class RSpec::Core::Metadata

def apply?(predicate, filters)
  filters.send(predicate) do |key, value|
    apply_condition(key, value)
  end
end

def apply_condition(key, value, metadata=self)
  case value
  when Hash
    value.all? { |k, v| apply_condition(k, v, metadata[key]) }
  when Regexp
    metadata[key] =~ value
  when Proc
    if value.arity == 2
      # Pass the metadata hash to allow the proc to check if it even has the key.
      # This is necessary for the implicit :if exclusion filter:
      #   {            } # => run the example
      #   { :if => nil } # => exclude the example
      # The value of metadata[:if] is the same in these two cases but
      # they need to be treated differently.
      value.call(metadata[key], metadata) rescue false
    else
      value.call(metadata[key]) rescue false
    end
  when Fixnum
    if key == :line_number
      relevant_line_numbers(metadata).include?(world.preceding_declaration_line(value))
    else
      metadata[key] == value
    end
  else
    metadata[key].to_s == value.to_s
  end
end

def configure_for_example(description, user_metadata)
  store(:description, description.to_s)
  store(:full_description, "#{self[:example_group][:full_description]} #{self[:description]}")
  store(:execution_result, {})
  store(:caller, user_metadata.delete(:caller) || caller)
  update(user_metadata)
end

def described_class_from(*args)
  superclass_metadata[:example_group][:describes] || begin
    args.first unless args.first.is_a?(String) || args.first.is_a?(Symbol)
  end
end

def description_from(*args)
  args.inject("") do |result, a|
    a = a.to_s.strip
    if result == ""
      a
    elsif a =~ /^(#|::|\.)/
      "#{result}#{a}"
    else
      "#{result} #{a}"
    end
  end
end

def ensure_valid_keys(user_metadata)
  RESERVED_KEYS.each do |key|
    if user_metadata.keys.include?(key)
      raise <<-EOM
50}
} is not allowed
reserves some hash keys for its own internal use,
ing :#{key}, which is used on:
ller(0)[4]}.
re all of RSpec's reserved hash keys:
SERVED_KEYS.join("\n  ")}
50}
      raise ":#{key} is not allowed"
    end
  end
end

def for_example(description, user_metadata)
  dup.extend(LocationKeys).configure_for_example(description, user_metadata)
end

def full_description_from(*args)
  if superclass_metadata[:example_group][:full_description]
    description_from(superclass_metadata[:example_group][:full_description], *args)
  else
    description_from(*args)
  end
end

def initialize(superclass_metadata=nil)
  @superclass_metadata = superclass_metadata
  if @superclass_metadata
    update(@superclass_metadata)
    example_group = {:example_group => @superclass_metadata[:example_group]}
  else
    example_group = {}
  end
  store(:example_group, example_group.extend(LocationKeys))
  yield self if block_given?
end

def process(*args)
  user_metadata = args.last.is_a?(Hash) ? args.pop : {}
  ensure_valid_keys(user_metadata)
  self[:example_group].store(:caller, user_metadata.delete(:caller) || caller)
  self[:example_group].store(:describes, described_class_from(*args))
  self[:example_group].store(:description, description_from(*args))
  self[:example_group].store(:full_description, full_description_from(*args))
  self[:example_group].store(:block, user_metadata.delete(:example_group_block))
  update(user_metadata)
end

def relevant_line_numbers(metadata)
  line_numbers = [metadata[:line_number]]
  if metadata[:example_group]
    line_numbers + relevant_line_numbers(metadata[:example_group])
  else
    line_numbers
  end
end

def superclass_metadata
  @superclass_metadata ||= { :example_group => {} }
end

def world
  RSpec.world
end