#include "xxcc.h"
#include "client.h"
#include "direction.h"
#include "accounts.h"
#include "contacts.h"
#include "conversation.h"
#include "message.h"
#include <QXmppMessage.h>
#include <QXmppOmemoElement_p.h>
#include <QXmppRosterManager.h>
#include <QXmppUtils.h>
#include <QKeyEvent>
#include <QPushButton>
#include <QScroller>
#include <iostream>
#include <stdexcept>
#include <utility>
#include <variant>

xxcc::xxcc(QWidget *const parent) :
    QWidget(parent),
    selected(nullptr)
{
    ui.setupUi(this);
    QScroller::grabGesture(ui.conversations_list, QScroller::TouchGesture);
    QScroller::grabGesture(ui.messages, QScroller::TouchGesture);

    creds.load().then(this,
    [=] (Credentials::PairListResult &&result)
    {
        if (std::holds_alternative<Credentials::PairList>(result))
        {
            const auto &pairs = std::get<Credentials::PairList>(result);

            connectAccounts(pairs);
            retrieveConversations();
        }
        else if (std::holds_alternative<Credentials::Error>(result))
        {
            const auto &error = std::get<Credentials::Error>(result);

            std::cerr << qPrintable(error.description) << std::endl;
        }
    });


    connect(ui.accounts, &QPushButton::released, this,
    [this]
    {
        Accounts a(clients, this);

        a.connect(&a, &Accounts::new_account, this, &xxcc::addAccount);
        a.connect(&a, &Accounts::new_account, this,
        [&] (Client *c)
        {
            creds.store(c);
        });

        a.exec();
    });

    connect(ui.contacts, &QPushButton::released, this,
    [this]
    {
        Contacts c(clients, this);

        connect(&c, &Contacts::startChat, this, &xxcc::startChat);

        for (const auto cl : clients)
        {
            const auto db = &cl->database();

            c.connect(db, &JidDb::addedToRoster, &c,
            [&c, db] (const QString jid)
            {
                c.add(db->jid, jid);
            });
        }

        c.exec();
    });

    connect(ui.send, &QPushButton::released, this, &xxcc::send);
    connect(ui.back, &QPushButton::released, this,
    [this]
    {
        ui.sw->setCurrentIndex(Tab::Conversations);
        ui.messages->clear();
        selected = nullptr;
    });

    connect(ui.conversations_list, &QListWidget::itemActivated, this,
    [this] (QListWidgetItem *const it)
    {
        const auto conv = static_cast<const Conversation *>(it);

        for (const auto c : clients)
            if (c->jidBare() == conv->from)
            {
                selected = c;
                break;
            }

        if (selected)
        {
            const auto &db = selected->database();
            static const auto n_messages = 20;
            const auto messages = db.messages(conv->to, n_messages);

            for (auto it = messages.rbegin(); it != messages.rend(); it++)
                new Message(it->body, it->dt, it->direction, ui.messages);
        }

        ui.sw->setCurrentIndex(Tab::Chat);
        ui.jid->setText(conv->to);
        ui.messages->scrollToBottom();
        ui.chatinput->setFocus();
    });

    connect(ui.messages->model(), &QAbstractItemModel::rowsInserted,
        ui.messages, &QListWidget::scrollToBottom);
}

xxcc::~xxcc()
{
    for (const auto c : clients)
        delete c;
}

void xxcc::connectAccounts(const QList<Credentials::Pair> &pairs)
{
    for (const auto &p : pairs)
    {
        QXmppConfiguration cfg;

        cfg.setStreamSecurityMode(QXmppConfiguration::TLSRequired);
        cfg.setJid(p.first);
        cfg.setPassword(p.second);
        cfg.setAutoReconnectionEnabled(true);

        const auto client = new Client(p.first);

        addAccount(client);
        client->connectToServer(cfg);
    }
}

void xxcc::startChat(const QString from, const QString to)
{
    bool found = false;

    for (int i = 0; i < ui.conversations_list->count(); i++)
    {
        const auto it =
            static_cast<const Conversation *>(ui.conversations_list->item(i));

        if (it->from == from && it->to == to)
        {
            found = true;
            break;
        }
    }

    if (!found)
        new Conversation(from, to, ui.conversations_list);

    for (const auto c : clients)
        if (c->jidBare() == from)
        {
            selected = c;
            break;
        }

    ui.sw->setCurrentIndex(Tab::Chat);
    ui.jid->setText(to);
    ui.messages->scrollToBottom();
}

void xxcc::addInMessage(const QXmppMessage &msg)
{
    new Message(msg.body(), msg.stamp().toLocalTime(), Direction::In,
        ui.messages);
}

void xxcc::addOutMessage(const QString &msg, const QDateTime &dt)
{
    new Message(msg, dt.toLocalTime(), Direction::Out,
        ui.messages);
}

void xxcc::addAccount(Client *const c)
{
    c->configuration().setAutoReconnectionEnabled(true);
    clients.append(c);

    c->connect(c, &Client::messageReceived, this,
    [this] (QXmppMessage msg)
    {
        if (msg.body().isEmpty())
            return;
        else if (msg.stamp().isNull())
            msg.setStamp(QDateTime::currentDateTimeUtc());

        storeMessage(msg, Direction::In);

        if (selected)
            addInMessage(msg);
    });

    const auto roster = c->findExtension<QXmppRosterManager>();

    if (roster)
        roster->connect(roster, &QXmppRosterManager::rosterReceived, c,
        [this, c, roster]
        {
            c->database().addToRoster(roster->getRosterBareJids());
        });
    else
        throw std::runtime_error("Expected non-null QXmppRosterManager");
}

#include <QDebug>

void xxcc::send(void)
{
    if (!selected)
        throw std::runtime_error("Expected non-null selected client");

    const auto from = selected->jidBare(),
        to = ui.jid->text(), msg = ui.chatinput->toPlainText();
    QXmppMessage out(from, to, msg);
    const auto dt = QDateTime::currentDateTimeUtc();

    out.setStamp(dt);

    auto fn = [=](const QXmpp::SendResult &&result) mutable
    {
        qDebug() << "result.index(): " << result.index();

        if (std::holds_alternative<QXmpp::SendSuccess>(result))
        {
            const auto &success = std::get<QXmpp::SendSuccess>(result);
            qDebug() << "acknowledged: " << success.acknowledged;
            addOutMessage(msg, dt);
            storeMessage(from, to, msg, dt, Direction::Out);
            ui.chatinput->clear();
        }
        else if (std::holds_alternative<QXmppError>(result))
        {
            const auto &error = std::get<QXmppError>(result);
            qDebug() << error.description;
        }
    };

    if (ui.omemo->isChecked())
    {
        out.setE2eeFallbackBody("[xxcc: This is an OMEMO-encrypted message]");
        // TODO: QXmpp forces OMEMO 2 (XEP-0384 version >= 0.8.0).
        // This breaks compatibility with Dino and Gajim, who still use 0.1.0.
        // out.setEncryptionMethod(QXmpp::Omemo0);

        selected->sendSensitive(std::move(out)).then(this, fn);
    }
    else
        selected->send(std::move(out)).then(this, fn);
}

void xxcc::storeMessage(const QString &from, const QString &to,
    const QString &msg, const QDateTime &dt, const Direction dir) const
{
    QString jid, contact;

    switch (dir)
    {
        case Direction::In:
            jid = QXmppUtils::jidToBareJid(to);
            contact = QXmppUtils::jidToBareJid(from);
            break;

        case Direction::Out:
            jid = from;
            contact = to;
            break;
    }

    for (const auto c : clients)
    {
        if (c->jidBare() == jid)
        {
            const auto &db = c->database();
            JidDb::Message m;

            m.body = msg;
            m.dt = dt;
            m.direction = dir;
            m.contact = contact;
            db.store(m);
        }
    }
}

void xxcc::storeMessage(const QXmppMessage &msg, const Direction dir) const
{
    storeMessage(msg.from(), msg.to(), msg.body(), msg.stamp(), dir);
}

void xxcc::retrieveConversations()
{
    for (const auto c : clients)
    {
        const auto &db = c->database();

        for (const auto &conv : db.conversations())
            new Conversation(db.jid, conv.to,
                ui.conversations_list, conv.last_msg, conv.dt);
    }
}