#!/usr/bin/ruby
require "aitask.rb"

# See http://sartak.katron.org/nh/mastermind.html for a discussion of this
# code, including figures for the average and max number of attempts we'll 
# need.

class TaskFindCastleTune < ElAITask
  @@tune = ""
  @@notes = %w(A B C D E F G)
  @@seen = {};

  def desire()
    return 0
  end

  def execute()
    instrument = inventory.find_tonal_instrument()

    # apply instrument, no we don't want to improvise
    response = send "a" + instrument.invletter + "n"

    # Ack!
    if response !~ /What tune are you playing\?/
      return
    end

    # we've seen five unique notes, so remove any others
    if (@@seen.keys.size == 5)
      @@notes.delete_if {|note| not @@seen.has_key?[note] }
    end

    if (@@notes.size == 1) # easy optimization to make, so why not :)
      @@tune += @@notes[0] * (5 - @@tune.length)
      send @@tune
      return
    end

    response = send @@tune + @@notes[0]

    if response =~ /You hear \d tumblers? click/ 
      # "You hear 1 tumbler click and 1 gear turn."
      # "You hear 1 tumbler click."

      # Move this note to the end of the list (so we're sure to get the
      # correct note before we see this one again)
      note = @@notes.delete_at(0)
      @@seen[note] = 1
      @@notes.push(note)

    elsif response =~ /You hear (\d) gears? turn\./ && 
          $1.to_i > @@tune.length()

      # Got the correct note, yay!
      # We check for tune length because as soon as we get the first note,
      # all responses will have this text.
      # Consider correct tune "AGGGG" and we play "AB"
      # It'll say "You hear 1 gear turn." even though the current note ("B")
      # isn't in the tune at all.

      @@seen[@@notes[0]] = 1
      @@tune += @@notes[0]

    else

      # No tumblers, no new gears, so this note is no longer possible in the
      # rest of the tune.
      @@notes.delete_at(0)

    end
  end
end

if __FILE__ == $0
  require "../utils/assert.rb"

  print "unit test succeeded\n"
end