magame

#!/usr/bin/env ruby
# encoding: utf-8

# Developed using Ruby 1.9.3, should run under any version of Ruby 1.9

# Create a small command line game in Ruby that does the following:
#
#- Player 1 enters a letter. The program uses the google api to search for that
#  letter and outputs the number of search results. - Player 2 adds a letter.
#  The program displays the whole series of letters and outputs the number of
#  search results. - This continues until the combined word doesn't yield any
#  results. The player who entered the last letter loses the game
#

GOOGLE_API_KEY = 'AIzaSyDWaZ8-dqAPHXSeRrqBu2QXYt9zkwOA31w'

require 'cgi'
require 'open-uri'
require 'yaml'

class Hash
  # Formats the hash as a URI query string (not including the “?”)
  # HACK: only handles flat query strings, not nested hashes/arrays
  # like ActiveSupport’s Object#to_query
  def to_query
    collect {|k,v| CGI.escape(k.to_s)+'='+CGI.escape(v.to_s)  }.join('&')
  end
end

# Find +term+ using the Google “Ajax” Web Search API
# HACK: The web search API is deprecated! This should probably migrate
# to using the Custom Search API (http://code.google.com/apis/websearch/docs/)
# This requires more setup before in setting up a search context etc.
# so we use the deprecated API for now
def google_search term
  # search_endpoint = 'https://www.googleapis.com/customsearch/v1'
  search_endpoint = 'https://ajax.googleapis.com/ajax/services/search/web'
  uri = URI.parse search_endpoint
  uri.query = {v: '1.0', key: GOOGLE_API_KEY, q: term}.to_query
  
  # exploiting the fact that YAML is a super-set of JSON here
  YAML.load(uri.read)
end

# Returns the results of a google search
def google_result_count term
  # google gives us a string like "85,800,000"
  count = google_search(term)['responseData']['cursor']['resultCount']
  count.gsub(',','').to_i rescue 0
end

# Prompt the named player for a letter on the console
def prompt player_name
  print "#{player_name}, please enter a letter: "
  input = gets.chomp
  if input =~ /^[A-Za-zÆæÅåØøÄäÖöÜüß]$/
    input
  else
    puts "“#{input}” isn’t a single letter, please try again."
    prompt player_name
  end
end

if __FILE__ == $PROGRAM_NAME
  trap("INT") { abort "(Cancelled)" }
  term = ''
  loop do
    ["Player 1", "Player 2"].each do |name|
      term << prompt(name)
      count = google_result_count(term)
      if count > 0
        puts "#{count} results for “#{term}”"
      else
        puts "No results for “#{term}”. You lose, #{name}!"
        exit
      end
    end
    
  end
end

sample_interaction.txt

 ➔ ./magame 
Player 1, please enter a letter: R
464000000 results for “R”
Player 2, please enter a letter: a
68000000 results for “Ra”
Player 1, please enter a letter: ro
“ro” isn’t a single letter, please try again.
Player 1, please enter a letter: r
50200000 results for “Rar”
Player 2, please enter a letter: o
6100000 results for “Raro”
Player 1, please enter a letter: t
1980 results for “Rarot”
Player 2, please enter a letter: o
n1360 results for “Raroto”
Player 1, please enter a letter: n
“nn” isn’t a single letter, please try again.
Player 1, please enter a letter: n
342 results for “Raroton”
Player 2, please enter a letter: g
531 results for “Rarotong”
Player 1, please enter a letter: a
244000 results for “Rarotonga”
Player 2, please enter a letter:  
“ ” isn’t a single letter, please try again.
Player 2, please enter a letter: i
2270 results for “Rarotongai”
Player 1, please enter a letter: s
3360 results for “Rarotongais”
Player 2, please enter a letter: v
No results for “Rarotongaisv”. You lose, Player 2!