###############################################################################
# Stores and retrieves FAQ questions.
#
# > add faq: What is an FAQ? answer: FAQ means Frequently Asked Questions.
# Okay, I have added FAQ means Frequently Asked Questions to faq What is an FAQ
#
# > find faq
# What is an faq?
# FAQ means Frequently Asked Questions.
#
# > what is a FAQ = what is an FAQ
# Okay, I have added what is a FAQ = what is an FAQ
#
# > What is a FAQ?
# What is an FAQ? 
# FAQ means Frequently Asked Questions. 
#
# > 
################################################################################

require 'yaml'
require 'graph'

$Quitwords = [':q', 'quit', 'exit', 'bye']

class MyAgent 

   attr_accessor :DEBUG

   def initialize(args=Array.new)
     @workingDir = File.expand_path(File.dirname(__FILE__))
     @filename = @workingDir + "/faqagent-api.yaml"
     unless load_message = load_synonyms
       @patterns = [ [/^(.*?) is a synonym for (.*)/, :add_synonym], 
                     [/^save syn/, :save_synonyms],
                     [/^load syn/, :load_synonyms], 
                     [/^add pattern (.*), (.*)/, :add_pattern], 
                     [/^>(.*)/, :defining_method],
                     [/^restart/, :restart],
                     [/^show api/, :show_api],
                     [/^show (.*)'s api/, :show_one_method_api]
                   ]
       save_synonyms # creates patterns.yaml on first use.
     else
       puts load_message 
     end
     @method_def = ''
     @DEBUG = 0

     @FAQFILE = "graph.yaml"
     @graph = Graph.new
     @question_words = ['what', 'why', 'who', 'when', 'how', 'can', 'may', 
                        'did', 'do', 'does', 'will', 'is', 'are']
   end

   def def_method method_def
     file = IO.read(__FILE__)
     return "Doesn't have 'end # class'" unless file =~ /(.*)end # class(.*)if \$0 == __FILE__(.*)/m
     grp1 = $1.to_s; grp2 = $2.to_s; grp3 = $3.to_s

     new_filename = get_new_filename
     File.open(new_filename, "w+") { |f|
        f.puts grp1 + method_def + "\n\nend # class\n\nif $0 == __FILE__" + grp3
     }
     #@patterns.push( [@new_regexp, @new_symbol] )
     # replace above line with 'smart push'
     @patterns.each_with_index { |e,i|
       found = false
       puts "[def_method]: e.inspect==#{e.inspect}" unless @DEBUG == 0
       pattern = e[0].to_s
       puts "[def_method]: pattern==#{pattern}" unless @DEBUG == 0
       if pattern =~ Regexp.new(Regexp.escape("(?i-mx:(.*)"))
         puts "[def_method]: pattern matched!"
         @patterns.insert(i, [@new_regexp, @new_symbol])
         found = true
       end
       if found then break end
      }
 

     save_synonyms
     puts "#{method_def}"
     MyAgent.class_eval(method_def)
   end

   # If this file has a '.' + a number before the '.rb' extension 
   # (i.e. foo.0.rb), increment the number (i.e. return foo.1.rb).
   # Otherwise return the name of this file unchanged.
   def get_new_filename
      old_filename = __FILE__
      if old_filename =~ /(.*)\.(\d+)\.rb$/
        incr = $2.to_i + 1
        return new_filename = $1.to_s + "." + incr.to_s + ".rb"
      end
      return old_filename  # Dangerous!
   end

   # Match input against each regexp pattern in @patterns; 
   # if there's a match, call the method associated with the pattern.
   def getResponse input
     r = "Default response."

     #puts "input==#{input}"
     @score = 2
     @patterns.each { |pattern|
       if input =~ pattern[0]
          return [self.send(pattern[1], pattern[0], input), @score] rescue return r
       end
     }
     return r
   end

   def load_synonyms(pattern=nil, input=nil)
     if File.exist?(@filename)
        @patterns = YAML.load_file(@filename)
        return "I have loaded #{@filename}."
     end 
     return false
   end

   def save_synonyms(pattern=nil, input=nil)
      r = "Eep! error saving synonyms! "
      begin
        File.open(@filename, 'w') do |out|
          YAML.dump(@patterns, out)
        end
        return "Okay I have saved the synonyms to disk."
      rescue => error
        return r << error
      end
   end

   # a is a synonym for b, or /a/ is a synonym for /b/
   def add_synonym(pattern, input)
     return "Problem matching pattern." unless input =~ pattern
     g1 = $1; g2 = $2; #puts "[add_synonym] g1==#{g1}; g2=#{g2}" 
     # Remove enclosing "/", if present.
     if g1 =~ /^\// then g1.sub!(/^\//, '') end
     if g1 =~ /\/$/ then g1.sub!(/\/$/, '') end
     if g2 =~ /^\// then g2.sub!(/^\//, '') end
     if g2 =~ /\/$/ then g2.sub!(/\/$/, '') end
     #puts "[add_synonym] g1==#{g1}; g2=#{g2}"
     grp1 = %r{(?i-mx:^#{g1})}
     grp2 = %r{(?i-mx:^#{g2})}
     #puts "[add_synonym] grp1==#{grp1}; grp2=#{grp2}"
     method =''
     index = -1
     @patterns.each_with_index { |p,i| 
       #puts "p[0]==#{p[0]}; p[0].class==#{p[0].class}; grp2==#{grp2}; grp2.class==#{grp2.class}"
       if p[0].to_s == grp2.to_s
          method = p[1]
          index = i
          break
       end
     }
     # If still no match, try again with slightly different regexps.
    if method == '' then grp1 = %r{(?i-mx:#{g1})}; grp2 = %r{(?i-mx:#{g2})}; end
     @patterns.each_with_index {|p,i| 
       if p[0].to_s == grp2.to_s; method = p[1]; index = i; break; end}
     if method == '' then grp1 = %r{#{g1}}; grp2 = %r{#{g2}}; end
     @patterns.each_with_index {|p,i| 
       if p[0].to_s == grp2.to_s; method = p[1]; index = i; break; end}
     if method == '' then grp1 = %r{^#{g1}}; grp2 = %r{^#{g2}}; end
     @patterns.each_with_index {|p,i| 
       if p[0].to_s == grp2.to_s; method = p[1]; index = i; break; end}
 
     return unless method.to_s != nil
     puts "add_synonym: index==#{index}" unless @DEBUG == 0
     @patterns.insert(index, [grp1, method] )
     save_synonyms
     return "Okay, #{grp1} has been added, and will now call #{method}." 
   end

   def add_pattern(pattern=nil, input=nil)
     if input =~ pattern 
       @new_regexp = $1
       @new_symbol = $2
       @new_regexp.gsub!(/\//, '')
       new_re = %r{#{@new_regexp}}

       # Make the regexp case insensitive.
       new_re_s = new_re.to_s
       if new_re_s =~ /(-mix)/
         new_re_s = $~.pre_match << "i-mx" << $~.post_match
       end
       @new_regexp = %r{#{new_re_s}}
       #puts "@new_regexp==#{@new_regexp}"

       method_def = "   def #{@new_symbol}(pattern=nil, input=nil)\n     return \"#\{input} doesn't match #\{pattern}\" unless input =~ pattern\n     return 'Default response from " + @new_symbol + "'\n   end # method_def"
       return def_method(method_def)
     else
       return "#{input} doesn't match #{pattern}."
     end
   end

   def defining_method(pattern=nil, input=nil)
     if input =~ pattern
       @method_def << "\n " << $1.to_s
       if @method_def =~ /end # method_def/
         return def_method(@method_def)
       end
       return ''
     else
       return "#{input} doesn't match #{pattern}."
     end
   end

   def method_missing input, *rest
     return getResponse(input.to_s) 
   end

   # Strips delimiters.
   def process str
      str.strip!
      str.sub!(/\?$/, '')
      str.sub!(/^\[/, '')
      str.sub!(/\]$/, '')
      str.sub!(/^(?:"|')/, '')
      str.sub!(/(?:"|')$/, '')
      str.sub!(/\.$/, '')
      str.sub!(/;$/, '')
      str.sub!(/,$/, '')
      str.sub!(/!$/, '')
      str.sub!(/\?$/, '')
      str.sub!(/^\//, '')
      str.sub!(/\/$/, '')
      return str 
   end

   def restart(pattern=nil,input=nil)
     exec "ruby #{__FILE__}" 
   end # method_def

   def show_api(pattern=nil, input=nil)
     return "#{input} doesn't match #{pattern}" unless input =~ pattern
     apiarr= Array.new # Contains methods and patterns from MyAgent-api.yaml.
     @patterns.each { |p|
       regexp = p[0].to_s; method = p[1].to_s; found = false
       puts "regexp=#{regexp}; method=#{method}" unless @DEBUG == 0
       apiarr.each { |arr| if arr.include? method then found = true end }
       next unless not found
       apiarr.push [regexp, method] 
     } # If more than one pattern maps to a method, only the first is stored.
     # Try to pretty-print.
     toReturn = ''
     puts "apiarr.inspect=#{apiarr.inspect}" unless @DEBUG == 0
     apiarr.each { |arr|
       puts "1. arr=#{arr}" unless @DEBUG == 0
       regex = arr[0]; method = arr[1] 
       if regex =~ /\(\?(?:[i\-mx]*)(?:\:)?(?:\^)?(.*)\)/ # try to clean regex
         regex = $1.to_s
       end
       if method == nil or method == '' then method = "Default response" end
       toReturn << method.to_s << " | " << regex.to_s << "\n"
     }
     return toReturn
   end # method_def

   def show_one_method_api(pattern=nil, input=nil)
     return "#{input} doesn't match #{pattern}" unless input =~ pattern
     grp1 = process $1 # Supplied method name.
     apiarr= Array.new # To hold methods and patterns from MyAgent-api.yaml.
     @patterns.each { |p| # Collect all the regexps for the supplied method.
       regexp = p[0].to_s; method = p[1].to_s
       puts "regexp=#{regexp}; method=#{method}." unless @DEBUG == 0
       if method == grp1 then apiarr.push [regexp, method] end 
     } 
     # Try to pretty-print.
     toReturn = ''
     puts "apiarr.inspect=#{apiarr.inspect}" unless @DEBUG == 0
     apiarr.each { |arr|
       puts "1. arr=#{arr}" unless @DEBUG == 0
       regex = arr[0]; method = arr[1] 
       if regex =~ /\(\?(?:[i\-mx]*)(?:\:)?(?:\^)?(.*)\)/ # try to clean regex
         regex = $1.to_s
       end
       if method == nil or method == '' then method = "Default response" end
       toReturn << method.to_s << " | " << regex.to_s << "\n"
     }
     return toReturn
   end # method_def

# Start faqagent-specific methods.

# Note: If questions do not have a final '?', it is added before storing

   def find_faq(pattern=nil, input=nil)
     return "#{input} doesn't match #{pattern}" unless input =~ pattern
     grp1 = process $1
     #puts "[find_faq] grp1==#{grp1}" #unless @DEBUG == 0
     q = grp1; if q !~ /\?$/ then q << '?' end
     returnArr = @graph.a_r_?(q.downcase, ["is answered by"])
     puts "returnArr==#{returnArr}" unless @DEBUG == 0
     # if returnArr is blank, look for the = relation and ask those questions
     questionArr = Array.new
     if returnArr.empty? or returnArr == nil
       questionArr = @graph.a_r_?(q.downcase, "=")
     end
     # flatten questionArray
     flatArray = Array.new
     questionArr.each { |elem|
       elem.each{ |e| flatArray.push(e) }
     }
     questionArr = flatArray 
     #puts "questionArr==#{questionArr}" #unless @DEBUG == 0
     tempArr = Array.new
     if questionArr.size > 0 and questionArr != nil
       questionArr.each { |question|
         #puts "1. tempArr==#{tempArr}"
         q2 = question; if q2 !~ /\?$/ then q2 << '?' end
         tempArr.push @graph.a_r_?(q2, "is answered by")
         #puts "2. tempArr==#{tempArr}"
         tempArr.each { |elem| returnArr.push elem }
       }
     end
     returnArr.uniq!
     #puts "returnArr (2) == #{returnArr}"

     # Pretty-print response TODO: put into separate method
     grp1 << "?" unless grp1.split.size < 3
     grp1.capitalize! unless grp1.split.size < 3

     if grp1 =~ /\?\?$/ then grp1.sub!(/\?\?$/, '?') end
     period = "." unless grp1 =~ /\?$/
     if returnArr.size == 0 then return "I can't find #{grp1}#{period}" end
     @score = 4
     # Get the main faq answered by the response, so both can be returned. 
     questions = Array.new
     returnArr.each { |elem|
       #puts "elem==#{elem}"
       if elem == nil then next end
       if elem.size == 0 then next end
       if elem.class == String then elem.chomp! end
       if elem.class == Array then elem = elem[0] end
       q = @graph.what_r_b?("is answered by", elem)
       #puts "[find_faq] q==#{q}" #unless @DEBUG == 0
       if q.class == Array then q.each { |e| e.capitalize!; e.strip! } end
       if q.class == String then q.capitalize!; q.strip! end
       questions.push(q)
     }
     answers = returnArr.join("; "); 
     if answers =~ /; $/ then answers.sub!(/; $/, '') end
     if answers =~ /^; / then answers.sub!(/^; /, '') end
     return questions.uniq.join(" ") << "\n" << answers << "."
   end # method_def

   def show_faq_questions(pattern=nil, input=nil)
     return "#{input} doesn't match #{pattern}" unless input =~ pattern
     arr = @graph.vertex_hash.keys
     returnArr = Array.new
     arr.each { |elem|
       if elem =~ /\?$/ then returnArr.push(elem) end
     }
     return returnArr.join(" ") unless returnArr.size == 0
     return "There are no faq questions."
   end # method_def

   def set_faq_file(pattern=nil, input=nil)
     return "#{input} doesn't match #{pattern}" unless input =~ pattern
     grp1 = process $1
     @FAQFILE = grp1 
     if @FAQFILE !~ /\.yaml$/ then @FAQFILE << ".yaml" end
     load_graph(@FAQFILE)
     @score = 4
     return "Okay, I have set the faq file to #{@FAQFILE}."
   end # method_def

   def what_is_the_faq_file(pattern=nil, input=nil)
     @score = 4
     return "The faq file is currently #{@FAQFILE}."
   end # method_def

   def add_faq_and_answer(pattern=nil, input=nil)
     return "#{input} doesn't match #{pattern}" unless input =~ pattern
     grp1 = process $1; #puts "grp1==#{grp1}"
     grp1 << "?"
     grp2 = process $2; #puts "grp2=#{grp2}"
     @graph.a_r_b!(grp1.downcase, "is answered by", grp2)
     return "Okay I have added answer #{grp2} to faq #{grp1}"
   end # method_def

   def print_graph(pattern=nil, input=nil)
     return "#{input} doesn't match #{pattern}" unless input =~ pattern
     s = @graph.to_s
     arr = s.split("\n")
     @score = 5
     return arr.join("\n") unless arr.empty?
     return "The graph is empty."
   end # method_def

   def save_graph(pattern=nil, input=nil)
     return "#{input} doesn't match #{pattern}" unless input =~ pattern
     begin; file = process $1; rescue; file = @FILENAME; end
     r = @graph.save(file)
     @score = 4
     return "#{r}"
   end # method_def

   def reset_graph(pattern=nil, input=nil)
     return "#{input} doesn't match #{pattern}" unless input =~ pattern
     @graph = Graph.new(false)
     @save = false
     return "Okay, I have reset the graph."
   end # method_def

   def load_graph(pattern=nil, input=nil)
     return "#{input} doesn't match #{pattern}" unless input =~ pattern
     file = process $1
     @score = 5
     return @graph.load(file)
   end # method_def

   def reset_graph(pattern=nil, input=nil)
     return "#{input} doesn't match #{pattern}" unless input =~ pattern
     @graph = Graph.new(false)
     @score = 5
     return "Okay, I have reset the graph."
   end # method_def
     
   def a_equals_b(pattern=nil, input=nil)
     return "#{input} doesn't match #{pattern}" unless input =~ pattern
     grp1 = process $1; grp2 = process $2
     @graph.a_r_b!(grp1.downcase, "=", grp2.downcase)
     @graph.a_r_b!(grp2.downcase, "=", grp1.downcase)
     return "Okay, I have added #{grp1} = #{grp2}."
   end # method_def

   def a_is_answered_by_b(pattern=nil, input=nil)
     return "#{input} doesn't match #{pattern}" unless input =~ pattern
     grp1 = process $1; grp2 = process $2
     @graph.a_r_b!(grp1.downcase, "is answered by", grp2.downcase)
     return "Okay, I have added #{$1} is answered by #{$2}."
   end # method_def

   def isQuestion?(s = '')
     if s =~ /^(#{@question_words.join('|')})/ then return true end
     if s =~ /\?$/ then return true end
     return false
   end # method_def

   def default_handler(pattern=nil, input=nil)
     return "#{input} doesn't match #{pattern}" unless input =~ pattern
     if not isQuestion?($1) then return 'Default response'; @score -= 2 end
     #return self.send("find faq: #{$1}")
     str, sc =  self.send("find faq: #{$1}")
     @score = sc
     return str
   end # method_def

end # class

if $0 == __FILE__
  bot = MyAgent.new
  print "\n> "; $stdout.flush
  while (line = gets) !~ /^#{$Quitwords.join('|')}$/i and line !~ /^$/
    response = bot.send(line.to_s).to_s
    if response.class == "Array" then response = response[0] end 
    response = response.chop # remove the score
    puts response + "\n\n"
    print "> "; $stdout.flush
  end
  puts "Bye"
end # of file