#!/usr/bin/env ruby
require "date"
require "bencode"
class TorrentFile
  include Bencode
  class FileSegment
    attr_accessor :sha1_hash
    def initialize(sha1_hash)
      @sha1_hash = sha1_hash
    end
  end

  attr_accessor :file_location, :file_data, :data, :info, :announce_list
  attr_accessor :encoding, :creation_date, :created_by, :comment, :announce

  #inside of info
  attr_accessor :name, :pieces, :piece_length, :length, :private

  #single file
  attr_accessor :md5sum

  #multi file
  attr_accessor :files

  def initialize(file_location)
    @file_data = File.read(file_location)
    @file_location = file_location

  end

  #
  # Returns an array of the file names
  #
  def file_list
    parsed_data = @data ||= Bencode.decode(@file_data)
    if is_single_file?
      [parsed_data["info"]["name"]]
    else
      files = Bencode.decode(parsed_data["info"]["files"])
    end

  end

  #
  # True if there is only one file
  #
  def is_single_file?
    parsed_data = @data ||= Bencode.decode(@file_data)
    !parsed_data["info"].has_key?("files")
  end

  #
  # True if there is more then one file
  #
  def is_multi_file?
    parsed_data = @data ||= Bencode.decode(@file_data)
    parsed_data["info"].has_key?("files")
  end

  #
  # Returns the info hash
  #
  def info
    parsed_data = @data ||= Bencode.decode(@file_data)
    parsed_data["info"]
  end

  #
  # returns array of back up trackers.
  # this is an extention to the official specification,
  # which is also backwards compatible.
  # This key is used to implement lists of backup trackers.
  #
  def announce_list
    parsed_data = @data ||= Bencode.decode(@file_data)
    parsed_data["announce-list"].flatten
  end

  #
  # returns a string of an annouce
  #
  def announce
    parsed_data = @data ||= Bencode.decode(@file_data)
    parsed_data["announce"]
  end

  #
  # returns the string of the encoding
  #
  def encoding
    parsed_data = @data ||= Bencode.decode(@file_data)
    parsed_data["encoding"]
  end

  #
  # Returns the data the torrent was created
  #
  def creation_date
    parsed_data = @data ||= Bencode.decode(@file_data)
    Time.at(parsed_data["creation date"])
  end

  #
  # returns the created by string
  #
  def created_by
    parsed_data = @data ||= Bencode.decode(@file_data)
    parsed_data["created by"]
  end

  #
  # returns the comment string
  #
  def comment
    parsed_data = @data ||= Bencode.decode(@file_data)
  end

  #
  # returns the file name
  #
  def name
    parsed_data = @data ||= Bencode.decode(@file_data)
    parsed_data["info"]["name"]
  end

  #
  # returns the pieces data
  #
  def pieces
    unless @parsed_peices
      parsed_data = @data ||= Bencode.decode(@file_data)
      @parsed_peices = parsed_data["info"]["pieces"].unpack("H*").first.scan(/.{20}/).map{|hash| FileSegment.new(hash)}
    end
    @parsed_peices
  end

  #
  # returns the piece_length
  #
  def piece_length
    parsed_data = @data ||= Bencode.decode(@file_data)
    parsed_data["info"]["piece length"]
  end

  #
  # returns the length
  #
  def length
    parsed_data = @data ||= Bencode.decode(@file_data)
    parsed_data["info"]["length"]
  end

  #
  # returns the private flag
  #
  def private
    parsed_data = @data ||= Bencode.decode(@file_data)
    parsed_data["info"]["private"]
  end

end


if __FILE__ == $0

  require 'test/unit'
  class TorrentFileTest 
< Test::Unit::TestCase
    def setup
      @test_file = File.join(File.dirname(__FILE__),"test.torrent")
    end


    def test_torrent_single_file
      tf = TorrentFile.new(@test_file)
      assert_equal("UTF-8",tf.encoding)
      assert(tf.info["name"])
      assert_equal("College Basketball - ''Colorado State at Utah'' (Recorded Jan 17, 2009, MTN).mpg",tf.name)
      assert_equal(1232424648,tf.creation_date.to_i)
      assert_equal(["http://tracker.thepiratebay.org/announce","udp://tracker.thepiratebay.org:80/announce"],tf.announce_list)
      assert_equal(["College Basketball - ''Colorado State at Utah'' (Recorded Jan 17, 2009, MTN).mpg"],tf.file_list)
      assert_equal(1692,tf.pieces.size)

    end

  end


end