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

TEST_CASE(test_directed_cycle_detection_with_vertex_list) {
    c_Digraph_t g;

    /* 1. Initialize a directed graph with 4 vertices using the default allocator */
    c_err_t err = c_Digraph_Init(&g, 4, NULL);
    ASSERT_INT_EQ(C_SUCCESS, err);

    /*
     * 2. Construct an explicit cyclical loop topology:
     * 0 -> 1 -> 2 -> 0  (Cyclic core group)
     * 2 -> 3            (Dead-end branch link)
     */
    c_Digraph_AddEdge(&g, 0, 1);
    c_Digraph_AddEdge(&g, 1, 2);
    c_Digraph_AddEdge(&g, 2, 0); /* Creates back edge link closing the loop */
    c_Digraph_AddEdge(&g, 2, 3);

    /* 3. Initialize the cycle processing engine (explicitly passing graph's allocator) */
    c_DirectedCycle_t detector;
    err = c_DirectedCycle_Init(&detector, &g, &g.allocator);
    ASSERT_INT_EQ(C_SUCCESS, err);

    /* 4. Assert that a directed cycle was successfully intercepted */
    ASSERT_TRUE(c_DirectedCycle_HasCycle(&detector));

    /* 5. Extract the tracked cycle loop vertices into an external c_VertexIdList_t container */
    c_VertexIdList_t extracted_cycle;
    c_VertexIdList_Init(&extracted_cycle, 0, NULL);

    err = c_DirectedCycle_GetCycle(&detector, &extracted_cycle);
    ASSERT_INT_EQ(C_SUCCESS, err);

    /* The cyclic sequence path count should be 4 elements long (e.g., 0 -> 1 -> 2 -> 0) */
    c_size_t cycle_size = (c_size_t)c_VertexIdList_GetSize(&extracted_cycle);
    ASSERT_LL_EQ(4, cycle_size);

    /* 6. Verify the sequential order of vertices inside the cycle using safe c_VertexIdList_Get specs */
    c_uint_t v0 = 0, v1 = 0, v2 = 0, v3 = 0;

    ASSERT_INT_EQ(C_SUCCESS, c_VertexIdList_Get(&extracted_cycle, 0, &v0));
    ASSERT_INT_EQ(C_SUCCESS, c_VertexIdList_Get(&extracted_cycle, 1, &v1));
    ASSERT_INT_EQ(C_SUCCESS, c_VertexIdList_Get(&extracted_cycle, 2, &v2));
    ASSERT_INT_EQ(C_SUCCESS, c_VertexIdList_Get(&extracted_cycle, 3, &v3));

    /* A valid cycle validation check ensures the sequence loops cleanly back to its origin vertex */
    ASSERT_LL_EQ(v0, v3);

    /* 7. Clean up and reclaim all tracked buffer allocations safely */
    c_VertexIdList_Destroy(&extracted_cycle);
    c_DirectedCycle_Destroy(&detector);
    c_Digraph_Destroy(&g);
}

int main(void) {
    /* Bootstrapping the testing test suite environment */
    TEST_START(DirectedCycle_Verification_Suite);

    /* Run specified structural topology edge cases */
    RUN_TEST(test_directed_cycle_detection_with_vertex_list);

    /* Generate the total reporting tracking sheet metrics summary */
    TEST_REPORT();

    /* Unwind back with correct failure signal flag checking patterns */
    RETURN_TEST_STATUS;
}