#include <iostream>
#include <cstdlib>   //for the exit function
#include "wabbit.h"
using namespace std;

//Definition of static data member.
list<wabbit *> wabbit::master;

wabbit::wabbit(const terminal& init_t, unsigned init_x, unsigned init_y,
	char init_c):
	t {&init_t}, x {init_x}, y {init_y}, c {init_c}
{

	if (!t->in_range(x, y)) {
		cerr << "Initial wabbit position (" << x << ", " << y
			<< ") off " << t->xmax() << " by " << t->ymax()
			<< " terminal.\n";
		exit(EXIT_FAILURE);
	}

	const char other {t->get(x, y)};
	const char background {t->background()};

	if (other != background) {
		cerr << "Initial wabbit position (" << x << ", " << y
			<< ") already occupied by '" << other << "'.\n";
		exit(EXIT_FAILURE);
	}

	if (c == background) {
		cerr << "wabbit character '" << c << "' can't be the same as "
			"the terminal's background character.\n";
		exit(EXIT_FAILURE);
	}

	t->put(x, y, c);
	master.push_back(this);
}

wabbit::~wabbit()
{
	master.remove(this);
	t->beep();
	t->wait(1000);   //Dying wabbit stands frozen in the headlights.

	if (t->get(x, y) == c) {  //If no other animal is here,
		t->put(x, y);     //draw the terminal's background character.
	}
}

bool wabbit::move()
{
	int dx {0};
	int dy {0};
	decide(&dx, &dy);    //Put new values into dx and dy.

	if (dx == 0 && dy == 0) {
		return true; //This wabbit decided not to move.
	}

	const unsigned newx {x + dx};
	const unsigned newy {y + dy};

	if (!t->in_range(newx, newy)) {
		punish();
		return true;
	}

	if (wabbit *const other {wabbit::get(newx, newy)}) {
		const bool I_ate_him { this->hungry() > other->bitter()};
		const bool he_ate_me {other->hungry() >  this->bitter()};

		if (I_ate_him) {
			//Call the other's destructor,
			//which removes the other from the master list.
			delete other;
		}

		if (he_ate_me) {
			return false;   //not allowed to delete myself
		}

		if (!I_ate_him) {
			//I bumped into a wabbit that I could neither eat nor be
			//eaten by.
			punish();
			return true;
		}
	}

	t->put(x, y);      //Erase this wabbit from its old location.
	x = newx;
	y = newy;
	t->put(x, y, c);   //Redraw this wabbit at its new location.

	return true;
}

//Return a pointer to the wabbit at the specified coordinates.

wabbit *wabbit::get(unsigned x, unsigned y)
{
	for (auto& p: master) {
		if (p->x == x && p->y == y) {
			return p;
		}
	}

	return nullptr;  //No such wabbit.
}