mijin2/source/mijin/net/url.hpp

#pragma once

#if !defined(MIJIN_NET_URL_HPP_INCLUDED)
#define MIJIN_NET_URL_HPP_INCLUDED 1

#include <cstdint>
#include <string>
#include "../util/string.hpp"

namespace mijin
{
template<typename TChar, typename TTraits = std::char_traits<TChar>, typename TAllocator = std::allocator<TChar>>
class URLBase
{
public:
    using string_t = std::basic_string<TChar, TTraits, TAllocator>;
    using string_view_t = std::basic_string_view<TChar, TTraits>;
private:
    string_t base_;
    string_view_t scheme_;
    string_view_t userinfo_;
    string_view_t host_;
    string_view_t path_;
    string_view_t query_;
    string_view_t fragment_;
    string_view_t pathQueryFragment_;
    std::uint16_t port_ = 0;
public:
    constexpr URLBase() noexcept = default;
    constexpr URLBase(const URLBase&) = default;
    constexpr URLBase(URLBase&&) noexcept = default;
    constexpr URLBase(string_t base) noexcept : base_(std::move(base)) { parse(); }
    constexpr URLBase(string_view_t base) : URLBase(string_t(base.begin(), base.end())) {}
    constexpr URLBase(const TChar* base) : URLBase(string_t(base)) {}

    constexpr URLBase& operator=(const URLBase&) = default;
    constexpr URLBase& operator=(URLBase&&) noexcept = default;

    [[nodiscard]] constexpr bool isValid() const noexcept { return !base_.empty(); }
    [[nodiscard]] constexpr string_view_t getScheme() const noexcept { return scheme_; }
    [[nodiscard]] constexpr string_view_t getUserInfo() const noexcept { return userinfo_; }
    [[nodiscard]] constexpr string_view_t getHost() const noexcept { return host_; }
    [[nodiscard]] constexpr string_view_t getPath() const noexcept { return path_; }
    [[nodiscard]] constexpr string_view_t getQuery() const noexcept { return query_; }
    [[nodiscard]] constexpr string_view_t getFragment() const noexcept { return fragment_; }
    [[nodiscard]] constexpr string_view_t getPathQueryFragment() const noexcept { return pathQueryFragment_; }
    [[nodiscard]] constexpr std::uint16_t getPort() const noexcept { return port_; }


    constexpr void clear() noexcept;
private:
    constexpr void parse() noexcept;
    constexpr bool parseAuthority(string_view_t authority) noexcept;
};

using URL = URLBase<char>;

template<typename TChar, typename TTraits, typename TAllocator>
constexpr void URLBase<TChar, TTraits, TAllocator>::clear() noexcept
{
    base_.clear();
    scheme_ = {};
    userinfo_ = {};
    host_ = {};
    path_ = {};
    query_ = {};
    fragment_ = {};
    port_ = 0;
}

template<typename TChar, typename TTraits, typename TAllocator>
constexpr void URLBase<TChar, TTraits, TAllocator>::parse() noexcept
{
    if (base_.empty())
    {
        return;
    }

    string_view_t toParse = base_;
    typename string_view_t::size_type pos = toParse.find(TChar(':'));
    if (pos == string_t::npos)
    {
        clear();
        return;
    }
    scheme_ = toParse.substr(0, pos);
    toParse = toParse.substr(pos + 1);

    const TChar DOUBLE_SLASH[] = {TChar('/'), TChar('/'), TChar(0)};
    if (!toParse.starts_with(DOUBLE_SLASH))
    {
        userinfo_ = host_ = {};
        port_ = 0;
    }
    else
    {
        toParse = toParse.substr(2); // skip the slashes
        pos = toParse.find(TChar('/'));
        if (!parseAuthority(toParse.substr(0, pos)))
        {
            clear();
            return;
        }
        if (pos == string_view_t::npos)
        {
            path_ = query_ = fragment_ = pathQueryFragment_ = {};
            return;
        }
        toParse = toParse.substr(pos);
    }
    pathQueryFragment_ = toParse;
    pos = toParse.find(TChar('#'));
    if (pos == string_view_t::npos)
    {
        fragment_ = {};
    }
    else
    {
        fragment_ = toParse.substr(pos + 1);
        toParse = toParse.substr(0, pos);
    }
    pos = toParse.find(TChar('?'));
    if (pos == string_view_t::npos)
    {
        query_ = {};
        path_ = toParse;
    }
    else
    {
        query_ = toParse.substr(pos + 1);
        path_ = toParse.substr(0, pos);
    }
}

template<typename TChar, typename TTraits, typename TAllocator>
constexpr bool URLBase<TChar, TTraits, TAllocator>::parseAuthority(string_view_t authority) noexcept
{
    string_view_t toParse = authority;
    typename string_view_t::size_type pos = toParse.find(TChar('@'));
    if (pos == string_view_t::npos)
    {
        userinfo_ = {};
    }
    else
    {
        userinfo_ = toParse.substr(0, pos);
        toParse = toParse.substr(pos + 1);
    }
    pos = toParse.find(TChar(':')); // TODO: IPv6
    if (pos == string_view_t::npos)
    {
        port_ = 0;
        host_ = toParse;
    }
    else
    {
        if (!toNumber(toParse.substr(pos + 1), port_))
        {
            return false;
        }
        host_ = toParse.substr(0, pos);
    }
    return true;
}
}


#endif // !defined(MIJIN_NET_URL_HPP_INCLUDED)