//! Pass conditions for RUST.md's I4, exercised the same way
//! `layout_tests.rs` exercises LAYOUT.md's: `AccessTree` only touches
//! `Widgets`/`UiRenderState`, neither of which needs a GPU or a window, so
//! it can be driven directly against `layout_tests::TestRsc`.

use crate::layout_tests::TestRsc;
use crate::prelude::*;

#[test]
fn a_named_widget_reaches_the_tree_with_its_role_and_bounds() {
    let mut rsc = TestRsc {
        ui: UiData::default(),
    };
    let leaf: WeakWidget<Rect> = rect(UiColor::WHITE).label("Add task").add(&mut rsc);
    let root = leaf.upgrade(&mut rsc).any();
    let mut render = UiRenderState::new();
    render.resize((800.0, 600.0));
    render.update(&root, &mut rsc);

    let mut access = AccessTree::new();
    let update = access
        .update(rsc.widgets(), &render, &rsc)
        .expect("a first draw with a named widget must produce a tree");

    // One node for the widget, one for the synthetic window root.
    assert_eq!(update.nodes.len(), 2);
    let (_, node) = update
        .nodes
        .iter()
        .find(|(_, n)| n.role() != accesskit::Role::Window)
        .expect("the named widget's own node");
    assert_eq!(node.label(), Some("Add task"));
    assert_eq!(node.role(), accesskit::Role::Unknown);
    let bounds = node.bounds().expect("a drawn widget reports its bounds");
    let region = render
        .window_region(&leaf, &rsc)
        .expect("the widget is active after render.update");
    assert_eq!(bounds.x0, region.top_left.x as f64);
    assert_eq!(bounds.y0, region.top_left.y as f64);
    assert_eq!(bounds.x1, region.bot_right.x as f64);
    assert_eq!(bounds.y1, region.bot_right.y as f64);
}

#[test]
fn a_widget_with_no_label_never_reaches_the_tree() {
    let mut rsc = TestRsc {
        ui: UiData::default(),
    };
    let root = rsc.ui.widgets.add_strong(rect(UiColor::WHITE));
    let mut render = UiRenderState::new();
    render.resize((800.0, 600.0));
    render.update(&root.any(), &mut rsc);

    let mut access = AccessTree::new();
    assert!(
        access.update(rsc.widgets(), &render, &rsc).is_none(),
        "no widget was ever `.label()`ed, so there is nothing to report -- \
         not even an empty tree change"
    );
}

/// LAYOUT.md's "a moved subtree" lesson applies here too: `resolved_region`
/// (which `window_region` sits on) walks the move-offset chain, so a
/// widget moved via `Offset` -- not redrawn from scratch -- must still
/// report where it actually ended up.
#[test]
fn bounds_follow_a_moved_widget_and_updates_stay_incremental() {
    let mut rsc = TestRsc {
        ui: UiData::default(),
    };
    let leaf: WeakWidget<Rect> = rect(UiColor::WHITE).label("thing").add(&mut rsc);
    let leaf_strong = leaf.upgrade(&mut rsc).any();
    let offset = rsc.ui.widgets.add_strong(Offset {
        inner: leaf_strong,
        amt: UiVec2::ZERO,
    });
    let offset_id = offset.weak();
    let root = offset.any();
    let mut render = UiRenderState::new();
    render.resize((800.0, 600.0));
    render.update(&root, &mut rsc);

    let mut access = AccessTree::new();
    access
        .update(rsc.widgets(), &render, &rsc)
        .expect("the first draw is always a change");
    assert_eq!(access.take_rebuilds(), 1);

    // Unchanged frame: nothing moved, nothing renamed -- `update` must
    // report no change, and the rebuild counter (I4's twin of
    // `take_counters`) must stay at 0.
    render.update(&root, &mut rsc);
    assert!(access.update(rsc.widgets(), &render, &rsc).is_none());
    assert_eq!(access.take_rebuilds(), 0);

    // Move the child via `Offset` (a move-offset write, not necessarily a
    // full redraw of the leaf -- see `resolve_move_chain`) and confirm the
    // reported bounds shifted by exactly that amount, in exactly one more
    // rebuild.
    let before = render
        .window_region(&leaf, &rsc)
        .expect("active before the move");
    rsc.ui.widgets.get_mut(&offset_id).unwrap().amt = UiVec2::abs(Vec2::new(50.0, 0.0));
    render.update(&root, &mut rsc);
    let update = access
        .update(rsc.widgets(), &render, &rsc)
        .expect("a moved named widget is a change");
    assert_eq!(access.take_rebuilds(), 1);

    let after = render
        .window_region(&leaf, &rsc)
        .expect("still active after the move");
    // Not asserting the exact delta: `Offset`'s own `amt` -> pixel mapping
    // is that widget's business, not this tree's. What I4 owns is that
    // `AccessTree` reports whatever `window_region` says *now* -- so the
    // node must have moved, and in the direction the offset moved it.
    assert!(
        after.top_left.x > before.top_left.x,
        "the leaf's reported bounds must move right along with its offset"
    );

    let (_, node) = update
        .nodes
        .iter()
        .find(|(_, n)| n.role() != accesskit::Role::Window)
        .unwrap();
    let bounds = node.bounds().unwrap();
    assert_eq!(bounds.x0, after.top_left.x as f64);
}