#include "ftpshareplugin.h"

#include <KPluginFactory>
#include <KLocalizedString>

#include <QFormLayout>
#include <QGroupBox>
#include <QInputDialog>
#include <QLabel>
#include <QMessageBox>
#include <QProcess>
#include <QScrollArea>
#include <QVBoxLayout>

K_PLUGIN_CLASS_WITH_JSON(FtpSharePlugin, "ftpshareplugin.json")

// Permission levels for the combo boxes
static const QStringList permissionLabels = {
    QStringLiteral("---"),
    QStringLiteral("Read Only"),
    QStringLiteral("Read-Write")
};

// Map combo index to ACL string
static QString aclForIndex(int index)
{
    switch (index) {
    case 1: return QStringLiteral("ro");
    case 2: return QStringLiteral("rw");
    default: return QString();
    }
}

// Map ACL string back to combo index
static int indexForAcl(const QString &acl)
{
    if (acl == QLatin1String("ro")) return 1;
    if (acl == QLatin1String("rw")) return 2;
    return 0;
}

// Check if a virtual FTP user exists
static bool ftpUserExists(const QString &username)
{
    QProcess proc;
    proc.start(QStringLiteral("dolphin-ftp-share"),
               {QStringLiteral("userexists"), username});
    proc.waitForFinished(5000);
    return proc.exitCode() == 0;
}

// Create a virtual FTP user with password
static bool createFtpUser(const QString &username, const QString &password)
{
    QProcess proc;
    proc.start(QStringLiteral("dolphin-ftp-share"),
               {QStringLiteral("passwd"), username, password});
    proc.waitForFinished(5000);
    return proc.exitCode() == 0;
}

// Get list of local users (UID >= 1000, excluding nobody)
static QStringList getLocalUsers()
{
    QStringList users;
    QFile passwd(QStringLiteral("/etc/passwd"));
    if (passwd.open(QIODevice::ReadOnly | QIODevice::Text)) {
        while (!passwd.atEnd()) {
            const QString line = QString::fromLocal8Bit(passwd.readLine()).trimmed();
            if (line.isEmpty() || line.startsWith(QLatin1Char('#')))
                continue;
            const QStringList fields = line.split(QLatin1Char(':'));
            if (fields.size() < 7)
                continue;
            const int uid = fields[2].toInt();
            const QString shell = fields[6];
            if (uid >= 1000 && uid < 65534
                && !shell.endsWith(QLatin1String("/nologin"))
                && !shell.endsWith(QLatin1String("/false"))) {
                users << fields[0];
            }
        }
    }
    return users;
}

FtpSharePlugin::FtpSharePlugin(QObject *parent, const QVariantList &args)
    : KPropertiesDialogPlugin(qobject_cast<KPropertiesDialog *>(parent))
{
    Q_UNUSED(args)

    m_path = properties->item().localPath();
    if (m_path.isEmpty())
        return;

    // Default share name = folder name
    m_defaultShareName = m_path.section(QLatin1Char('/'), -1);

    // --- Build the UI ---
    m_page = new QWidget();
    auto *mainLayout = new QVBoxLayout(m_page);

    // Share checkbox
    m_shareCheckBox = new QCheckBox(
        i18n("Share this folder via FTP"));
    mainLayout->addWidget(m_shareCheckBox);

    // Share name
    auto *nameLayout = new QFormLayout();
    m_nameEdit = new QLineEdit(m_defaultShareName);
    nameLayout->addRow(i18n("Name:"), m_nameEdit);
    mainLayout->addLayout(nameLayout);

    // User permissions section
    auto *usersGroup = new QGroupBox(i18n("User Permissions"));
    auto *usersLayout = new QVBoxLayout(usersGroup);

    // Scroll area for user list
    auto *scrollArea = new QScrollArea();
    scrollArea->setWidgetResizable(true);
    scrollArea->setFrameShape(QFrame::NoFrame);

    m_usersWidget = new QWidget();
    auto *usersFormLayout = new QFormLayout(m_usersWidget);
    usersFormLayout->setContentsMargins(0, 0, 0, 0);

    // Add local users
    const QStringList users = getLocalUsers();
    for (const QString &user : users) {
        auto *combo = new QComboBox();
        combo->addItems(permissionLabels);
        combo->setCurrentIndex(0); // Default: ---
        usersFormLayout->addRow(user, combo);
        m_userPerms.append({user, combo});
        connect(combo, QOverload<int>::of(&QComboBox::currentIndexChanged),
                this, [this]() { setDirty(true); });
    }

    scrollArea->setWidget(m_usersWidget);
    usersLayout->addWidget(scrollArea);
    mainLayout->addWidget(usersGroup);

    // Change password section
    auto *pwGroup = new QGroupBox(i18n("FTP Password"));
    auto *pwLayout = new QHBoxLayout(pwGroup);
    m_pwUserCombo = new QComboBox();
    m_pwUserCombo->addItems(users);
    auto *pwButton = new QPushButton(i18n("Change Password..."));
    pwLayout->addWidget(m_pwUserCombo);
    pwLayout->addWidget(pwButton);
    mainLayout->addWidget(pwGroup);

    connect(pwButton, &QPushButton::clicked, this, &FtpSharePlugin::onChangePassword);

    mainLayout->addStretch();

    // Connect signals
    connect(m_shareCheckBox, &QCheckBox::toggled,
            this, &FtpSharePlugin::onShareToggled);
    connect(m_nameEdit, &QLineEdit::textChanged,
            this, [this]() { setDirty(true); });

    // Load existing share info
    loadCurrentShare();

    // Initial UI state
    onShareToggled(m_shareCheckBox->isChecked());

    // Add the page as a tab
    properties->addPage(m_page, i18n("FTP"));
}

void FtpSharePlugin::onShareToggled(bool checked)
{
    m_nameEdit->setEnabled(checked);
    m_usersWidget->setEnabled(checked);
    setDirty(true);
}

void FtpSharePlugin::loadCurrentShare()
{
    // Run: dolphin-ftp-share info
    QProcess proc;
    proc.start(QStringLiteral("dolphin-ftp-share"),
               {QStringLiteral("info")});
    proc.waitForFinished(5000);

    const QString output = QString::fromLocal8Bit(proc.readAllStandardOutput());
    if (output.isEmpty())
        return;

    // Parse the output to find a share matching our path
    // Format:
    // [sharename]
    // path=/some/path
    // user_acl=user1:rw,user2:ro
    QString currentSection;
    QString sharePath;
    QString shareAcl;

    const QStringList lines = output.split(QLatin1Char('\n'));
    for (const QString &line : lines) {
        if (line.startsWith(QLatin1Char('['))) {
            // If we had a previous section that matched, break
            if (!currentSection.isEmpty() && sharePath == m_path)
                break;

            // New section
            currentSection = line.mid(1, line.indexOf(QLatin1Char(']')) - 1);
            sharePath.clear();
            shareAcl.clear();
        } else if (line.startsWith(QLatin1String("path="))) {
            sharePath = line.mid(5);
        } else if (line.startsWith(QLatin1String("user_acl="))) {
            shareAcl = line.mid(9);
        }
    }

    // Check if last section matched
    if (sharePath != m_path)
        return;

    // Found an existing share!
    m_isShared = true;
    m_originalShareName = currentSection;
    m_shareCheckBox->setChecked(true);
    m_nameEdit->setText(currentSection);

    // Parse ACL: "user1:rw,user2:ro"
    if (!shareAcl.isEmpty()) {
        const QStringList aclEntries = shareAcl.split(QLatin1Char(','));
        for (const QString &entry : aclEntries) {
            const int colonPos = entry.lastIndexOf(QLatin1Char(':'));
            if (colonPos < 0)
                continue;
            const QString name = entry.left(colonPos);
            const QString perm = entry.mid(colonPos + 1);

            for (auto &up : m_userPerms) {
                if (up.username.compare(name, Qt::CaseInsensitive) == 0) {
                    up.combo->setCurrentIndex(indexForAcl(perm));
                    break;
                }
            }
        }
    }

    // Reset dirty state after loading
    setDirty(false);
}

void FtpSharePlugin::applyChanges()
{
    const bool wantShared = m_shareCheckBox->isChecked();
    const QString shareName = m_nameEdit->text().trimmed();

    // If unchecked and was previously shared, delete the share
    if (!wantShared && m_isShared) {
        QProcess proc;
        proc.start(QStringLiteral("dolphin-ftp-share"),
                   {QStringLiteral("delete"), m_originalShareName});
        proc.waitForFinished(5000);
        m_isShared = false;
        m_originalShareName.clear();
        return;
    }

    if (!wantShared)
        return;

    // If name changed, delete old share first
    if (m_isShared && !m_originalShareName.isEmpty()
        && m_originalShareName != shareName) {
        QProcess proc;
        proc.start(QStringLiteral("dolphin-ftp-share"),
                   {QStringLiteral("delete"), m_originalShareName});
        proc.waitForFinished(5000);
    }

    // Create FTP users for users that have permissions but no FTP account yet
    for (const auto &up : m_userPerms) {
        if (up.combo->currentIndex() == 0)
            continue; // No permission set, skip

        if (ftpUserExists(up.username))
            continue; // Already has FTP account

        // Ask for FTP password
        bool ok = false;
        const QString password = QInputDialog::getText(
            m_page,
            i18n("FTP Password"),
            i18n("Set FTP password for user '%1':", up.username),
            QLineEdit::Password,
            QString(),
            &ok);

        if (!ok || password.isEmpty()) {
            QMessageBox::warning(m_page,
                i18n("FTP Share"),
                i18n("No password set for '%1'. This user will be skipped.", up.username));
            up.combo->setCurrentIndex(0);
            continue;
        }

        if (!createFtpUser(up.username, password)) {
            QMessageBox::warning(m_page,
                i18n("FTP Share"),
                i18n("Failed to create FTP user '%1'.", up.username));
            up.combo->setCurrentIndex(0);
            continue;
        }
    }

    // Build ACL string
    QStringList aclParts;
    for (const auto &up : m_userPerms) {
        const QString acl = aclForIndex(up.combo->currentIndex());
        if (!acl.isEmpty()) {
            aclParts << up.username + QLatin1Char(':') + acl;
        }
    }

    const QString aclString = aclParts.join(QLatin1Char(','));

    // dolphin-ftp-share add <name> <path> <acl>
    QProcess proc;
    proc.start(QStringLiteral("dolphin-ftp-share"),
               {QStringLiteral("add"), shareName, m_path, aclString});
    proc.waitForFinished(5000);

    if (proc.exitCode() == 0) {
        m_isShared = true;
        m_originalShareName = shareName;
    }
}

void FtpSharePlugin::onChangePassword()
{
    const QString username = m_pwUserCombo->currentText();
    if (username.isEmpty())
        return;

    if (!ftpUserExists(username)) {
        QMessageBox::information(m_page,
            i18n("FTP Password"),
            i18n("User '%1' has no FTP account yet.\nSet permissions for this user first.", username));
        return;
    }

    bool ok = false;
    const QString password = QInputDialog::getText(
        m_page,
        i18n("FTP Password"),
        i18n("New FTP password for '%1':", username),
        QLineEdit::Password,
        QString(),
        &ok);

    if (!ok || password.isEmpty())
        return;

    if (createFtpUser(username, password)) {
        QMessageBox::information(m_page,
            i18n("FTP Password"),
            i18n("Password for '%1' updated.", username));
    } else {
        QMessageBox::warning(m_page,
            i18n("FTP Password"),
            i18n("Failed to update password for '%1'.", username));
    }
}

#include "ftpshareplugin.moc"