#include "c_GraphDFS.h"
#include "c_Test.h"
#include <stdlib.h>
#include <stdio.h>

// Struct context to keep track of discovered traversal orders inside the callback
typedef struct {
    c_size_t order_buffer[10];
    c_size_t count;
} DFS_Tracker;

// Dummy callback processor mapping discovery steps
static c_bool_t mock_dfs_visitor(c_size_t vertex, void* context) {
    DFS_Tracker* tracker = (DFS_Tracker*)context;
    if (tracker->count < 10) {
        tracker->order_buffer[tracker->count++] = vertex;
    }
    return C_TRUE; // Keep traversing
}

TEST_CASE(test_graph_dfs_traversal) {
    c_Graph_t graph;
    c_Graph_Init(&graph, 4, 0);

    // Build a simple line-graph with a branch: 0-1, 1-2, 1-3
    c_Graph_AddEdge(&graph, 0, 1);
    c_Graph_AddEdge(&graph, 1, 2);
    c_Graph_AddEdge(&graph, 1, 3);

    DFS_Tracker tracker = { .count = 0 };

    // Execute Depth First Scan starting from Root node 0
    c_err_t err = c_Graph_DFS(&graph, 0, mock_dfs_visitor, &tracker, 0);

    ASSERT_INT_EQ(C_SUCCESS, err);
    ASSERT_LL_EQ(4, tracker.count); // All nodes should be found

    // The first node discovered must be the start node (0)
    ASSERT_LL_EQ(0, tracker.order_buffer[0]);
    // The second node discovered must be 1, since it's 0's only neighbor
    ASSERT_LL_EQ(1, tracker.order_buffer[1]);

    // Nodes 2 and 3 are structural branches out of 1.
    // DFS will traverse one completely before popping back to process the other.
    // Hence, positions 2 and 3 must contain some permutation of nodes 2 and 3.
    c_size_t pos2 = tracker.order_buffer[2];
    c_size_t pos3 = tracker.order_buffer[3];
    ASSERT_TRUE((pos2 == 2 && pos3 == 3) || (pos2 == 3 && pos3 == 2));

    c_Graph_Destroy(&graph);
}

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

    TEST_START(Unit Tests);

    // 运行普通无环境要求的用例
    RUN_TEST(test_graph_dfs_traversal);

    // 打印最终统计报告
    TEST_REPORT();

    RETURN_TEST_STATUS;
    return 0;
}