module Psych

def self.add_builtin_type type_tag, &block
  domain = 'yaml.org,2002'
  key = ['tag', domain, type_tag].join ':'
  @domain_types[key] = [key, block]
end

def self.add_domain_type domain, type_tag, &block
  key = ['tag', domain, type_tag].join ':'
  @domain_types[key] = [key, block]
  @domain_types["tag:#{type_tag}"] = [key, block]
end

def self.add_private_type type_tag, &block
  warn "#{caller[0]}: add_private_type is deprecated, use add_domain_type" if $VERBOSE
  domain = 'x-private'
  key = [domain, type_tag].join ':'
  @domain_types[key] = [key, block]
end

def self.add_ruby_type type_tag, &block
  warn "#{caller[0]}: add_ruby_type is deprecated, use add_domain_type" if $VERBOSE
  domain = 'ruby.yaml.org,2002'
  key = ['tag', domain, type_tag].join ':'
  @domain_types[key] = [key, block]
end

def self.add_tag tag, klass
  @load_tags[tag] = klass.name
  @dump_tags[klass] = tag
end

def self.detect_implicit thing
  warn "#{caller[0]}: detect_implicit is deprecated" if $VERBOSE
  return '' unless String === thing
  return 'null' if '' == thing
  ss = ScalarScanner.new(ClassLoader.new)
  ss.tokenize(thing).class.name.downcase
end

def self.dump o, io = nil, options = {}
  if Hash === io
    options = io
    io      = nil
  end
  visitor = Psych::Visitors::YAMLTree.create options
  visitor << o
  visitor.tree.yaml io, options
end

def self.dump_stream *objects
  visitor = Psych::Visitors::YAMLTree.create({})
  objects.each do |o|
    visitor << o
  end
  visitor.tree.yaml
end

def self.load yaml, filename = nil
  result = parse(yaml, filename)
  result ? result.to_ruby : result
end

def self.load_documents yaml, &block
  if $VERBOSE
    warn "#{caller[0]}: load_documents is deprecated, use load_stream"
  end
  list = load_stream yaml
  return list unless block_given?
  list.each(&block)
end

def self.load_file filename
  File.open(filename, 'r:bom|utf-8') { |f| self.load f, filename }
end

def self.load_stream yaml, filename = nil
  if block_given?
    parse_stream(yaml, filename) do |node|
      yield node.to_ruby
    end
  else
    parse_stream(yaml, filename).children.map { |child| child.to_ruby }
  end
end

def self.object_maker klass, hash
  warn "#{caller[0]}: object_maker is deprecated" if $VERBOSE
  klass.allocate.tap do |obj|
    hash.each { |k,v| obj.instance_variable_set(:"@#{k}", v) }
  end
end

def self.parse yaml, filename = nil
  parse_stream(yaml, filename) do |node|
    return node
  end
  false
end

def self.parse_file filename
  File.open filename, 'r:bom|utf-8' do |f|
    parse f, filename
  end
end

def self.parse_stream yaml, filename = nil, &block
  if block_given?
    parser = Psych::Parser.new(Handlers::DocumentStream.new(&block))
    parser.parse yaml, filename
  else
    parser = self.parser
    parser.parse yaml, filename
    parser.handler.root
  end
end

def self.parser
  Psych::Parser.new(TreeBuilder.new)
end

def self.quick_emit thing, opts = {}, &block # :nodoc:
  warn "#{caller[0]}: YAML.quick_emit is deprecated" if $VERBOSE && !caller[0].start_with?(File.dirname(__FILE__))
  target = eval 'self', block.binding
  target.extend DeprecatedMethods
  metaclass = class << target; self; end
  metaclass.send(:define_method, :encode_with) do |coder|
    target.taguri        = coder.tag
    target.to_yaml_style = coder.style
    block.call coder
  end
  target.psych_to_yaml unless opts[:nodump]
end

def self.read_type_class type, reference
  warn "#{caller[0]}: read_type_class is deprecated" if $VERBOSE
  _, _, type, name = type.split ':', 4
  reference = name.split('::').inject(reference) do |k,n|
    k.const_get(n.to_sym)
  end if name
  [type, reference]
end

def self.remove_type type_tag
  @domain_types.delete type_tag
end

def self.safe_load yaml, whitelist_classes = [], whitelist_symbols = [], aliases = false, filename = nil
  result = parse(yaml, filename)
  return unless result
  class_loader = ClassLoader::Restricted.new(whitelist_classes.map(&:to_s),
                                             whitelist_symbols.map(&:to_s))
  scanner      = ScalarScanner.new class_loader
  if aliases
    visitor = Visitors::ToRuby.new scanner, class_loader
  else
    visitor = Visitors::NoAliasRuby.new scanner, class_loader
  end
  visitor.accept result
end

def self.tagurize thing
  warn "#{caller[0]}: add_private_type is deprecated, use add_domain_type" if $VERBOSE
  return thing unless String === thing
  "tag:yaml.org,2002:#{thing}"
end

def self.to_json object
  visitor = Psych::Visitors::JSONTree.create
  visitor << object
  visitor.tree.yaml
end