class YARD::DocstringParser

def self.after_parse(&block)
  after_parse_callbacks << block
end

def self.after_parse_callbacks
  @after_parse_callbacks ||= []
end

def call_after_parse_callbacks
  self.class.after_parse_callbacks.each do |cb|
    cb.call(self)
  end
end

def call_directives_after_parse
  directives.each(&:after_parse)
end

def create_directive(tag_name, tag_buf)
  if library.has_directive?(tag_name)
    dir = library.directive_create(tag_name, tag_buf, self)
    if dir.is_a?(Tags::Directive)
      @directives << dir
      dir
    end
  else
    log.warn "Unknown directive @!#{tag_name}" +
             (object ? " in file `#{object.file}` near line #{object.line}" : "")
    nil
  end
rescue Tags::TagFormatError
  log.warn "Invalid directive format for @!#{tag_name}" +
           (object ? " in file `#{object.file}` near line #{object.line}" : "")
  nil
end

def create_ref_tag(tag_name, name, object_name)
  @tags << Tags::RefTagList.new(tag_name, P(object, object_name), name)
end

def create_tag(tag_name, tag_buf = '')
  if tag_buf =~ /\A\s*(?:(\S+)\s+)?\(\s*see\s+(\S+)\s*\)\s*\Z/
    return create_ref_tag(tag_name, $1, $2)
  end
  if library.has_tag?(tag_name)
    @tags += [library.tag_create(tag_name, tag_buf)].flatten
  else
    log.warn "Unknown tag @#{tag_name}" +
             (object ? " in file `#{object.file}` near line #{object.line}" : "")
  end
rescue Tags::TagFormatError
  log.warn "Invalid tag format for @#{tag_name}" +
           (object ? " in file `#{object.file}` near line #{object.line}" : "")
end

def detect_reference(content)
  if content =~ /\A\s*\(see (\S+)\s*\)(?:\s|$)/
    path = $1
    extra = $'
    [CodeObjects::Proxy.new(namespace, path), extra]
  else
    [nil, content]
  end
end

def initialize(library = Tags::Library.instance)
  @text = ""
  @raw_text = ""
  @tags = []
  @directives = []
  @library = library
  @object = nil
  @reference = nil
  @handler = nil
  @state = OpenStruct.new
end

def namespace
  object && object.namespace
end

def parse(content, object = nil, handler = nil)
  @object = object
  @handler = handler
  @reference, @raw_text = detect_reference(content)
  text = parse_content(@raw_text)
  @text = text.strip
  call_directives_after_parse
  post_process
  self
end

def parse_content(content)
  content = content.split(/\r?\n/) if content.is_a?(String)
  return '' if !content || content.empty?
  docstring = String.new("")
  indent = content.first[/^\s*/].length
  last_indent = 0
  orig_indent = 0
  directive = false
  last_line = ""
  tag_name = nil
  tag_buf = []
  (content + ['']).each_with_index do |line, index|
    indent = line[/^\s*/].length
    empty = (line =~ /^\s*$/ ? true : false)
    done = content.size == index
    if tag_name && (((indent < orig_indent && !empty) || done ||
        (indent == 0 && !empty)) || (indent <= last_indent && line =~ META_MATCH))
      buf = tag_buf.join("\n")
      if directive || tag_is_directive?(tag_name)
        directive = create_directive(tag_name, buf)
        if directive
          docstring << parse_content(directive.expanded_text).chomp
        end
      else
        create_tag(tag_name, buf)
      end
      tag_name = nil
      tag_buf = []
      directive = false
      orig_indent = 0
    end
    # Found a meta tag
    if line =~ META_MATCH
      directive = $1
      tag_name = $2
      tag_buf = [($3 || '')]
    elsif tag_name && indent >= orig_indent && !empty
      orig_indent = indent if orig_indent == 0
      # Extra data added to the tag on the next line
      last_empty = last_line =~ /^[ \t]*$/ ? true : false
      tag_buf << '' if last_empty
      tag_buf << line.gsub(/^[ \t]{#{orig_indent}}/, '')
    elsif !tag_name
      # Regular docstring text
      docstring << line
      docstring << "\n"
    end
    last_indent = indent
    last_line = line
  end
  docstring
end

def post_process
  call_after_parse_callbacks
end

def tag_is_directive?(tag_name)
  list = %w(attribute endgroup group macro method scope visibility)
  list.include?(tag_name)
end

def to_docstring
  Docstring.new!(text, tags, object, raw_text, reference)
end