#include <compiler/fzl_reader.h>
#include <compiler/internals/reader.h>
#include <stddef.h>
#include <stdio.h>

// Move cursor forward
size_t move(fzl_reader_t *reader, size_t len)
{
  if (!reader)
    return 0;

  return reader->position += len;
}

// Add single-char token
fzl_token_t *rd_single(fzl_reader_t *reader, fzl_toktype_t type)
{
  fzl_file_loc l;
  bool ok = fzl_linked_getpos(reader->linked, reader->position, &l);
  if (!ok)
  {
    snprintf(last_err, sizeof(last_err), "failed to locate line:col");
    return NULL;
  }

  move(reader, 1);
  return fzl_mktoken(type, l.line, l.col, "", 0, l.filename);
}

// Add double-char token
fzl_token_t *rd_double(fzl_reader_t *reader, fzl_toktype_t type)
{
  fzl_file_loc l;
  bool ok = fzl_linked_getpos(reader->linked, reader->position, &l);
  if (!ok)
  {
    snprintf(last_err, sizeof(last_err), "failed to locate line:col");
    return NULL;
  }

  move(reader, 2);
  return fzl_mktoken(type, l.line, l.col, "", 0, l.filename);
}

// Skip symbols until '\n' or EOF
void rd_comment(fzl_reader_t *reader)
{
  move(reader, 2);

  while (reader->position < reader->size)
  {
    if (reader->source[reader->position++] == '\n')
      break;
  }
}