#include <stdio.h>
#include <stdlib.h>
unsigned char cells[30000] = {0};   //the tape

FILE *inFile = NULL;            //file to read brainfuck from
int fileSize = 0;               //length of file text

int position = 0;           //where i am on the tape
int loopcount = 0;          //how far i am nested in a loop
int counter;

char *bf;                   //string containing brainfuck to be interpretted

int main()
{
    inFile = fopen("test.bf", "r");
    while(fgetc(inFile) != EOF)
    {
        fileSize++;
    }

    rewind(inFile);
        bf = (char *)malloc(sizeof(char) * (fileSize + 1 + 1)); // one for space one for null
    for(counter = 0; counter < fileSize; counter++)
    {
            *(bf + counter) = fgetc(inFile);
    }
    printf("\n%s", bf); //print the .bf source code
    if (inFile)
    {
            for (counter = 0; counter < fileSize; counter++)
        switch(bf[counter])
        {
            case '+':
                    cells[position]++;
            break;
            case '-':
                cells[position]--;
            break;
            case '>':
                position++;
                if (position > 30000)
                {
                    position = 0;
                }
            break;
            case '<':
                position--;
                if (position < 0)
                {
                    position = 30000;
                }
            break;
            case '[':
                if(!cells[position])
                {
                    loopcount++;
                    while(loopcount)
                    {
                        loopcount++;
                        if(bf[counter] == ']')
                        {
                                loopcount--;
                        }
                        else if(bf[counter] == '[')
                        {
                                loopcount++;
                        }
                    }
                }
            break;
            case ']':
                if(cells[position])
                {
                    loopcount++;
                    while(loopcount)
                    {
                            counter--;
                        if(bf[counter] == '[')
                        {
                            loopcount--;
                        }
                        else if(bf[counter] == ']')
                        {
                            loopcount++;
                        }
                    }
                }
            break;
            case '.': // output pointer value
                putchar(cells[position]);
            break;
            case ',': // read in value
                cells[position] = getchar();
            break;
        }
    }
    return 0;
}