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

#include "table.h"
#include "program.h"

static void *row_clone(void *p)
{
    struct instruction *row;

    row = (struct instruction *)malloc(sizeof(struct instruction));
    memcpy((void *)row, p, sizeof(struct instruction));

    return (void *)row;
}

static int row_cmp(void *a, void *b)
{
    struct instruction *ra, *rb;

    ra = (struct instruction *)a;
    rb = (struct instruction *)b;

    if (ra->state < rb->state)
        return -1;
    if (ra->state > rb->state)
        return 1;
    if (ra->symbol < rb->symbol)
        return -1;
    if (ra->symbol > rb->symbol)
        return 1;

    return 0;
}

static void row_repr(void *p, char *buf, int size)
{
    struct instruction *row;
    static char *moves = "LNR";

    row = (struct instruction *)p;

    snprintf(buf, size, "[%d %d | %d %d %c]",
             row->state, row->symbol, row->nextstate, row->write,
             ((row->move >= -1) && (row->move <=1) ? moves[1+row->move] : '?'));
    buf[size-1] = '\0';
}

static short int parse_move(char *m)
{
    char c;

    c = (char)tolower(m[0]);
    if (c == 'l')
        return -1;
    if (c == 'r')
        return 1;
    if (c == 'n')
        return 0;

    return atoi(m);
}

struct table *program_new()
{
    return table_new(20, 10, row_clone, free, row_cmp, row_repr);
}

int program_load(FILE *f, struct table *prg, struct table *st, struct table *sym)
{
    char line[LINE_LEN+1];
    char state[STATE_LEN+1];
    char symbol[SYMBOL_LEN+1];
    char write[SYMBOL_LEN+1];
    char move[8];
    char nextstate[STATE_LEN+1];
    int ll;
    char *l;
    char *p;
    int r;
    struct instruction row;
    int cnt;

    line[LINE_LEN] = '\0';
    cnt = 0;
    for (;;) {
        l = fgets(line, sizeof(line)-1, f);
        if (l == NULL)
            break;
        ll = strlen(l);
        if (ll > 0) {
            p = &line[ll-1];
            while ((ll > 0) && ((*p == '\r') || (*p == '\n'))) {
                *p = '\0';
                ll--;
            }
        }
        p = strchr(l, '#');
        if (p != NULL)
            *p = '\0';
        r = sscanf(l, "%s %s %s %s %s",
                   state, symbol, nextstate, write, move);
        if (r == 0)
            continue;
        if (r != 5) {
            printf("Parsing error!\n");
        } else {
            row.state = table_insert(st, state);
            row.symbol = table_insert(sym, symbol);
            row.write = table_insert(sym, write);
            row.move = parse_move(move);
            row.nextstate = table_insert(st, nextstate);
            table_insert(prg, &row);
            cnt++;
        }
    }

    return cnt;
}