const io = @import("io.zig");
const Cursor = @import("cursor.zig").Self;
const Map = @import("map.zig");
neck: Map,
head: Cursor,
tail: Cursor,
const Self = @This();
pub fn init(start: Cursor) Self {
    return .{
        .head = start,
        .tail = start,
        .neck = .{},
    };
}
pub fn pushdir(self: *Self, dir: u2) void {
    self.neck.store(self.head, dir);
    self.head.dir = dir ^ 2;
}
pub fn popdir(self: *Self) void {
    self.neck.load(&self.tail);
    self.neck.zero(self.tail);
}
pub fn collide(self: Self) bool {
    return self.head.mask() & self.neck.blank() == 0;
}
pub fn empty(self:Self) u64 {
    return self.neck.blank() & ~self.head.mask();
}
//todo
pub fn print() void {
    unreachable;
}

const cursor = @import("cursor.zig");

const Snake = @import("snake.zig");

var map = @import("map.zig"){};

var snake: Snake = undefined;

var head = cursor.init(0o40);
var tail = cursor.init(0o40);

    snake = Snake.init(.{ .pos = 0o40, .dir = 2 });

        io.print(head.pos, "<^>V"[head.dir]);

        io.print(snake.head.pos, "<^>V"[snake.head.dir]);

        const newdir = io.scandir(head.dir);
        io.print(head.pos, " lqml kxqk jmxj"[4 * @as(u4, newdir) + head.dir]);
        //push
        map.store(head, newdir);
        head.dir = newdir ^ 2;
        head.move() orelse break;

        const newdir = io.scandir(snake.head.dir);
        io.print(snake.head.pos, " lqml kxqk jmxj"[4 * @as(u4, newdir) + snake.head.dir]);

        if (head.pos != fruit.pos) {
            //pop
            map.load(&tail);
            map.zero(tail);

        snake.pushdir(newdir);
	snake.head.move() orelse break;
        if (snake.head.pos != fruit.pos) {
            snake.popdir();

            if (head.mask() & map.blank() == 0)

            if (snake.collide())

            io.print(tail.pos, ' ');
            tail.move() orelse unreachable;

            io.print(snake.tail.pos, ' ');
            snake.tail.move() orelse unreachable;

    fruit.newfruit(map.blank() ^ cursor.mask(head)) orelse return null;

    fruit.newfruit(snake.empty()) orelse return null;