/*
 * \brief  Child representation
 * \author Norman Feske
 * \date   2018-01-23
 */

/*
 * Copyright (C) 2018 Genode Labs GmbH
 *
 * This file is part of the Genode OS framework, which is distributed
 * under the terms of the GNU Affero General Public License version 3.
 */

#ifndef _CHILD_H_
#define _CHILD_H_

/* Genode includes */
#include <util/list_model.h>
#include <base/service.h>
#include <os/reporter.h>
#include <os/buffered_xml.h>
#include <depot/archive.h>

namespace Depot_deploy {
	using namespace Depot;
	struct Child;
}


class Depot_deploy::Child : public List_model<Child>::Element
{
	public:

		typedef String<100> Name;
		typedef String<80>  Binary_name;
		typedef String<80>  Config_name;

	private:

		Allocator &_alloc;

		Reconstructible<Buffered_xml> _start_xml;     /* from config */
		Constructible<Buffered_xml>   _pkg_xml { };   /* from blueprint */

		Name const _name;

		Archive::Path _config_pkg_path() const
		{
			return _start_xml->xml().attribute_value("pkg", Archive::Path());
		}

		/*
		 * The pkg-archive path of the current blueprint query, which may
		 * deviate from pkg path given in the config, once the config is
		 * updated.
		 */
		Archive::Path _blueprint_pkg_path = _config_pkg_path();

		Ram_quota   _ram_quota { 0 };
		Cap_quota   _cap_quota { 0 };
		Binary_name _binary_name { };
		Config_name _config_name { };

		/*
		 * Set if the depot query for the child's blueprint failed.
		 */
		bool _pkg_incomplete = false;

		bool _configured() const
		{
			return _pkg_xml.constructed()
			   && (_config_pkg_path() == _blueprint_pkg_path);
		}

		inline void _gen_routes(Xml_generator &, Xml_node common) const;

		static void _gen_provides_sub_node(Xml_generator &xml, Xml_node service,
		                                   Xml_node::Type const &node_type,
		                                   Service::Name  const &service_name)
		{
			if (service.type() == node_type)
				xml.node("service", [&] () {
					xml.attribute("name", service_name); });
		}

		static void _gen_copy_of_sub_node(Xml_generator &xml, Xml_node from_node,
		                                  Xml_node::Type const &sub_node_type)
		{
			if (!from_node.has_sub_node(sub_node_type.string()))
				return;

			Xml_node const sub_node = from_node.sub_node(sub_node_type.string());
			xml.append(sub_node.addr(), sub_node.size());
		}

	public:

		Child(Allocator &alloc, Xml_node start_node)
		:
			_alloc(alloc),
			_start_xml(_alloc, start_node),
			_name(_start_xml->xml().attribute_value("name", Name()))
		{ }

		Name name() const { return _name; }

		void apply_config(Xml_node start_node)
		{
			/*
			 * String-compare new with current start node to quicky skip
			 * the start nodes that have not changed.
			 */
			bool const start_node_changed =
				(start_node.size() != _start_xml->xml().size()) ||
				(strcmp(start_node.addr(), _start_xml->xml().addr(),
				        start_node.size()) != 0);

			if (!start_node_changed)
				return;

			Archive::Path const pkg =
				start_node.attribute_value("pkg", Archive::Path());

			/* invalidate blueprint if 'pkg' attribute of start node changed */
			if (pkg != _config_pkg_path())
				_pkg_xml.destruct();

			_blueprint_pkg_path = pkg;

			/* import new start node */
			_start_xml.construct(_alloc, start_node);

			/* reset error state, attempt to obtain the blueprint again */
			_pkg_incomplete = false;
		}

		void apply_blueprint(Xml_node pkg)
		{
			if (pkg.attribute_value("path", Archive::Path()) != _blueprint_pkg_path)
				return;

			Xml_node const runtime = pkg.sub_node("runtime");

			Number_of_bytes const ram { runtime.attribute_value("ram", Number_of_bytes()) };
			_ram_quota = Ram_quota { _start_xml->xml().attribute_value("ram",  ram) };

			unsigned long const caps = runtime.attribute_value("caps", 0UL);
			_cap_quota = Cap_quota { _start_xml->xml().attribute_value("caps", caps) };

			_binary_name = runtime.attribute_value("binary", Binary_name());
			_config_name = runtime.attribute_value("config", Config_name());

			/* keep copy of the blueprint info */
			_pkg_xml.construct(_alloc, pkg);
		}

		void mark_as_incomplete(Xml_node missing)
		{
			/* print error message only once */
			if(_pkg_incomplete)
				return;

			Archive::Path const path = missing.attribute_value("path", Archive::Path());
			if (path != _blueprint_pkg_path)
				return;

			error(path, " incomplete or missing");

			_pkg_incomplete = true;
		}

		void gen_query(Xml_generator &xml) const
		{
			if (_configured() || _pkg_incomplete)
				return;

			xml.node("blueprint", [&] () {
				xml.attribute("pkg", _blueprint_pkg_path); });
		}

		/**
		 * Generate start node of init configuration
		 *
		 * \param common  session routes to be added in addition to the ones
		 *                found in the pkg blueprint
		 */
		inline void gen_start_node(Xml_generator &, Xml_node common) const;
};


void Depot_deploy::Child::gen_start_node(Xml_generator &xml, Xml_node common) const
{
	if (!_configured())
		return;

	if (!_pkg_xml->xml().has_sub_node("runtime")) {
		warning("blueprint for '", _name, "' lacks runtime information");
		return;
	}

	xml.node("start", [&] () {

		xml.attribute("name", _name);
		xml.attribute("caps", _cap_quota.value);

		typedef String<64> Version;
		Version const version = _start_xml->xml().attribute_value("version", Version());
		if (version.valid())
			xml.attribute("version", version);

		xml.node("binary", [&] () { xml.attribute("name", _binary_name); });

		xml.node("resource", [&] () {
			xml.attribute("name", "RAM");
			xml.attribute("quantum", String<32>(Number_of_bytes(_ram_quota.value)));
		});

		Xml_node const runtime = _pkg_xml->xml().sub_node("runtime");

		/*
		 * Insert inline '<config>' node if provided by the start node or the
		 * blueprint. The former is preferred over the latter.
		 */
		if (_start_xml->xml().has_sub_node("config")) {
			_gen_copy_of_sub_node(xml, _start_xml->xml(), "config");
		} else {
			if (runtime.has_sub_node("config"))
				_gen_copy_of_sub_node(xml, runtime, "config");
		}

		/*
		 * Declare services provided by the subsystem.
		 */
		if (runtime.has_sub_node("provides")) {
			xml.node("provides", [&] () {
				runtime.sub_node("provides").for_each_sub_node([&] (Xml_node service) {
					_gen_provides_sub_node(xml, service, "rom",         "ROM");
					_gen_provides_sub_node(xml, service, "log",         "LOG");
					_gen_provides_sub_node(xml, service, "timer",       "Timer");
					_gen_provides_sub_node(xml, service, "block",       "Block");
					_gen_provides_sub_node(xml, service, "report",      "Report");
					_gen_provides_sub_node(xml, service, "nic",         "Nic");
					_gen_provides_sub_node(xml, service, "nitpicker",   "Nitpicker");
					_gen_provides_sub_node(xml, service, "framebuffer", "Framebuffer");
					_gen_provides_sub_node(xml, service, "input",       "Input");
					_gen_provides_sub_node(xml, service, "audio_out",   "Audio_out");
					_gen_provides_sub_node(xml, service, "audio_in",    "Audio_in");
					_gen_provides_sub_node(xml, service, "file_system", "File_system");
				});
			});
		}

		xml.node("route", [&] () { _gen_routes(xml, common); });
	});
}


void Depot_deploy::Child::_gen_routes(Xml_generator &xml, Xml_node common) const
{
	if (!_pkg_xml.constructed())
		return;

	typedef String<160> Path;

	/*
	 * Add routes given in the start node.
	 */
	if (_start_xml->xml().has_sub_node("route")) {
		Xml_node const route = _start_xml->xml().sub_node("route");
		xml.append(route.content_base(), route.content_size());
	}

	/*
	 * Redirect config ROM request to label as given in the 'config' attribute,
	 * if present. We need to search the blueprint's <rom> nodes for the
	 * matching ROM module to rewrite the label with the configuration's path
	 * within the depot.
	 */
	if (_config_name.valid()) {
		_pkg_xml->xml().for_each_sub_node("rom", [&] (Xml_node rom) {

			if (!rom.has_attribute("path"))
				return;

			if (rom.attribute_value("label", Name()) != _config_name)
				return;

			/* we found the <rom> node for the config ROM */
			xml.node("service", [&] () {
				xml.attribute("name",  "ROM");
				xml.attribute("label", "config");
				xml.node("parent", [&] () {
					typedef String<160> Path;
					xml.attribute("label", rom.attribute_value("path", Path()));
				});
			});
		});
	}

	/*
	 * Add common routes as defined in our config.
	 */
	xml.append(common.content_base(), common.content_size());

	/*
	 * Add ROM routing rule with the label rewritten to the path within the
	 * depot.
	 */
	_pkg_xml->xml().for_each_sub_node("rom", [&] (Xml_node rom) {

		if (!rom.has_attribute("path"))
			return;

		typedef Name Label;
		Path  const path  = rom.attribute_value("path",  Path());
		Label const label = rom.attribute_value("label", Label());

		xml.node("service", [&] () {
			xml.attribute("name", "ROM");
			xml.attribute("label_last", label);
			xml.node("parent", [&] () {
				xml.attribute("label", path); });
		});
	});
}

#endif /* _CHILD_H_ */