#include "licensedata.h"
#include <QDataStream>
#include <QtDebug>

LicenseData::LicenseData()
    : productId(0), verMajor(0), verMinor(0), activeState(0)
{
}

QByteArray LicenseData::toBinary() const
{
    QByteArray data;
    data.reserve(64);
    QDataStream stream(&data, QIODevice::WriteOnly);
    stream.setByteOrder(QDataStream::BigEndian);

    // 1. 主板UUID：固定16字节
    QByteArray uuid = boardUuid.left(16);
    uuid.append(QByteArray(16 - uuid.size(), '\0'));
    stream.writeRawData(uuid.constData(), 16);

    // 2. CPU序列号：固定8字节
    QByteArray cpu = cpuSerial.left(8);
    cpu.append(QByteArray(8 - cpu.size(), '\0'));
    stream.writeRawData(cpu.constData(), 8);

    // 3. 用户名：长度前缀(1B) + UTF-8数据
    QByteArray userBytes = userName.toUtf8();
    if (userBytes.size() > 255) {
        userBytes = userBytes.left(255);
    }
    stream << static_cast<quint8>(userBytes.size());
    stream.writeRawData(userBytes.constData(), userBytes.size());

    // 4. 失效日期：2字节（距2000-01-01的天数）
    stream << dateToDays(expireDate);

    // 5. 产品号：1字节
    stream << productId;

    // 6. 版本号：主版本 + 次版本，各1字节
    stream << verMajor << verMinor;

    // 7. 激活状态：1字节
    stream << activeState;

    return data;
}

bool LicenseData::fromBinary(const QByteArray &data)
{
    if (data.size() < 30) {
        qWarning() << "LicenseData::fromBinary: data too short, need at least 30 bytes";
        return false;
    }

    QDataStream stream(data);
    stream.setByteOrder(QDataStream::BigEndian);

    // 1. UUID
    boardUuid.resize(16);
    stream.readRawData(boardUuid.data(), 16);

    // 2. CPU序列号
    cpuSerial.resize(8);
    stream.readRawData(cpuSerial.data(), 8);

    // 3. 用户名
    quint8 nameLen = 0;
    stream >> nameLen;
    if (data.size() < 25 + nameLen + 5) {
        qWarning() << "LicenseData::fromBinary: insufficient data for remaining fields";
        return false;
    }
    QByteArray userBytes(nameLen, '\0');
    stream.readRawData(userBytes.data(), nameLen);
    userName = QString::fromUtf8(userBytes);

    // 4. 日期
    quint16 days = 0;
    stream >> days;
    expireDate = daysToDate(days);

    // 5. 产品号
    stream >> productId;

    // 6. 版本
    stream >> verMajor >> verMinor;

    // 7. 激活状态
    stream >> activeState;

    return true;
}

QString LicenseData::toDebugString() const
{
    return QString("{UUID:%1, CPU:%2, User:%3, Expire:%4, Prod:%5, Ver:%6.%7, State:%8}")
        .arg(uuidBinaryToString(boardUuid))
        .arg(binaryToHexString(cpuSerial))
        .arg(userName)
        .arg(expireDate.toString("yyyy-MM-dd"))
        .arg(productId)
        .arg(verMajor).arg(verMinor)
        .arg(activeState);
}

quint16 LicenseData::dateToDays(const QDate &date) const
{
    QDate base(BASE_YEAR, BASE_MONTH, BASE_DAY);
    if (!date.isValid() || date < base) {
        return 0;
    }
    return static_cast<quint16>(base.daysTo(date));
}

QDate LicenseData::daysToDate(quint16 days) const
{
    QDate base(BASE_YEAR, BASE_MONTH, BASE_DAY);
    return base.addDays(days);
}

QByteArray LicenseData::uuidStringToBinary(const QString &uuidStr)
{
    QString clean = uuidStr;
    clean.remove('-');
    clean.remove('{');
    clean.remove('}');
    clean = clean.toUpper();
    if (clean.size() != 32) {
        return QByteArray();
    }
    return hexStringToBinary(clean);
}

QString LicenseData::uuidBinaryToString(const QByteArray &bin)
{
    if (bin.size() != 16) {
        return QString();
    }
    QString hex = binaryToHexString(bin);
    return QString("%1-%2-%3-%4-%5")
        .arg(hex.mid(0, 8))
        .arg(hex.mid(8, 4))
        .arg(hex.mid(12, 4))
        .arg(hex.mid(16, 4))
        .arg(hex.mid(20, 12));
}

QByteArray LicenseData::hexStringToBinary(const QString &hexStr)
{
    QString clean = hexStr;
    clean.remove(' ');
    QByteArray result;
    result.reserve(clean.size() / 2);
    for (int i = 0; i + 1 < clean.size(); i += 2) {
        bool ok;
        result.append(static_cast<char>(clean.mid(i, 2).toUInt(&ok, 16)));
    }
    return result;
}

QString LicenseData::binaryToHexString(const QByteArray &bin)
{
    return QString::fromLatin1(bin.toHex()).toUpper();
}