module Pikk

# File lib/pikk/main.rb, line 14
def pool(list = [{}], iteration: 50, pp: false)
  raise ArgumentError, 'Input is empty!' if list == [{}]
  $iteration = iteration

  arr = calculate_prob(list)

  $iteration.times do
    selected_object = pick_from(arr)
    selected_object[:count] += 1
  end

  pp ? to_table(arr) : arr.sort_by { |h| h[:weight] }.reverse
end

# File lib/pikk/main.rb, line 5
def single_select(list = [{}])
  raise ArgumentError, 'Input is empty!' if list == [{}]

  arr = calculate_prob(list)

  selected_object = pick_from(arr)
  return selected_object
end

# File lib/pikk/main.rb, line 30
def calculate_prob(list = [{}])
  tmp = []
  sum = list.map { |h| h[:weight] }.sum.to_f

  list.each do |hash|
    tmp << hash.merge({count: 0, probability: (hash[:weight] / sum)})
  end

  return tmp
end

# File lib/pikk/main.rb, line 41
def pick_from(list = [{}])
  index = 0
  r = rand(0.0...1.0);

  while r > 0
    r = r - list[index][:probability]
    index += 1 if r > 0
  end

  list[index]
end

# File lib/pikk/main.rb, line 53
def to_table(list = [{}])
  list.sort_by! { |h| h[:weight] }.reverse!

  lsum = 0

  ltable = table do
    self.headings = "Name", "Weight", "Count", "Probability", "(C/(P*I))"

    list.each do |f|
      add_row [f[:name], f[:weight], f[:count], f[:probability], (f[:count].to_f/(f[:probability] * $iteration))]

      lsum += f[:count].to_f/(f[:probability] * $iteration)
    end
    add_separator
    add_row ['Iteration Count', { value: $iteration, colspan: 4, alignment: :right }]
    add_separator
    add_row ['Sum Ratio', { value: (1 - lsum / list.count).abs, colspan: 4, alignment: :right }]
  end

  puts ltable
end