/*
   game/ship.cc
   This file is part of the Osirion project and is distributed under 
   the terms and conditions of the GNU General Public License version 2 
*/

// project headers
#include "auxiliary/functions.h"
#include "core/gameserver.h"
#include "core/entity.h"
#include "game/game.h"
#include "game/ship.h"
#include "math/mathlib.h"

// C++ headers
#include <iostream>

using math::degrees360f;
using math::degrees180f;

namespace game {

const float 		MIN_DELTA = 10e-10;

Ship::Ship(core::Player *owner, ShipModel *shipmodel) :
	core::EntityControlable(owner, ship_enttype)
{
	entity_modelname = "ships/" + shipmodel->modelname();
	entity_name = shipmodel->name() + ": <^B" + owner->name() + "^N>";
	entity_label = shipmodel->label();

	entity_moduletypeid = ship_enttype;

	current_target_direction = 0.0f;
	current_target_pitch = 0.0f;;
	current_target_roll = 0.0f;

	entity_color = owner->color();
	entity_color_second = owner->color_second();

	ship_shipmodel = shipmodel;
	ship_jumpdrive = shipmodel->shipmodel_jumpdrive;
	
	ship_jumptargetzone = 0;

	ship_impulsedrive_timer = 0;
	ship_jumpdrive_timer = 0;
}

Ship::~Ship() 
{

}

void Ship::impulse()
{
	if (entity_eventstate == core::Entity::Jump) {
		return;

	} else if ((entity_eventstate == core::Entity::Impulse) || (entity_eventstate == core::Entity::ImpulseInitiate)) {
		entity_eventstate = core::Entity::Normal;
		
	} else { 

		if (entity_eventstate == core::Entity::JumpInitiate) {
			ship_jumpdrive_timer = 0;
			ship_jumptargetzone = 0;
			entity_timer = 0;
		}
	
		entity_eventstate = core::Entity::ImpulseInitiate;
		if (Game::instance()->g_devel->value()) {
			entity_timer = 0;
		} else {
			entity_timer = 10;
		}
		ship_impulsedrive_timer = core::server()->time();
		entity_dirty = true;
	}

	entity_dirty = true;
}

void Ship::jump(std::string const &args)
{
	if (!jumpdrive() && !Game::instance()->g_devel->value()) {
		core::server()->send(owner(), "This ship is not equiped with a hyperspace drive!");
		return;

	} else 	if (entity_eventstate == core::Entity::Jump) {
		return;

	} else if (entity_eventstate == core::Entity::JumpInitiate) {
		core::server()->send(owner(), "Jump aborted, hyperspace drive deactivated.");
		ship_jumptargetzone = 0;
		ship_jumpdrive_timer = 0;
		entity_timer = 0;
		entity_eventstate = core::Entity::Normal;
		return;
	}

	std::string target;
	std::istringstream is(args);
	if (!(is >> target)) {
		std::string helpstr;
		for (core::Zone::Registry::iterator it = core::Zone::registry().begin(); it != core::Zone::registry().end(); it++) {
			core::Zone *zone = (*it).second;
			if (helpstr.size())
				helpstr.append("^N|^B");
			helpstr.append(zone->label());
		}

		core::server()->send(owner(), "Usage: jump [^B" + helpstr + "^N]");
		return;
	}

	aux::to_lowercase(target);
	ship_jumptargetzone = core::Zone::find_zone(target);
	if (!ship_jumptargetzone) {
		core::server()->send(owner(), "Unknown system '" + target + '\'');
		return;
	}

	if (ship_jumptargetzone == zone()) {
		core::server()->send(owner(), "Already in the " + ship_jumptargetzone->name() + '.');
		ship_jumptargetzone = 0;
		return;
	}

	entity_eventstate = core::Entity::JumpInitiate;
	if (Game::instance()->g_devel->value()) {
		entity_timer = 0;
	} else {
		entity_timer = 10;
	}
	ship_jumpdrive_timer = core::server()->time();
	entity_dirty = true;
}

void Ship::frame(float seconds) 
{
	const float direction_change_speed = 2;
	float cosangle;		// cosine of an angle
	float angle;		// angle in radians	
	math::Vector3f n;	// normal of a plane

	float actual_maxspeed = ship_shipmodel->maxspeed();
	float actual_turnspeed = ship_shipmodel->turnspeed();
	float actual_acceleration = ship_shipmodel->acceleration();

	// speed might get set to 0 on this update
	if (entity_speed != 0.0f)
		entity_dirty = true;

	// jumpdrive
	// target axis
	math::Axis target_axis(entity_axis);

	if (entity_eventstate == core::Entity::JumpInitiate) {

		if (ship_jumpdrive_timer + 1.0f <= core::server()->time()) {
			entity_timer -= 1.0f;

			if (entity_timer <= 0) {
				core::server()->send(owner(), "Jumping to '" + ship_jumptargetzone->name() + '\'');
				set_zone(ship_jumptargetzone);
				if (owner()->control() == (EntityControlable*) this)
					owner()->set_zone(ship_jumptargetzone);
				ship_jumpdrive_timer = 0;
				ship_jumptargetzone = 0;
				entity_timer = 0;
				entity_eventstate = core::Entity::Jump;
				entity_dirty = true;
				return;
			} else {
				ship_jumpdrive_timer = core::server()->time();
				entity_dirty = true;
			}
		}

		// control is disabled while the jumpdrive is activated
		target_thrust = 0;
		target_pitch = 0;
		target_roll = 0;
		target_direction = 0;

	} else if (entity_eventstate == core::Entity::Jump) {
		// FIXME jump location and axis		
		math::Axis default_axis;
		entity_axis.assign(default_axis);
		entity_dirty = true;

		// FIXME 5 second cooldown
		entity_eventstate =  core::Entity::Normal;

	} else if  (entity_eventstate == core::Entity::ImpulseInitiate) {

		if (ship_impulsedrive_timer + 1.0f <= core::server()->time()) {
			entity_timer -= 1.0f;

			if (entity_timer <= 0) {
				actual_maxspeed = Game::instance()->g_impulsespeed->value();
				actual_acceleration = Game::instance()->g_impulseacceleration->value();
				entity_eventstate = core::Entity::Impulse;
				entity_timer = 0;
				entity_dirty = true;
			} else {
				ship_impulsedrive_timer = core::server()->time();
				entity_dirty = true;
			}
		}

		// clamp input values
		target_thrust = 1.0f;
		math::clamp(target_pitch, -1.0f, 1.0f);
		math::clamp(target_roll, -1.0f, 1.0f);
		math::clamp(target_direction, -1.0f, 1.0f);

		actual_turnspeed *= 0.5;

	} else if (entity_eventstate == core::Entity::Impulse) {

		// clamp input values
		target_thrust = 1.0f;
		math::clamp(target_pitch, -1.0f, 1.0f);
		math::clamp(target_roll, -1.0f, 1.0f);
		math::clamp(target_direction, -1.0f, 1.0f);

		actual_maxspeed = Game::instance()->g_impulsespeed->value();
		actual_acceleration = Game::instance()->g_impulseacceleration->value();
		actual_turnspeed *= 0.5;

	} else if (entity_eventstate == core::Entity::Normal) {

		// clamp input values
		math::clamp(target_thrust, 0.0f, 1.0f);
		math::clamp(target_pitch, -1.0f, 1.0f);
		math::clamp(target_roll, -1.0f, 1.0f);
		math::clamp(target_direction, -1.0f, 1.0f);

		if (speed() > actual_maxspeed) {
			actual_acceleration = Game::instance()->g_impulseacceleration->value();
			actual_turnspeed *= 0.5;
		}

	}

	// update thrust
	if (entity_thrust < target_thrust) {
		entity_thrust += seconds  * 0.5f;
		if (entity_thrust > target_thrust)
			entity_thrust = target_thrust;
	} else if (entity_thrust > target_thrust) {
		entity_thrust -= seconds * 0.5f;
		if (entity_thrust < target_thrust)
			entity_thrust = target_thrust;
	}
	//math::clamp(entity_thrust, 0.0f, 1.0f);

	// update roll
	if (current_target_roll < target_roll) {
		current_target_roll += direction_change_speed * seconds;
		if (current_target_roll > target_roll)
			current_target_roll = target_roll;
	} else if (current_target_roll > target_roll) {
		current_target_roll -= direction_change_speed * seconds;
		if (current_target_roll < target_roll)
			current_target_roll = target_roll;
	}
	math::clamp(current_target_roll, -1.0f, 1.0f);

	if (fabs(current_target_roll) > MIN_DELTA) {	
		float roll_offset = seconds * current_target_roll;
		entity_axis.change_roll(actual_turnspeed * roll_offset);
	} else {
		current_target_roll = 0.0f;
	}

	// update target_axis direction	
	if (current_target_direction < target_direction) {
		current_target_direction += direction_change_speed * seconds;
		if (current_target_direction > target_direction) {
			current_target_direction = target_direction;
		}
	} else if (current_target_direction > target_direction) {
		current_target_direction -= direction_change_speed * seconds;
		if (current_target_direction < target_direction) {
			current_target_direction = target_direction;
		}
	}

	if (fabs(current_target_direction) > MIN_DELTA ) {
		math::clamp(current_target_direction, -1.0f, 1.0f);
		target_axis.change_direction(actual_turnspeed * current_target_direction);
	} else {
		current_target_direction = 0.0f;
	}

	if (current_target_pitch < target_pitch) {
		current_target_pitch += direction_change_speed * seconds;
		if (current_target_pitch > target_pitch)
			current_target_pitch = target_pitch;
	} else if (current_target_pitch > target_pitch) {
		current_target_pitch -= direction_change_speed * seconds;
		if (current_target_pitch < target_pitch)
			current_target_pitch = target_pitch;
	}
	
	if (fabs(current_target_pitch) > MIN_DELTA) {
		math::clamp(current_target_pitch, -1.0f, 1.0f);
		target_axis.change_pitch(actual_turnspeed * current_target_pitch);
	} else {
		current_target_pitch = 0.0f;
	}

	n.assign(math::crossproduct(entity_axis.forward(), target_axis.forward()));
	if (!(n.length() < MIN_DELTA)) {
		n.normalize();
		cosangle = math::dotproduct(entity_axis.forward(), target_axis.forward());
		angle = acos(cosangle) * seconds; // * 180.0f / M_PI;
		if (angle > MIN_DELTA)
			entity_axis.rotate(n, -angle);
	}

	// update speed
	if (entity_speed < entity_thrust * actual_maxspeed) {
		entity_speed += actual_acceleration * seconds;
		if (entity_speed > entity_thrust * actual_maxspeed) {
			entity_speed = entity_thrust * actual_maxspeed;
		}
	} else if(entity_speed > entity_thrust * actual_maxspeed) {
		entity_speed -= actual_acceleration * seconds;
		if (entity_speed < 0.0f) entity_speed = 0.0f;
	}

	if (entity_speed != 0.0f) {
		entity_location += entity_axis.forward() * entity_speed * seconds;
		entity_dirty = true;
	} else if ((current_target_pitch != 0.0f) || (current_target_direction != 0.0f) || (current_target_roll != 0.0f)) {
		entity_dirty = true;
	}
}

} // namespace game