#include <stdio.h>
#include <stdlib.h>
#include "part1.h"
#include <stdbool.h>


Node * STARTOFHEAP;
char * endofheap;

void initialise(void *memory, size_t size){

    STARTOFHEAP = (Node *) memory;

    STARTOFHEAP->free = true;
    STARTOFHEAP->blockSize = size - sizeof(Node);
    STARTOFHEAP->previous = NULL;
    STARTOFHEAP->next = NULL;
}

void *allocate(size_t bytes){
    Node * allocatedNode = (Node *) STARTOFHEAP;
    Node * freeNode;

    while(allocatedNode != NULL) {
        if ((allocatedNode->free == true) && (allocatedNode->blockSize >= bytes)) {
            char *tempHead = (char *) allocatedNode;
            int sizeLeft = allocatedNode->blockSize - (sizeof(Node) + bytes);

            freeNode = (Node *) (tempHead + sizeof(Node) + bytes);  //create a new node at the address location that is =
            freeNode->free = true;                                  //the start of the head + size of a node + requested bytes

            if(sizeLeft <= sizeof(Node) + 1){
                freeNode->blockSize = allocatedNode->blockSize;
            } else {
                freeNode->blockSize = allocatedNode->blockSize - bytes;
            }

            if(allocatedNode->next != NULL) {

                allocatedNode->next->previous = freeNode;   //go into allocated node next and set the next nodes previous to the free node
                freeNode->next = allocatedNode->next;       //set the freenodes next to the allocated nodes next
                allocatedNode->next = freeNode;             //set the allocatednodes next to the free node
                freeNode->previous = allocatedNode;
            } else{
                allocatedNode->next = freeNode;
                freeNode->previous = allocatedNode;
                freeNode->next = NULL;
            }
//          freeNode->next = NULL;
//          freeNode->previous = allocatedNode;

            allocatedNode->next = freeNode;
            allocatedNode->free = false;
            printf("next Free Node address: %d\n", freeNode);

            return freeNode->previous + 1;
        }
        allocatedNode = allocatedNode->next;
    }
    return (NULL);
}


int main(int argc, const char* argv[]) {

    size_t heapSize = 200;
    STARTOFHEAP = (Node *) malloc(heapSize);

    printf("Size of requested heap: %d\n", heapSize);
    printf("Size of node: %d\n", sizeof(Node));

    initialise(STARTOFHEAP, heapSize);

    endofheap = (char *) STARTOFHEAP;

    printf("Start of heap address: %d\n", STARTOFHEAP);
    printf("End of heap address: %d\n", endofheap = (endofheap + heapSize));
    printf("Size of struct Node: %d\n\n", sizeof(Node));

    printf("Node 1: \n");
    Node *nodeOne = (Node *) allocate(18);
    printf("Memory Address location returned to no#include <stdio.h>
#include <stdlib.h>
#include "part1.h"
#include <stdbool.h>


Node * STARTOFHEAP;
char * endofheap;

void initialise(void *memory, size_t size){

    STARTOFHEAP = (Node *) memory;

    STARTOFHEAP->free = true;
    STARTOFHEAP->blockSize = size - sizeof(Node);
    STARTOFHEAP->previous = NULL;
    STARTOFHEAP->next = NULL;
}

void *allocate(size_t bytes){
    Node * allocatedNode = (Node *) STARTOFHEAP;
    Node * freeNode;

    while(allocatedNode != NULL) {
        if ((allocatedNode->free == true) && (allocatedNode->blockSize >= bytes)) {
            char *tempHead = (char *) allocatedNode;
            int sizeLeft = allocatedNode->blockSize - (sizeof(Node) + bytes);

            freeNode = (Node *) (tempHead + sizeof(Node) + bytes);  //create a new node at the address location that is =
            freeNode->free = true;                                  //the start of the head + size of a node + requested bytes

            if(sizeLeft <= sizeof(Node) + 1){
                freeNode->blockSize = allocatedNode->blockSize;
            } else {
                freeNode->blockSize = allocatedNode->blockSize - bytes;
            }

            if(allocatedNode->next != NULL) {

                allocatedNode->next->previous = freeNode;   //go into allocated node next and set the next nodes previous to the free node
                freeNode->next = allocatedNode->next;       //set the freenodes next to the allocated nodes next
                allocatedNode->next = freeNode;             //set the allocatednodes next to the free node
                freeNode->previous = allocatedNode;
            } else{
                allocatedNode->next = freeNode;
                freeNode->previous = allocatedNode;
                freeNode->next = NULL;
            }
//          freeNode->next = NULL;
//          freeNode->previous = allocatedNode;

            allocatedNode->next = freeNode;
            allocatedNode->free = false;
            printf("next Free Node address: %d\n", freeNode);

            return freeNode->previous + 1;
        }
        allocatedNode = allocatedNode->next;
    }
    return (NULL);
}


int main(int argc, const char* argv[]) {

    size_t heapSize = 200;
    STARTOFHEAP = (Node *) malloc(heapSize);

    printf("Size of requested heap: %d\n", heapSize);
    printf("Size of node: %d\n", sizeof(Node));

    initialise(STARTOFHEAP, heapSize);

    endofheap = (char *) STARTOFHEAP;

    printf("Start of heap address: %d\n", STARTOFHEAP);
    printf("End of heap address: %d\n", endofheap = (endofheap + heapSize));
    printf("Size of struct Node: %d\n\n", sizeof(Node));

    printf("Node 1: \n");
    Node *nodeOne = (Node *) allocate(18);
    printf("Memory Address location returned to node 1: %d\n", nodeOne);
    printf("Node Address location returned to node 1: %d\n\n", nodeOne - 1);

    printf("Node 2: \n");
    Node *nodeTwo = (Node *) allocate(18);
    printf("Address returned to node 2: %d\n", nodeTwo);
    printf("Node Address location returned to node 2: %d\n\n", nodeTwo - 1);

    printf("Node 3: \n");
    Node *nodeThree = (Node *) allocate(68);
    printf("Address returned to node 3: %d\n", nodeThree);
    printf("Node Address location returned to node 3: %d\n\n", nodeThree - 1);

    printf("Node 4: \n");
    Node *nodeFour = (Node *) allocate(18
            );
    printf("Address returned to node 4: %d\n", nodeFour);
    printf("Node Address location returned to node 4: %d\n\n", nodeFour - 1);


    return 0;
}


de 1: %d\n", nodeOne);
    printf("Node Address location returned to node 1: %d\n\n", nodeOne - 1);

    printf("Node 2: \n");
    Node *nodeTwo = (Node *) allocate(18);
    printf("Address returned to node 2: %d\n", nodeTwo);
    printf("Node Address location returned to node 2: %d\n\n", nodeTwo - 1);

    printf("Node 3: \n");
    Node *nodeThree = (Node *) allocate(68);
    printf("Address returned to node 3: %d\n", nodeThree);
    printf("Node Address location returned to node 3: %d\n\n", nodeThree - 1);

    printf("Node 4: \n");
    Node *nodeFour = (Node *) allocate(18
            );
    printf("Address returned to node 4: %d\n", nodeFour);
    printf("Node Address location returned to node 4: %d\n\n", nodeFour - 1);


    return 0;
}