#include "c_Test.h"
#include "c_EdgeWeightedDigraph.h"
#include "c_AcyclicSP.h"
#include "c_VertexIdList.h"

TEST_CASE(test_acyclic_shortest_paths_dag) {
    c_EdgeWeightedDigraph_t g;
    c_err_t err = c_EdgeWeightedDigraph_Init(&g, 4, NULL);
    ASSERT_INT_EQ(C_SUCCESS, err);

    /*
     * Construct a valid DAG containing negative weights:
     * 0 -> 1 (Weight:  2.0) [Edge 0]
     * 0 -> 2 (Weight:  5.0) [Edge 1]
     * 1 -> 2 (Weight: -4.0) [Edge 2] -> Path 0->1->2 total is 2.0 + (-4.0) = -2.0
     * 2 -> 3 (Weight:  1.0) [Edge 3] -> Path 0->1->2->3 total is -2.0 + 1.0 = -1.0
     */
    c_EdgeWeightedDigraph_AddEdge(&g, 0, 1,  2.0);
    c_EdgeWeightedDigraph_AddEdge(&g, 0, 2,  5.0);
    c_EdgeWeightedDigraph_AddEdge(&g, 1, 2, -4.0);
    c_EdgeWeightedDigraph_AddEdge(&g, 2, 3,  1.0);

    c_AcyclicSP_t sp;
    err = c_AcyclicSP_Init(&sp, &g, 0, &g.allocator);
    ASSERT_INT_EQ(C_SUCCESS, err);

    /* Distance mappings verification */
    ASSERT_TRUE(c_AcyclicSP_HasPathTo(&sp, 3));
    ASSERT_DOUBLE_EQ_MSG(-2.0, c_AcyclicSP_DistTo(&sp, 2), "Negative distance processing check failed");
    ASSERT_DOUBLE_EQ_MSG(-1.0, c_AcyclicSP_DistTo(&sp, 3), "DAG terminal target computation failed");

    /* Reconstruct edge collection paths sequence */
    c_VertexIdList_t edge_path;
    c_VertexIdList_Init(&edge_path, 0, 0 );

    err = c_AcyclicSP_PathTo(&sp, 3, &edge_path);
    ASSERT_INT_EQ(C_SUCCESS, err);
    ASSERT_LL_EQ(3, (c_size_t)c_VertexIdList_GetSize(&edge_path));

    c_uint_t e_id = 0;
    c_VertexIdList_Get(&edge_path, 0, &e_id); ASSERT_LL_EQ(0, e_id); /* Edge 0 (0->1) */
    c_VertexIdList_Get(&edge_path, 1, &e_id); ASSERT_LL_EQ(2, e_id); /* Edge 2 (1->2) */
    c_VertexIdList_Get(&edge_path, 2, &e_id); ASSERT_LL_EQ(3, e_id); /* Edge 3 (2->3) */

    c_VertexIdList_Destroy(&edge_path);
    c_AcyclicSP_Destroy(&sp);
    c_EdgeWeightedDigraph_Destroy(&g);
}

int main(void) {
    TEST_START(AcyclicSP_DAG_Optimization_Suite);
    RUN_TEST(test_acyclic_shortest_paths_dag);
    TEST_REPORT();
    RETURN_TEST_STATUS;
}