# Coudal School of Government Challenge
# Author: Scott Ahten

# Fish Class
class Fish

    attr_accessor :name
    
    # create a new fish
    def initialize(aName)
        @name = aName
        @objections = Array.new
    end
    
    # add an objection to this fish
    def addObjection (objection)
        @objections.push(objection)
    end 
    
    # check for objections by this fish
    def assertObjections (nominations) 
        result = false
        @objections.each do |objection|
            begin
            result = true if objection.assert(nominations)
             rescue 
                #catch method calls to nil objects in objection expresssions
                #failed objections are false
            end
        end    
        return result  
    end
    
end # of fish class

# Office Class
class Office

    attr_accessor :fish
    attr_accessor :name
    attr_accessor :rank

    def initialize(aName, aRank) 
        @fish = nil
        @name = aName
        @rank = aRank
    end
    
    # shortcut that retreives a fish's name from the office
    def fishName 
        return @fish.name if @fish != nil
        return nil
    end
    
end # of Office class

# Nominations Class - holds canidates, offices and shows valid combinations
class Nominations 
    
    attr_accessor :offices

    def initialize (offices, nominees) 
        @nominees = nominees
        @offices = offices
    end 
    
    def find
    
        for i in 0...offices.size
            value = offices[i]
            return value if yield(value)
        end
        return nil        
    end 
    
    def objections
    
        conflict = false
        
        @offices.each do |office|
            conflict = true if office.fish.assertObjections(self)
        end    
        
        # check for duplicates (This is really ugly. I'm new to Ruby, is there a better way to do this?)
        @nominees.each do |aFish|       
            count = 0     
            totalFish = @offices.collect {|office| office.fishName == aFish.name}
            count += 1 if totalFish[0]
            count += 1 if totalFish[1]
            count += 1 if totalFish[2] 
            conflict = true if count > 1  
            #puts totalFish.inspect       
        end
        
        return conflict 
    end
    
    def showValid 
    
        solutions = 0
    
        for president in 0...@nominees.size
            for vicePresident in 0...@nominees.size
                for secretary in 0...@nominees.size
   
                    @offices[0].fish = @nominees[president]
                    @offices[1].fish = @nominees[vicePresident]
                    @offices[2].fish = @nominees[secretary]
                    if ! self.objections
                        puts "President: #{@offices[0].fishName} | Vice-President: #{@offices[1].fishName} | Secretary: #{@offices[2].fishName}"
                        solutions += 1
                    end
                end
            end
        end
        
        puts "#{solutions} found"
   end 
end  # Nominations class
   

# Objection class
class Objection 
    
    def initialize (&expression)
        @expression = expression
    end
    
    def assert(nominations)
        return @expression.call(nominations)
    end
    
end # Objection class

class Challenge 

    def initialize 
        
        # create canidate fish
        nominees = [Fish.new("Mr. Grouper"), Fish.new("Dr. Trout"), Fish.new("Mr. Ray"), Fish.new("Mr. Mackerel"), Fish.new("The Snapper"), Fish.new("Mr. Bass")]
        
        # assign objections to Fish as Objection objects with Ruby proc blocks
        
        # Grouper won't be an officer unless Snapper is President
        nominees[0].addObjection(Objection.new { |noms| (noms.find {|office| office.fishName =="Mr. Grouper" } != nil) && (noms.find {|office| office.name =="President"}.fishName !="The Snapper") });
       
        # Trout won't serve if he outranks Ray
        nominees[1].addObjection(Objection.new { |noms| noms.find {|office| office.fishName =="Dr. Trout"}.rank > noms.find {|office| office.fishName =="Mr. Ray"}.rank });
        
        # Trout won't serve with Bass under any conditions
        nominees[1].addObjection(Objection.new { |noms| noms.find {|office| office.fishName =="Dr. Trout"} != nil && noms.find {|office| office.fishName =="Mr. Bass"} != nil });

        # Ray won't serve with both Snapper & Bass    
        nominees[2].addObjection(Objection.new { |noms| (noms.find {|office| office.fishName =="Mr. Ray" } != nil) && (noms.find {|office| office.fishName =="Mr. Bass" } != nil)});

        # Ray won't serve if Bass is President or Trout is secretary   
        nominees[2].addObjection(Objection.new { |noms| (noms.find {|office| office.fishName =="Mr. Ray" } !=nil ) && (noms.find {|office| office.name =="President" }.fishName == "Mr. Bass")});
        nominees[2].addObjection(Objection.new { |noms| (noms.find {|office| office.fishName =="Mr. Ray" } !=nil ) && (noms.find {|office| office.name =="Secretary" }.fishName == "Dr. Trout")});
        
        # Mackerel won't serve with Ray or Snapper unless he outranks him  
        nominees[3].addObjection(Objection.new { |noms| (noms.find {|office| office.fishName =="Mr. Mackerel" }.rank) < (noms.find {|office| office.fishName =="Mr. Ray" }.rank)});
        nominees[3].addObjection(Objection.new { |noms| (noms.find {|office| office.fishName =="Mr. Mackerel" }.rank) < (noms.find {|office| office.fishName =="The Snapper" }.rank)});
        
        # Snapper won't be Vice-President  
        nominees[4].addObjection(Objection.new { |noms| (noms.find {|office| office.fishName =="The Snapper" }.name == "Vice-President") });
    
        # Snapper won't be secretary if Mackerel is an officer  
        nominees[4].addObjection(Objection.new { |noms| (noms.find {|office| office.fishName =="Mr. Mackerel" } != nil) && (noms.find {|office| office.name =="Secretary" }.fishName == "The Snapper")});
    
        # Snapper won't serve with Grouper unless Bass serves too 
        nominees[4].addObjection(Objection.new { |noms| (noms.find {|office| office.fishName =="The Snapper" } != nil) && (noms.find {|office| office.fishName =="Mr. Grouper" } != nil) && (noms.find {|office| office.fishName =="Mr. Bass" } == nil) });

        # Bass won't serve unless either he or Ray is President 
        nominees[5].addObjection(Objection.new { |noms| (noms.find {|office| office.fishName =="Mr. Bass" } != nil) && (noms.find {|office| office.name =="President" }.fishName != "Mr. Bass") &&(noms.find {|office| office.name =="President" }.fishName != "Mr. Ray") });
        
        # create offices
        offices = [Office.new("President", 3), Office.new("Vice-President", 2), Office.new("Secretary", 1)]  
        @nominations = Nominations.new(offices,nominees) 
        
    end
 
    def solve
       @nominations.showValid
    end
     
end # Challenge class

# Solve the Challenge
Challenge.new.solve