pub const SECONDS_PER_DAY: i32 = 86_400;
pub const WEEKDAYS: i32 = 7;
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct ShopCycle {
    pub seed: i32,
    pub weekday_index: i32,
    pub seconds_to_cycle: i32,
}
impl ShopCycle {
    pub fn at(timestamp: i32) -> Self {
        let day = timestamp.div_euclid(SECONDS_PER_DAY);
        let seconds_into_day = timestamp.rem_euclid(SECONDS_PER_DAY);
        Self {
            seed: day.wrapping_mul(2_654_435_761u32 as i32) | 1,
            weekday_index: day.rem_euclid(WEEKDAYS) + 1,
            seconds_to_cycle: SECONDS_PER_DAY - seconds_into_day,
        }
    }
}