/*
 * \brief  Pseudo launcher for the Genode version of Scout
 * \author Norman Feske
 * \date   2006-08-28
 */

/*
 * Copyright (C) 2006-2017 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.
 */

#include <base/env.h>
#include <base/attached_rom_dataspace.h>
#include <launchpad/launchpad.h>
#include "elements.h"

using namespace Genode;
using namespace Scout;

/* initialized by 'Launcher::init' */
static Launchpad *_launchpad_ptr;
static Allocator *_alloc_ptr;
static Env       *_env_ptr;


/**********************************************
 ** Registry containing child configurations **
 **********************************************/

/**
 * The registry contains config dataspaces for given program names. It is
 * filled lazily as a side effect of 'Launcher::launch()'.
 */
class Config_registry
{
	private:

		struct Entry;
		List<Entry> _configs { };

	public:

		/**
		 * Obtain configuration for specified program name from ROM module
		 * named '<prg_name>.config'
		 */
		Dataspace_capability config(char const *name);
};


struct Config_registry::Entry : List<Config_registry::Entry>::Element
{
	String<128> const name;

	Constructible<Attached_rom_dataspace> dataspace { };

	Dataspace_capability ds_cap { };

	Entry(char const *prg_name) : name(prg_name)
	{
		try {
			dataspace.construct(*_env_ptr, String<256>(name, ".config").string());
			ds_cap = dataspace->cap();
		}
		catch (...) { }
	}
};


Dataspace_capability Config_registry::config(char const *name)
{
	/* lookup existing configuration */
	for (Entry *e = _configs.first(); e; e = e->next())
		if (e->name == name)
			return e->ds_cap;

	/* if lookup failed, create and register new config */
	Entry *entry = new (*_alloc_ptr) Entry(name);
	_configs.insert(entry);

	return entry->ds_cap;
}


/************************
 ** Launcher interface **
 ************************/

void Launcher::init(Genode::Env &env, Allocator &alloc)
{
	static Launchpad launchpad(env, env.pd().avail_ram().value);
	_launchpad_ptr = &launchpad;
	_alloc_ptr     = &alloc;
	_env_ptr       = &env;
}


void Launcher::launch()
{
	static Config_registry config_registry;

	if (!_launchpad_ptr) {
		class Missing_launchpad_init_call { };
		throw Missing_launchpad_init_call();
	}

	_launchpad_ptr->start_child(prg_name(),
	                            Launchpad::Cap_quota{caps()},
	                            Launchpad::Ram_quota{quota()},
	                            config_registry.config(prg_name().string()));
}