#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <ctype.h>

#include "pencil.h"

/*
 * This function is called before anything else, to initialize the
 * state machine. It is certainly possible to create implementations
 * which don't require any initialization, so just leave this blank if
 * you don't need it.
 */

int states[20][20];

void
init_transtab(void) {
    states[0]['s'] = 4;
    states[0]['t'] = 2;
    states[0]['o'] = 1;
    states[0]['f'] = 3;
    states[1]['n'] = 8;
    states[2]['w'] = 7;
    states[2]['h'] = 9;
    states[3]['f'] = 13;
    states[4]['t'] = 16;
    states[5]['e'] = 6;
    states[7]['o'] = 8;
    states[9]['n'] = 10;
    states[10]['e'] = 11;
    states[11]['e'] = 12;
    states[13]['w'] = 14;
    states[14]['r'] = 15;
    states[16]['o'] = 17;
    states[17]['p'] = 18;
}

command_t
getCommandAtAcceptingState(int state) {
    switch (state) {
        case 6:
            return ONE;
        case 8:
            return TWO;
        case 12:
            return THREE;
        case 15:
            return FOUR;
        case 18:
            return STOP;
        default:
            return NULL;
    }
}

/*
 * Return the next token from reading the given input stream.
 * The words to be recognized are 'turn', 'draw' and 'move',
 * while the returned tokens may be TURN, DRAW, MOVE or END (as
 * enumerated in 'pencil.h').
 */
command_t
next(FILE *input) {

    int currentState = 0;

    while (getCommandAtAcceptingState(currentState) == NULL) {
        // Get next character
        int c = fgetc(input);

        // If we're at the End Of File, break out.
        if (c == EOF) break;
        if (isspace(c)) continue;

        // Make a move based on next character and current state.
        // currentState = getState(c, currentState);
        currentState = states[currentState][tolower(c)];
    }

    return getCommandAtAcceptingState(currentState);
}