class HexaPDF::CLI::Files

def attach_files(doc)
  @attach_files.each {|file, desc| doc.files.add(file, description: desc) }
end

def each_file(doc, &block) # :yields: obj, index
  doc.files.each(search: @search).select(&:embedded_file?).each_with_index(&block)
end

def execute(pdf, output = nil) #:nodoc:
  if @indices.empty? && !@attach_files.empty?
    raise Error, "Missing output file" unless output
    maybe_raise_on_existing_file(output)
  end
  with_document(pdf, password: @password, out_file: output) do |doc|
    if @indices.empty? && @attach_files.empty?
      list_files(doc)
    elsif !@indices.empty? && !@attach_files.empty?
      raise Error, "Use either --attach or --extract but not both"
    elsif !@attach_files.empty?
      attach_files(doc)
    else
      extract_files(doc)
    end
  end
end

def extract_files(doc)
  each_file(doc) do |obj, index|
    next unless @indices.include?(index + 1) || @indices.include?(0)
    maybe_raise_on_existing_file(obj.path)
    puts "Extracting #{obj.path}..." if command_parser.verbosity_info?
    File.open(obj.path, 'wb') do |file|
      fiber = obj.embedded_file_stream.stream_decoder
      while fiber.alive? && (data = fiber.resume)
        file << data
      end
    end
  end
end

def initialize #:nodoc:
  super('files', takes_commands: false)
  short_desc("List and extract embedded files from a PDF or attach files")
  long_desc(<<~EOF)
    If neither the option --attach nor the option --extract is given, the available
    files are listed with their names and indices. The --extract option can then be
    used to extract one or more files. Or the --attach option can be used to attach
    files to the PDF.
  EOF
  options.on("--attach FILE", "-a FILE", String,
             "The file that should be attached. Can be used multiple times.") do |file|
    @attach_files << [file, nil]
  end
  options.on("--description DESC", "-d DESC", String,
             "Adds a description to the last file to be attached.") do |description|
    @attach_files[-1][1] = description
  end
  options.on("--extract [a,b,c,...]", "-e [a,b,c,...]", Array,
             "The indices of the files that should be extracted. Use 0 or no argument to " \
             "extract all files.") do |indices|
    @indices = (indices ? indices.map(&:to_i) : [0])
  end
  options.on("--[no-]search", "-s", "Search the whole PDF instead of the " \
             "standard locations (default: false)") do |search|
    @search = search
  end
  options.on("--password PASSWORD", "-p", String,
             "The password for decryption. Use - for reading from standard input.") do |pwd|
    @password = (pwd == '-' ? read_password : pwd)
  end
  @attach_files = []
  @indices = []
  @password = nil
  @search = false
end

def list_files(doc)
  each_file(doc) do |obj, index|
    $stdout.write(sprintf("%4i: %s", index + 1, obj.path))
    ef_stream = obj.embedded_file_stream
    if (params = ef_stream[:Params]) && !params.empty?
      data = []
      data << "size: #{params[:Size]}" if params.key?(:Size)
      data << "md5: #{params[:CheckSum].unpack1('H*')}" if params.key?(:CheckSum)
      data << "ctime: #{params[:CreationDate]}" if params.key?(:CreationDate)
      data << "mtime: #{params[:ModDate]}" if params.key?(:ModDate)
      $stdout.write(" (#{data.join(', ')})")
    end
    $stdout.puts
    $stdout.puts("      #{obj[:Desc]}") if obj[:Desc] && !obj[:Desc].empty?
  end
end