class RuboCop::Cop::Metrics::Utils::AbcSizeCalculator

def self.calculate(node, discount_repeated_attributes: false)
  new(node, discount_repeated_attributes: discount_repeated_attributes).calculate
end

def argument?(node)
  node.argument_type? && capturing_variable?(node.children.first)
end

def assignment?(node)
  return compound_assignment(node) if node.masgn_type? || node.shorthand_asgn?
  node.for_type? ||
    (node.respond_to?(:setter_method?) && node.setter_method?) ||
    simple_assignment?(node) ||
    argument?(node)
end

def branch?(node)
  BRANCH_NODES.include?(node.type)
end

def calculate
  visit_depth_last(@node) { |child| calculate_node(child) }
  [
    Math.sqrt((@assignment**2) + (@branch**2) + (@condition**2)).round(2),
    "<#{@assignment}, #{@branch}, #{@condition}>"
  ]
end

def calculate_node(node)
  @assignment += 1 if assignment?(node)
  if branch?(node)
    evaluate_branch_nodes(node)
  elsif condition?(node)
    evaluate_condition_node(node)
  end
end

def capturing_variable?(name)
  name && !name.start_with?('_')
end

def compound_assignment(node)
  # Methods setter cannot be detected for multiple assignments
  # and shorthand assigns, so we'll count them here instead
  children = node.masgn_type? ? node.children[0].children : node.children
  will_be_miscounted = children.count do |child|
    child.respond_to?(:setter_method?) && !child.setter_method?
  end
  @assignment += will_be_miscounted
  false
end

def condition?(node)
  return false if iterating_block?(node) == false
  CONDITION_NODES.include?(node.type)
end

def else_branch?(node)
  %i[case if].include?(node.type) && node.else? && node.loc.else.is?('else')
end

def evaluate_branch_nodes(node)
  if node.comparison_method?
    @condition += 1
  else
    @branch += 1
    @condition += 1 if node.csend_type? && !discount_for_repeated_csend?(node)
  end
end

def evaluate_condition_node(node)
  @condition += 1 if else_branch?(node)
  @condition += 1
end

def initialize(node)
  @assignment = 0
  @branch = 0
  @condition = 0
  @node = node
  reset_repeated_csend
end

def simple_assignment?(node)
  if !node.equals_asgn?
    false
  elsif node.lvasgn_type?
    reset_on_lvasgn(node)
    capturing_variable?(node.children.first)
  else
    true
  end
end

def visit_depth_last(node, &block)
  node.each_child_node { |child| visit_depth_last(child, &block) }
  yield node
end