// networksettingspage.cpp — Network configuration form
#include "networksettingspage.h"
#include "../transport/config_updater.h"
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QLabel>
#include <QNetworkInterface>
#include <QFile>
#include <QTextStream>

static const char* SECTION = "server:lan";

NetworkSettingsPage::NetworkSettingsPage(QWidget* parent)
    : QWidget(parent)
{
    auto* layout = new QVBoxLayout(this);
    layout->setSpacing(12);
    layout->setContentsMargins(0, 0, 0, 0);

    auto* title = new QLabel("Listen Address", this);
    title->setStyleSheet("font-weight: bold; font-size: 13px;");
    layout->addWidget(title);

    // Interface
    auto* ifRow = new QHBoxLayout();
    ifRow->addWidget(new QLabel("Interface:", this));
    m_interfaceCombo = new QComboBox(this);
    m_interfaceCombo->setMinimumWidth(180);
    ifRow->addWidget(m_interfaceCombo, 1);
    layout->addLayout(ifRow);

    // IP
    auto* ipRow = new QHBoxLayout();
    ipRow->addWidget(new QLabel("IP Address:", this));
    m_ipCombo = new QComboBox(this);
    m_ipCombo->setEditable(true);
    m_ipCombo->setMinimumWidth(180);
    ipRow->addWidget(m_ipCombo, 1);
    layout->addLayout(ipRow);

    // Port
    auto* portRow = new QHBoxLayout();
    portRow->addWidget(new QLabel("Port:", this));
    m_portSpin = new QSpinBox(this);
    m_portSpin->setRange(1, 65535);
    m_portSpin->setValue(1333);
    m_portSpin->setMinimumWidth(100);
    portRow->addWidget(m_portSpin);
    portRow->addStretch();
    layout->addLayout(portRow);

    // Protocol
    auto* protoRow = new QHBoxLayout();
    protoRow->addWidget(new QLabel("Protocol:", this));
    m_protoCombo = new QComboBox(this);
    m_protoCombo->addItems({"UDP", "TCP"});
    m_protoCombo->setMinimumWidth(100);
    protoRow->addWidget(m_protoCombo);
    protoRow->addStretch();
    layout->addLayout(protoRow);

    auto* note = new QLabel("Changes take effect after restart.", this);
    note->setStyleSheet("color: gray; font-size: 11px;");
    layout->addWidget(note);

    layout->addStretch();

    populateInterfaces();
    connect(m_interfaceCombo, QOverload<int>::of(&QComboBox::currentIndexChanged),
            this, &NetworkSettingsPage::onInterfaceChanged);
}

void NetworkSettingsPage::loadFromConfig(const QString& configPath) {
    // Read [server:lan] section from INI file
    QString addr, netif, transport;
    QFile f(configPath);
    if (f.open(QIODevice::ReadOnly | QIODevice::Text)) {
        bool inSection = false;
        QTextStream in(&f);
        while (!in.atEnd()) {
            QString line = in.readLine();
            if (line.startsWith('[') && line.endsWith(']')) {
                inSection = (line.mid(1, line.length() - 2) == SECTION);
                continue;
            }
            if (!inSection || !line.contains('=')) continue;
            QString key = line.section('=', 0, 0).trimmed();
            QString val = line.section('=', 1).trimmed();
            if (key == "addr") addr = val;
            else if (key == "netif") netif = val;
            else if (key == "transport") transport = val;
        }
        f.close();
    }

    // Parse addr: IP:port
    QString ip;
    if (!addr.isEmpty()) {
        int lastColon = addr.lastIndexOf(':');
        if (lastColon > 0) {
            ip = addr.left(lastColon);
            int port = addr.mid(lastColon + 1).toInt();
            if (port > 0 && port <= 65535) m_portSpin->setValue(port);
        }
    }

    // Set protocol
    int protoIdx = (transport == "tcp") ? 1 : 0;
    m_protoCombo->setCurrentIndex(protoIdx);

    // Set interface
    int ifIdx = m_interfaceCombo->findText(netif);
    if (ifIdx >= 0) m_interfaceCombo->setCurrentIndex(ifIdx);

    // Set IP — populate addresses first, then select
    populateAddresses(netif.isEmpty() ? QString() : netif);
    if (ip.isEmpty() || ip == "0.0.0.0") ip = "Auto (0.0.0.0)";
    int ipIdx = m_ipCombo->findText(ip);
    if (ipIdx >= 0)
        m_ipCombo->setCurrentIndex(ipIdx);
    else
        m_ipCombo->setCurrentText(ip);
}

void NetworkSettingsPage::saveToConfig(const QString& configPath) const {
    // addr
    QString ip = m_ipCombo->currentText().trimmed();
    if (ip.isEmpty() || ip == "Auto (0.0.0.0)") ip = "0.0.0.0";
    config_update_option(configPath, SECTION, "addr",
                         QString("%1:%2").arg(ip).arg(m_portSpin->value()),
                         CONFIG_UPDATE_REPLACE);

    // netif: set or remove (empty value means no netif binding)
    QString iface = m_interfaceCombo->currentText();
    if (iface.startsWith("Auto"))
        iface.clear();
    config_update_option(configPath, SECTION, "netif", iface, CONFIG_UPDATE_REPLACE);

    // transport
    config_update_option(configPath, SECTION, "transport",
                         m_protoCombo->currentText().toLower(),
                         CONFIG_UPDATE_REPLACE);
}

void NetworkSettingsPage::onInterfaceChanged(int index) {
    Q_UNUSED(index);
    QString iface = m_interfaceCombo->currentText();
    populateAddresses(iface.startsWith("Auto") ? QString() : iface);
}

void NetworkSettingsPage::populateInterfaces() {
    m_interfaceCombo->addItem("Auto (any)");
    for (const QNetworkInterface& iface : QNetworkInterface::allInterfaces()) {
        if (iface.flags() & QNetworkInterface::IsLoopBack) continue;
        if (!(iface.flags() & QNetworkInterface::IsUp)) continue;
        m_interfaceCombo->addItem(iface.name());
    }
}

void NetworkSettingsPage::populateAddresses(const QString& ifaceName) {
    QString current = m_ipCombo->currentText();
    m_ipCombo->clear();
    m_ipCombo->addItem("Auto (0.0.0.0)");

    if (ifaceName.isEmpty()) {
        for (const QNetworkInterface& iface : QNetworkInterface::allInterfaces()) {
            if (iface.flags() & QNetworkInterface::IsLoopBack) continue;
            if (!(iface.flags() & QNetworkInterface::IsUp)) continue;
            for (const QNetworkAddressEntry& entry : iface.addressEntries()) {
                if (entry.ip().protocol() == QAbstractSocket::IPv4Protocol)
                    m_ipCombo->addItem(entry.ip().toString());
            }
        }
    } else {
        QNetworkInterface iface = QNetworkInterface::interfaceFromName(ifaceName);
        if (iface.isValid()) {
            for (const QNetworkAddressEntry& entry : iface.addressEntries()) {
                if (entry.ip().protocol() == QAbstractSocket::IPv4Protocol)
                    m_ipCombo->addItem(entry.ip().toString());
            }
        }
    }

    int idx = m_ipCombo->findText(current);
    if (idx >= 0) m_ipCombo->setCurrentIndex(idx);
}