class Opal::Nodes::Base

def self.children(*names)
  names.each_with_index do |name, idx|
    define_method(name) do
      @sexp.children[idx]
    end
  end
end

def self.handle(*types)
  types.each do |type|
    Base.handlers[type] = self
  end
end

def self.handlers
  @handlers ||= {}
end

def self.truthy_optimize?
  false
end

def add_gvar(name)
  scope.add_scope_gvar name
end

def add_ivar(name)
  scope.add_scope_ivar name
end

def add_local(name)
  scope.add_scope_local name.to_sym
end

def add_temp(temp)
  scope.add_scope_temp temp
end

def children
  @sexp.children
end

def class_variable_owner
  if scope
    "#{scope.nesting}[#{class_variable_owner_nesting_level}]"
  else
    'Opal.Object'
  end
end

def class_variable_owner_nesting_level
  cvar_scope = scope
  nesting_level = 0
  while cvar_scope && !cvar_scope.class_scope?
    # Needs only `class << self`, `module`, and `class`
    # can increase nesting, but `class` & `module` are
    # covered by `class_scope?`.
    nesting_level += 1 if cvar_scope.sclass?
    cvar_scope = cvar_scope.parent
  end
  nesting_level
end

def comments
  compiler.comments[@sexp.loc]
end

def compile
  raise 'Not Implemented'
end

def compile_to_fragments
  return @fragments if defined?(@fragments)
  @fragments = []
  compile
  @fragments
end

def error(msg)
  @compiler.error msg
end

def expr(sexp)
  @compiler.process sexp, :expr
end

def expr?
  @level == :expr
end

def expr_or_empty(sexp)
  sexp && sexp.type != :nil ? expr(sexp) : ''
end

def expr_or_nil(sexp)
  sexp ? expr(sexp) : 'nil'
end

def fragment(str, loc: true)
  Opal::Fragment.new str, scope, loc && @sexp
end

def has_rescue_else?
  scope.has_rescue_else?
end

def helper(name)
  @compiler.helper name
end

def in_ensure(&block)
  scope.in_ensure(&block)
end

def in_ensure?
  scope.in_ensure?
end

def in_resbody(&block)
  scope.in_resbody(&block)
end

def in_resbody?
  scope.in_resbody?
end

def in_rescue(node, &block)
  scope.in_rescue(node, &block)
end

def in_while?
  @compiler.in_while?
end

def initialize(sexp, level, compiler)
  @sexp = sexp
  @type = sexp.type
  @level = level
  @compiler = compiler
  @compiler.top_scope ||= self
end

def process(sexp, level = :expr)
  @compiler.process sexp, level
end

def push(*strs)
  strs.each do |str|
    str = fragment(str) if str.is_a?(String)
    @fragments << str
  end
end

def recv(sexp)
  @compiler.process sexp, :recv
end

def recv?
  @level == :recv
end

def s(type, *children)
  ::Opal::AST::Node.new(type, children, location: @sexp.loc)
end

def scope
  @compiler.scope
end

def source_location
  expr = @sexp.loc.expression
  if expr.respond_to? :source_buffer
    file = expr.source_buffer.name
    file = "<internal:#{file}>" if file.start_with?("corelib/")
    file = "<js:#{file}>" if file.end_with?(".js")
  else
    file = "(eval)"
  end
  line = @sexp.loc.line
  "['#{file}', #{line}]"
end

def stmt(sexp)
  @compiler.process sexp, :stmt
end

def stmt?
  @level == :stmt
end

def top_scope
  @compiler.top_scope
end

def unshift(*strs)
  strs.reverse_each do |str|
    str = fragment(str) if str.is_a?(String)
    @fragments.unshift str
  end
end

def while_loop
  @compiler.instance_variable_get(:@while_loop)
end

def with_temp(&block)
  @compiler.with_temp(&block)
end

def wrap(pre, post)
  unshift pre
  push post
end