use std::fmt::Debug;

use crate::traits::GraphTopologyAddition;

#[doc(hidden)]
#[macro_export]
macro_rules! graph_topology_addition_tests {
    ($T:ty) => {
        $crate::graph_topology_addition_tests!(@wrap $T,
            reserve_vertices_increases_capacity,
            reserve_vertices_prevents_reallocation_on_add,
            reserve_vertices_does_not_affect_edge_capacity,
            reserve_edges_increases_capacity,
            reserve_edges_prevents_reallocation_on_add,
            reserve_edges_does_not_affect_vertex_capacity,
            add_vertex,
            add_edge,
            sync_vertex_map_after_add,
            sync_edge_map_after_add,
            sync_vertex_map_preserves_values,
            sync_edge_map_preserves_values,
        );
    };

    (@wrap $T:ty, $($name:ident),* $(,)?) => {
        $(
            #[test]
            fn $name() {
                $crate::testing::graph_topology_addition_testing::$name::<$T>();
            }
        )*
    };
}

pub fn reserve_vertices_increases_capacity<G: GraphTopologyAddition>() {
    let mut graph = G::default();
    let capacity_before = graph.vertex_capacity();
    graph.reserve_vertices(capacity_before + 10);
    assert!(
        graph.vertex_capacity() > capacity_before,
        "expected sufficient capacity increase after reserve"
    );
}

pub fn reserve_vertices_prevents_reallocation_on_add<G: GraphTopologyAddition>() {
    let mut graph = G::default();
    graph.reserve_vertices(10);
    let capacity_before = graph.vertex_capacity();
    for _ in 0..10 {
        graph.add_vertex();
    }
    assert_eq!(
        graph.vertex_capacity(),
        capacity_before,
        "writes within reserved capacity should not reallocate"
    );
}

pub fn reserve_vertices_does_not_affect_edge_capacity<G: GraphTopologyAddition>() {
    let mut graph = G::default();
    let capacity_before = graph.edge_capacity();
    graph.reserve_vertices(10);
    assert_eq!(
        graph.edge_capacity(),
        capacity_before,
        "reserve_vertices must not change edge capacity"
    );
}

pub fn reserve_edges_increases_capacity<G: GraphTopologyAddition>() {
    let mut graph = G::default();
    let capacity_before = graph.edge_capacity();
    graph.reserve_edges(capacity_before + 10);
    assert!(
        graph.edge_capacity() > capacity_before,
        "expected sufficient capacity increase after reserve"
    );
}

pub fn reserve_edges_prevents_reallocation_on_add<G: GraphTopologyAddition>() {
    let mut graph = G::default();
    let u = graph.add_vertex();
    let v = graph.add_vertex();
    graph.reserve_edges(10);
    let capacity_before = graph.edge_capacity();
    for _ in 0..10 {
        graph.add_edge(u, v);
    }
    assert_eq!(
        graph.edge_capacity(),
        capacity_before,
        "writes within reserved capacity should not reallocate"
    );
}

pub fn reserve_edges_does_not_affect_vertex_capacity<G: GraphTopologyAddition>() {
    let mut graph = G::default();
    let capacity_before = graph.vertex_capacity();
    graph.reserve_edges(10);
    assert_eq!(
        graph.vertex_capacity(),
        capacity_before,
        "reserve_edges must not change vertex capacity"
    );
}

pub fn add_vertex<G: GraphTopologyAddition>()
where
    G::Vertex: Debug,
{
    let mut graph = G::default();
    let v = graph.add_vertex();
    assert_ne!(graph.add_vertex(), v, "unexpected duplicate vertex");
}

pub fn add_edge<G: GraphTopologyAddition>()
where
    G::Edge: Debug,
{
    let mut graph = G::default();
    let u = graph.add_vertex();
    let v = graph.add_vertex();
    let e = graph.add_edge(u, v);
    assert_ne!(graph.add_edge(u, v), e, "unexpected duplicate edge");
}

pub fn sync_vertex_map_after_add<G: GraphTopologyAddition>() {
    let mut graph = G::default();
    let mut map = graph.vertex_map(27);
    let u = graph.add_vertex();
    let v = graph.add_vertex();
    graph.sync_vertex_map(&mut map);
    assert_eq!(
        map[u], 27,
        "unexpected value from default map read for new vertex"
    );
    map[u] = 9;
    assert_eq!(
        map[u], 9,
        "unexpected value from map read after write for new vertex"
    );
    assert_eq!(
        map[v], 27,
        "unexpected value from default map read for second new vertex"
    );
}

pub fn sync_edge_map_after_add<G: GraphTopologyAddition>() {
    let mut graph = G::default();
    let u = graph.add_vertex();
    let v = graph.add_vertex();
    let mut map = graph.edge_map(28);
    let e = graph.add_edge(u, v);
    let f = graph.add_edge(u, v);
    graph.sync_edge_map(&mut map);
    assert_eq!(
        map[e], 28,
        "unexpected value from default map read for new edge"
    );
    map[e] = 8;
    assert_eq!(
        map[e], 8,
        "unexpected value from map read after write for new edge"
    );
    assert_eq!(
        map[f], 28,
        "unexpected value from default map read for second new edge"
    );
}

pub fn sync_vertex_map_preserves_values<G: GraphTopologyAddition>() {
    let mut graph = G::default();
    let v = graph.add_vertex();
    let mut map = graph.vertex_map(0);
    map[v] = 5;
    graph.reserve_vertices(20);
    graph.sync_vertex_map(&mut map);
    assert_eq!(map[v], 5, "sync should not change existing map values");
}

pub fn sync_edge_map_preserves_values<G: GraphTopologyAddition>() {
    let mut graph = G::default();
    let u = graph.add_vertex();
    let v = graph.add_vertex();
    let e = graph.add_edge(u, v);
    let mut map = graph.edge_map(0);
    map[e] = 6;
    graph.reserve_edges(20);
    graph.sync_edge_map(&mut map);
    assert_eq!(map[e], 6, "sync should not change existing map values");
}