add bittorrent client

.rubocop.yml

@@ -1,8 +1,13 @@
 AllCops:
+  NewCops: enable
   TargetRubyVersion: 3.0
 
 Style/StringLiterals:
   EnforcedStyle: double_quotes
 
 Style/StringLiteralsInInterpolation:
   EnforcedStyle: double_quotes
+Documentation:
+  Enabled: false
+Style/FrozenStringLiteralComment:
+  Enabled: false

Gemfile.lock

@@ -3,19 +3,32 @@ PATH
   specs:
     rutorrent (0.1.0)
       bencode (~> 0.8.2)
+      bytesize (~> 0.1.0)
+      concurrent-ruby (~> 1.2)
+      pry (~> 0.14.1)
+      tty-prompt (~> 0.23.1)
 
 GEM
   remote: https://rubygems.org/
   specs:
     ast (2.4.2)
     bencode (0.8.2)
+    bytesize (0.1.2)
+    coderay (1.1.3)
+    concurrent-ruby (1.2.3)
     diff-lcs (1.5.1)
     json (2.7.2)
     language_server-protocol (3.17.0.3)
+    method_source (1.1.0)
     parallel (1.24.0)
     parser (3.3.1.0)
       ast (~> 2.4.1)
       racc
+    pastel (0.8.0)
+      tty-color (~> 0.5)
+    pry (0.14.2)
+      coderay (~> 1.1)
+      method_source (~> 1.0)
     racc (1.8.0)
     rainbow (3.1.1)
     rake (13.2.1)
@@ -50,7 +63,18 @@ GEM
       parser (>= 3.3.1.0)
     ruby-progressbar (1.13.0)
     strscan (3.1.0)
+    tty-color (0.6.0)
+    tty-cursor (0.7.1)
+    tty-prompt (0.23.1)
+      pastel (~> 0.8)
+      tty-reader (~> 0.8)
+    tty-reader (0.9.0)
+      tty-cursor (~> 0.7)
+      tty-screen (~> 0.8)
+      wisper (~> 2.0)
+    tty-screen (0.8.2)
     unicode-display_width (2.5.0)
+    wisper (2.0.1)
 
 PLATFORMS
   ruby

README.md

@@ -1,8 +1,6 @@
 # Rutorrent
 
-TODO: Delete this and the text below, and describe your gem
-
-Welcome to your new gem! In this directory, you'll find the files you need to be able to package up your Ruby library into a gem. Put your Ruby code in the file `lib/rutorrent`. To experiment with that code, run `bin/console` for an interactive prompt.
+A Ruby torrent client made using concurrent-ruby for your CLI. Still in development.
 
 ## Installation
 
@@ -18,7 +16,7 @@ If bundler is not being used to manage dependencies, install the gem by executin
 
 ## Usage
 
-TODO: Write usage instructions here
+You can simply run `bundle exec rutorrent` and follow the instructions in the console.
 
 ## Development
 

bin/rutorrent

@@ -1,3 +1,5 @@
 #!/usr/bin/env ruby
-require 'rutorrent'
-puts Rutorrent::VERSION
+
+require "rutorrent"
+
+Rutorrent::CLI.start

lib/rutorrent.rb

@@ -1,8 +1,7 @@
 # frozen_string_literal: true
 
-require_relative "rutorrent/version"
+Dir["#{__dir__}/rutorrent/**/*.rb"].each { |f| require f }
 
 module Rutorrent
   class Error < StandardError; end
-  # Your code goes here...
 end

lib/rutorrent/available_piece.rb

@@ -0,0 +1,13 @@
+module Rutorrent
+  class AvailablePiece
+    attr_accessor :payload
+
+    def initialize(payload)
+      @payload = payload.chars.map!(&:to_i)
+    end
+
+    def available_pieces
+      payload.each_index.select { |i| payload[i] == 1 }
+    end
+  end
+end

lib/rutorrent/cli.rb

@@ -0,0 +1,43 @@
+require "tty-prompt"
+require "bencode"
+require "bytesize"
+
+module Rutorrent
+  class CLI
+    def self.start
+      puts Rutorrent::MESSAGES[:no_torrents_available] if Dir["#{Dir.home}/**/*.torrent"].empty? && exit
+
+      selected_torrent_path = prompt.select(Rutorrent::MESSAGES[:select_torrent], Dir["#{Dir.home}/**/*.torrent"])
+      decoded_torrent = BEncode.load_file(selected_torrent_path)
+      torrent_files = prompt.multi_select(Rutorrent::MESSAGES[:instructions],
+                                          format_torrent_files_with_size(decoded_torrent))
+
+      torrent_files = format_torrent_files_with_size(decoded_torrent, show_byte_size: false) if torrent_files.empty?
+
+      Rutorrent::Downloader.new(decoded_torrent, torrent_files).start
+    end
+
+    def self.format_torrent_files_with_size(torrent, show_byte_size: true)
+      formatted_files = if torrent["info"]["files"].nil?
+                          [torrent["info"]["name"]]
+                        else
+                          torrent["info"]["files"].map { |f| f["path"].join("/") }
+                        end
+
+      if show_byte_size
+        formatted_files = formatted_files.map do |file|
+          return "#{file} (#{ByteSize.new(torrent["info"]["length"])})" if torrent["info"]["files"].nil?
+
+          index = torrent["info"]["files"].find_index { |f| f["path"].join("/") == file }
+          "#{file} (#{ByteSize.new(torrent["info"]["files"][index]["length"])})"
+        end
+      end
+
+      formatted_files
+    end
+
+    def self.prompt
+      @prompt ||= TTY::Prompt.new
+    end
+  end
+end

lib/rutorrent/cli_messages.rb

@@ -0,0 +1,7 @@
+module Rutorrent
+  MESSAGES = {
+    select_torrent: "Please select a .torrent file to download",
+    instructions: "Use ↑/↓ arrow keys to choose a file, press Space to select and Enter to finish (by default, all files will be downloaded):",
+    no_torrents_available: "No .torrent files found in your home directory. Please download at least one and try again."
+  }.freeze
+end

lib/rutorrent/constants.rb

@@ -0,0 +1,15 @@
+module Rutorrent
+  module Constants
+    PEER_MESSAGES_MAPPING = {
+      0x0 => "choke",
+      0x1 => "unchoke",
+      0x2 => "interested",
+      0x3 => "not interested",
+      0x4 => "have",
+      0x5 => "bitfield",
+      0x6 => "request",
+      0x7 => "piece",
+      0x8 => "cancel"
+    }.freeze
+  end
+end

lib/rutorrent/downloader.rb

@@ -0,0 +1,20 @@
+module Rutorrent
+  class Downloader
+    def initialize(torrent, torrent_files)
+      @torrent = torrent
+      @torrent_files = torrent_files
+    end
+
+    def start
+      tracker.connect
+    end
+
+    private
+
+    def tracker
+      @tracker ||= Rutorrent::Tracker.new(torrent, torrent_files)
+    end
+
+    attr_reader :torrent, :torrent_files
+  end
+end

lib/rutorrent/file_saver.rb

@@ -0,0 +1,46 @@
+require "digest/sha1"
+
+class FileSaver
+  attr_reader :expected_hashes, :pieces, :total_pieces, :piece_length, :file_path, :file
+
+  def initialize(file_path, piece_length, total_pieces, expected_hashes)
+    @file_path = file_path
+    @file = File.open(file_path, "wb")
+    @piece_length = piece_length
+    @total_pieces = total_pieces
+    @expected_hashes = expected_hashes
+    @pieces = Array.new(total_pieces) { "" }
+  end
+
+  def save_block(piece_index, begin_offset, block_data)
+    @pieces[piece_index] ||= ""
+    @pieces[piece_index][begin_offset, block_data.length] = block_data
+
+    @file.seek(piece_index * @piece_length)
+    @file.write(@pieces[piece_index])
+    verify_piece(piece_index)
+    @pieces[piece_index] = nil
+  end
+
+  def save_piece_to_file(piece_index)
+    @file.seek(piece_index * piece_length)
+    @file.write(pieces[piece_index])
+    puts "Verified and saved piece #{piece_index}"
+  end
+
+  def expected_final_piece_size
+    @total_length - (@piece_length * (@total_pieces - 1))
+  end
+
+  def verify_piece(piece_index)
+    piece_data = @pieces[piece_index]
+    piece_hash = Digest::SHA1.digest(piece_data)
+    expected_hash = @expected_hashes[piece_index]
+
+    return save_piece_to_file(piece_index)
+  end
+
+  def close
+    file.close
+  end
+end

lib/rutorrent/http_connection.rb

@@ -0,0 +1,74 @@
+require "net/http"
+
+module Rutorrent
+  class HTTPConnection
+    attr_reader :torrent, :options, :torrent_files
+
+    def initialize(torrent, torrent_files, options = {})
+      @torrent = torrent
+      @options = options
+      @torrent_files = torrent_files
+
+      create_methods_by_options
+    end
+
+    def connect
+      uri = build_uri
+      response = fetch_response(uri)
+      handle_response(response)
+    end
+
+    private
+
+    def request_params
+      {
+        info_hash: info_hash,
+        peer_id: peer_id,
+        port: port,
+        uploaded: uploaded,
+        downloaded: downloaded,
+        left: left,
+        compact: compact,
+        event: event
+      }
+    end
+
+    def build_uri
+      URI("#{torrent["announce"]}?#{URI.encode_www_form(request_params)}")
+    end
+
+    def create_methods_by_options
+      options.each do |method_name, method_value|
+        define_singleton_method(method_name) { method_value }
+      end
+    end
+
+    def fetch_response(uri)
+      Net::HTTP.get_response(uri)
+    rescue StandardError => e
+      puts "Something went wrong: #{e}"
+      exit
+    end
+
+    def handle_response(response)
+      return if response.nil?
+
+      response = BEncode.load(response.body)
+
+      peers = response["peers"].scan(/.{6}/)
+      puts "There are #{peers.size} peers available"
+
+      unpacked_peers = unpack_peers(peers)
+      peer_classes = []
+
+      unpacked_peers.map do |ip, port|
+        handshake = "\x13BitTorrent protocol\x00\x00\x00\x00\x00\x00\x00\x00#{info_hash}#{peer_id}"
+        peer_classes << Peer.new(ip, port, handshake, info_hash)
+      end
+    end
+
+    def unpack_peers(peers)
+      peers.map { |peer| peer.unpack("a4n") }
+    end
+  end
+end