#include "queue.h"

#include <stdlib.h>
#include <string.h>
#include <stddef.h>

struct QueueHeadStruct;
struct QueueNodeStruct;

struct QueueNodeStruct{
    struct QueueHeadStruct* head;
    struct QueueNodeStruct* next;
    char buf[];
};
struct QueueHeadStruct{
    uint size;
    struct QueueNodeStruct* first;
    struct QueueNodeStruct* last ;
    struct QueueNodeStruct  data;
};

typedef struct QueueNodeStruct QueueNode;
typedef struct QueueHeadStruct QueueHead;

#define getHead(X) (((QueueNode*)(pChar(X)-offsetof(QueueNode, buf)))->head)
#define getSize(X) (sizeof(QueueNode) + (getHead(X)->size))

pvoid ctl_queue_initX(ppvoid q, uint size){
    QueueHead* head = (QueueHead*)ctl_malloc(sizeof(QueueHead));
    head->size = size;
    head->first = NULL;
    head->last  = NULL;
    head->data.head = head;
    head->data.next = NULL;
    if(q != NULL){
        *q = pVoid(head->data.buf);
    }
    return pVoid(head->data.buf);
}
pvoid ctl_queue_freeX(ppvoid q){
    QueueHead* head = getHead(*q);
    QueueNode* node;
    QueueNode* temp;
    for(node = head->first; node != NULL; node = temp){
        temp = node->next;
        free(node);
    }
    free(head);
    *q = NULL;
    return NULL;
}

uint ctl_queue_getEntrySizeX(ppcvoid q){
    return getHead(*q)->size;
}
    
pcvoid ctl_queue_getX(ppcvoid q){
    return *q;
}
int ctl_queue_isEmptyX(ppcvoid q){
    return (getHead(*q)->first == NULL ? 1 : 0);
}

pcvoid ctl_queue_addX(ppvoid q, pcvoid data){
    QueueHead* head = getHead(*q);
    if(head->first == NULL){
        head->first = (QueueNode*)ctl_malloc(getSize(*q));
        head->last  = head->first;
        *q = pVoid(head->first->buf);
    }else{
        head->last->next = (QueueNode*)ctl_malloc(getSize(*q));
        head->last = head->last->next;
    }
    head->last->head = head;
    head->last->next = NULL;
    memcpy(head->last->buf, data, head->size);
    return pVoid(head->last->buf);
}
int ctl_queue_delX(ppvoid q){
    QueueHead* head = getHead(*q);
    QueueNode* temp = head->first;
    head->first = head->first->next;
    free(temp);
    if(head->first == NULL){
        head->last = NULL;
        *q = pVoid(head->data.buf);
        return 1;
    }else{
        *q = pVoid(head->first->buf);
        return 0;
    }
}

pvoid ctl_queue_copyX(ppcvoid q, ppvoid q2){
    ctl_queue_initX(q2, getHead(q)->size);
    if(!ctl_queue_isEmpty(q)){
        QueueNode* node = getHead(q)->first;
        for( ; node != NULL; node = node->next){
            ctl_queue_addX(q2, node->buf);
        }
    }
    return *q2;
}