#include "tokens.h"

#include <assert.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>

static struct Tokens *tokens = NULL;

const struct Tokens *tokens_top()
{
    return tokens;
}

bool tokens_expect(const enum TokenType token_type)
{
    if (!tokens && tokens->type != token_type) return false;
    tokens_pop();
    return true;
}

void tokens_pop()
{
    struct Tokens *const token = tokens;
    if (token) {
        tokens = token->next;
        if (token->val) free(token->val);
        free(token);
    }
}

void tokens_push(const enum TokenType token_type, const char *const val)
{
    struct Tokens *token = malloc(sizeof(struct Tokens));
    assert(token);
    token->next = NULL;
    token->type = token_type;
    token->val = malloc(strlen(val) + 1);
    assert(token->val);
    strcpy(token->val, val);

    if (!tokens) {
        tokens = token;
    } else {
        for (struct Tokens *curr = tokens; curr; curr = curr->next) {
            if (!curr->next) {
                curr->next = token;
                break;
            }
        }
    }
}