use client_domain::{BoundingBox, LayoutEngine};
use domain::{ContainerNode, Direction, LayoutChild, LayoutNode, Sizing};

fn screen() -> BoundingBox {
    BoundingBox::screen(240, 320)
}

#[test]
fn diff_detects_moved_widget_after_layout_change() {
    let layout_a = LayoutNode::Container(ContainerNode {
        direction: Direction::Row,
        gap: 0,
        padding: 0,
        children: vec![
            LayoutChild {
                sizing: Sizing::Flex(1),
                node: LayoutNode::Leaf(1),
            },
            LayoutChild {
                sizing: Sizing::Flex(1),
                node: LayoutNode::Leaf(2),
            },
        ],
    });

    let layout_b = LayoutNode::Container(ContainerNode {
        direction: Direction::Column,
        gap: 0,
        padding: 0,
        children: vec![
            LayoutChild {
                sizing: Sizing::Flex(1),
                node: LayoutNode::Leaf(1),
            },
            LayoutChild {
                sizing: Sizing::Flex(1),
                node: LayoutNode::Leaf(2),
            },
        ],
    });

    let tree_a = LayoutEngine::compute(&layout_a, screen());
    let tree_b = LayoutEngine::compute(&layout_b, screen());

    let mut changed = tree_b.diff(&tree_a);
    changed.sort();
    assert_eq!(changed, vec![1, 2]);
}

#[test]
fn diff_returns_empty_for_identical_layouts() {
    let layout = LayoutNode::Container(ContainerNode {
        direction: Direction::Row,
        gap: 0,
        padding: 0,
        children: vec![
            LayoutChild {
                sizing: Sizing::Flex(1),
                node: LayoutNode::Leaf(1),
            },
            LayoutChild {
                sizing: Sizing::Flex(1),
                node: LayoutNode::Leaf(2),
            },
        ],
    });

    let tree_a = LayoutEngine::compute(&layout, screen());
    let tree_b = LayoutEngine::compute(&layout, screen());

    assert!(tree_b.diff(&tree_a).is_empty());
}

#[test]
fn diff_detects_added_and_removed_widgets() {
    let layout_a = LayoutNode::Container(ContainerNode {
        direction: Direction::Row,
        gap: 0,
        padding: 0,
        children: vec![LayoutChild {
            sizing: Sizing::Flex(1),
            node: LayoutNode::Leaf(1),
        }],
    });

    let layout_b = LayoutNode::Container(ContainerNode {
        direction: Direction::Row,
        gap: 0,
        padding: 0,
        children: vec![LayoutChild {
            sizing: Sizing::Flex(1),
            node: LayoutNode::Leaf(2),
        }],
    });

    let tree_a = LayoutEngine::compute(&layout_a, screen());
    let tree_b = LayoutEngine::compute(&layout_b, screen());

    let mut changed = tree_b.diff(&tree_a);
    changed.sort();
    // widget 1 was removed (in old but not new), widget 2 was added (in new but not old)
    assert_eq!(changed, vec![1, 2]);
}