ravenmasker

#!/usr/bin/env ruby

# === === === === === === === === === === === === === === === === === === === #
# filename: ravenmasker
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require 'thor'
require_relative 'masker'
require_relative 'raven'

class RavenMasker < Thor
  # override implemented from https://stackoverflow.com/a/45730659/5103831
  # this is to make sure the ordering of commands is true to the ordering here
  class << self
    def help(shell, subcommand = false)
      list = printable_commands(true, subcommand)
      Thor::Util.thor_classes_in(self).each do |klass|
        list += klass.printable_commands(false)
      end

      # Remove this line to disable alphabetical sorting
      # list.sort! { |a, b| a[0] <=> b[0] }

      # Add this line to remove the help-command itself from the output
      list.reject! {|l| l[0].split[1] == 'help'}

      if defined?(@package_name) && @package_name
        shell.say "#{@package_name} commands:"
      else
        shell.say "Commands:"
      end

      shell.print_table(list, :indent => 2, :truncate => false)
      shell.say
      class_options_help(shell)

      # Add this line if you want to print custom text at the end of your help output.
      # (similar to how Rails does it)
      shell.say "Run `#{self.basename} help <command>` for a more detailed description"
    end
  end

  AUTH_FILE = __dir__ + '/auth.json'

  desc 'mask <img> <msg> <tags>', 'encrypt <msg> into <img> using <tags>'
  option :output, :aliases => '-o'
  long_desc <<-LONGDESC
    `ravenmasker mask` will encrypt a message <msg> into a given image <img>, utilizing a provided set of tags, suitable for Twitter hashtags

    e.g. ravenmasker mask image.png 'hello world' foo,bar,ravenmasker2018

    It is recommended that the image be at least 128x128px to work, however the encryption is more effective for larger messages. Additionally, the image must not have any pre-existing transparency. Lastly, this will not work in the unlikely case the payload has more characters than the image has pixels, but it is recommended the payload length be no more than 1% of the image pixel count.

    Tags must be provided as a comma-separated list. Valid tags have only letters, numbers, and underscores, and cannot start with a number.

    An output file may be optionally provided with `--output FILENAME` or `-o FILENAME`, otherwise the default output image will be `<img>_masked.png`
  LONGDESC
  def mask( img_name, msg, tags )
    begin
      Masker.img_file_valid?( img_name )
    rescue => err
      @shell.say "\tERROR // Provided image file, #{img_name}, is not valid..."
      @shell.say "\t#{err.message}"
      return
    end

    begin
      Masker.msg_valid?( msg )
    rescue => err
      @shell.say "\tERROR // Provided message, #{msg}, is not valid..."
      @shell.say "\t#{err.message}"
      return
    end

    tag_arr = tags.split( ',' )

    begin
      Masker.tags_valid?( tag_arr )
    rescue => err
      @shell.say "\tERROR // Provided tags, #{tag_arr}, are not valid..."
      @shell.say "\t#{err.message}"
      return
    end

    if options[:output]
      output = options[:output]
    else
      output = img_name.chomp( '.png' ) + '_masked.png'
    end

    begin
      Masker.mask( img_name, msg, tag_arr, output )
    rescue ArgumentError => err
      @shell.say "\tERROR // Masking process..."
      @shell.say "\t#{err.message}"
    end

    puts "\t'#{msg}' was encrypted into #{output} using the tags #{tags.split ','}"

    output
  end

  desc 'unmask <img> <tags>', 'decrypt a message from <img> using <tags>'
  long_desc <<-LONGDESC
    `ravenmasker unmask` will decrypt a message from <img>, using the given <tags> as a cipher.

    e.g. ravenmasker unmask mask masked_image.png foo,bar,ravenmasker2018

    Tags must be provided as a comma-separated list. Valid tags have only letters, numbers, and underscores, and cannot start with a number.

    If a message is not found (either the cipher was incorrect, or the image was not encrypted to begin with), an error will be printed. Otherwise, the decrypted message will be the only output.
  LONGDESC
  def unmask( img_name, tags )
    begin
      Masker.img_file_valid?( img_name )
    rescue => err
      @shell.say "\tERROR // Provided image file, #{img_name}, is not valid..."
      @shell.say "\t#{err.message}"
      return
    end

    if tags.is_a? String
      tag_arr = tags.split( ',' )
    elsif tags.is_a? Array
      tag_arr = tags
    else
      @shell.say "\tERROR // Provided invalid Type for tags: #{tags.class}"
      return
    end

    begin
      Masker.tags_valid?( tag_arr )
    rescue => err
      @shell.say "\tERROR // Provided tags, #{tag_arr}, are not valid..."
      @shell.say "\t#{err.message}"
      return
    end

    begin
      msg = Masker.unmask( img_name, tag_arr )
    rescue ArgumentError => err
      @shell.say "\tERROR // unmasking failed..."
      @shell.say "\t#{err.message}"
      return
    end

    if msg.length == 0
      msg = "\tERROR // A message could not be decrypted from #{img_name}."
    end

    @shell.say "\t#{msg}"
  end

  desc 'pull <status>', 'read <status> tweet and check for an encrypted message'
  long_desc <<-LONGDESC
  LONGDESC
  def pull( status, output=nil )
    if !File.exist? AUTH_FILE
      @shell.say "\tERROR // Could not find auth file at " + AUTH_FILE
    end

    auth = JSON.parse( File.read( AUTH_FILE ) )
    raven = Raven.new( auth )

    tweet = raven.get_tweet( status )

    @shell.say raven.tweet_to_s( tweet )
    @shell.say # newline

    if !raven.valid_tweet?( tweet )
      @shell.say "\tERROR // Provided tweet does not have an attached PNG"
      return
    end

    img_name = raven.pull_img_from_tweet( tweet, output )
    tags = raven.get_tags_as_strs( tweet )

    unmask( img_name, tags )
  end

  desc 'send <img> <msg> <tweet> <tags>', 'tweet <tweet> with <msg> encrypted into <img> using <tags>'
  long_desc <<-LONGDESC
  LONGDESC
  def send( img_name, msg, tweet, tags )
    if !File.exist? AUTH_FILE
      @shell.say "\tERROR // Could not find auth file at " + AUTH_FILE
    end

    auth = JSON.parse( File.read( __dir__ + '/auth.json' ) )

    raven = Raven.new( auth )
    tweet = raven.add_tags_to_msg( tweet, tags )

    @shell.say "Encypting..."
    masked = mask( img_name, msg, tags )

    @shell.say #newline
    @shell.say """Tweeting:
    Message:      #{tweet}
    Source Image: #{img_name}"""

    begin
      raven.send_tweet tweet, masked
    rescue Twitter::Error::Unauthorized => err
      @shell.say "\t#{err.msg}"
    end
  end

end


RavenMasker.start( ARGV )