!.backtrace.join $/
    abort "#{$!.class}: #{$!.message}"
end