#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "Memory.h"
#include "loadMemory.h"
#include "Registers.h"

// -------------------------------------------------------
// constants used
// -------------------------------------------------------

    const char storeCom[] = "store";
    const char fetchCom[] = "fetch";
    const char printCom[] = "print";
    const char quitCom[] = "quit";

    enum {maxComLen=200};
    enum {maxInfoLen = 4};

// -------------------------------------------------------
//   functions used
// -------------------------------------------------------

    void runMachine(int, int);
    void readln(FILE *f);

int main(int argc, const char *argv[])
{
    FILE *f;
    long numBytes;
    int trace, startLocation;

    if (argc != 2) {
        fprintf(stderr, "usage: a.out filename\n");
        exit(1);
    }

    if ((f=fopen(argv[1],"rb")) == 0) {
        fprintf(stderr, "cannot open [%s] for input\n", argv[1]);
        exit(1);
    }

    fprintf(stdout, "size of memory in bytes ?> ");
    fscanf(stdin, "%ld", &numBytes);

    if (numBytes < 1) {
        fprintf(stderr, "bad number of bytes [%ld]\n", numBytes);
        exit(1);
    }

    if (!allocateMemory(numBytes)) {
        fprintf(stderr, "memory allocation error\n");
        exit(1);
    }

    if (!loadMemory(f,0)) {
        fprintf(stderr, "error loading memory\n");
        exit(1);
    }

    fclose(f);

    fprintf(stdout, "starting address for program ?> ");
    fscanf(stdin, "%d", &startLocation);

    if ( startLocation < 0){
        fprintf(stderr, "bad start address loading memory\n");
        exit(1);
    }

    fprintf(stdout, "boolean (1/0) for trace (on/off) ?> ");
    fscanf(stdin, "%d", &trace);

    if (!(trace == 1 || trace == 0)){
        fprintf(stderr, "bad input for trace\n");
        exit(1);
    }

    runMachine(startLocation,trace);

    deallocateMemory();

    return 0;
}

// -------------------------------------------------------------
/* this is the interactive portion of the program - it allows
 * a specified number of bytes of information to be stored into
 * memory, fetched from memory, or dumped.
*/

void runMachine(int start, int trace)
{
    int pc = start;

    while(fetch_exec(&pc));

}

// -------------------------------------------------------------
/* this procedure inputs characters from the specified file until
 * end of line is reached
*/

void readln(FILE *f)
{
    while (fgetc(f) != '\n');
}