#include <iostream>
#include <cstdlib>   //for rand and exit functions
#include "rabbit.h"
using namespace std;

rabbit::rabbit(const terminal& init_t, unsigned init_x, unsigned init_y)
    : t {&init_t}, x {init_x}, y {init_y}, c {'r'}
{
    if (!t->in_range(x, y)) {
        cerr << "Initial rabbit 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 rabbit position (" << x << ", " << y
             << ") already occupied by '" << other << "'.\n";
        exit(EXIT_FAILURE);
    }

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

    t->put(x, y, c);
}

rabbit::~rabbit() {
    t->beep();  // Beep the terminal
    t->wait(1000);  // Pause for one second
    if (t->get(x, y) == c) {
        t->put(x, y);  // Erase the rabbit
    }
    cout << "Rabbit has died." << endl;
}

bool rabbit::move()
{
    const int dx {rand() % 3 - 1};
    const int dy {rand() % 3 - 1};

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

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

    if (!t->in_range(newx, newy)) {
        return true;   // Can't move off the screen.
    }

    const char other {t->get(newx, newy)};

    if (other != t->background()) {
        if (other == c) {
            return true; // Rabbit collided with another rabbit.
        } else {
            return false; // Rabbit was eaten.
        }
    }

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

    return true;
}