#include <stdio.h>
#include <string.h>
#include <getopt.h>
#include "mem.h"
#include "stack.h"
#include "disasm.h"
#include "debug.h"

uint32_t load_program(const char* path)
{
    FILE *fp = fopen(path,"r");
    fseek(fp, 0L, SEEK_END);
    long file_size = ftell(fp);
    rewind(fp);
    fread(mem,1,(size_t)file_size,fp);
    fclose(fp);
    return file_size/2;
}

void initializevm(char *program)
{
    initialize_stack();
    memset(regs,0x00,sizeof(uint16_t)*NUM_REGISTERS);
    memset(mem,0x00,sizeof(uint16_t)*MEMSIZE);
    load_program(program);
}

void startvm(char *program)
{
    initializevm(program);
    start_execution();
    free_stack();
}

void disasm(char *program)
{
    stderr = stdout;
    disassemble_program(load_program(program));
}

void debug(char *program)
{
    initializevm(program);
    debug_program();
    free_stack();
}

int main(int argc, char** argv)
{
    uint8_t debug_flag = 0;
    uint8_t disasm_flag = 0;
    uint8_t err = 0;
    char c;
    char *program;
    while ((c = getopt(argc, argv, "s:d:")) != -1)
    {
        switch(c)
        {
            case 'd':
                debug_flag = 1;
                program = optarg;
                break;
            case 's':
                disasm_flag = 1;
                program = optarg;
                break;
            case '?':
                err = 1;
                break;
        }
    }
    if(err)
    {
        fprintf(stderr,"Error parsing arguments\n");
        return 1;
    }
    else if(debug_flag && disasm_flag)
    {
        fprintf(stderr,"-d and -s are mutually exclusive\n");
        return 1;
    }
    else if(!(debug_flag || disasm_flag))
    {
        if(argc != 2)
        {
            fprintf(stderr,"No program specified\n");
            return 1;
        }
        startvm(argv[1]);
    }
    else if(debug_flag)
    {
        debug(program);
    }
    else if(disasm_flag)
    {
        disasm(program);
    }
    return 0;
}