module RBS
  # Writer prints RBS AST to String.
  #
  class Writer
    interface _IO
      def puts: (*untyped) -> void

      def flush: () -> void
    end

    # Channel to output the result.
    #
    attr_reader out: _IO

    # Array of indentations.
    #
    attr_reader indentation: Array[String]

    def initialize: (out: _IO) -> void

    # Output the array of declarations.
    # It automatically inserts empty lines between the declarations.
    #
    def write: (Array[AST::Declarations::t]) -> void

    def preserve?: () -> bool

    def preserve!: (?preserve: bool) -> self

    private

    @preserve: bool

    # Increases the indentation and yields the block.
    #
    def indent: (?Integer size) { () -> void } -> void

    # Returns the current indentation of lines.
    #
    def prefix: () -> String

    # Prints a string.
    # Automatically appends the `#prefix` and newline at the end.
    #
    def puts: (?String) -> void

    # Prints a (possibly) multi-line string.
    #
    # Drops `leading_spaces` of spaces at the beginning of each line.
    #
    # ```ruby
    # put_lines(<<TEXT, leading_spaces: 0)
    # Hello
    #   world!
    # TEXT
    #
    # # Outputs
    # # Hello
    # #   world!
    #
    # put_lines(<<TEXT, leading_spaces: 2)
    # Hello
    #   world!
    # TEXT
    #
    # # Outputs
    # # Hello
    # # world!
    # ```
    #
    # This is for `Location#source`.
    # The `#source` returns the text spans from the beginning to end of the element.
    # It will look like the following.
    #
    # ```rbs
    # module Foo
    #   type t = Integer     # the definition of `t` starts from line=2, column=2
    #          | String
    #          | :false      # the definition of `t` ends from line=4, column=17
    # end
    # ```
    #
    # The expected output will be something like:
    #
    # ```rbs
    # type t = Integer       # Extracted from `Foo` definition and keeps the line breaks
    #        | String
    #        | :false
    # ```
    #
    # And it can be done with a `#put_lines(source, leading_spaces: 2)` call.
    #
    def put_lines: (String, leading_spaces: Integer) -> void

    def write_loc_source: (_Located) { () -> void } -> void

    def write_annotation: (Array[AST::Annotation]) -> void

    def write_comment: (AST::Comment?) -> void

    def write_decl: (AST::Declarations::t) -> void

    def write_member: (AST::Declarations::Module::member) -> void

    def name_and_params: (TypeName, Array[AST::TypeParam]) -> String?

    def name_and_args: (TypeName, Array[Types::t]) -> String?

    def write_alias: (AST::Declarations::Alias) -> void

    def method_name: (Symbol) -> String

    def write_def: (AST::Members::MethodDefinition) -> void

    def attribute: (:reader | :writer | :accessor, AST::Members::Attribute) -> void

    interface _Located
      def location: () -> Location[untyped, untyped]?
    end

    def preserve_empty_line: (_Located?, _Located) -> void
  end
end