#include <iostream>
#include <cstdlib>    //for exit function
#include "wolf.h"
#include "rabbit.h"   //for lines 66-68
using namespace std;

//const char wolf::c = 'W';   //not needed if line 8 of wolf.h has = 'W'

wolf::wolf(const game *initial_g, unsigned initial_x, unsigned initial_y)
	: g(initial_g), x(initial_x), y(initial_y)
{
	if (c == g->term.background()) {
		cerr << "Wolf character '" << c << "' can't be the same as "
			"the terminal's background character.\n";
		exit(EXIT_FAILURE);
	}

	if (!g->term.in_range(x, y)) {
		cerr << "wolf out of range: (" << x << ", " << y << ")\n";
		exit(EXIT_FAILURE);
	}

	while (g->term.get(x, y) != g->term.background()) {
		g->term.next(x, y);
		if (!g->term.in_range(x, y)) {
			cerr << "No free space for wolf.\n";
			exit(EXIT_FAILURE);
		}
	}

	g->term.put(x, y, c);
}

wolf::~wolf()
{
	g->term.beep();
	g->term.put(x, y);
}

void wolf::move()
{
	struct keystroke {
		char c;
		int dx;   //horizontal motion
		int dy;   //vertical motion
	};

	static const keystroke a[] = {
		{'h',   -1,    0},   //left
		{'j',    0,    1},   //down
		{'k',    0,   -1},   //up
		{'l',    1,    0}    //right
	};
	static const size_t n = sizeof a / sizeof a[0];

	if (const char k = g->term.key()) {
		for (const keystroke *p = a; p < a + n; ++p) {
			if (k == p->c) {
				const unsigned newx = x + p->dx;
				const unsigned newy = y + p->dy;

				if (!g->term.in_range(newx, newy)) {
					break;   //Go to line 80.
				}

				if (rabbit *const other = g->get(newx, newy)) {
					delete other;
				}

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

				return;
			}
		}

		//Punish user who pressed illegal key or tried to move off screen.
		g->term.beep();
	}
}