Class: RBS::Prototype::RB

# File 'lib/rbs/prototype/rb.rb', line 43

attr_reader :toplevel_members

# File 'lib/rbs/prototype/rb.rb', line 532

def body_type(node)
  return Types::Bases::Nil.new(location: nil) unless node

  case node.type
  when :IF, :UNLESS
    if_unless_type(node)
  when :BLOCK
    block_type(node)
  else
    literal_to_type(node)
  end
end

# File 'lib/rbs/prototype/rb.rb', line 451

def const_to_name(node, context:)
  if node
    case node.type
    when :SELF
      context.namespace.to_type_name
    when :CONST, :COLON2, :COLON3
      const_to_name!(node) rescue nil
    end
  end
end

# File 'lib/rbs/prototype/rb.rb', line 432

def const_to_name!(node)
  case node.type
  when :CONST
    TypeName.new(name: node.children[0], namespace: Namespace.empty)
  when :COLON2
    if node.children[0]
      namespace = const_to_name!(node.children[0]).to_namespace
    else
      namespace = Namespace.empty
    end

    TypeName.new(name: node.children[1], namespace: namespace)
  when :COLON3
    TypeName.new(name: node.children[0], namespace: Namespace.root)
  else
    raise
  end
end

# File 'lib/rbs/prototype/rb.rb', line 730

def current_accessibility(decls, index = decls.size)
  slice = decls.slice(0, index) or raise
  idx = slice.rindex { |decl| decl == private || decl == public }
  if idx
    _ = decls[idx]
  else
    public
  end
end

# File 'lib/rbs/prototype/rb.rb', line 49

def decls
  # @type var decls: Array[AST::Declarations::t]
  decls = []

  # @type var top_decls: Array[AST::Declarations::t]
  # @type var top_members: Array[AST::Members::t]
  top_decls, top_members = _ = source_decls.partition {|decl| decl.is_a?(AST::Declarations::Base) }

  decls.push(*top_decls)

  unless top_members.empty?
    top = AST::Declarations::Class.new(
      name: TypeName.new(name: :Object, namespace: Namespace.empty),
      super_class: nil,
      members: top_members,
      annotations: [],
      comment: nil,
      location: nil,
      type_params: []
    )
    decls << top
  end

  decls
end

# File 'lib/rbs/prototype/rb.rb', line 770

def find_def_index_by_name(decls, name)
  index = decls.find_index do |decl|
    case decl
    when AST::Members::MethodDefinition, AST::Members::AttrReader
      decl.name == name
    when AST::Members::AttrWriter
      :"#{decl.name}=" == name
    end
  end

  if index
    [
      index,
      _ = decls[index]
    ]
  end
end

# File 'lib/rbs/prototype/rb.rb', line 527

def function_return_type_from_body(node)
  body = node.children[2]
  body_type(body)
end

# File 'lib/rbs/prototype/rb.rb', line 471

def function_type_from_body(node, def_name)
  table_node, args_node, *_ = node.children

  pre_num, _pre_init, opt, _first_post, post_num, _post_init, rest, kw, kwrest, _block = args_from_node(args_node)

  return_type = if def_name == :initialize
                  Types::Bases::Void.new(location: nil)
                else
                  function_return_type_from_body(node)
                end

  fun = Types::Function.empty(return_type)

  table_node.take(pre_num).each do |name|
    fun.required_positionals << Types::Function::Param.new(name: name, type: untyped)
  end

  while opt&.type == :OPT_ARG
    lvasgn, opt = opt.children
    name = lvasgn.children[0]
    fun.optional_positionals << Types::Function::Param.new(
      name: name,
      type: param_type(lvasgn.children[1])
    )
  end

  if rest
    rest_name = rest == :* ? nil : rest # # For `def f(...) end` syntax
    fun = fun.update(rest_positionals: Types::Function::Param.new(name: rest_name, type: untyped))
  end

  table_node.drop(fun.required_positionals.size + fun.optional_positionals.size + (fun.rest_positionals ? 1 : 0)).take(post_num).each do |name|
    fun.trailing_positionals << Types::Function::Param.new(name: name, type: untyped)
  end

  while kw
    lvasgn, kw = kw.children
    name, value = lvasgn.children

    case value
    when nil, :NODE_SPECIAL_REQUIRED_KEYWORD
      fun.required_keywords[name] = Types::Function::Param.new(name: nil, type: untyped)
    when RubyVM::AbstractSyntaxTree::Node
      fun.optional_keywords[name] = Types::Function::Param.new(name: nil, type: param_type(value))
    else
      raise "Unexpected keyword arg value: #{value}"
    end
  end

  if kwrest && kwrest.children.any?
    fun = fun.update(rest_keywords: Types::Function::Param.new(name: kwrest.children[0], type: untyped))
  end

  fun
end

# File 'lib/rbs/prototype/rb.rb', line 545

def if_unless_type(node)
  raise unless node.type == :IF || node.type == :UNLESS

  _exp_node, true_node, false_node = node.children
  types_to_union_type([body_type(true_node), body_type(false_node)])
end

# File 'lib/rbs/prototype/rb.rb', line 766

def is_accessibility?(decl)
  decl == public || decl == private
end

# File 'lib/rbs/prototype/rb.rb', line 462

def literal_to_symbol(node)
  case node.type
  when :LIT
    node.children[0] if node.children[0].is_a?(Symbol)
  when :STR
    node.children[0].to_sym
  end
end

# File 'lib/rbs/prototype/rb.rb', line 566

def literal_to_type(node)
  case node.type
  when :STR
    lit = node.children[0]
    if lit.ascii_only?
      Types::Literal.new(literal: lit, location: nil)
    else
      BuiltinNames::String.instance_type
    end
  when :DSTR, :XSTR
    BuiltinNames::String.instance_type
  when :DSYM
    BuiltinNames::Symbol.instance_type
  when :DREGX
    BuiltinNames::Regexp.instance_type
  when :TRUE
    Types::Literal.new(literal: true, location: nil)
  when :FALSE
    Types::Literal.new(literal: false, location: nil)
  when :NIL
    Types::Bases::Nil.new(location: nil)
  when :LIT
    lit = node.children[0]
    case lit
    when Symbol
      if lit.to_s.ascii_only?
        Types::Literal.new(literal: lit, location: nil)
      else
        BuiltinNames::Symbol.instance_type
      end
    when Integer
      Types::Literal.new(literal: lit, location: nil)
    else
      type_name = TypeName.new(name: lit.class.name.to_sym, namespace: Namespace.root)
      Types::ClassInstance.new(name: type_name, args: [], location: nil)
    end
  when :ZLIST, :ZARRAY
    BuiltinNames::Array.instance_type(untyped)
  when :LIST, :ARRAY
    elem_types = node.children.compact.map { |e| literal_to_type(e) }
    t = types_to_union_type(elem_types)
    BuiltinNames::Array.instance_type(t)
  when :DOT2, :DOT3
    types = node.children.map { |c| literal_to_type(c) }
    type = range_element_type(types)
    BuiltinNames::Range.instance_type(type)
  when :HASH
    list = node.children[0]
    if list
      children = list.children
      children.pop
    else
      children = []
    end

    key_types = []
    value_types = []
    children.each_slice(2) do |k, v|
      if k
        key_types << literal_to_type(k)
        value_types << literal_to_type(v)
      else
        key_types << untyped
        value_types << untyped
      end
    end

    if !key_types.empty? && key_types.all? { |t| t.is_a?(Types::Literal) }
      fields = key_types.map { |t| t.literal }.zip(value_types).to_h
      Types::Record.new(fields: fields, location: nil)
    else
      key_type = types_to_union_type(key_types)
      value_type = types_to_union_type(value_types)
      BuiltinNames::Hash.instance_type(key_type, value_type)
    end
  when :SELF
    Types::Bases::Self.new(location: nil)
  when :CALL
    receiver, method_name, * = node.children
    case method_name
    when :freeze, :tap, :itself, :dup, :clone, :taint, :untaint, :extend
      literal_to_type(receiver)
    else
      untyped
    end
  else
    untyped
  end
end

# File 'lib/rbs/prototype/rb.rb', line 720

alias node_type param_type

# File 'lib/rbs/prototype/rb.rb', line 687

def param_type(node, default: Types::Bases::Any.new(location: nil))
  case node.type
  when :LIT
    case node.children[0]
    when Symbol
      BuiltinNames::Symbol.instance_type
    when Integer
      BuiltinNames::Integer.instance_type
    when Float
      BuiltinNames::Float.instance_type
    else
      default
    end
  when :STR, :DSTR
    BuiltinNames::String.instance_type
  when :NIL
    # This type is technical non-sense, but may help practically.
    Types::Optional.new(
      type: Types::Bases::Any.new(location: nil),
      location: nil
    )
  when :TRUE, :FALSE
    Types::Bases::Bool.new(location: nil)
  when :ARRAY, :LIST
    BuiltinNames::Array.instance_type(default)
  when :HASH
    BuiltinNames::Hash.instance_type(default, default)
  else
    default
  end
end

# File 'lib/rbs/prototype/rb.rb', line 75

def parse(string)
  # @type var comments: Hash[Integer, AST::Comment]
  comments = Ripper.lex(string).yield_self do |tokens|
    code_lines = {}
    tokens.each.with_object({}) do |token, hash|
      case token[1]
      when :on_sp, :on_ignored_nl
        # skip
      when :on_comment
        line = token[0][0]
        # skip like `module Foo # :nodoc:`
        next if code_lines[line]
        body = token[2][2..-1] or raise

        body = "\n" if body.empty?

        comment = AST::Comment.new(string: body, location: nil)
        if prev_comment = hash.delete(line - 1)
          hash[line] = AST::Comment.new(string: prev_comment.string + comment.string,
                                        location: nil)
        else
          hash[line] = comment
        end
      else
        code_lines[token[0][0]] = true
      end
    end
  end

  process RubyVM::AbstractSyntaxTree.parse(string), decls: source_decls, comments: comments, context: Context.initial
end

# File 'lib/rbs/prototype/rb.rb', line 722

def private
  @private ||= AST::Members::Private.new(location: nil)
end

# File 'lib/rbs/prototype/rb.rb', line 107

def process(node, decls:, comments:, context:)
  case node.type
  when :CLASS
    class_name, super_class_node, *class_body = node.children
    super_class_name = const_to_name(super_class_node, context: context)
    super_class =
      if super_class_name
        AST::Declarations::Class::Super.new(name: super_class_name, args: [], location: nil)
      else
        # Give up detect super class e.g. `class Foo < Struct.new(:bar)`
        nil
      end
    kls = AST::Declarations::Class.new(
      name: const_to_name!(class_name),
      super_class: super_class,
      type_params: [],
      members: [],
      annotations: [],
      location: nil,
      comment: comments[node.first_lineno - 1]
    )

    decls.push kls

    new_ctx = context.enter_namespace(kls.name.to_namespace)
    each_node class_body do |child|
      process child, decls: kls.members, comments: comments, context: new_ctx
    end
    remove_unnecessary_accessibility_methods! kls.members
    sort_members! kls.members

  when :MODULE
    module_name, *module_body = node.children

    mod = AST::Declarations::Module.new(
      name: const_to_name!(module_name),
      type_params: [],
      self_types: [],
      members: [],
      annotations: [],
      location: nil,
      comment: comments[node.first_lineno - 1]
    )

    decls.push mod

    new_ctx = context.enter_namespace(mod.name.to_namespace)
    each_node module_body do |child|
      process child, decls: mod.members, comments: comments, context: new_ctx
    end
    remove_unnecessary_accessibility_methods! mod.members
    sort_members! mod.members

  when :SCLASS
    this, body = node.children

    if this.type != :SELF
      RBS.logger.warn "`class <<` syntax with not-self may be compiled to incorrect code: #{this}"
    end

    accessibility = current_accessibility(decls)

    ctx = Context.initial.tap { |ctx| ctx.singleton = true }
    process_children(body, decls: decls, comments: comments, context: ctx)

    decls << accessibility

  when :DEFN, :DEFS
    # @type var kind: Context::method_kind

    if node.type == :DEFN
      def_name, def_body = node.children
      kind = context.method_kind
    else
      _, def_name, def_body = node.children
      kind = :singleton
    end

    types = [
      MethodType.new(
        type_params: [],
        type: function_type_from_body(def_body, def_name),
        block: block_from_body(def_body),
        location: nil
      )
    ]

    member = AST::Members::MethodDefinition.new(
      name: def_name,
      location: nil,
      annotations: [],
      overloads: types.map {|type| AST::Members::MethodDefinition::Overload.new(annotations: [], method_type: type )},
      kind: kind,
      comment: comments[node.first_lineno - 1],
      overloading: false,
      visibility: nil
    )

    decls.push member unless decls.include?(member)

    new_ctx = context.update(singleton: kind == :singleton, in_def: true)
    each_node def_body.children do |child|
      process child, decls: decls, comments: comments, context: new_ctx
    end

  when :ALIAS
    new_name, old_name = node.children.map { |c| literal_to_symbol(c) }
    member = AST::Members::Alias.new(
      new_name: new_name,
      old_name: old_name,
      kind: context.singleton ? :singleton : :instance,
      annotations: [],
      location: nil,
      comment: comments[node.first_lineno - 1],
    )
    decls.push member unless decls.include?(member)

  when :FCALL, :VCALL
    # Inside method definition cannot reach here.
    args = node.children[1]&.children || []

    case node.children[0]
    when :include
      args.each do |arg|
        if (name = const_to_name(arg, context: context))
          klass = context.singleton ? AST::Members::Extend : AST::Members::Include
          decls << klass.new(
            name: name,
            args: [],
            annotations: [],
            location: nil,
            comment: comments[node.first_lineno - 1]
          )
        end
      end
    when :prepend
      args.each do |arg|
        if (name = const_to_name(arg, context: context))
          decls << AST::Members::Prepend.new(
            name: name,
            args: [],
            annotations: [],
            location: nil,
            comment: comments[node.first_lineno - 1]
          )
        end
      end
    when :extend
      args.each do |arg|
        if (name = const_to_name(arg, context: context))
          decls << AST::Members::Extend.new(
            name: name,
            args: [],
            annotations: [],
            location: nil,
            comment: comments[node.first_lineno - 1]
          )
        end
      end
    when :attr_reader
      args.each do |arg|
        if arg && (name = literal_to_symbol(arg))
          decls << AST::Members::AttrReader.new(
            name: name,
            ivar_name: nil,
            type: Types::Bases::Any.new(location: nil),
            kind: context.attribute_kind,
            location: nil,
            comment: comments[node.first_lineno - 1],
            annotations: []
          )
        end
      end
    when :attr_accessor
      args.each do |arg|
        if arg && (name = literal_to_symbol(arg))
          decls << AST::Members::AttrAccessor.new(
            name: name,
            ivar_name: nil,
            type: Types::Bases::Any.new(location: nil),
            kind: context.attribute_kind,
            location: nil,
            comment: comments[node.first_lineno - 1],
            annotations: []
          )
        end
      end
    when :attr_writer
      args.each do |arg|
        if arg && (name = literal_to_symbol(arg))
          decls << AST::Members::AttrWriter.new(
            name: name,
            ivar_name: nil,
            type: Types::Bases::Any.new(location: nil),
            kind: context.attribute_kind,
            location: nil,
            comment: comments[node.first_lineno - 1],
            annotations: []
          )
        end
      end
    when :alias_method
      if args[0] && args[1] && (new_name = literal_to_symbol(args[0])) && (old_name = literal_to_symbol(args[1]))
        decls << AST::Members::Alias.new(
          new_name: new_name,
          old_name: old_name,
          kind: context.singleton ? :singleton : :instance,
          annotations: [],
          location: nil,
          comment: comments[node.first_lineno - 1],
        )
      end
    when :module_function
      if args.empty?
        context.module_function = true
      else
        module_func_context = context.update(module_function: true)
        args.each do |arg|
          if arg && (name = literal_to_symbol(arg))
            if (i, defn = find_def_index_by_name(decls, name))
              if defn.is_a?(AST::Members::MethodDefinition)
                decls[i] = defn.update(kind: :singleton_instance)
              end
            end
          elsif arg
            process arg, decls: decls, comments: comments, context: module_func_context
          end
        end
      end
    when :public, :private
      accessibility = __send__(node.children[0])
      if args.empty?
        decls << accessibility
      else
        args.each do |arg|
          if arg && (name = literal_to_symbol(arg))
            if (i, _ = find_def_index_by_name(decls, name))
              current = current_accessibility(decls, i)
              if current != accessibility
                decls.insert(i + 1, current)
                decls.insert(i, accessibility)
              end
            end
          end
        end

        # For `private def foo` syntax
        current = current_accessibility(decls)
        decls << accessibility
        process_children(node, decls: decls, comments: comments, context: context)
        decls << current
      end
    else
      process_children(node, decls: decls, comments: comments, context: context)
    end

  when :ITER
    # ignore

  when :CDECL
    const_name = case
                 when node.children[0].is_a?(Symbol)
                   TypeName.new(name: node.children[0], namespace: Namespace.empty)
                 else
                   const_to_name!(node.children[0])
                 end

    value_node = node.children.last
    type = if value_node.nil?
            # Give up type prediction when node is MASGN.
            Types::Bases::Any.new(location: nil)
          else
            literal_to_type(value_node)
          end
    decls << AST::Declarations::Constant.new(
      name: const_name,
      type: type,
      location: nil,
      comment: comments[node.first_lineno - 1]
    )

  when :IASGN
    case [context.singleton, context.in_def]
    when [true, true], [false, false]
      member = AST::Members::ClassInstanceVariable.new(
        name: node.children.first,
        type: Types::Bases::Any.new(location: nil),
        location: nil,
        comment: comments[node.first_lineno - 1]
      )
    when [false, true]
      member = AST::Members::InstanceVariable.new(
        name: node.children.first,
        type: Types::Bases::Any.new(location: nil),
        location: nil,
        comment: comments[node.first_lineno - 1]
      )
    when [true, false]
      # The variable is for the singleton class of the class object.
      # RBS does not have a way to represent it. So we ignore it.
    else
      raise 'unreachable'
    end

    decls.push member if member && !decls.include?(member)

  when :CVASGN
    member = AST::Members::ClassVariable.new(
      name: node.children.first,
      type: Types::Bases::Any.new(location: nil),
      location: nil,
      comment: comments[node.first_lineno - 1]
    )
    decls.push member unless decls.include?(member)
  else
    process_children(node, decls: decls, comments: comments, context: context)
  end
end

# File 'lib/rbs/prototype/rb.rb', line 426

def process_children(node, decls:, comments:, context:)
  each_child node do |child|
    process child, decls: decls, comments: comments, context: context
  end
end

# File 'lib/rbs/prototype/rb.rb', line 726

def public
  @public ||= AST::Members::Public.new(location: nil)
end

# File 'lib/rbs/prototype/rb.rb', line 667

def range_element_type(types)
  types = types.reject { |t| t == untyped }
  return untyped if types.empty?

  types = types.map do |t|
    if t.is_a?(Types::Literal)
      type_name = TypeName.new(name: t.literal.class.name.to_sym, namespace: Namespace.root)
      Types::ClassInstance.new(name: type_name, args: [], location: nil)
    else
      t
    end
  end.uniq

  if types.size == 1
    types.first or raise
  else
    untyped
  end
end

# File 'lib/rbs/prototype/rb.rb', line 740

def remove_unnecessary_accessibility_methods!(decls)
  # @type var current: decl
  current = public
  idx = 0

  loop do
    decl = decls[idx] or break
    if current == decl
      decls.delete_at(idx)
      next
    end

    if 0 < idx && is_accessibility?(decls[idx - 1]) && is_accessibility?(decl)
      decls.delete_at(idx - 1)
      idx -= 1
      current = current_accessibility(decls, idx)
      next
    end

    current = decl if is_accessibility?(decl)
    idx += 1
  end

  decls.pop while decls.last && is_accessibility?(decls.last || raise)
end

# File 'lib/rbs/prototype/rb.rb', line 788

def sort_members!(decls)
  i = 0
  orders = {
    AST::Members::ClassVariable => -3,
    AST::Members::ClassInstanceVariable => -2,
    AST::Members::InstanceVariable => -1,
  }
  decls.sort_by! { |decl| [orders.fetch(decl.class, 0), i += 1] }
end

# File 'lib/rbs/prototype/rb.rb', line 656

def types_to_union_type(types)
  return untyped if types.empty?

  uniq = types.uniq
  if uniq.size == 1
    return uniq.first || raise
  end

  Types::Union.new(types: uniq, location: nil)
end