/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

/*
 * File:   main.c
 * Author: saheel
 *
 * Created on 28 May 2016, 12:18 PM
 */



/*
 *
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define TO_HEX(i) (i <= 9 ? '0' + i : 'A' - 10 + i)
char * toHex(int val);
void print_format(int * registers[]);
char * toHex(int val);
void print_format(int *registers[]);
short *buffer;
unsigned long fileLength;
int regs[11];
int rego;
int opcode;
int pc = 1;
unsigned short offset;

int main(int argc, char**argv) {
    printf("Initial state\n");
    print_format(regs);
    printf("==================\n");
    FILE*f;
    f = fopen(argv[1], "r");
    fseek(f, 0, SEEK_END);
    fileLength = ftell(f);
    fseek(f, 0, SEEK_SET);
    buffer = malloc(fileLength + 1);
    fread(buffer, 1,fileLength, f);
    fclose(f);
    int i = 0;
    int store;
    int halfsize= fileLength/2;
    int function[halfsize];
    int instruction[halfsize];
    int offset[halfsize];
    int regs[11];
    int rego;


    int r0=0;
    int r1=0;
    int r2=0;
    int r3=0;
    int r4=0;
    int r5=0;
    int r6=0;
    int r7=0;

    int x=0;
    int y=0;
    int dr[halfsize];

    for (i = 1; i <halfsize ; i++) {
        instruction[i]= (buffer[x]*0x100) +buffer[y];
        x=x+2;
        y=y+2;}
    pc=instruction[0];
    print_format(regs);

    int j;
    for(j=0; j<halfsize+1; j++)
    {
        offset[0]=instruction[j]& 0x01ff;
        dr[0] = instruction[j] &0xE00 >> 9;

        function[0]= instruction[j] & 0xf000 >>12;

        if (opcode != 15) {
            if (opcode == 2) {
                pc=pc+1;
            store= instruction[j+1+offset[0]];
            if (dr[0]==0){r0= store;}
            if (dr[0]==1){r1= store;}
            if (dr[0]==2){r2= store;}
            if (dr[0]==3){r3= store;}
            if (dr[0]==4){r4= store;}
            if (dr[0]==5){r5= store;}
            if (dr[0]==6){r6= store;}
            if (dr[0]==7){r7= store;}
            printf("after executing instruction\n");
            printf("R0\t0x%04x\n", r0);
            }


    }
    }


//        opcode = (buffer[i] & 0xf000) >> 12;
//        if (opcode != 15) {
//
//            if (opcode == 14 ) {
//                regs[8] = regs[8] + 1;
//                rego = (buffer[i] & 0x0e00) >> 9;
//                offset = buffer[i] & 0x01ff ;
//                printf("offset\%d\n", rego);
//                //printf("offset\%d\n", pc);
//                regs[rego] = offset + regs[8] ;
//                regs[9] = buffer[i];
//            }
//            if (opcode == 2) {
//                regs[8] = regs[8] + 1;
//                rego = (buffer[i] & 0x0e00) >> 9;
//
//                offset = buffer[i] & 0x01ff;
//                //printf("offset\%d\n", offset);
//                regs[rego] = buffer[pc +offset];
//                printf("offset\%x\n", buffer);
//                printf("offset\%d\n", offset);
//                //regs[9] = buffer[i];
//            }
//        }
//    }

    printf("==================\n");
    return 0;
}

char * toHex(int val) {
    int x = val;
    char *res = (char *) malloc(sizeof (char) * 5);
    if (x <= 0xFFFF) {
        res[0] = TO_HEX(((x & 0xF000) >> 12));
        res[1] = TO_HEX(((x & 0x0F00) >> 8));
        res[2] = TO_HEX(((x & 0x00F0) >> 4));
        res[3] = TO_HEX((x & 0x000F));
        res[4] = '\0';
    }
    return res;
}

void print_format(int * registers[]) {
    int i = 0;
    for (i; i < 11; i++) {
        if (i == 8)
        {printf("PC\t0x%s\n", toHex(registers[8]));}
        else if (i == 9)
        {  printf("IR\t0x%s\n", toHex(registers[9]));}
        else if (i == 10)
        //{printf("CC\t%s\n", "P");}
        {  //counter(registers[10]);}
            if (registers[9]==0x0000)
            { printf("CC\t%s\n", "Z");}
            if (registers[9] <0)
            {printf("CC\t%s\n", "N");}
            if (registers[9] >0)
            {printf("CC\t%s\n", "P");}
        }
        else {
            printf("R%d\t0x%s\n", i, toHex(registers[i]));

        }
    }
}