# Fill in the defect rates and decay factor however.
# Decay factor is 1-f: if 10% fewer people defect in generation n+1 than generation n, set defector_decay_factor to 0.9.
# Pulled the stats here from http://www.patheos.com/blogs/lovejoyfeminism/2012/01/quiverfull-outbreeding-the-world.html
# Quiverfulls currently have a high defect rate, and Amish currently have a low defect rate...
# ...so change the strings in the puts commands as necessary.
# Could be modified to have specific decay factors for each defect rate, but I didn't do that.
atheists = 90000000
atheist_birth_rate = 2.0
christians = 8000000
christian_birth_rate = 4.0
quiverfulls = 2000000
quiverfull_birth_rate = 8.0
a_c_defect_rate = 0.0
a_q_defect_rate = 0.0
c_a_defect_rate = 0.0
c_q_defect_rate = 0.0
q_a_defect_rate = 0.0
q_c_defect_rate = 0.0
generations = 3
defector_decay_factor = 1.0

def percent(n, total)
  return ((n.to_f / total) * 100).round
end

def round(n)
  return (n / 1000000).round.to_s + " million"
end

total = atheists + christians + quiverfulls

(generations+1).times do |i|
  puts "Generation #{i}"
  puts "Atheists: #{percent(atheists, total)}%, #{round(atheists)}, decay rates = #{a_c_defect_rate.round(2)}, #{a_q_defect_rate.round(2)}"
  puts "Christians: #{percent(christians, total)}%, #{round(christians)}, decay rates = #{c_a_defect_rate.round(2)}, #{c_q_defect_rate.round(2)}"
  puts "Quiverfulls: #{percent(quiverfulls, total)}%, #{round(quiverfulls)}, decay rates = #{q_a_defect_rate.round(2)}, #{q_c_defect_rate.round(2)}"
  puts ''

  atheists = (atheists / 2) * atheist_birth_rate
  christians = (christians / 2) * christian_birth_rate
  quiverfulls = (quiverfulls / 2) * quiverfull_birth_rate
  total = atheists + christians + quiverfulls

  a_c_defectors = atheists * a_c_defect_rate
  a_q_defectors = atheists * a_q_defect_rate
  c_a_defectors = christians * c_a_defect_rate
  c_q_defectors = christians * c_q_defect_rate
  q_a_defectors = quiverfulls * q_a_defect_rate
  q_c_defectors = quiverfulls * q_c_defect_rate

  atheists -= a_c_defectors
  christians += a_c_defectors
  atheists -= a_q_defectors
  quiverfulls += a_q_defectors

  christians -= c_a_defectors
  atheists += c_a_defectors
  christians -= c_q_defectors
  quiverfulls += c_q_defectors

  quiverfulls -= q_a_defectors
  atheists += q_a_defectors
  quiverfulls -= q_c_defectors
  christians += q_c_defectors

  a_c_defect_rate = a_c_defect_rate * defector_decay_factor
  a_q_defect_rate = a_q_defect_rate * defector_decay_factor
  c_a_defect_rate = c_a_defect_rate * defector_decay_factor
  c_c_defect_rate = c_q_defect_rate * defector_decay_factor
  q_a_defect_rate = q_a_defect_rate * defector_decay_factor
  q_c_defect_rate = q_c_defect_rate * defector_decay_factor
end