class Phlex::HTML

def _attributes(**attributes)
	if attributes[:href]&.start_with?(/\s*javascript/)
		attributes[:href] = attributes[:href].sub(/^\s*(javascript:)+/, "")
	end
	buffer = +""
	_build_attributes(attributes, buffer: buffer)
	unless self.class.rendered_at_least_once
		Phlex::ATTRIBUTE_CACHE[attributes.hash] = buffer.freeze
	end
	buffer
end

def _build_attributes(attributes, buffer:)
	attributes.each do |k, v|
		next unless v
		name = case k
		when String
			k
		when Symbol
			k.name.tr("_", "-")
		else
			k.to_s
		end
		if HTML::EVENT_ATTRIBUTES[name] || name.match?(/[<>&"']/)
			raise ArgumentError, "Unsafe attribute name detected: #{k}."
		end
		case v
		when true
			buffer << " " << name
		when String
			buffer << " " << name << '="' << Hescape.escape_html(v) << '"'
		when Symbol
			buffer << " " << name << '="' << Hescape.escape_html(v.name) << '"'
		when Hash
			_build_attributes(v.transform_keys { "#{k}-#{_1.name.tr('_', '-')}" }, buffer: buffer)
		else
			buffer << " " << name << '="' << Hescape.escape_html(v.to_s) << '"'
		end
	end
	buffer
end

def _output(content)
	case content
	when String then Hescape.escape_html(content)
	when Symbol then Hescape.escape_html(content.name)
	else Hescape.escape_html(content.to_s)
	end
end

def append=(value)
	return unless value
	if value.html_safe?
		self.safe_append = value
	else
		@_target << case value
		when String then Hescape.escape_html(value)
		when Symbol then Hescape.escape_html(value.name)
		else Hescape.escape_html(value.to_s)
		end
	end
end

def call(buffer = +"", view_context: nil, parent: nil, &block)
	return buffer unless render?
	raise "The same view instance shouldn't be rendered twice" if rendered?
	@_rendered = true
	@_target = buffer
	@_view_context = view_context
	@_parent = parent
	@output_buffer = self
	template(&block)
	self.class.rendered_at_least_once ||= true
	buffer
end

def capture(&block)
	return unless block_given?
	original_buffer = @_target
	new_buffer = +""
	@_target = new_buffer
	yield
	@_target = original_buffer
	new_buffer.html_safe
end

def comment(content = "")
	@_target << "<!-- " << Hescape.escape_html(content.to_s) << " -->"
	nil
end

def doctype
	@_target << DOCTYPE
	nil
end

def helpers
	@_view_context
end

def html_safe?
	true
end

def render?
	true
end

def rendered?
	@_rendered ||= false
end

def safe_append=(value)
	return unless value
	@_target << case value
	when String then value
	when Symbol then value.name
	else value.to_s
	end
end

def text(content)
	@_target << _output(content)
	nil
end

def unsafe_raw(content = nil, &block)
	@_target << (content || instance_exec(&block))
	nil
end

def whitespace
	@_target << " "
	if block_given?
		yield
		@_target << " "
	end
	nil
end

def yield_content(&block)
	return unless block_given?
	original_length = @_target.length
	output = yield(self)
	unchanged = (original_length == @_target.length)
	if unchanged
		case output
		when String, Symbol, Integer, Float
			text(output)
		end
	end
	nil
end