#include "c_Test.h"
#include "c_Digraph.h"
#include "c_Topological.h"
#include "c_VertexIdList.h"

TEST_CASE(test_topological_sort_dag) {
    c_Digraph_t g;
    c_Digraph_Init(&g, 3, NULL);

    /* Construct a valid DAG:
     * 0 -> 1
     * 1 -> 2
     * 0 -> 2
     */
    c_Digraph_AddEdge(&g, 0, 1);
    c_Digraph_AddEdge(&g, 1, 2);
    c_Digraph_AddEdge(&g, 0, 2);

    c_Topological_t topo;
    c_err_t err = c_Topological_Init(&topo, &g, 0);
    ASSERT_INT_EQ(C_SUCCESS, err);

    /* It must successfully identify the graph as a DAG */
    ASSERT_TRUE(c_Topological_HasOrder(&topo));

    c_VertexIdList_t result_order;
    c_VertexIdList_Init(&result_order, 0, 0);

    err = c_Topological_GetOrder(&topo, &result_order);
    ASSERT_INT_EQ(C_SUCCESS, err);
    ASSERT_INT_EQ(3, c_VertexIdList_GetSize(&result_order));

    /* Verify the sequence yields a valid dependency layout (0, 1, 2) */
    c_uint_t v0 = 0, v1 = 0, v2 = 0;
    c_VertexIdList_Get(&result_order, 0, &v0);
    c_VertexIdList_Get(&result_order, 1, &v1);
    c_VertexIdList_Get(&result_order, 2, &v2);

    ASSERT_LL_EQ(0, v0);
    ASSERT_LL_EQ(1, v1);
    ASSERT_LL_EQ(2, v2);

    c_VertexIdList_Destroy(&result_order);
    c_Topological_Destroy(&topo);
    c_Digraph_Destroy(&g);
}

TEST_CASE(test_topological_sort_cyclic_fail) {
    c_Digraph_t g;
    c_Digraph_Init(&g, 2, NULL);

    /* Construct a cyclic graph (0 -> 1 -> 0) */
    c_Digraph_AddEdge(&g, 0, 1);
    c_Digraph_AddEdge(&g, 1, 0);

    c_Topological_t topo;
    c_err_t err = c_Topological_Init(&topo, &g, &g.allocator);
    ASSERT_INT_EQ(C_SUCCESS, err);

    /* It should gracefully determine that no valid topological order exists */
    ASSERT_FALSE(c_Topological_HasOrder(&topo));

    c_VertexIdList_t result_order;
    c_VertexIdList_Init(&result_order, 0, 0);

    err = c_Topological_GetOrder(&topo, &result_order);
    ASSERT_INT_EQ(C_ERR_FAIL, err); /* Query must fail */

    c_VertexIdList_Destroy(&result_order);
    c_Topological_Destroy(&topo);
    c_Digraph_Destroy(&g);
}

int main(int argc, char** argv){

    TEST_START(c_NonrecursiveDFS Component Tests);

    // Execution list configurations
    RUN_TEST(test_topological_sort_dag);
    RUN_TEST(test_topological_sort_cyclic_fail);

    TEST_REPORT();

    RETURN_TEST_STATUS;
}