module Tapioca::Static::SymbolLoader

def engine_symbols(gem)
  gem_engine = engines.find do |engine|
    gem.full_gem_path == engine.config.root.to_s
  end
  return Set.new unless gem_engine
  # https://github.com/rails/rails/commit/ebfca905db14020589c22e6937382e6f8f687664
  config = gem_engine.config
  eager_load_paths = if config.respond_to?(:all_eager_load_paths)
    config.all_eager_load_paths
  else
    config.eager_load_paths
  end
  paths = eager_load_paths.flat_map do |load_path|
    Pathname.glob("#{load_path}/**/*.rb")
  end
  symbols_from_paths(paths)
rescue
  Set.new
end

def engines
  @engines ||= T.let(
    if Object.const_defined?("Rails::Engine")
      descendants_of(Object.const_get("Rails::Engine"))
        .reject(&:abstract_railtie?)
    else
      []
    end,
    T.nilable(T::Array[T.class_of(Rails::Engine)]),
  )
end

def gem_symbols(gem)
  symbols_from_paths(gem.files)
end

def payload_symbols
  unless @payload_symbols
    output = symbol_table_json_from("-e ''", table_type: "symbol-table-full-json")
    @payload_symbols = T.let(SymbolTableParser.parse_json(output), T.nilable(T::Set[String]))
  end
  T.must(@payload_symbols)
end

def symbol_table_json_from(input, table_type: "symbol-table-json")
  sorbet("--no-config", "--quiet", "--print=#{table_type}", input).out
end

def symbols_from_paths(paths)
  return Set.new if paths.empty?
  output = Tempfile.create("sorbet") do |file|
    file.write(Array(paths).join("\n"))
    file.flush
    symbol_table_json_from("@#{file.path.shellescape}")
  end
  return Set.new if output.empty?
  SymbolTableParser.parse_json(output)
end