// Helpers de multi-seleccion del viewport (issue 0049i). Logica pura sobre
// GraphData + GraphViewportState — sin ImGui ni OpenGL. Vive en su propio TU
// para que los tests unitarios puedan ejercerla sin pintar nada.

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

#include <algorithm>

void graph_viewport_clear_selection(GraphData& graph, GraphViewportState& state) {
    for (int idx : state.selection) {
        if (idx >= 0 && idx < graph.node_count) {
            graph.nodes[idx].flags &= ~NF_SELECTED;
        }
    }
    state.selection.clear();
    state.selected_node = -1;
}

bool graph_viewport_is_selected(const GraphViewportState& state, int node_idx) {
    return std::find(state.selection.begin(), state.selection.end(), node_idx)
           != state.selection.end();
}

void graph_viewport_add_to_selection(GraphData& graph, GraphViewportState& state, int node_idx) {
    if (node_idx < 0 || node_idx >= graph.node_count) return;
    if (graph_viewport_is_selected(state, node_idx)) return;
    state.selection.push_back(node_idx);
    graph.nodes[node_idx].flags |= NF_SELECTED;
    state.selected_node = node_idx;
}

void graph_viewport_toggle_selection(GraphData& graph, GraphViewportState& state, int node_idx) {
    if (node_idx < 0 || node_idx >= graph.node_count) return;
    auto it = std::find(state.selection.begin(), state.selection.end(), node_idx);
    if (it != state.selection.end()) {
        state.selection.erase(it);
        graph.nodes[node_idx].flags &= ~NF_SELECTED;
        state.selected_node = state.selection.empty() ? -1 : state.selection.back();
    } else {
        state.selection.push_back(node_idx);
        graph.nodes[node_idx].flags |= NF_SELECTED;
        state.selected_node = node_idx;
    }
}