/*
 * libfud
 * Copyright 2024 Dominick Allen
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "fud_utf8_iterator.hpp"

namespace fud {

std::optional<FudUtf8> Utf8Iterator::peek() const
{
    if (m_index >= m_view.length()) {
        return std::nullopt;
    }

    auto utf8 = FudUtf8::fromStringView(m_view, m_index);

    if (!utf8.valid()) {
        return std::nullopt;
    }

    return utf8;
}

std::optional<FudUtf8> Utf8Iterator::next()
{
    if (m_index >= m_view.length()) {
        m_index = m_view.length();
        return std::nullopt;
    }

    auto utf8 = FudUtf8::fromStringView(m_view, m_index);

    if (!utf8.valid()) {
        m_index = m_view.length();
        return std::nullopt;
    }

    m_index += utf8.size();
    return utf8;
}

} // namespace fud