sixdegreesofbacon.rb

class Connection < ActiveRecord::Base

  def self.dfs(poi, target, dos, mas, gas)
  # dfs & poi = depth first search for person of interest
  # dos = degrees of separation
    paths_between_poi_and_target = []
    members_already_searched = mas
    groups_already_searched = gas
    # members = []

    if dos <= 6 
      # Iterate over all the groups of the group member
      poi.groups.each do |group|
      # Check to see if that group has already been searched
      if groups_already_searched[group.name] 
        next
      else
        groups_already_searched[group.name] = true
          
        group.members.each do |member|
          # dos = degrees of separation
          if members_already_searched[member.name] 
            next
          else
            members_already_searched[member.name] = true
            if member == target && dos != 1

              return [group.name, member.name]
            else
              dos += 1
              response = dfs(member, target, dos, members_already_searched, groups_already_searched)
              if dos == 1 && response != nil
                paths_between_poi_and_target << response
              elsif dos == 1 && response == nil
                next
              elsif response != nil
                return response.unshift({group: member.name})
              else
                return nil 
              end  
            end
          end
        end
        end
      end
    else 
      return nil
    end


    return paths_between_poi_and_target

  end

end