module Opal::Nodes::Helpers

def current_indent
  compiler.parser_indent
end

def empty_line
  push "\n"
end

def indent(&block)
  compiler.indent(&block)
end

def js_falsy(sexp)
  if sexp.type == :call
    mid = sexp[2]
    if mid == :block_given?
      scope.uses_block!
      return "#{scope.block_name} === nil"
    end
  end
  with_temp do |tmp|
    [fragment("(#{tmp} = "), expr(sexp), fragment(") === false || #{tmp} === nil")]
  end
end

def js_truthy(sexp)
  if optimize = js_truthy_optimize(sexp)
    return optimize
  end
  with_temp do |tmp|
    [fragment("(#{tmp} = "), expr(sexp), fragment(") !== false && #{tmp} !== nil")]
  end
end

def js_truthy_optimize(sexp)
  if sexp.type == :call
    mid = sexp[2]
    if mid == :block_given?
      expr(sexp)
    elsif Compiler::COMPARE.include? mid.to_s
      expr(sexp)
    elsif mid == :"=="
      expr(sexp)
    end
  elsif [:lvar, :self].include? sexp.type
    [expr(sexp.dup), fragment(" !== false && "), expr(sexp.dup), fragment(" !== nil")]
  end
end

def line(*strs)
  push "\n#{current_indent}"
  push(*strs)
end

def lvar_to_js(var)
  var = "#{var}$" if RESERVED.include? var.to_s
  var.to_sym
end

def mid_to_jsid(mid)
  if /\=|\+|\-|\*|\/|\!|\?|\<|\>|\&|\||\^|\%|\~|\[/ =~ mid.to_s
    "['$#{mid}']"
  else
    '.$' + mid
  end
end

def property(name)
  reserved?(name) ? "['#{name}']" : ".#{name}"
end

def reserved?(name)
  RESERVED.include? name
end

def variable(name)
  reserved?(name.to_s) ? "#{name}$" : name
end