#include "self_thread.hpp"

#include "connection.hpp"

#include <mybase64.hpp>

#include <boost/container/flat_map.hpp>
#include <boost/log/trivial.hpp>

using namespace std::literals;

auto SelfThread::on_welcome(IrcMsg const& irc) -> void
{
    nickname_ = irc.args[0];
}

auto SelfThread::on_nick(IrcMsg const& irc) -> void
{
    if (is_my_mask(irc.source))
    {
        nickname_ = irc.args[0];
    }
}

auto SelfThread::on_umodeis(IrcMsg const& irc) -> void
{
    mode_ = irc.args[1];
}

auto SelfThread::on_join(IrcMsg const& irc) -> void
{
    if (is_my_mask(irc.source))
    {
        channels_.insert(std::string{irc.args[0]});
    }
}

auto SelfThread::on_kick(IrcMsg const& irc) -> void
{
    if (is_my_nick(irc.args[1]))
    {
        channels_.erase(std::string{irc.args[0]});
    }
}

auto SelfThread::on_part(IrcMsg const& irc) -> void
{
    if (is_my_mask(irc.source))
    {
        channels_.erase(std::string{irc.args[0]});
    }
}

auto SelfThread::on_mode(IrcMsg const& irc) -> void
{
    if (is_my_nick(irc.args[0]))
    {
        auto polarity = true;
        for (char const c : irc.args[1])
        {
            switch (c)
            {
            case '+':
                polarity = true;
                break;
            case '-':
                polarity = false;
                break;
            default:
                if (polarity)
                {
                    mode_ += c;
                }
                else
                {
                    auto const ix = mode_.find(c);
                    if (ix != std::string::npos)
                    {
                        mode_.erase(ix, 1);
                    }
                }
                break;
            }
        }
    }
}

auto SelfThread::on_isupport(const IrcMsg &msg) -> void
{
    auto const hi = msg.args.size() - 1;
    for (int i = 1; i < hi; ++i)
    {
        auto &entry = msg.args[i];

        // Leading minus means to stop support
        if (entry.starts_with("-")) {
            auto const key = std::string{entry.substr(1)};
            if (auto cursor = isupport_.find(key); cursor != isupport_.end()) {
                isupport_.erase(cursor);
            }
        } else if (auto const cursor = entry.find('='); cursor != entry.npos) {
            isupport_.emplace(entry.substr(0, cursor), entry.substr(cursor+1));
        } else {
            isupport_.emplace(entry, std::string{});
        }
    }
}

auto SelfThread::start(Connection& connection) -> std::shared_ptr<SelfThread>
{
    auto thread = std::make_shared<SelfThread>(connection);

    connection.sig_ircmsg.connect([thread](auto cmd, auto& msg)
    {
        switch (cmd)
        {
            case IrcCommand::JOIN:              thread->on_join(msg); break;
            case IrcCommand::KICK:              thread->on_kick(msg); break;
            case IrcCommand::MODE:              thread->on_mode(msg); break;
            case IrcCommand::NICK:              thread->on_nick(msg); break;
            case IrcCommand::PART:              thread->on_part(msg); break;
            case IrcCommand::RPL_ISUPPORT:      thread->on_isupport(msg); break;
            case IrcCommand::RPL_UMODEIS:       thread->on_umodeis(msg); break;
            case IrcCommand::RPL_WELCOME:       thread->on_welcome(msg); break;
            default: break;
        }
    });

    connection.sig_authenticate.connect([thread](auto msg) {
        thread->on_authenticate(msg);
    });

    return thread;
}

auto SelfThread::get_my_nickname() const -> std::string const&
{
    return nickname_;
}

auto SelfThread::get_my_mode() const -> std::string const&
{
    return mode_;
}

auto SelfThread::get_my_channels() const -> std::unordered_set<std::string> const&
{
    return channels_;
}

auto SelfThread::is_my_nick(std::string_view nick) const -> bool
{
    return nick == nickname_;
}

auto SelfThread::is_my_mask(std::string_view mask) const -> bool
{
    auto const bang = mask.find('!');
    return bang != std::string_view::npos && nickname_ == mask.substr(0, bang);
}

auto SelfThread::on_authenticate(const std::string_view body) -> void
{
    if (not sasl_mechanism_)
    {
        BOOST_LOG_TRIVIAL(warning) << "Unexpected AUTHENTICATE from server"sv;
        connection_.send_authenticate_abort();
        return;
    }

    if (auto reply = sasl_mechanism_->step(body)) {

        connection_.send_authenticate_encoded(*reply);

        // Clean up completed SASL transactions
        if (sasl_mechanism_->is_complete())
        {
            sasl_mechanism_.reset();
        }
    }
}

auto SelfThread::start_sasl(std::unique_ptr<SaslMechanism> mechanism) -> void
{
    if (sasl_mechanism_) {
        connection_.send_authenticate("*"sv); // abort SASL
    }

    sasl_mechanism_ = std::move(mechanism);
    connection_.send_authenticate(sasl_mechanism_->mechanism_name());
}