#include <assert.h>
#include <stdlib.h>
#include "queue.h"

/**
 * @brief struct queue struct used for queueing string name  
 * 
 * @param charLen lenght of tabChar pointeur
 * @param tabChar char array pointer
 * @param pNextE point next element 
 */
struct queue {
    int charLen;
    char * tabChar;
    Pqueue  pNextE;
};

typedef struct queue *Pqueue;

/**
 * @brief Create Element of queue
 * 
 * @param lenChar size of char array that will be created 
 * @return Pqueue new element created
 */
Pqueue createE(int lenChar){
    Pqueue new = (Pqueue) malloc(sizeof(struct queue));
    assert(new);
                                                            /* ???? tab char create or give pointer ???*/
    new->charLen = lenChar;
    new->tabChar = (char *) malloc(lenChar * sizeof(char));
    new->pNextE = NULL;
    return new;
}

/**
 * @brief switch to the next element
 * 
 * @param elem current element
 * @return Pqueue next element
 */
Pqueue pNextE(Pqueue elem){
    assert(elem);
    return elem->pNextE;
}

/**
 * @brief remove and free the last element of queue
 * 
 * @param elem current element
 * @return Pqueue current element
 */
Pqueue rmLastE(Pqueue elem){
    assert(elem);
    Pqueue tmp = elem, previous = NULL;
    while(elem->pNextE != NULL){
        previous = tmp;
        tmp = pNextE(tmp);
    }
    free(tmp->tabChar);
    free(tmp);
    previous->pNextE = NULL;
    return elem;
}

/**
 * @brief remove and free the first element of queue
 * 
 * @param elem target to remove (the element need to be the first)
 * @return Pqueue the second element after remove first
 */
Pqueue rmFrstE(Pqueue elem){
    assert(elem);
    Pqueue tmp = elem->pNextE;
    free(elem->tabChar);
    free(elem);
    return tmp;
}

/**
 * @brief delete the first value and return the next value
 * 
 * @param elem 
 * @return Pqueue 
 */
Pqueue nextDelFrst(Pqueue elem){
    assert(elem);
    Pqueue tmp = elem->pNextE;
    rmFrstE(elem);
    return tmp;
}

/**
 * @brief add in the end of queue element with string parameter 
 * 
 * @param elem Pqueue will be added at the end of queue
 * @param str the string will be bind at the element
 * @param len the lenght of char array
 * @return Pqueue pointer to the last element
 */
Pqueue addLastQ(Pqueue elem, const char* str, int len){
    assert(elem);
    assert(str);
    Pqueue tmp = elem, previous = NULL;
    while(elem->pNextE != NULL){
        previous = tmp;
        tmp = pNextE(tmp);
    }
    tmp = createE(len);
    tmp->tabChar = str;
    tmp->charLen = len;
    return tmp;
}