#include "c_BreadthFirstDirectedPaths.h"
#include "c_Test.h"
#include "c_Digraph.h"

TEST_CASE(test_breadth_first_directed_paths) {
    c_Digraph_t g;
    c_Digraph_Init(&g, 4, NULL);

    /* Construct graph with multiple paths to 3:
     * Path A (Longer): 0 -> 1 -> 2 -> 3
     * Path B (Shortest): 0 -> 3
     */
    c_Digraph_AddEdge(&g, 0, 1);
    c_Digraph_AddEdge(&g, 1, 2);
    c_Digraph_AddEdge(&g, 2, 3);
    c_Digraph_AddEdge(&g, 0, 3); /* Short-circuit edge directly to 3 */

    c_BreadthFirstDirectedPaths_t bfs_paths;
    c_err_t err = c_BreadthFirstDirectedPaths_Init(&bfs_paths, &g, 0, &g.allocator);
    ASSERT_INT_EQ(C_SUCCESS, err);

    /* Assert reachability and verified shortest path metrics */
    ASSERT_TRUE(c_BreadthFirstDirectedPaths_HasPathTo(&bfs_paths, 3, g.V));
    ASSERT_LL_EQ(1, c_BreadthFirstDirectedPaths_DistTo(&bfs_paths, 3, g.V)); /* Distance must be exactly 1 edge */

    c_VertexIdList_t final_path;
    c_VertexIdList_Init(&final_path, 0, NULL);

    err = c_BreadthFirstDirectedPaths_PathTo(&bfs_paths, 3, g.V, &final_path);
    ASSERT_INT_EQ(C_SUCCESS, err);

    /* Path size should be 2 for the short circuit route: [0, 3] */
    ASSERT_INT_EQ(2, c_VertexIdList_GetSize(&final_path));

    c_uint_t val = 0;
    c_VertexIdList_Get(&final_path, 0, &val);
    ASSERT_LL_EQ(0, val);

    c_VertexIdList_Get(&final_path, 1, &val);
    ASSERT_LL_EQ(3, val);

    c_VertexIdList_Destroy(&final_path);
    c_BreadthFirstDirectedPaths_Destroy(&bfs_paths);
    c_Digraph_Destroy(&g);
}



int main(int argc, char** argv){
    TEST_START(Component Tests);

    // Execution list configurations
    RUN_TEST(test_breadth_first_directed_paths);

    TEST_REPORT();

    RETURN_TEST_STATUS;
}