require './doubly_linked_list'
require 'pry'

class HashTable < Array
  attr_reader :hash_function

  ListElement = Struct.new(:key, :value)

  class KeyedDoublyLinkedList < DoublyLinkedList
    def initialize(elem)
      super
    end

    def search(k, node = @head)
      if node.nil?
        nil
      elsif node.elem.key == k
        node.elem
      else
        self.search(k, node.right)
      end
    end
  end

  def initialize(size = 100, default = nil)
    super
    @hash_function = Proc.new {|m, k| k % m}
  end

  def add(k, v)
    i = get_slot(k)
    if self[i].nil?
        self[i] = KeyedDoublyLinkedList.new( ListElement.new(k, v) )
    else
      if self[i].search(k).nil?
        self[i].push( ListElement.new(k, v) )
      else
        self[i].search(k).value = v
      end
    end
  end

  ## This is how I would like to call "add" but its not working
  ## Self doesn't update when I reassign the local variable
  # def add(k, v)
  #   list = self[get_slot(k)]
  #   if list.nil?
  #       list = KeyedDoublyLinkedList.new( ListElement.new(k, v) )
  #   else
  #     node = list.search(k)
  #     if node.nil?
  #       node.push( ListElement.new(k, v) )
  #     else
  #       node.value = v
  #     end
  #   end
  # end

  def contains_key(k)
    i = get_slot(k)
    if self[i].nil?
      false
    else
      if self[i].search(k) then true else false end
    end
  end

  def to_s
    self.select {|p| !p.nil? }.each do |slot|
      slot.to_s
    end
  end

  private
    def get_slot(k)
      @hash_function.call(self.length, k)
    end
end


table = HashTable.new(100)
(1..5).each do |i|
  table.add(i, "test")
end

table.add(1, "updated")

puts table.to_s
binding.pry