class RuboCop::Cop::Style::TernaryCorrector

def correct(corrector, node)
  corrector.replace(node, correction(node))
end

def correction(node)
  "#{lhs(node.if_branch)}#{ternary(node)}"
end

def element_assignment?(node)
  node.send_type? && node.method_name != :[]=
end

def extract_branches(node)
  *_var, rhs = *node
  condition, = *rhs if rhs.begin_type? && rhs.children.one?
  _condition, if_branch, else_branch = *(condition || rhs)
  [if_branch, else_branch]
end

def move_assignment_inside_condition(corrector, node)
  *_var, rhs = *node
  if_branch, else_branch = extract_branches(node)
  assignment = assignment(node)
  remove_parentheses(corrector, rhs) if Util.parentheses?(rhs)
  corrector.remove(assignment)
  move_branch_inside_condition(corrector, if_branch, assignment)
  move_branch_inside_condition(corrector, else_branch, assignment)
end

def move_branch_inside_condition(corrector, branch, assignment)
  corrector.insert_before(branch, assignment.source)
end

def remove_parentheses(corrector, node)
  corrector.remove(node.loc.begin)
  corrector.remove(node.loc.end)
end

def ternary(node)
  _variable, *_operator, if_rhs = *node.if_branch
  _else_variable, *_operator, else_rhs = *node.else_branch
  expr = "#{node.condition.source} ? #{if_rhs.source} : #{else_rhs.source}"
  element_assignment?(node.if_branch) ? "(#{expr})" : expr
end