class RuboCop::Cop::Style::RedundantInterpolation

def self.autocorrect_incompatible_with
  [Style::LineEndConcatenation]
end

def autocorrect_other(corrector, embedded_node, node)
  loc = node.loc
  embedded_loc = embedded_node.loc
  corrector.replace(loc.begin, '')
  corrector.replace(loc.end, '')
  corrector.replace(embedded_loc.begin, '(')
  corrector.replace(embedded_loc.end, ').to_s')
end

def autocorrect_single_variable_interpolation(corrector, embedded_node, node)
  variable_loc = embedded_node.children.first.loc
  replacement = "#{variable_loc.expression.source}.to_s"
  corrector.replace(node, replacement)
end

def autocorrect_variable_interpolation(corrector, embedded_node, node)
  replacement = "#{embedded_node.loc.expression.source}.to_s"
  corrector.replace(node, replacement)
end

def embedded_in_percent_array?(node)
  node.parent&.array_type? &&
    percent_literal?(node.parent)
end

def implicit_concatenation?(node)
  node.parent&.dstr_type?
end

def interpolation?(node)
  variable_interpolation?(node) || node.begin_type?
end

def on_dstr(node)
  return unless single_interpolation?(node)
  add_offense(node) do |corrector|
    embedded_node = node.children.first
    if variable_interpolation?(embedded_node)
      autocorrect_variable_interpolation(corrector, embedded_node, node)
    elsif single_variable_interpolation?(embedded_node)
      autocorrect_single_variable_interpolation(corrector, embedded_node, node)
    else
      autocorrect_other(corrector, embedded_node, node)
    end
  end
end

def single_interpolation?(node)
  node.children.one? &&
    interpolation?(node.children.first) &&
    !implicit_concatenation?(node) &&
    !embedded_in_percent_array?(node)
end

def single_variable_interpolation?(node)
  return false unless node.children.one?
  first_child = node.children.first
  variable_interpolation?(first_child) ||
    first_child.send_type? && !first_child.operator_method?
end

def variable_interpolation?(node)
  node.variable? || node.reference?
end