Enhancing a Voting System in Ruby

class VotingSystem
  def initialize
    @candidates = {}  # Stores candidate_id as key and votes as value
    @voters = {}  # Tracks each voter's voting history
  end

  def register_candidate(candidate_id)
    return false if @candidates.key?(candidate_id)  # Candidate is already registered
    
    @candidates[candidate_id] = 0  # Initialize candidates with 0 votes
    true
  end

  def vote(timestamp, voter_id, candidate_id)
    return false unless @candidates.key?(candidate_id)  # Return false if candidate is not registered
    
    voter_history = @voters[voter_id] ||= { votes: [], timestamps: [] }
    voter_history[:votes] << candidate_id  # Record the vote
    voter_history[:timestamps] << timestamp  # Record the time of the vote
    @candidates[candidate_id] += 1  # Increment vote count for the candidate
    true
  end

  def get_votes(candidate_id)
    @candidates[candidate_id] || nil  # Retrieve vote count for a candidate or nil if not found
  end

  def top_n_candidates(n)
    @candidates.sort_by { |_, votes| -votes }
               .take(n)
               .map { |candidate_id, _| candidate_id }  # Return top n candidates based on votes
  end
end