use client_domain::ScrollState;
use std::time::Duration;

#[test]
fn no_overflow_means_zero_offset() {
    let scroll = ScrollState::new(100, 80);
    assert_eq!(scroll.offset(), 0);
    assert!(!scroll.is_active());
}

#[test]
fn overflow_starts_at_zero_offset() {
    let scroll = ScrollState::new(100, 200);
    assert_eq!(scroll.offset(), 0);
    assert!(scroll.is_active());
}

#[test]
fn tick_advances_offset_after_initial_pause() {
    let mut scroll = ScrollState::new(100, 200);
    // Overflow = 100px. Initial pause = 2s.
    // Tick past the pause
    assert!(scroll.tick(Duration::from_secs(3)));
    assert!(scroll.offset() > 0);
}

#[test]
fn tick_returns_false_when_no_movement() {
    let mut scroll = ScrollState::new(100, 80);
    assert!(!scroll.tick(Duration::from_millis(100)));
}

#[test]
fn offset_never_exceeds_overflow() {
    let mut scroll = ScrollState::new(100, 200);
    // Tick many times — offset should cap at overflow (100)
    for _ in 0..1000 {
        scroll.tick(Duration::from_millis(100));
    }
    assert!(scroll.offset() <= 100);
}

#[test]
fn bounces_back_after_reaching_end() {
    let mut scroll = ScrollState::new(100, 150);
    // Overflow = 50px. Tick until we reach the end and bounce back.
    // After enough ticks, offset should return to 0.
    let mut seen_nonzero = false;
    let mut returned_to_zero = false;
    for _ in 0..2000 {
        scroll.tick(Duration::from_millis(50));
        if scroll.offset() > 0 {
            seen_nonzero = true;
        }
        if seen_nonzero && scroll.offset() == 0 {
            returned_to_zero = true;
            break;
        }
    }
    assert!(seen_nonzero, "should have scrolled");
    assert!(returned_to_zero, "should have bounced back to 0");
}

#[test]
fn reset_restarts_scroll() {
    let mut scroll = ScrollState::new(100, 200);
    for _ in 0..100 {
        scroll.tick(Duration::from_millis(100));
    }
    scroll.reset(100, 200);
    assert_eq!(scroll.offset(), 0);
}