#include "priv_thread.hpp"

#include "command_thread.hpp"
#include "connection.hpp"
#include "write_irc.hpp"

#include <toml++/toml.hpp>

#include <cstdio>
#include <fstream>
#include <sstream>
#include <filesystem>

PrivThread::PrivThread(Connection& connection, std::string config_path)
: connection_{connection}
, config_path_{std::move(config_path)}
{
}

auto PrivThread::check_command(CommandEvent& event, std::string priv) -> bool
{
    return
        (not event.account.empty() &&
            (check(account_privs_, priv, wildcard) ||
            check(account_privs_, priv, std::string{event.account}))) ||
        (not event.oper.empty() &&
            (check(oper_privs_, priv, wildcard) ||
            check(oper_privs_, priv, std::string{event.oper})));
}

auto PrivThread::check(
    std::unordered_map<std::string, std::unordered_set<std::string>> const& privs,
    std::string const& priv,
    std::string const& name
) -> bool
{
    auto const cursor = privs.find(name);
    return cursor != privs.end() && cursor->second.contains(priv);
}

auto PrivThread::list_privs(std::string_view nick) -> void
{
    for (auto const& [oper, privset] : oper_privs_)
    {
        std::string message = "Oper ";
        message += oper;
        message += ":";

        for (auto const& priv : privset)
        {
            message += " ";
            message += priv;
        }

        send_notice(connection_, nick, message);
    }

    for (auto const& [account, privset] : account_privs_)
    {
        std::string message = "Account ";
        message += account;
        message += ":";

        for (auto const& priv : privset)
        {
            message += " ";
            message += priv;
        }

        send_notice(connection_, nick, message);
    }
}

auto PrivThread::on_command(CommandEvent& event) -> void
{
    if ("list_privs" == event.command)
    {
        if (check_command(event, PrivThread::owner_priv))
        {
            list_privs(event.nick);
        }
    }
    else if ("add_priv" == event.command)
    {
        if (check_command(event, PrivThread::owner_priv))
        {
            auto in = std::istringstream{std::string{event.arg}};
            std::string kind, name, priv;
            if (in >> kind >> name >> priv)
            {
                if ("oper" == kind)
                {
                    oper_privs_[name].insert(priv);
                    save_config();
                    send_notice(connection_, event.nick, "ack");
                    return;
                }
                else if ("account" == kind)
                {
                    account_privs_[name].insert(priv);
                    save_config();
                    send_notice(connection_, event.nick, "ack");
                    return;
                }
            }
            send_notice(connection_, event.nick, "nak");
        }
    }
    else if ("remove_priv" == event.command)
    {
        if (check_command(event, PrivThread::owner_priv))
        {
            auto in = std::istringstream{std::string{event.arg}};
            std::string kind, name, priv;
            if (in >> kind >> name >> priv)
            {
                if ("oper" == kind)
                {
                    oper_privs_[name].erase(priv);
                    if (oper_privs_[name].empty()) oper_privs_.erase(name);
                    save_config();
                    send_notice(connection_, event.nick, "ack");
                    return;
                }
                else if ("account" == kind)
                {
                    account_privs_[name].erase(priv);
                    if (account_privs_[name].empty()) account_privs_.erase(name);
                    save_config();
                    send_notice(connection_, event.nick, "ack");
                    return;
                }
            }
            send_notice(connection_, event.nick, "nak");
        }
    }
}

auto PrivThread::save_config() -> void
{
    auto serialize_table = [](auto map) {
        auto tab = toml::table{};
        for (auto const& [oper, privs] : map)
        {
            auto privset = toml::array{};
            for (auto const& priv : privs)
            {
                privset.push_back(priv);
            }
            tab.insert(oper, privset);
        }
        return tab;
    };

    auto config = toml::table{};
    if (not oper_privs_.empty()) {
        config.insert("oper", serialize_table(oper_privs_));
    }
    if (not account_privs_.empty()) {
        config.insert("account", serialize_table(account_privs_));
    }

    std::string tmp = config_path_ + ".tmp";
    std::ofstream{tmp} << config;
    std::filesystem::rename(tmp, config_path_);
}

auto PrivThread::load_config() -> void
{
    if (auto in = std::ifstream{config_path_})
    {
        auto const config = toml::parse(in);

        if (config.contains("oper"))
        {
            for (auto const [oper, privs] : *config["oper"].as_table())
            {
                auto& privset = oper_privs_[std::string{oper.str()}];
                for (auto const& priv : *privs.as_array())
                {
                    privset.insert(priv.as_string()->get());
                }
            }
        }

        if (config.contains("account"))
        {
            for (auto const [account, privs] : *config["account"].as_table())
            {
                auto& privset = account_privs_[std::string{account.str()}];
                for (auto const& priv : *privs.as_array())
                {
                    privset.insert(priv.as_string()->get());
                }
            }
        }
    }
}

auto PrivThread::start(Connection& connection, std::string config_path) -> std::shared_ptr<PrivThread>
{
    auto thread = std::make_shared<PrivThread>(connection, config_path);

    thread->load_config();

    connection.add_listener<CommandEvent>([thread](CommandEvent& event)
    {
        thread->on_command(event);
    });

    return thread;
}