/*
Danger from the Deep - Open source submarine simulation
Copyright (C) 2003-2006  Thorsten Jordan, Luis Barrancos and others.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

// Sonar operator simulation
// subsim (C) + (W). See LICENSE

#include "sonar.h"
#include <map>

#ifndef SONAR_OPERATOR_H
#define SONAR_OPERATOR_H

class sonar_operator
{
 public:
	// defined here because global sonar_contact already exists, but has a different
	// form (should be replaced later?) weird...
	struct contact
	{
		double strength_dB;
		shipclass type;
		contact(double s = 1e-10, shipclass t = NONE) : strength_dB(s), type(t) {}
	};

 protected:
	enum states {
		initial,
		find_growing_signal,
		find_max_peak_coarse,
		find_max_peak_fine,
		track_signal
	};
	states state;
	angle current_angle;
	double current_signal_strength;
	// store angle and contact, per contact strength (dB) and ship type
	// angle is absolute nautical angle, to make contacts invariant of sub's heading.
	// fixme: good idea, but a contact is reported many times then while the sub turns, fixme!
	std::map<double, contact> contacts;
	bool active;	// disabled, when user does the work

	static const double turn_speed_fast; //= 6.0;	// degrees per second.
	static const double turn_speed_slow; //= 2.0;	// degrees per second.
	static const double simulation_step; //= 0.1;	// in seconds

	double last_simulation_step_time;

	angle find_peak_lower_limit, find_peak_upper_limit;
	unsigned find_peak_try;

	bool keeps_in_find_peak_limit(angle add);
	void advance_angle_and_erase_old_contacts(double addang, angle sub_heading);
	void add_contact(angle absang, const contact& ct);

 public:
	sonar_operator();
	virtual ~sonar_operator() {}
	// only make a simulation step each n seconds, n ca. 0.1 or so, simulate
	// human reaction on events.
	virtual void simulate(class game& gm, double delta_t);
	const std::map<double, contact>& get_contacts() const { return contacts; }
	void load(const class xml_elem& parent);
	void save(class xml_elem& parent) const;
};

#endif /* SONAR_OPERATOR_H */