#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include "queues.h"

List newEmptyList() {
    return NULL;
}

int isEmptyList (List li) {
    return ( li==NULL );
}

void listEmptyError() {
    printf("list empty\n");
    abort();
}

List addItem(State s, List li) {
    List newList = malloc(sizeof(struct ListNode));
    assert(newList!=NULL);
    newList->item = s;
    newList->next = li;
    return newList;
}

State firstItem(List li) {
    if ( li == NULL ) {
        listEmptyError();
    }
    return li->item;
}

List removeFirstNode(List li) {
    List returnList;
    if ( li == NULL ) {
        listEmptyError();
    }
    returnList = li->next;
    free(li);
    return returnList;
}

void freeList(List li) {
    List li1;
    while ( li != NULL ) {
        li1 = li->next;
        free(li);
        li = li1;
    }
    return;
}

Queue newEmptyQueue () {
    Queue q;
    q.list = newEmptyList();
    q.lastNode = NULL;
    return q;
}

int isEmptyQueue (Queue q) {
    return isEmptyList(q.list);
}

void emptyQueueError () {
    printf("queue empty\n");
    exit(0);
}

int compare(State s, Queue *qp) {
    while(qp->lastNode != NULL) {
        if ((s.time == (qp->list)->item.time) &&
            (s.sg1bot == (qp->list)->item.sg1bot) &&
            (s.sg2bot == (qp->list)->item.sg2bot) &&
            (s.sg1top == (qp->list)->item.sg1top) &&
            (s.sg2top == (qp->list)->item.sg2top)) {
            return 0;
        }
        qp->lastNode = (qp->lastNode->next);
    }
    return 1;
}

void enqueue (State s, Queue *qp) {
    if (isEmptyList(qp->list)) {
        qp->list = addItem(s,NULL);
        qp->lastNode = qp->list;
    } else {
        while(qp->lastNode != NULL) {
            if (compare(s,qp) == 1) {

                (qp->lastNode)->next = addItem(s,NULL);
                qp->lastNode = (qp->lastNode->next);
                return;
            }
            if (compare(s,qp) == 0) {
                printf("helped\n");
                qp->lastNode = (qp->lastNode->next);
                return;
            }
        }
    }
}

State dequeue(Queue *qp) {
    State s = firstItem(qp->list);
    qp->list = removeFirstNode(qp->list);
    if ( isEmptyList(qp->list) )  {
        qp->lastNode = NULL;
    }
    return s;
}

void freeQueue (Queue q) {
    freeList(q.list);
}