#include "c_List.h"
#include <stdlib.h>
#include <stdio.h>

// Custom User Type showcasing intrusive inclusion
typedef struct {
    int value;
    c_ListNode_t node; // Intrusive node payload linkage
} CustomData_t;

static void test2(void) {
    printf("==================================================\n");
    printf(" Starting Intrusive Safe-Iterator Unit Tests\n");
    printf("==================================================\n\n");

    c_List_t head;
    c_List_Init(&head);

    CustomData_t d1 = {10};
    CustomData_t d2 = {20};
    CustomData_t d3 = {30};

    // Linking nodes to tail: [Head] <-> [10] <-> [20] <-> [30]
    c_List_InsertBefore(&head, &d1.node);
    c_List_InsertBefore(&head, &d2.node);
    c_List_InsertBefore(&head, &d3.node);

    // ==========================================
    // 1. Verify Lookups via ForEachEntry
    // ==========================================
    CustomData_t* pos;
    int index = 0;
    int expected[] = {10, 20, 30};

    printf("Reading nodes using standard ForEachEntry:\n");
    c_List_ForEachEntry(&head, pos, CustomData_t, node) {
        printf("  Found Entry value: %d\n", pos->value);
        assert(pos->value == expected[index++]);
    }
    assert(index == 3);
    printf("[PASS] Standard lookup loop complete.\n\n");

    // ==========================================
    // 2. Verify Mutations via ForEachEntrySafe
    // ==========================================
    CustomData_t* tmp; // Cache variable for safe traversal tracking
    index = 0;

    printf("Filtering and removing matching entry elements via Safe Loop:\n");
    c_List_ForEachEntrySafe(&head, pos, tmp, CustomData_t, node) {
        if (pos->value == 20) {
            printf("  Modifying layout: Safely dropping element (%d)\n", pos->value);
            c_List_Remove(&pos->node); // Remove middle item mid-flight
        }
        index++;
    }
    assert(index == 3); // Iterated through all three bounds

    // ==========================================
    // 3. Confirm Final Structure Integrity
    // ==========================================
    // List must now structurally bridge to bypass item 20: [10] <-> [30]
    index = 0;
    c_List_ForEachEntry(&head, pos, CustomData_t, node) {
        if (index == 0) assert(pos->value == 10);
        if (index == 1) assert(pos->value == 30);
        index++;
    }
    assert(index == 2);
    printf("[PASS] Structural integrity verified following safe removal mutation.\n");

    printf("\n==================================================\n");
    printf(" Success! Intrusive layout traversal operates flawlessly!\n");
    printf("==================================================\n");
}

int main() {
    printf("==================================================\n");
    printf(" Starting Intrusive Circular Doubly Linked List Tests\n");
    printf("==================================================\n\n");

    // Initialize list head context anchor
    c_List_t head;
    c_List_Init(&head);
    assert(c_List_IsEmpty(&head) == 1);

    CustomData_t d1 = {100};
    CustomData_t d2 = {200};
    CustomData_t d3 = {300};

    // ==========================================
    // 1. Insertion Testing
    // ==========================================
    // Insert d1 after head -> List: [Head] <-> [100]
    c_List_InsertAfter(&head, &d1.node);
    assert(c_List_IsEmpty(&head) == 0);

    // Insert d3 before head -> List: [Head] <-> [100] <-> [300]
    c_List_InsertBefore(&head, &d3.node);

    // Insert d2 after d1 -> List: [Head] <-> [100] <-> [200] <-> [300]
    c_List_InsertAfter(&d1.node, &d2.node);

    printf("[PASS] Sequence insertions complete.\n");

    // ==========================================
    // 2. Linear Traversal Verification
    // ==========================================
    c_ListNode_t* curr = c_List_Next(&head);
    int expected_values[] = {100, 200, 300};
    int idx = 0;

    while (curr != &head) {
        CustomData_t* entry = c_List_Entry(curr, CustomData_t, node);
        assert(entry->value == expected_values[idx]);
        curr = c_List_Next(curr);
        idx++;
    }
    assert(idx == 3);
    printf("[PASS] Intrusive forward iterator matching sequential expectations.\n");

    // ==========================================
    // 3. Deletion and Mutation Verification
    // ==========================================
    // Target and drop middle node (200)
    c_List_Remove(&d2.node);

    // Structure must bridge gaps smoothly: [100] <-> [300]
    assert(c_List_Next(&d1.node) == &d3.node);
    assert(c_List_Prev(&d3.node) == &d1.node);

    // Eliminated isolated node must be self-referencing via macro assignment
    assert(c_List_IsEmpty(&d2.node) == 1);
    printf("[PASS] Drop operation and isolated reference initialization verified.\n");

    printf("\n==================================================\n");
    printf(" Success! Intrusive macro mutations match layout specs!\n");
    printf("==================================================\n");

    test2();
    return 0;
}