/*
 * 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.
 */

#ifndef FUD_STRING_VIEW_HPP
#define FUD_STRING_VIEW_HPP

#include "fud_status.hpp"
#include "fud_utf8.hpp"
#include "fud_config.hpp"
#include "fud_assert.hpp"

#include <string_view>

namespace fud {

class String;

struct StringView {
    template <size_t N>
    consteval StringView(const utf8 (&input)[N]) : m_length{N - 1}, m_data{input}
    {
        static_assert(N > 0);
    }

    constexpr StringView() noexcept = default;

    constexpr StringView(const StringView& rhs) noexcept = default;

    constexpr StringView(StringView&& rhs) noexcept = default;

    constexpr ~StringView() noexcept = default;

    constexpr StringView& operator=(const StringView& rhs) = default;
    constexpr StringView& operator=(StringView&& rhs) = default;

    constexpr StringView(size_t strLen, const utf8* strData) : m_length(strLen), m_data{strData}
    {
    }

    template <size_t N>
    StringView(const char (&input)[N]) : m_length{N - 1}, m_data{reinterpret_cast<const utf8*>(input)}
    {
        static_assert(N > 0);
    }

    StringView(size_t strLen, const char* strData) :
        m_length(strLen), // line break
        m_data{reinterpret_cast<const utf8*>(strData)} // NOLINT(cppcoreguidelines-pro-type-reinterpret-cast)
    {
    }

    StringView(std::string_view rhs) noexcept : StringView(rhs.length(), rhs.data()) {}

    explicit StringView(const String& fudString) noexcept;

    template <size_t N>
    constexpr static StringView cStringView(const char (&input)[N])
    {
        static_assert(N > 0);
        return StringView{N, reinterpret_cast<const utf8*>(input)};
    }

    [[nodiscard]] constexpr size_t length() const
    {
        return m_length;
    }

    [[nodiscard]] constexpr const utf8* data() const
    {
        return m_data;
    }

    constexpr const utf8& operator[](size_t index) const
    {
        if constexpr (fudBoundsChecking) {
            fudAssert(m_data != nullptr);
            fudAssert(index < m_length);
        }
        return m_data[index];
    }

    constexpr const utf8* begin() const noexcept
    {
        return m_data;
    }

    constexpr const utf8* end() const noexcept
    {
        return m_data + m_length;
    }

    [[nodiscard]] bool nullTerminated() const;

    [[nodiscard]] bool utf8Valid() const;

    Result<size_t, FudStatus> skipWhitespace();

    Result<size_t, FudStatus> trimWhitespace();

    [[nodiscard]] bool advance();

    void advanceUnsafe();

    [[nodiscard]] bool advance(size_t size);

    void advanceUnsafe(size_t size);

    size_t m_length{0};

    const utf8* m_data{nullptr};

    auto operator<=>(const StringView& rhs) const noexcept = default;
};

} // namespace fud

#endif