#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>

const int MAX_PROGRAM_LENGTH = 38911;
FILE* outfile; 
int next_reg = 1;
char* input;
char* token;
char delims[] = " \n\r\t";

int next_register() 
{
  return next_reg++;
}

typedef enum opcode {LOADI=0, AND, OR, EXOR, NOT, OUTPUT} opcode;

void emit (opcode op, int arg1, int arg2, int arg3)
{
    switch (op) {
    case LOADI:
        fprintf(outfile, "loadI %s => r%d\n", arg1 ? "true" : "false", arg2);
        break;
    case AND:
        fprintf(outfile, "and r%d, r%d => r%d\n", arg1, arg2, arg3);
        break;
    case OR:
        fprintf(outfile, "or r%d, r%d => r%d\n", arg1, arg2, arg3);
        break;
    case EXOR:
        fprintf(outfile, "exor r%d, r%d => r%d\n", arg1, arg2, arg3);
        break;
    case NOT:
        fprintf(outfile, "not r%d => r%d\n", arg1, arg2);
        break;
    case OUTPUT:
        fprintf(outfile, "output r%d\n", arg1);
        break;
    default:
        fprintf(stderr, "Illegal opcode %d passed to \"emit\" \n", op);
    }
}

void next_token()
{
    static int started = 0;
    if (! started) {
        token = strtok (input, delims);
        started = 1;
    }
    else {
        token = strtok (NULL, delims);
    }
    if (token == NULL) token = "EOF";
}

void error(char* nt)
{
    fprintf(stderr, "Error in %s at token '%s'\n", nt, token);
    exit(1);
}

int Opnd ()
{
    int rreg = next_register();

    if (! strcmp (token, "true")) {
        next_token();
        emit(LOADI, true, rreg, 0);
        return rreg;
    }
    else if (! strcmp(token, "false")) {
        next_token();
        emit(LOADI, false, rreg, 0);
        return rreg;
    }
    else error("Opnd");
}

int Expr ()
{
    int rreg, rreg1, rreg2;

    if (! strcmp(token,"or")) {
        next_token(); rreg1 = Expr(); rreg2 = Expr();
        emit(OR, rreg1, rreg2, rreg = next_register());
        return rreg;
    }
    else if (! strcmp(token,"and")){
        next_token(); rreg1 = Expr(); rreg2 = Expr();
        emit(AND, rreg1, rreg2, rreg = next_register());
        return rreg;
    }
    else if (! strcmp(token,"exor")){ 
        next_token(); rreg1 = Expr(); rreg2 = Expr();
        emit(EXOR, rreg1, rreg2, rreg = next_register());
        return rreg;
    }
    else if (! strcmp(token,"not")) {
        next_token(); rreg1 = Expr();
        emit(NOT, rreg1, rreg = next_register(), 0);
        return rreg;
    }
    else Opnd();
}

void Start ()
{
    int rreg;
    
    next_token();
    rreg = Expr();
    if (strcmp(token, "EOF")) {
        error("Start");
    }
    emit(OUTPUT, rreg, 0, 0);
}

int main(void)
{
    int result;
    FILE* infile = fopen("in.truth", "r");
    input = malloc(MAX_PROGRAM_LENGTH);
    fgets(input, MAX_PROGRAM_LENGTH, infile);
    outfile = fopen("code.out", "w");
    Start();
    fclose(infile); fclose(outfile);
    return 0; 
}