wesnoth/src/ai/manager.cpp

/* $Id$ */
/*
   Copyright (C) 2009 - 2010 by Yurii Chernyi <terraninfo@terraninfo.net>
   Part of the Battle for Wesnoth Project http://www.wesnoth.org/

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License version 2
   or at your option any later version.
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY.

   See the COPYING file for more details.
*/

/**
 * Managing the AI lifecycle and interface for the rest of Wesnoth
 * @file ai/manager.cpp
 */

#include "composite/ai.hpp"
#include "configuration.hpp"
#include "contexts.hpp"
#include "default/ai.hpp"
#include "manager.hpp"
#include "formula/ai.hpp"
#include "registry.hpp"
#include "../game_events.hpp"
#include "../game_preferences.hpp"
#include "../foreach.hpp"
#include "../log.hpp"
#include "../replay.hpp"
#include "../serialization/string_utils.hpp"
#include "../statistics.hpp"
#include "composite/component.hpp"

#include <map>
#include <stack>
#include <vector>

namespace ai {

const std::string manager::AI_TYPE_COMPOSITE_AI = "composite_ai";
const std::string manager::AI_TYPE_SAMPLE_AI = "sample_ai";
const std::string manager::AI_TYPE_IDLE_AI = "idle_ai";
const std::string manager::AI_TYPE_FORMULA_AI = "formula_ai";
const std::string manager::AI_TYPE_DEFAULT = "default";


static lg::log_domain log_ai_manager("ai/manager");
#define DBG_AI_MANAGER LOG_STREAM(debug, log_ai_manager)
#define LOG_AI_MANAGER LOG_STREAM(info, log_ai_manager)
#define ERR_AI_MANAGER LOG_STREAM(err, log_ai_manager)

static lg::log_domain log_ai_mod("ai/mod");
#define DBG_AI_MOD LOG_STREAM(debug, log_ai_mod)
#define LOG_AI_MOD LOG_STREAM(info, log_ai_mod)
#define WRN_AI_MOD LOG_STREAM(warn, log_ai_mod)
#define ERR_AI_MOD LOG_STREAM(err, log_ai_mod)

holder::holder( side_number side, const config &cfg )
	: ai_(), side_context_(NULL), readonly_context_(NULL), readwrite_context_(NULL), default_ai_context_(NULL), side_(side), cfg_(cfg)
{
	DBG_AI_MANAGER << describe_ai() << "Preparing new AI holder" << std::endl;
}


void holder::init( side_number side )
{
	if (side_context_ == NULL) {
		side_context_ = new side_context_impl(side,cfg_);
	} else {
		side_context_->set_side(side);
	}
	if (readonly_context_ == NULL){
		readonly_context_ = new readonly_context_impl(*side_context_,cfg_);
		readonly_context_->on_readonly_context_create();
	}
	if (readwrite_context_ == NULL){
		readwrite_context_ = new readwrite_context_impl(*readonly_context_,cfg_);
	}
	if (default_ai_context_ == NULL){
		default_ai_context_ = new default_ai_context_impl(*readwrite_context_,cfg_);
	}
	if (!this->ai_){
		ai_ = boost::shared_ptr<ai_composite>(new ai_composite(*default_ai_context_,cfg_));
	}

	if (this->ai_) {
		ai_->on_create();
		foreach (config &mod_ai, cfg_.child_range("modify_ai")) {
			if (!mod_ai.has_attribute("side")) {
				mod_ai["side"] = side;
			}
			modify_ai(mod_ai);
		}
		cfg_.clear_children("modify_ai");

	} else {
		ERR_AI_MANAGER << describe_ai()<<"AI lazy initialization error!" << std::endl;
	}

}

holder::~holder()
{
	if (this->ai_) {
		LOG_AI_MANAGER << describe_ai() << "Managed AI will be deleted" << std::endl;
	}
	delete this->default_ai_context_;
	delete this->readwrite_context_;
	delete this->readonly_context_;
	delete this->side_context_;
}


interface& holder::get_ai_ref()
{
	if (!this->ai_) {
		this->init(this->side_);
	}
	assert(this->ai_);

	return *this->ai_;
}


void holder::modify_ai_config_old( const config::const_child_itors &ai_parameters)
{
	// only handle aspects
	// transform ai_parameters to new-style config

	config cfg;
	configuration::upgrade_aspect_configs_from_1_07_02_to_1_07_03(this->side_,ai_parameters,cfg);
	//at this point we have a single config which contains [aspect][facet] tags
	DBG_AI_MANAGER << "after transforming [modify_side][ai] into new syntax, config contains:"<< std::endl << cfg << std::endl;

	if (this->readonly_context_ == NULL) {
		// if not initialized, append that config to the bottom of base cfg
		// then, merge aspects with the same id
		cfg_.merge_with(cfg);
		cfg_.merge_children_by_attribute("aspect","id");
	} else {
		// else run 'add_facet' command on each [aspect][facet]
		foreach (const config &cfg_a, cfg.child_range("aspect")) {
			foreach (const config &cfg_f, cfg_a.child_range("facet")) {
				readonly_context_->add_facet(cfg_a["id"],cfg_f);
			}
		}
	}
}


void holder::modify_ai(const config &cfg)
{
	if (!this->ai_) {
		// if not initialized, initialize now.
		get_ai_ref();
	}
	const std::string &act = cfg["action"];
	LOG_AI_MOD << "side "<< side_ << "        [modify_ai] "<<act<<" \""<<cfg["path"]<<"\""<<std::endl;
	DBG_AI_MOD << std::endl << cfg << std::endl;
	DBG_AI_MOD << "side "<< side_ << " before [modify_ai]"<<std::endl << to_config() << std::endl;
	bool res = false;
	if (act == "add") {
		res = component_manager::add_component(&*this->ai_,cfg["path"],cfg);
	} else if (act == "change") {
		res = component_manager::change_component(&*this->ai_,cfg["path"],cfg);
	} else if (act == "delete") {
		res = component_manager::delete_component(&*this->ai_,cfg["path"]);
	} else if (act == "try_delete") {
		res = component_manager::delete_component(&*this->ai_,cfg["path"]);
		if (!res) {
			LOG_AI_MOD << "[modify_ai] "<<act<<" failed, ignoring because it's a try_delete"<< std::endl;
			res = true;
		}
	} else {
		ERR_AI_MOD << "modify_ai tag has invalid 'action' attribute " << act << std::endl;
	}
	DBG_AI_MOD << "side "<< side_ << "  after [modify_ai]"<<act<<std::endl << to_config() << std::endl;
	if (!res) {
		LOG_AI_MOD << "[modify_ai] "<<act<<" failed"<< std::endl;
	} else {
		LOG_AI_MOD << "[modify_ai] "<<act<<" success"<< std::endl;
	}

}

config holder::to_config() const
{
	if (!this->ai_) {
		return cfg_;
	} else {
		config cfg = ai_->to_config();
		cfg["version"] = "10703";
		if (this->side_context_!=NULL) {
			cfg.merge_with(this->side_context_->to_side_context_config());
		}
		if (this->readonly_context_!=NULL) {
			cfg.merge_with(this->readonly_context_->to_readonly_context_config());
		}
		if (this->readwrite_context_!=NULL) {
			cfg.merge_with(this->readwrite_context_->to_readwrite_context_config());
		}
		if (this->default_ai_context_!=NULL) {
			cfg.merge_with(this->default_ai_context_->to_default_ai_context_config());
		}

		return cfg;
	}
}



const std::string holder::describe_ai()
{
	std::string sidestr = lexical_cast<std::string>(this->side_);

	if (this->ai_!=NULL) {
		return this->ai_->describe_self()+std::string(" for side ")+sidestr+std::string(" : ");
	} else {
		return std::string("not initialized ai with id=[")+cfg_["id"]+std::string("] for side ")+sidestr+std::string(" : ");
	}
}


const std::string holder::get_ai_overview()
{
	if (!this->ai_) {
		get_ai_ref();
	}
	std::stringstream s;
	s << "aggression:  " << this->ai_->get_aggression() << std::endl;
	s << "attack_depth:  " << this->ai_->get_attack_depth() << std::endl;
	s << "caution:  " << this->ai_->get_caution() << std::endl;
	s << "grouping:  " << this->ai_->get_grouping() << std::endl;
	s << "leader_aggression:  " << this->ai_->get_leader_aggression() << std::endl;
	s << "leader_value:  " << this->ai_->get_leader_value() << std::endl;
	s << "number_of_possible_recruits_to_force_recruit:  " << this->ai_->get_number_of_possible_recruits_to_force_recruit() << std::endl;
	s << "passive_leader:  " << this->ai_->get_passive_leader() << std::endl;
	s << "passive_leader_shares_keep:  " << this->ai_->get_passive_leader_shares_keep() << std::endl;
	s << "recruitment_ignore_bad_combat:  " << this->ai_->get_recruitment_ignore_bad_movement() << std::endl;
	s << "recruitment_ignore_bad_movement:  " << this->ai_->get_recruitment_ignore_bad_combat() << std::endl;
//	s << "recruitment_pattern:  ";
//	for(std::vector<std::string>::const_iterator i =  this->ai_->get_recruitment_pattern().begin(); i !=  this->ai_->get_recruitment_pattern().end(); ++i) {
//		if(i != this->ai_->get_recruitment_pattern().begin())
//			s << ",";
//
//		s << *i;
//	}
//	s << std::endl;
	s << "scout_village_targeting:  " << this->ai_->get_scout_village_targeting() << std::endl;
	s << "simple_targeting:  " << this->ai_->get_simple_targeting() << std::endl;
	s << "support_villages:  " << this->ai_->get_support_villages() << std::endl;
	s << "village_value:  " << this->ai_->get_village_value() << std::endl;
	s << "villages_per_scout:  " << this->ai_->get_villages_per_scout() << std::endl;
	return s.str();
}



const std::string holder::get_ai_structure()
{
	if (!this->ai_) {
		get_ai_ref();
	}
	return component_manager::print_component_tree(&*this->ai_,"");
}


const std::string holder::get_ai_identifier() const
{
	return cfg_["id"];
}

// =======================================================================
// LIFECYCLE
// =======================================================================


manager::AI_map_of_stacks manager::ai_map_;
game_info *manager::ai_info_;
events::generic_event manager::user_interact_("ai_user_interact");
events::generic_event manager::sync_network_("ai_sync_network");
events::generic_event manager::gamestate_changed_("ai_gamestate_changed");
events::generic_event manager::turn_started_("ai_turn_started");
events::generic_event manager::recruit_list_changed_("ai_recruit_list_changed");
events::generic_event manager::map_changed_("ai_map_changed");
int manager::last_interact_ = 0;
int manager::num_interact_ = 0;


void manager::set_ai_info(const game_info& i)
{
	if (ai_info_!=NULL){
		clear_ai_info();
	}
	ai_info_ = new game_info(i);
	registry::init();
}


void manager::clear_ai_info(){
	if (ai_info_ != NULL){
		delete ai_info_;
		ai_info_ = NULL;
	}
}


void manager::add_observer( events::observer* event_observer){
	user_interact_.attach_handler(event_observer);
	sync_network_.attach_handler(event_observer);
	turn_started_.attach_handler(event_observer);
	gamestate_changed_.attach_handler(event_observer);
}


void manager::remove_observer(events::observer* event_observer){
	user_interact_.detach_handler(event_observer);
	sync_network_.detach_handler(event_observer);
	turn_started_.detach_handler(event_observer);
	gamestate_changed_.detach_handler(event_observer);
}


void manager::add_gamestate_observer( events::observer* event_observer){
	gamestate_changed_.attach_handler(event_observer);
	turn_started_.attach_handler(event_observer);
	map_changed_.attach_handler(event_observer);
}


void manager::remove_gamestate_observer(events::observer* event_observer){
	gamestate_changed_.detach_handler(event_observer);
	turn_started_.detach_handler(event_observer);
	map_changed_.detach_handler(event_observer);
}



void manager::add_map_changed_observer( events::observer* event_observer )
{
	map_changed_.attach_handler(event_observer);
}


void manager::add_recruit_list_changed_observer( events::observer* event_observer )
{
	recruit_list_changed_.attach_handler(event_observer);
}


void manager::add_turn_started_observer( events::observer* event_observer )
{
	turn_started_.attach_handler(event_observer);
}


void manager::remove_recruit_list_changed_observer( events::observer* event_observer )
{
	recruit_list_changed_.detach_handler(event_observer);
}


void manager::remove_map_changed_observer( events::observer* event_observer )
{
	map_changed_.detach_handler(event_observer);
}


void manager::remove_turn_started_observer( events::observer* event_observer )
{
	turn_started_.detach_handler(event_observer);
}

void manager::raise_user_interact() {
        const int interact_time = 30;
        const int time_since_interact = SDL_GetTicks() - last_interact_;
        if(time_since_interact < interact_time) {
                return;
        }

	++num_interact_;
        user_interact_.notify_observers();

        last_interact_ = SDL_GetTicks();

}

void manager::raise_sync_network() {
	sync_network_.notify_observers();
}


void manager::raise_gamestate_changed() {
	gamestate_changed_.notify_observers();
}


void manager::raise_turn_started() {
	turn_started_.notify_observers();
}


void manager::raise_recruit_list_changed() {
	recruit_list_changed_.notify_observers();
}


void manager::raise_map_changed() {
	map_changed_.notify_observers();
}


// =======================================================================
// EVALUATION
// =======================================================================

const std::string manager::evaluate_command( side_number side, const std::string& str )
{
	//insert new command into history
	history_.push_back(command_history_item(history_item_counter_++,str));

	//prune history - erase 1/2 of it if it grows too large
	if (history_.size()>MAX_HISTORY_SIZE){
		history_.erase(history_.begin(),history_.begin()+MAX_HISTORY_SIZE/2);
		LOG_AI_MANAGER << "AI MANAGER: pruned history" << std::endl;
	}

	if (!should_intercept(str)){
		interface& ai = get_active_ai_for_side(side);
		raise_gamestate_changed();
		return ai.evaluate(str);
	}

	return internal_evaluate_command(side,str);
}


bool manager::should_intercept( const std::string& str )
{
	if (str.length()<1) {
		return false;
	}
	if (str.at(0)=='!'){
		return true;
	}
	if (str.at(0)=='?'){
		return true;
	}
	return false;

}

std::deque< command_history_item > manager::history_;
long manager::history_item_counter_ = 1;

//this is stub code to allow testing of basic 'history', 'repeat-last-command', 'add/remove/replace ai' capabilities.
//yes, it doesn't look nice. but it is usable.
//to be refactored at earliest opportunity
//@todo 1.9 extract to separate class which will use fai or lua parser
const std::string manager::internal_evaluate_command( side_number side, const std::string& str ){
	const int MAX_HISTORY_VISIBLE = 30;

	//repeat last command
	if (str=="!") {
			//this command should not be recorded in history
			if (!history_.empty()){
				history_.pop_back();
				history_item_counter_--;
			}

			if (history_.empty()){
				return "AI MANAGER: empty history";
			}
			return evaluate_command(side, history_.back().get_command());//no infinite loop since '!' commands are not present in history
	};
	//show last command
	if (str=="?") {
		//this command should not be recorded in history
		if (!history_.empty()){
			history_.pop_back();
			history_item_counter_--;
		}

		if (history_.empty()){
			return "AI MANAGER: History is empty";
		}

		int n = std::min<int>( MAX_HISTORY_VISIBLE, history_.size() );
		std::stringstream strstream;
		strstream << "AI MANAGER: History - last "<< n <<" commands:\n";
		std::deque< command_history_item >::reverse_iterator j = history_.rbegin();

		for (int cmd_id=n; cmd_id>0; --cmd_id){
			strstream << j->get_number() << "    :" << j->get_command() << '\n';
			j++;//this is *reverse* iterator
		}

		return strstream.str();
	};


	std::vector< std::string > cmd = utils::parenthetical_split(str, ' ',"'","'");

	if (cmd.size()==3){
		//!add_ai side file
		if (cmd.at(0)=="!add_ai"){
			side_number side = lexical_cast<side_number>(cmd.at(1));
			std::string file = cmd.at(2);
			if (add_ai_for_side_from_file(side,file,false)){
				return std::string("AI MANAGER: added [")+manager::get_active_ai_identifier_for_side(side)+std::string("] AI for side ")+lexical_cast<std::string>(side)+std::string(" from file ")+file;
			} else {
				return std::string("AI MANAGER: failed attempt to add AI for side ")+lexical_cast<std::string>(side)+std::string(" from file ")+file;
			}
		}
		//!replace_ai side file
		if (cmd.at(0)=="!replace_ai"){
			side_number side = lexical_cast<side_number>(cmd.at(1));
			std::string file = cmd.at(2);
			if (add_ai_for_side_from_file(side,file,true)){
					return std::string("AI MANAGER: added [")+manager::get_active_ai_identifier_for_side(side)+std::string("] AI for side ")+lexical_cast<std::string>(side)+std::string(" from file ")+file;
			} else {
					return std::string("AI MANAGER: failed attempt to add AI for side ")+lexical_cast<std::string>(side)+std::string(" from file ")+file;
			}
		}

	} else if (cmd.size()==2){
		//!remove_ai side
		if (cmd.at(0)=="!remove_ai"){
			side_number side = lexical_cast<side_number>(cmd.at(1));
			remove_ai_for_side(side);
			return std::string("AI MANAGER: made an attempt to remove AI for side ")+lexical_cast<std::string>(side);
		}
		if (cmd.at(0)=="!"){
			//this command should not be recorded in history
			if (!history_.empty()){
				history_.pop_back();
				history_item_counter_--;
			}

			int command = lexical_cast<int>(cmd.at(1));
			std::deque< command_history_item >::reverse_iterator j = history_.rbegin();
			//yes, the iterator could be precisely positioned (since command numbers go 1,2,3,4,..). will do it later.
			while ( (j!=history_.rend()) && (j->get_number()!=command) ){
				j++;// this is *reverse* iterator
			}
			if (j!=history_.rend()){
				return evaluate_command(side,j->get_command());//no infinite loop since '!' commands are not present in history
			}
			return "AI MANAGER: no command with requested number found";
		}
	} else if (cmd.size()==1){
		if (cmd.at(0)=="!help") {
			return
				"known commands:\n"
				"!    - repeat last command (? and ! do not count)\n"
				"! NUMBER    - repeat numbered command\n"
				"?    - show a history list\n"
				"!add_ai TEAM FILE    - add a AI to side (0 - command AI, N - AI for side #N) from file\n"
				"!remove_ai TEAM    - remove AI from side (0 - command AI, N - AI for side #N)\n"
				"!replace_ai TEAM FILE    - replace AI of side (0 - command AI, N - AI for side #N) from file\n"
				"!help    - show this help message";
		}
	}


	return "AI MANAGER: nothing to do";
}

// =======================================================================
// ADD, CREATE AIs, OR LIST AI TYPES
// =======================================================================

//@todo 1.9 add error reporting
bool manager::add_ai_for_side_from_file( side_number side, const std::string& file, bool replace )
{
	config cfg;
	if (!configuration::get_side_config_from_file(file,cfg)){
		ERR_AI_MANAGER << " unable to read [SIDE] config for side "<< side << "from file [" << file <<"]"<< std::endl;
		return false;
	}
	return add_ai_for_side_from_config(side,cfg,replace);
}


bool manager::add_ai_for_side_from_config( side_number side, const config& cfg, bool replace ){
	config parsed_cfg;
	configuration::parse_side_config(side, cfg, parsed_cfg);

	if (replace) {
		remove_ai_for_side(side);
	}

	holder new_holder(side,parsed_cfg);
	std::stack<holder>& ai_stack_for_specific_side = get_or_create_ai_stack_for_side(side);
	ai_stack_for_specific_side.push(new_holder);
	return true;
}


//@todo 1.9 add error reporting
bool manager::add_ai_for_side( side_number side, const std::string& ai_algorithm_type, bool replace )
{
	if (replace) {
		remove_ai_for_side (side);
	}
	config cfg;
	cfg["ai_algorithm"] = ai_algorithm_type;
	holder new_holder(side,cfg);
	std::stack<holder>& ai_stack_for_specific_side = get_or_create_ai_stack_for_side(side);
	ai_stack_for_specific_side.push(new_holder);
	return true;
}


ai_ptr manager::create_transient_ai(const std::string &ai_algorithm_type, const config &cfg, ai_context *ai_context )
{
	assert(ai_context!=NULL);

	//to add your own ai, register it in registry,cpp
	ai_factory::factory_map::iterator aii = ai_factory::get_list().find(ai_algorithm_type);
	if (aii == ai_factory::get_list().end()){
		aii = ai_factory::get_list().find("");
		if (aii == ai_factory::get_list().end()){
			throw game::game_error("no default ai set!");
		}
	}
	LOG_AI_MANAGER << "Creating new AI of type [" << ai_algorithm_type << "]"<< std::endl;
	ai_ptr new_ai = aii->second->get_new_instance(*ai_context,cfg);
	return new_ai;
}


// =======================================================================
// REMOVE
// =======================================================================

void manager::remove_ai_for_side( side_number side )
{
	std::stack<holder>& ai_stack_for_specific_side = get_or_create_ai_stack_for_side(side);
	if (!ai_stack_for_specific_side.empty()){
		ai_stack_for_specific_side.pop();
	}
}


void manager::remove_all_ais_for_side( side_number side )
{
	std::stack<holder>& ai_stack_for_specific_side = get_or_create_ai_stack_for_side(side);

	//clear the stack. std::stack doesn't have a '.clear()' method to do it
	while (!ai_stack_for_specific_side.empty()){
			ai_stack_for_specific_side.pop();
	}
}


void manager::clear_ais()
{
	ai_map_.clear();
}

// =======================================================================
// Work with active AI parameters
// =======================================================================

void manager::modify_active_ai_config_old_for_side ( side_number side, const config::const_child_itors &ai_parameters )
{
	get_active_ai_holder_for_side(side).modify_ai_config_old(ai_parameters);
}


void manager::modify_active_ai_for_side ( side_number side, const config &cfg )
{
	if (ai_info_==NULL) {
		//replay ?
		return;
	}
	get_active_ai_holder_for_side(side).modify_ai(cfg);
}


std::string manager::get_active_ai_overview_for_side( side_number side)
{
	return get_active_ai_holder_for_side(side).get_ai_overview();
}


std::string manager::get_active_ai_structure_for_side( side_number side)
{
	return get_active_ai_holder_for_side(side).get_ai_structure();
}


std::string manager::get_active_ai_identifier_for_side( side_number side )
{
	return get_active_ai_holder_for_side(side).get_ai_identifier();
}


config manager::to_config( side_number side )
{
	return get_active_ai_holder_for_side(side).to_config();
}


game_info& manager::get_active_ai_info_for_side( side_number /*side*/ )
{
	return *ai_info_;
}


game_info& manager::get_ai_info()
{
	return *ai_info_;
}


// =======================================================================
// PROXY
// =======================================================================

void manager::play_turn( side_number side ){
	last_interact_ = 0;
	num_interact_ = 0;
	const int turn_start_time = SDL_GetTicks();
	/*hack. @todo 1.9 rework via extended event system*/
	get_ai_info().recent_attacks.clear();
	interface& ai_obj = get_active_ai_for_side(side);
	game_events::fire("ai turn");
	raise_turn_started();
	ai_obj.new_turn();
	ai_obj.play_turn();
	const int turn_end_time= SDL_GetTicks();
	DBG_AI_MANAGER << "side " << side << ": number of user interactions: "<<num_interact_<<std::endl;
	DBG_AI_MANAGER << "side " << side << ": total turn time: "<<turn_end_time - turn_start_time << " ms "<< std::endl;
}


// =======================================================================
// PRIVATE
// =======================================================================
// =======================================================================
// AI STACKS
// =======================================================================
std::stack<holder>& manager::get_or_create_ai_stack_for_side( side_number side )
{
	AI_map_of_stacks::iterator iter = ai_map_.find(side);
	if (iter!=ai_map_.end()){
		return iter->second;
	}
	return ai_map_.insert(std::make_pair(side, std::stack<holder>())).first->second;
}

// =======================================================================
// AI HOLDERS
// =======================================================================
holder& manager::get_active_ai_holder_for_side( side_number side )
{
	std::stack<holder>& ai_stack_for_specific_side = get_or_create_ai_stack_for_side(side);

	if (!ai_stack_for_specific_side.empty()){
		return ai_stack_for_specific_side.top();
	} else {
		config cfg = configuration::get_default_ai_parameters();
		holder new_holder(side, cfg);
		ai_stack_for_specific_side.push(new_holder);
		return ai_stack_for_specific_side.top();
	}
}

// =======================================================================
// AI POINTERS
// =======================================================================

interface& manager::get_active_ai_for_side( side_number side )
{
	return get_active_ai_holder_for_side(side).get_ai_ref();
}


// =======================================================================
// MISC
// =======================================================================

} //end of namespace ai