fn_registry/cpp/tests/test_graph_labels.cpp

// Unit tests para graph_labels (issue 0049j). Cubre la logica pura de
// seleccion (graph_labels_select) y graph_compute_degrees:
//   - culling por viewport (AABB)
//   - cap por max_visible
//   - min_node_pixel_size
//   - always_for_selected requiere estar en viewport
//   - empty graph no-op
//
// La parte de pintado (graph_labels_draw / graph_labels_draw_at) usa ImGui y
// se ejercita visualmente en primitives_gallery.

#define CATCH_CONFIG_MAIN
#include "catch_amalgamated.hpp"

#include "viz/graph_labels.h"
#include "viz/graph_types.h"

#include <vector>

namespace {

// Helper: construye un GraphData con N nodos en una rejilla de world coords
// donde el nodo i esta en (i*step, 0). Tamaño base = 5 px.
struct GridGraph {
    std::vector<GraphNode> nodes;
    std::vector<GraphEdge> edges;
    GraphData data{};

    void make(int N, float step = 10.0f, float size = 5.0f) {
        nodes.clear();
        edges.clear();
        for (int i = 0; i < N; ++i) {
            GraphNode n = graph_node((float)i * step, 0.0f);
            n.size_override = size;
            nodes.push_back(n);
        }
        sync();
    }

    void add_edge(uint32_t s, uint32_t t) {
        edges.push_back(graph_edge(s, t));
        sync();
    }

    void sync() {
        data.nodes = nodes.data();
        data.node_count = (int)nodes.size();
        data.node_capacity = (int)nodes.capacity();
        data.edges = edges.data();
        data.edge_count = (int)edges.size();
        data.edge_capacity = (int)edges.capacity();
        data.types = nullptr; data.type_count = 0;
        data.rel_types = nullptr; data.rel_type_count = 0;
    }
};

} // namespace

TEST_CASE("graph_compute_degrees counts incident edges", "[viz][labels][degrees]") {
    GridGraph g; g.make(4);
    g.add_edge(0, 1);
    g.add_edge(0, 2);
    g.add_edge(1, 2);

    int deg[4];
    graph::graph_compute_degrees(g.data, deg);
    REQUIRE(deg[0] == 2);
    REQUIRE(deg[1] == 2);
    REQUIRE(deg[2] == 2);
    REQUIRE(deg[3] == 0);
}

TEST_CASE("graph_compute_degrees skips invisible edges", "[viz][labels][degrees]") {
    GridGraph g; g.make(3);
    g.add_edge(0, 1);
    g.add_edge(0, 2);
    g.edges[0].flags &= ~EF_VISIBLE; // hide first edge

    int deg[3];
    graph::graph_compute_degrees(g.data, deg);
    REQUIRE(deg[0] == 1);
    REQUIRE(deg[1] == 0);
    REQUIRE(deg[2] == 1);
}

TEST_CASE("graph_labels_select respects max_visible cap", "[viz][labels][select]") {
    // 100 nodos en linea, todos en viewport, todos por encima de min_pixel.
    GridGraph g; g.make(100, 10.0f, 5.0f);

    graph::LabelPolicy p;
    p.max_visible          = 7;
    p.always_for_selected  = false;
    p.always_for_hovered   = false;
    p.always_for_pinned    = false;
    p.min_node_pixel_size  = 0.0f; // no cull por tamano

    int out[200];
    // Camara centrada en x=500 (medio de la linea), zoom 5 (5 px / world unit)
    // widget enorme para que todos esten en viewport.
    int n = graph::graph_labels_select(g.data, p,
                                        /*cam_x=*/500.0f, /*cam_y=*/0.0f,
                                        /*zoom=*/5.0f,
                                        /*w=*/100000.0f, /*h=*/100000.0f,
                                        /*degrees=*/nullptr,
                                        out, 200);
    REQUIRE(n == 7);
}

TEST_CASE("graph_labels_select skips nodes off-viewport", "[viz][labels][select]") {
    // 20 nodos en x = 0..190. Camara en x=0, zoom=1, widget 100x100.
    // Visible AABB = x in [-50, 50], y in [-50, 50].
    // Nodos visibles: i*10 in [-50,50] -> i in [0..5].
    GridGraph g; g.make(20, 10.0f, 5.0f);

    graph::LabelPolicy p;
    p.max_visible         = 100;
    p.min_node_pixel_size = 0.0f;
    p.always_for_selected = false;
    p.always_for_hovered  = false;

    int out[100];
    int n = graph::graph_labels_select(g.data, p,
                                        0.0f, 0.0f, 1.0f,
                                        100.0f, 100.0f,
                                        nullptr, out, 100);
    REQUIRE(n == 6); // i = 0..5
}

TEST_CASE("graph_labels_select drops nodes below min_node_pixel_size",
          "[viz][labels][select]") {
    // Nodos de tamano 1 world unit. zoom=1 -> 1 px en pantalla.
    // min_node_pixel_size=12 -> ninguno pasa el filtro top-N.
    GridGraph g; g.make(10, 5.0f, 1.0f);

    graph::LabelPolicy p;
    p.max_visible         = 100;
    p.min_node_pixel_size = 12.0f;
    p.always_for_selected = false;
    p.always_for_hovered  = false;

    int out[100];
    int n = graph::graph_labels_select(g.data, p,
                                        25.0f, 0.0f, 1.0f,
                                        1000.0f, 1000.0f,
                                        nullptr, out, 100);
    REQUIRE(n == 0);
}

TEST_CASE("graph_labels_select always_for_selected: in-viewport on, off-viewport off",
          "[viz][labels][select][selected]") {
    GridGraph g; g.make(20, 10.0f, 1.0f);
    // Nodo 0 (x=0, dentro del viewport) seleccionado y nodo 19 (x=190,
    // fuera) seleccionado. Solo el primero debe entrar en out.
    g.nodes[0].flags  |= NF_SELECTED;
    g.nodes[19].flags |= NF_SELECTED;
    g.sync();

    graph::LabelPolicy p;
    p.max_visible         = 0; // solo always_*
    p.min_node_pixel_size = 999.0f; // cualquier top-N descartado
    p.always_for_selected = true;
    p.always_for_hovered  = false;
    p.always_for_pinned   = false;

    int out[10];
    // viewport AABB en cam=0, zoom=1, w=h=100 -> x in [-50,50]
    int n = graph::graph_labels_select(g.data, p,
                                        0.0f, 0.0f, 1.0f,
                                        100.0f, 100.0f,
                                        nullptr, out, 10);
    REQUIRE(n == 1);
    REQUIRE(out[0] == 0);
}

TEST_CASE("graph_labels_select always_* skip min_pixel_size",
          "[viz][labels][select][selected]") {
    // Nodos de 1 px world. Sin always_*, max_visible=100, min_pixel=12 -> 0.
    // Con always_for_hovered y un nodo HOVERED en viewport, debe dibujarse
    // el HOVERED a pesar de ser pequenio.
    GridGraph g; g.make(5, 5.0f, 1.0f);
    g.nodes[0].flags |= NF_HOVERED;
    g.sync();

    graph::LabelPolicy p;
    p.max_visible         = 100;
    p.min_node_pixel_size = 12.0f;
    p.always_for_selected = false;
    p.always_for_hovered  = true;
    p.always_for_pinned   = false;

    int out[10];
    int n = graph::graph_labels_select(g.data, p,
                                        10.0f, 0.0f, 1.0f,
                                        1000.0f, 1000.0f,
                                        nullptr, out, 10);
    REQUIRE(n == 1);
    REQUIRE(out[0] == 0);
}

TEST_CASE("graph_labels_select max_visible=0 + always returns only always",
          "[viz][labels][select]") {
    GridGraph g; g.make(10, 5.0f, 5.0f);
    g.nodes[3].flags |= NF_PINNED;
    g.sync();

    graph::LabelPolicy p;
    p.max_visible         = 0;
    p.min_node_pixel_size = 0.0f;
    p.always_for_selected = false;
    p.always_for_hovered  = false;
    p.always_for_pinned   = true;

    int out[10];
    int n = graph::graph_labels_select(g.data, p,
                                        25.0f, 0.0f, 1.0f,
                                        1000.0f, 1000.0f,
                                        nullptr, out, 10);
    REQUIRE(n == 1);
    REQUIRE(out[0] == 3);
}

TEST_CASE("graph_labels_select picks top-N by size*degree", "[viz][labels][select][topn]") {
    // 5 nodos, todos en viewport. Tamano uniforme. Damos al nodo 2 mas grado
    // (3 aristas) — debe entrar primero en top-N=1.
    GridGraph g; g.make(5, 5.0f, 5.0f);
    g.add_edge(2, 0);
    g.add_edge(2, 1);
    g.add_edge(2, 3);

    int deg[5];
    graph::graph_compute_degrees(g.data, deg);

    graph::LabelPolicy p;
    p.max_visible         = 1;
    p.min_node_pixel_size = 0.0f;
    p.always_for_selected = false;
    p.always_for_hovered  = false;

    int out[5];
    int n = graph::graph_labels_select(g.data, p,
                                        10.0f, 0.0f, 1.0f,
                                        1000.0f, 1000.0f,
                                        deg, out, 5);
    REQUIRE(n == 1);
    REQUIRE(out[0] == 2);
}

TEST_CASE("graph_labels_select skips NF_VISIBLE=0 nodes", "[viz][labels][select]") {
    GridGraph g; g.make(5, 5.0f, 5.0f);
    g.nodes[2].flags &= ~NF_VISIBLE;
    g.sync();

    graph::LabelPolicy p;
    p.max_visible         = 100;
    p.min_node_pixel_size = 0.0f;
    p.always_for_selected = false;
    p.always_for_hovered  = false;

    int out[10];
    int n = graph::graph_labels_select(g.data, p,
                                        10.0f, 0.0f, 1.0f,
                                        1000.0f, 1000.0f,
                                        nullptr, out, 10);
    REQUIRE(n == 4);
    for (int k = 0; k < n; ++k) REQUIRE(out[k] != 2);
}

TEST_CASE("graph_labels_select empty graph no-op", "[viz][labels][select][empty]") {
    GridGraph g; g.make(0);
    graph::LabelPolicy p;
    int out[10];
    int n = graph::graph_labels_select(g.data, p,
                                        0.0f, 0.0f, 1.0f,
                                        100.0f, 100.0f,
                                        nullptr, out, 10);
    REQUIRE(n == 0);
}

TEST_CASE("graph_labels_select degenerate inputs return 0", "[viz][labels][select][edge]") {
    GridGraph g; g.make(5);
    graph::LabelPolicy p;
    int out[10];

    // zoom <= 0
    REQUIRE(graph::graph_labels_select(g.data, p, 0,0, 0.0f, 100,100, nullptr, out, 10) == 0);
    REQUIRE(graph::graph_labels_select(g.data, p, 0,0, -1.0f, 100,100, nullptr, out, 10) == 0);
    // widget invalido
    REQUIRE(graph::graph_labels_select(g.data, p, 0,0, 1.0f, 0.0f, 100, nullptr, out, 10) == 0);
    REQUIRE(graph::graph_labels_select(g.data, p, 0,0, 1.0f, 100, 0.0f, nullptr, out, 10) == 0);
    // out_capacity 0
    REQUIRE(graph::graph_labels_select(g.data, p, 0,0, 1.0f, 100,100, nullptr, out, 0) == 0);
    // out null
    REQUIRE(graph::graph_labels_select(g.data, p, 0,0, 1.0f, 100,100, nullptr, nullptr, 10) == 0);
}