class RDoc::Context

def <=>(other)
  return nil unless RDoc::CodeObject === other
  full_name <=> other.full_name
end

def add klass, name, comment
  if RDoc::Extend == klass then
    ext = RDoc::Extend.new name, comment
    add_extend ext
  elsif RDoc::Include == klass then
    incl = RDoc::Include.new name, comment
    add_include incl
  else
    raise NotImplementedError, "adding a #{klass} is not implemented"
  end
end

def add_alias an_alias
  return an_alias unless @document_self
  method_attr = find_method(an_alias.old_name, an_alias.singleton) ||
                find_attribute(an_alias.old_name, an_alias.singleton)
  if method_attr then
    method_attr.add_alias an_alias, self
  else
    add_to @external_aliases, an_alias
    unmatched_alias_list =
      @unmatched_alias_lists[an_alias.pretty_old_name] ||= []
    unmatched_alias_list.push an_alias
  end
  an_alias
end

def add_attribute attribute
  return attribute unless @document_self
  # mainly to check for redefinition of an attribute as a method
  # TODO find a policy for 'attr_reader :foo' + 'def foo=()'
  register = false
  key = nil
  if attribute.rw.index 'R' then
    key = attribute.pretty_name
    known = @methods_hash[key]
    if known then
      known.comment = attribute.comment if known.comment.empty?
    elsif registered = @methods_hash[attribute.pretty_name + '='] and
          RDoc::Attr === registered then
      registered.rw = 'RW'
    else
      @methods_hash[key] = attribute
      register = true
    end
  end
  if attribute.rw.index 'W' then
    key = attribute.pretty_name + '='
    known = @methods_hash[key]
    if known then
      known.comment = attribute.comment if known.comment.empty?
    elsif registered = @methods_hash[attribute.pretty_name] and
          RDoc::Attr === registered then
      registered.rw = 'RW'
    else
      @methods_hash[key] = attribute
      register = true
    end
  end
  if register then
    attribute.visibility = @visibility
    add_to @attributes, attribute
    resolve_aliases attribute
  end
  attribute
end

def add_class class_type, given_name, superclass = '::Object'
  # superclass +nil+ is passed by the C parser in the following cases:
  # - registering Object in 1.8 (correct)
  # - registering BasicObject in 1.9 (correct)
  # - registering RubyVM in 1.9 in iseq.c (incorrect: < Object in vm.c)
  #
  # If we later find a superclass for a registered class with a nil
  # superclass, we must honor it.
  # find the name & enclosing context
  if given_name =~ /^:+(\w+)$/ then
    full_name = $1
    enclosing = top_level
    name = full_name.split(/:+/).last
  else
    full_name = child_name given_name
    if full_name =~ /^(.+)::(\w+)$/ then
      name = $2
      ename = $1
      enclosing = @store.classes_hash[ename] || @store.modules_hash[ename]
      # HACK: crashes in actionpack/lib/action_view/helpers/form_helper.rb (metaprogramming)
      unless enclosing then
        # try the given name at top level (will work for the above example)
        enclosing = @store.classes_hash[given_name] ||
                    @store.modules_hash[given_name]
        return enclosing if enclosing
        # not found: create the parent(s)
        names = ename.split('::')
        enclosing = self
        names.each do |n|
          enclosing = enclosing.classes_hash[n] ||
                      enclosing.modules_hash[n] ||
                      enclosing.add_module(RDoc::NormalModule, n)
        end
      end
    else
      name = full_name
      enclosing = self
    end
  end
  # fix up superclass
  if full_name == 'BasicObject' then
    superclass = nil
  elsif full_name == 'Object' then
    superclass = '::BasicObject'
  end
  # find the superclass full name
  if superclass then
    if superclass =~ /^:+/ then
      superclass = $' #'
    else
      if superclass =~ /^(\w+):+(.+)$/ then
        suffix = $2
        mod = find_module_named($1)
        superclass = mod.full_name + '::' + suffix if mod
      else
        mod = find_module_named(superclass)
        superclass = mod.full_name if mod
      end
    end
    # did we believe it was a module?
    mod = @store.modules_hash.delete superclass
    upgrade_to_class mod, RDoc::NormalClass, mod.parent if mod
    # e.g., Object < Object
    superclass = nil if superclass == full_name
  end
  klass = @store.classes_hash[full_name]
  if klass then
    # if TopLevel, it may not be registered in the classes:
    enclosing.classes_hash[name] = klass
    # update the superclass if needed
    if superclass then
      existing = klass.superclass
      existing = existing.full_name unless existing.is_a?(String) if existing
      if existing.nil? ||
         (existing == 'Object' && superclass != 'Object') then
        klass.superclass = superclass
      end
    end
  else
    # this is a new class
    mod = @store.modules_hash.delete full_name
    if mod then
      klass = upgrade_to_class mod, RDoc::NormalClass, enclosing
      klass.superclass = superclass unless superclass.nil?
    else
      klass = class_type.new name, superclass
      enclosing.add_class_or_module(klass, enclosing.classes_hash,
                                    @store.classes_hash)
    end
  end
  klass.parent = self
  klass
end

def add_class_or_module mod, self_hash, all_hash
  mod.section = current_section # TODO declaring context? something is
                                # wrong here...
  mod.parent = self
  mod.full_name = nil
  mod.store = @store
  unless @done_documenting then
    self_hash[mod.name] = mod
    # this must be done AFTER adding mod to its parent, so that the full
    # name is correct:
    all_hash[mod.full_name] = mod
    if @store.unmatched_constant_alias[mod.full_name] then
      to, file = @store.unmatched_constant_alias[mod.full_name]
      add_module_alias mod, mod.name, to, file
    end
  end
  mod
end

def add_constant constant
  return constant unless @document_self
  # HACK: avoid duplicate 'PI' & 'E' in math.c (1.8.7 source code)
  # (this is a #ifdef: should be handled by the C parser)
  known = @constants_hash[constant.name]
  if known then
    known.comment = constant.comment if known.comment.empty?
    known.value = constant.value if
      known.value.nil? or known.value.strip.empty?
    known.is_alias_for ||= constant.is_alias_for
  else
    @constants_hash[constant.name] = constant
    add_to @constants, constant
  end
  constant
end

def add_extend ext
  add_to @extends, ext
  ext
end

def add_include include
  add_to @includes, include
  include
end

def add_method method
  return method unless @document_self
  # HACK: avoid duplicate 'new' in io.c & struct.c (1.8.7 source code)
  key = method.pretty_name
  known = @methods_hash[key]
  if known then
    if @store then # otherwise we are loading
      known.comment = method.comment if known.comment.empty?
      previously = ", previously in #{known.file}" unless
        method.file == known.file
      @store.rdoc.options.warn \
        "Duplicate method #{known.full_name} in #{method.file}#{previously}"
    end
  else
    @methods_hash[key] = method
    if @current_line_visibility
      method.visibility, @current_line_visibility = @current_line_visibility, nil
    else
      method.visibility = @visibility
    end
    add_to @method_list, method
    resolve_aliases method
  end
  method
end

def add_module(class_type, name)
  mod = @classes[name] || @modules[name]
  return mod if mod
  full_name = child_name name
  mod = @store.modules_hash[full_name] || class_type.new(name)
  add_class_or_module mod, @modules, @store.modules_hash
end

def add_module_alias from, from_name, to, file
  return from if @done_documenting
  to_full_name = child_name to.name
  # if we already know this name, don't register an alias:
  # see the metaprogramming in lib/active_support/basic_object.rb,
  # where we already know BasicObject is a class when we find
  # BasicObject = BlankSlate
  return from if @store.find_class_or_module to_full_name
  unless from
    @store.unmatched_constant_alias[child_name(from_name)] = [to, file]
    return to
  end
  new_to = from.dup
  new_to.name = to.name
  new_to.full_name = nil
  if new_to.module? then
    @store.modules_hash[to_full_name] = new_to
    @modules[to.name] = new_to
  else
    @store.classes_hash[to_full_name] = new_to
    @classes[to.name] = new_to
  end
  # Registers a constant for this alias.  The constant value and comment
  # will be updated later, when the Ruby parser adds the constant
  const = RDoc::Constant.new to.name, nil, new_to.comment
  const.record_location file
  const.is_alias_for = from
  add_constant const
  new_to
end

def add_module_by_normal_module(mod)
  add_class_or_module mod, @modules, @store.modules_hash
end

def add_require(require)
  return require unless @document_self
  if RDoc::TopLevel === self then
    add_to @requires, require
  else
    parent.add_require require
  end
end

def add_section title, comment = nil
  if section = @sections[title] then
    section.add_comment comment if comment
  else
    section = Section.new self, title, comment
    @sections[title] = section
  end
  section
end

def add_to array, thing
  array << thing if @document_self
  thing.parent  = self
  thing.store   = @store if @store
  thing.section = current_section
end

def any_content(includes = true)
  @any_content ||= !(
    @comment.empty? &&
    @method_list.empty? &&
    @attributes.empty? &&
    @aliases.empty? &&
    @external_aliases.empty? &&
    @requires.empty? &&
    @constants.empty?
  )
  @any_content || (includes && !(@includes + @extends).empty? )
end

def child_name name
  if name =~ /^:+/
    $'  #'
  elsif RDoc::TopLevel === self then
    name
  else
    "#{self.full_name}::#{name}"
  end
end

def class_attributes
  @class_attributes ||= attributes.select { |a| a.singleton }
end

def class_method_list
  @class_method_list ||= method_list.select { |a| a.singleton }
end

def classes
  @classes.values
end

def classes_and_modules
  classes + modules
end

def classes_hash
  @classes
end

def current_section
  if section = @temporary_section then
    @temporary_section = nil
  else
    section = @current_section
  end
  section
end

def defined_in?(file)
  @in_files.include?(file)
end

def display(method_attr) # :nodoc:
  if method_attr.is_a? RDoc::Attr
    "#{method_attr.definition} #{method_attr.pretty_name}"
  else
    "method #{method_attr.pretty_name}"
  end
end

def each_ancestor # :nodoc:
end

def each_attribute # :yields: attribute
  @attributes.each { |a| yield a }
end

def each_classmodule(&block) # :yields: module
  classes_and_modules.sort.each(&block)
end

def each_constant # :yields: constant
  @constants.each {|c| yield c}
end

def each_extend # :yields: extend
  @extends.each do |e| yield e end
end

def each_include # :yields: include
  @includes.each do |i| yield i end
end

def each_method # :yields: method
  return enum_for __method__ unless block_given?
  @method_list.sort.each { |m| yield m }
end

def each_section # :yields: section, constants, attributes
  return enum_for __method__ unless block_given?
  constants  = @constants.group_by  do |constant|  constant.section end
  attributes = @attributes.group_by do |attribute| attribute.section end
  constants.default  = []
  attributes.default = []
  sort_sections.each do |section|
    yield section, constants[section].select(&:display?).sort, attributes[section].select(&:display?).sort
  end
end

def find_attribute(name, singleton)
  name = $1 if name =~ /^(.*)=$/
  @attributes.find { |a| a.name == name && a.singleton == singleton }
end

def find_attribute_named(name)
  case name
  when /\A#/ then
    find_attribute name[1..-1], false
  when /\A::/ then
    find_attribute name[2..-1], true
  else
    @attributes.find { |a| a.name == name }
  end
end

def find_class_method_named(name)
  @method_list.find { |meth| meth.singleton && meth.name == name }
end

def find_constant_named(name)
  @constants.find do |m|
    m.name == name || m.full_name == name
  end
end

def find_enclosing_module_named(name)
  parent && parent.find_module_named(name)
end

def find_external_alias(name, singleton)
  @external_aliases.find { |m| m.name == name && m.singleton == singleton }
end

def find_external_alias_named(name)
  case name
  when /\A#/ then
    find_external_alias name[1..-1], false
  when /\A::/ then
    find_external_alias name[2..-1], true
  else
    @external_aliases.find { |a| a.name == name }
  end
end

def find_file_named name
  @store.find_file_named name
end

def find_instance_method_named(name)
  @method_list.find { |meth| !meth.singleton && meth.name == name }
end

def find_local_symbol(symbol)
  find_method_named(symbol) or
  find_constant_named(symbol) or
  find_attribute_named(symbol) or
  find_external_alias_named(symbol) or
  find_module_named(symbol) or
  find_file_named(symbol)
end

def find_method(name, singleton)
  @method_list.find { |m|
    if m.singleton
      m.name == name && m.singleton == singleton
    else
      m.name == name && !m.singleton && !singleton
    end
  }
end

def find_method_named(name)
  case name
  when /\A#/ then
    find_method name[1..-1], false
  when /\A::/ then
    find_method name[2..-1], true
  else
    @method_list.find { |meth| meth.name == name }
  end
end

def find_module_named(name)
  res = @modules[name] || @classes[name]
  return res if res
  return self if self.name == name
  find_enclosing_module_named name
end

def find_symbol(symbol)
  find_symbol_module(symbol) || find_local_symbol(symbol)
end

def find_symbol_module(symbol)
  result = nil
  # look for a class or module 'symbol'
  case symbol
  when /^::/ then
    result = @store.find_class_or_module symbol
  when /^(\w+):+(.+)$/
    suffix = $2
    top = $1
    searched = self
    while searched do
      mod = searched.find_module_named(top)
      break unless mod
      result = @store.find_class_or_module "#{mod.full_name}::#{suffix}"
      break if result || searched.is_a?(RDoc::TopLevel)
      searched = searched.parent
    end
  else
    searched = self
    while searched do
      result = searched.find_module_named(symbol)
      break if result || searched.is_a?(RDoc::TopLevel)
      searched = searched.parent
    end
  end
  result
end

def full_name
  '(unknown)'
end

def fully_documented?
  documented? and
    attributes.all? { |a| a.documented? } and
    method_list.all? { |m| m.documented? } and
    constants.all? { |c| c.documented? }
end

def http_url(prefix)
  path = name_for_path
  path = path.gsub(/<<\s*(\w*)/, 'from-\1') if path =~ /<</
  path = [prefix] + path.split('::')
  File.join(*path.compact) + '.html'
end

def initialize
  super
  @in_files = []
  @name    ||= "unknown"
  @parent  = nil
  @visibility = :public
  @current_section = Section.new self, nil, nil
  @sections = { nil => @current_section }
  @temporary_section = nil
  @classes = {}
  @modules = {}
  initialize_methods_etc
end

def initialize_methods_etc
  @method_list = []
  @attributes  = []
  @aliases     = []
  @requires    = []
  @includes    = []
  @extends     = []
  @constants   = []
  @external_aliases = []
  @current_line_visibility = nil
  # This Hash maps a method name to a list of unmatched aliases (aliases of
  # a method not yet encountered).
  @unmatched_alias_lists = {}
  @methods_hash   = {}
  @constants_hash = {}
  @params = nil
  @store ||= nil
end

def instance_attributes
  @instance_attributes ||= attributes.reject { |a| a.singleton }
end

def instance_method_list
  @instance_method_list ||= method_list.reject { |a| a.singleton }
end

def methods_by_type section = nil
  methods = {}
  TYPES.each do |type|
    visibilities = {}
    RDoc::VISIBILITIES.each do |vis|
      visibilities[vis] = []
    end
    methods[type] = visibilities
  end
  each_method do |method|
    next if section and not method.section == section
    methods[method.type][method.visibility] << method
  end
  methods
end

def methods_matching(methods, singleton = false, &block)
  (@method_list + @attributes).each do |m|
    yield m if methods.include?(m.name) and m.singleton == singleton
  end
  each_ancestor do |parent|
    parent.methods_matching(methods, singleton, &block)
  end
end

def modules
  @modules.values
end

def modules_hash
  @modules
end

def name_for_path
  full_name
end

def ongoing_visibility=(visibility)
  @visibility = visibility
end

def record_location(top_level)
  @in_files << top_level unless @in_files.include?(top_level)
end

def remove_from_documentation?
  @remove_from_documentation ||=
    @received_nodoc &&
    !any_content(false) &&
    @includes.all? { |i| !i.module.is_a?(String) && i.module.remove_from_documentation? } &&
    classes_and_modules.all? { |cm| cm.remove_from_documentation? }
end

def remove_invisible min_visibility
  return if [:private, :nodoc].include? min_visibility
  remove_invisible_in @method_list, min_visibility
  remove_invisible_in @attributes, min_visibility
  remove_invisible_in @constants, min_visibility
end

def remove_invisible_in array, min_visibility # :nodoc:
  if min_visibility == :public then
    array.reject! { |e|
      e.visibility != :public and not e.force_documentation
    }
  else
    array.reject! { |e|
      e.visibility == :private and not e.force_documentation
    }
  end
end

def resolve_aliases added
  # resolve any pending unmatched aliases
  key = added.pretty_name
  unmatched_alias_list = @unmatched_alias_lists[key]
  return unless unmatched_alias_list
  unmatched_alias_list.each do |unmatched_alias|
    added.add_alias unmatched_alias, self
    @external_aliases.delete unmatched_alias
  end
  @unmatched_alias_lists.delete key
end

def section_contents
  used_sections = {}
  each_method do |method|
    next unless method.display?
    used_sections[method.section] = true
  end
  # order found sections
  sections = sort_sections.select do |section|
    used_sections[section]
  end
  # only the default section is used
  return [] if
    sections.length == 1 and not sections.first.title
  sections
end

def sections
  @sections.values
end

def sections_hash # :nodoc:
  @sections
end

def set_constant_visibility_for(names, visibility)
  names.each do |name|
    constant = @constants_hash[name] or next
    constant.visibility = visibility
  end
end

def set_current_section title, comment
  @current_section = add_section title, comment
end

def set_visibility_for(methods, visibility, singleton = false)
  methods_matching methods, singleton do |m|
    m.visibility = visibility
  end
end

def sort_sections
  titles = @sections.map { |title, _| title }
  if titles.length > 1 and
     TOMDOC_TITLES_SORT ==
       (titles | TOMDOC_TITLES).sort_by { |title| title.to_s } then
    @sections.values_at(*TOMDOC_TITLES).compact
  else
    @sections.sort_by { |title, _|
      title.to_s
    }.map { |_, section|
      section
    }
  end
end

def to_s # :nodoc:
  "#{self.class.name} #{self.full_name}"
end

def top_level
  return @top_level if defined? @top_level
  @top_level = self
  @top_level = @top_level.parent until RDoc::TopLevel === @top_level
  @top_level
end

def upgrade_to_class mod, class_type, enclosing
  enclosing.modules_hash.delete mod.name
  klass = RDoc::ClassModule.from_module class_type, mod
  klass.store = @store
  # if it was there, then we keep it even if done_documenting
  @store.classes_hash[mod.full_name] = klass
  enclosing.classes_hash[mod.name]   = klass
  klass
end