#include "joindialog.h"
#include "invite_link.h"
#include "debug_ui.h"
#include "../transport/utun_node.h"
#include "../transport/gui_bridge.h"
#include "../transport/chat_sync.h"
#include "../db/db_manager.h"
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QPushButton>
#include <QTimer>
#include <QMessageBox>
#include <QApplication>
#include <cstring>

extern "C" {
#include "../../../lib/sha256.h"
}

JoinDialog::JoinDialog(UtunNode* node, DbManager* db, QWidget* parent)
    : QDialog(parent)
    , m_node(node)
    , m_db(db)
{
    setWindowTitle("Join Channel");
    setMinimumWidth(420);
    setModal(true);

    auto *layout = new QVBoxLayout(this);
    layout->setSpacing(12);
    layout->setContentsMargins(20, 16, 20, 16);

    auto *titleLabel = new QLabel("Paste invite link:", this);
    titleLabel->setStyleSheet("font-weight: bold; font-size: 13px;");
    layout->addWidget(titleLabel);

    m_linkEdit = new QLineEdit(this);
    m_linkEdit->setPlaceholderText("utun://...");
    m_linkEdit->setStyleSheet(
        "QLineEdit { border: 1px solid palette(mid); border-radius: 6px;"
        " padding: 8px 12px; font-size: 13px; background: palette(base); }");
    layout->addWidget(m_linkEdit);

    m_statusLabel = new QLabel(this);
    m_statusLabel->setWordWrap(true);
    m_statusLabel->setStyleSheet("color: gray; font-size: 12px; padding: 4px 0;");
    layout->addWidget(m_statusLabel);

    layout->addStretch();

    auto *btnLayout = new QHBoxLayout();
    btnLayout->setSpacing(8);
    btnLayout->addStretch();

    m_cancelBtn = new QPushButton("Cancel", this);
    m_cancelBtn->setFixedWidth(90);
    m_cancelBtn->setStyleSheet(
        "QPushButton { border: 1px solid palette(mid); border-radius: 4px;"
        " padding: 6px 16px; font-size: 13px; background: palette(button); }"
        "QPushButton:hover { background: palette(light); }");
    connect(m_cancelBtn, &QPushButton::clicked, this, &QDialog::reject);
    btnLayout->addWidget(m_cancelBtn);

    m_connectBtn = new QPushButton("Connect", this);
    m_connectBtn->setFixedWidth(90);
    m_connectBtn->setDefault(true);
    m_connectBtn->setStyleSheet(
        "QPushButton { border: none; border-radius: 4px;"
        " padding: 6px 16px; font-size: 13px; font-weight: bold;"
        " background: #3390EC; color: white; }"
        "QPushButton:hover { background: #2B7ED4; }"
        "QPushButton:disabled { background: palette(mid); color: palette(midlight); }");
    connect(m_connectBtn, &QPushButton::clicked, this, &JoinDialog::onConnectClicked);
    btnLayout->addWidget(m_connectBtn);

    layout->addLayout(btnLayout);

    connect(m_linkEdit, &QLineEdit::returnPressed, this, &JoinDialog::onConnectClicked);

    gui_bridge_set_connect_result_cb([](uint64_t nodeId, uint64_t channelId, int result) {
        JoinDialog* dlg = qobject_cast<JoinDialog*>(QApplication::activeModalWidget());
        if (dlg) dlg->onConnectResult(nodeId, channelId, result);
    });
}

JoinDialog::~JoinDialog() {
    gui_bridge_set_connect_result_cb(nullptr);
}

void JoinDialog::setStatus(const QString& text, bool isError) {
    if (isError)
        m_statusLabel->setStyleSheet("color: #D0021B; font-size: 12px; padding: 4px 0;");
    else
        m_statusLabel->setStyleSheet("color: gray; font-size: 12px; padding: 4px 0;");
    m_statusLabel->setText(text);
}

void JoinDialog::onConnectClicked() {
    if (m_connecting) return;
    QString link = m_linkEdit->text().trimmed();
    if (link.isEmpty()) {
        setStatus("Enter an invite link.", true);
        return;
    }

    setStatus("Parsing link...");
    InviteData d = decodeInviteLink(link);
    if (!d.error.isEmpty()) {
        setStatus("Invalid invite link: " + d.error, true);
        return;
    }
    if (d.pubkey.size() != 32) {
        setStatus(QString("Invalid invite link: pubkey is %1 bytes (need 32)").arg(d.pubkey.size()), true);
        return;
    }
    if (d.addrs.isEmpty()) {
        setStatus("No peer addresses in the invite link.", true);
        return;
    }

    uint8_t hash[32];
    SC_SHA256_CTX ctx;
    sc_sha256_init(&ctx);
    sc_sha256_update(&ctx, (const uint8_t*)d.pubkey.constData(), 32);
    sc_sha256_final(&ctx, hash);
    uint64_t nodeId;
    memcpy(&nodeId, hash, sizeof(nodeId));
    nodeId &= 0x7FFFFFFFFFFFFFFFULL;

    GUI_INFO("join: decoded invite ch=%llu pubkey=%016llx... nodeId=0x%016llx addrs=%d",
             d.channelId, *(const uint64_t*)d.pubkey.constData(), nodeId, d.addrs.size());

    m_pendingNodeId = nodeId;
    m_pendingChannelId = d.channelId;
    m_connecting = true;
    m_connectBtn->setEnabled(false);
    m_linkEdit->setReadOnly(true);

    setStatus("Connecting to peer...");

    QByteArray addrsBuf;
    for (const auto& a : d.addrs) {
        addrsBuf.append(static_cast<char>(a.family));
        addrsBuf.append(a.address);
        addrsBuf.append(static_cast<char>((a.port >> 8) & 0xFF));
        addrsBuf.append(static_cast<char>(a.port & 0xFF));
    }

    int addrCount = d.addrs.size();

    chat_sync_connect_from_invite(d.channelId, nodeId,
        (const uint8_t*)d.pubkey.constData(),
        (const uint8_t*)addrsBuf.constData(), addrCount);
}

void JoinDialog::onConnectResult(uint64_t nodeId, uint64_t channelId, int result) {
    if (!m_connecting || nodeId != m_pendingNodeId) return;

    if (result == 0) {
        setStatus("Connected! Waiting for channel data...");
        QTimer::singleShot(800, this, [this] {
            QString cid = QString::number(m_pendingChannelId);
            emit joined(cid);
            accept();
        });
    } else {
        m_connecting = false;
        m_connectBtn->setEnabled(true);
        m_linkEdit->setReadOnly(false);
        m_connectBtn->setFocus();

        const char* errMsg = "Unknown error.";
        switch (result) {
            case -1: errMsg = "Channel not found."; break;
            case -3: errMsg = "Connection timed out."; break;
            case -4: errMsg = "Peer is unreachable."; break;
            case -6: errMsg = "Already connected to this peer."; break;
            default: break;
        }
        setStatus(QString("Connection failed: %1").arg(errMsg), true);
    }
}