class Pdfinfo

# File lib/pdfinfo.rb, line 30
def initialize(source_path, opts = {})
  info_hash = parse_shell_response(exec(source_path, opts))

  @pages = []
  info_hash.delete_if do |key, value|
    @pages << Page.from_string(value) if key.match(/Page\s+\d+\ssize/)
  end

  encrypted_val = info_hash.delete('Encrypted')

  @title          = presence(info_hash.delete('Title'))
  @subject        = presence(info_hash.delete('Subject'))
  @author         = presence(info_hash.delete('Author'))
  @creator        = presence(info_hash.delete('Creator'))
  @producer       = presence(info_hash.delete('Producer'))
  @tagged         = !!(info_hash.delete('Tagged') =~ /yes/)
  @optimized      = !!(info_hash.delete('Optimized') =~ /yes/)
  @encrypted      = !!(encrypted_val =~ /yes/)
  @page_count     = info_hash.delete('Pages').to_i
  @file_size      = info_hash.delete('File size').to_i
  @form           = info_hash.delete('Form')
  @pdf_version    = info_hash.delete('PDF version')
  @keywords       = (info_hash.delete('Keywords') || '').split(/\s/)
  @creation_date  = parse_time(info_hash.delete('CreationDate'))
  @modified_date  = parse_time(info_hash.delete('ModDate'))

  raw_usage_rights = Hash[encrypted_val.scan(/(\w+):(\w+)/)]
  booleanize_usage_right = lambda {|val| raw_usage_rights[val] != 'no' }

  @usage_rights = {}.tap do |ur|
    ur[:print]     = booleanize_usage_right.call('print')
    ur[:copy]      = booleanize_usage_right.call('copy')
    ur[:change]    = booleanize_usage_right.call('change')
    ur[:add_notes] = booleanize_usage_right.call('addNotes')
  end
end

# File lib/pdfinfo.rb, line 14
def pdfinfo_command
  @pdfinfo_command || 'pdfinfo'
end

# File lib/pdfinfo.rb, line 18
def pdfinfo_command=(cmd)
  @pdfinfo_command = cmd
end

# File lib/pdfinfo.rb, line 23
def pdfinfo_command?
  system("type #{pdfinfo_command} >/dev/null 2>&1")
end

# File lib/pdfinfo.rb, line 82
def annotatable?
  @usage_rights[:add_notes]
end

# File lib/pdfinfo.rb, line 86
def to_hash
  super.tap {|h| h[:pages].map!(&:to_hash) }
end

# File lib/pdfinfo.rb, line 117
def build_options(opts = {})
  flags = []
  xpdfrc_path = opts.fetch(:config_path, self.class.config_path)

  # these flag will always be part of the cli options. Values have defaults and can be overridden
  flags.concat(['-f',   opts.fetch(:first_page, 0)])
  flags.concat(['-l',   opts.fetch(:last_page, -1)])
  flags.concat(['-enc', opts.fetch(:encoding, Encoding::UTF_8)])
  # optional flags.  if no value, the flag wont be added
  flags.concat(['-cfg', xpdfrc_path])           if xpdfrc_path
  flags.concat(['-opw', opts[:owner_password]]) if opts[:owner_password]
  flags.concat(['-upw', opts[:user_password]])  if opts[:user_password]
  flags.map(&:to_s)
end

# File lib/pdfinfo.rb, line 96
def exec(file_path, opts = {})
  validate_pdfinfo_command!

  flags = build_options(opts)

  command = [self.class.pdfinfo_command, *flags, file_path.to_s].shelljoin

  stdout, status = Open3.capture2(command)
  raise CommandFailed.new(command) unless status.success?
  force_utf8_encoding(stdout)
end

# File lib/pdfinfo.rb, line 134
def force_utf8_encoding(str)
  return str if str.valid_encoding?
  str = str.encode(Encoding::UTF_16, invalid: :replace, undef: :replace, replace: '')
  str.encode!(Encoding::UTF_8)
end

# File lib/pdfinfo.rb, line 145
def parse_shell_response(response_str)
  kv_pairs = response_str.split(/\n+/).map {|line| line.split(/:/, 2).map(&:strip) }
  Hash[kv_pairs.reject {|ary| ary.empty? }]
end

# File lib/pdfinfo.rb, line 150
def parse_time(str)
  return unless presence(str)
  DateTime.strptime(str, '%a %b %e %H:%M:%S %Y')
rescue ArgumentError => e
  nil
end

# File lib/pdfinfo.rb, line 141
def presence(val)
  (val.nil? || val.empty?) ? nil : val
end

# File lib/pdfinfo.rb, line 157
def validate_pdfinfo_command!
  unless self.class.pdfinfo_command?
    raise CommandNotFound, self.class.pdfinfo_command
  end
end