/**
 * 日期: 2026-04-01
 * 作者: coffee
 * 描述: 侵入式双向链表实现
 */

#include "HList.h"


static void __HListAdd(HList *node, HList *prev, HList *next) {
    next->prev = node;
    node->next = next;
    node->prev = prev;
    prev->next = node;
}

static void __HListDel(HList *prev, HList *next) {
    next->prev = prev;
    prev->next = next;
}

void HListInit(HList *list) {
    if (list == NULL) {
        return;
    }

    list->next = list;
    list->prev = list;
}

uint8_t HListIsSelf(const HList *list) {
    if (list == NULL) {
        return 0;
    }

    return (list->next == list && list->prev == list) ? 1u : 0u;
}

uint8_t HListEmpty(const HList *head) {
    if (head == NULL) {
        return 1;
    }

    return (head->next == head) ? 1u : 0u;
}

size_t HListLen(const HList *head) {
    size_t len = 0;
    const HList *pos;

    if (head == NULL) {
        return 0;
    }

    for (pos = head->next; pos != head; pos = pos->next) {
        ++len;
    }

    return len;
}

void HListAdd(HList *node, HList *head) {
    if (node == NULL || head == NULL) {
        return;
    }

    __HListAdd(node, head, head->next);
}

void HListAddTail(HList *node, HList *head) {
    if (node == NULL || head == NULL) {
        return;
    }

    __HListAdd(node, head->prev, head);
}

void HListDel(HList *node) {
    if (node == NULL || node->next == NULL || node->prev == NULL) {
        return;
    }

    __HListDel(node->prev, node->next);
    HListInit(node);
}

void HListReplace(HList *oldNode, HList *newNode) {
    if (oldNode == NULL || newNode == NULL ||
        oldNode->next == NULL || oldNode->prev == NULL) {
        return;
    }

    newNode->next = oldNode->next;
    newNode->next->prev = newNode;
    newNode->prev = oldNode->prev;
    newNode->prev->next = newNode;
    HListInit(oldNode);
}

void HListMove(HList *node, HList *head) {
    if (node == NULL || head == NULL) {
        return;
    }

    HListDel(node);
    HListAdd(node, head);
}

void HListMoveTail(HList *node, HList *head) {
    if (node == NULL || head == NULL) {
        return;
    }

    HListDel(node);
    HListAddTail(node, head);
}

HList *HListPop(HList *head) {
    HList *node;

    if (HListEmpty(head)) {
        return NULL;
    }

    node = head->next;
    HListDel(node);
    return node;
}