# frozen_string_literal: true

# games_dice/spec/helpers.rb
require 'pathname'
require 'coveralls'
Coveralls.wear!

require 'games_dice'

def fixture(name)
  "#{__dir__}/fixtures/#{name}"
end

# TestPRNG tests short predictable series
class TestPRNG
  def initialize
    @numbers = [0.123, 0.234, 0.345, 0.999, 0.876, 0.765, 0.543, 0.111, 0.333, 0.777]
  end

  def rand(num)
    Integer(num * @numbers.pop)
  end
end

# TestPRNGMax checks behaviour of re-rolls
class TestPRNGMax
  def rand(num)
    Integer(num) - 1
  end
end

# TestPRNGMin checks behaviour of re-rolls
class TestPRNGMin
  def rand(_num)
    1
  end
end

# A valid distribution is:
#  A hash
#  Keys are all Integers
#  Values are all positive Floats, between 0.0 and 1.0
#  Sum of values is 1.0
RSpec::Matchers.define :be_valid_distribution do
  match do |given|
    @error = nil
    if !given.is_a?(Hash)
      @error = "distribution should be a Hash, but it is a #{given.class}"
    elsif given.keys.any? { |k| !k.is_a?(Integer) }
      bad_key = given.keys.first { |k| !k.is_a?(Integer) }
      @error = "all keys should be Integers, but found '#{bad_key.inspect}' which is a #{bad_key.class}"
    elsif given.values.any? { |v| !v.is_a?(Float) }
      bad_value = given.values.find { |v| !v.is_a?(Float) }
      @error = "all values should be Floats, but found '#{bad_value.inspect}' which is a #{bad_value.class}"
    elsif given.values.any? { |v| v < 0.0 || v > 1.0 }
      bad_value = given.values.find { |v| v < 0.0 || v > 1.0 }
      @error = "all values should be in range (0.0..1.0), but found #{bad_value}"
    elsif (1.0 - given.values.inject(:+)).abs > 1e-6
      total_probs = given.values.inject(:+)
      @error = "sum of values should be 1.0, but got #{total_probs}"
    end
    !@error
  end

  failure_message do |_given|
    @error || 'Distribution is valid and complete'
  end

  failure_message_when_negated do |_given|
    @error || 'Distribution is valid and complete'
  end

  description do |_given|
    'a hash describing a complete probability distribution of integer results'
  end
end