#include "DeviceIdentityHelper.h"
#include "ConfigHelper.h"
#include <QCryptographicHash>
#include <QDateTime>
#include <QDir>
#include <QEventLoop>
#include <QFile>
#include <QJsonDocument>
#include <QJsonObject>
#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QSaveFile>
#include <QSysInfo>
#include <QUuid>
#ifdef HAVE_OPENSSL
#include <openssl/evp.h>
#include <openssl/pem.h>
#endif
DeviceIdentityHelper::DeviceIdentityHelper(const QString& dir):m_installDir(dir){}
QString DeviceIdentityHelper::deviceId() const{return m_deviceId;}
QString DeviceIdentityHelper::errorString() const{return m_error;}
bool DeviceIdentityHelper::verifySignature(const QByteArray& payload,const QString& sig64){
#ifndef HAVE_OPENSSL
 Q_UNUSED(payload);Q_UNUSED(sig64);m_error="OpenSSL unavailable";return false;
#else
 QFile f(QDir(m_installDir).filePath("config/manifest_public_key.pem")); if(!f.open(QIODevice::ReadOnly)){m_error="device public key missing";return false;}
 QByteArray kd=f.readAll();BIO* b=BIO_new_mem_buf(kd.constData(),kd.size());EVP_PKEY* k=b?PEM_read_bio_PUBKEY(b,nullptr,nullptr,nullptr):nullptr;if(b)BIO_free(b);if(!k){m_error="device public key invalid";return false;}
 EVP_MD_CTX* c=EVP_MD_CTX_new();QByteArray sig=QByteArray::fromBase64(sig64.toUtf8());bool ok=c&&EVP_DigestVerifyInit(c,nullptr,EVP_sha256(),nullptr,k)==1&&EVP_DigestVerifyUpdate(c,payload.constData(),payload.size())==1&&EVP_DigestVerifyFinal(c,reinterpret_cast<const unsigned char*>(sig.constData()),sig.size())==1;if(c)EVP_MD_CTX_free(c);EVP_PKEY_free(k);if(!ok)m_error="device credential RSA signature invalid";return ok;
#endif
}
bool DeviceIdentityHelper::loadAndVerify(const QString& appId,const QString& channel){
 QFile f(QDir(m_installDir).filePath("config/client_identity.dat"));if(!f.open(QIODevice::ReadOnly))return false;QJsonParseError e;auto d=QJsonDocument::fromJson(f.readAll(),&e);if(e.error!=QJsonParseError::NoError||!d.isObject()){m_error="device credential JSON invalid";return false;}auto w=d.object();QByteArray text=w.value("identity_text").toString().toUtf8();if(text.isEmpty()||!verifySignature(text,w.value("signature").toString()))return false;auto identity=QJsonDocument::fromJson(text).object();QDateTime expiry=QDateTime::fromString(identity.value("valid_until").toString(),Qt::ISODate);if(identity.value("app_id").toString()!=appId||identity.value("channel").toString()!=channel||identity.value("license_id").toString().isEmpty()||identity.value("installation_id").toString().isEmpty()||identity.value("device_id").toString().isEmpty()){m_error="device/license credential identity mismatch";return false;}if(!expiry.isValid()||expiry<=QDateTime::currentDateTimeUtc()){m_error="license expired";return false;}m_deviceId=identity.value("device_id").toString();return true;
}
bool DeviceIdentityHelper::verifyLocal(const QString& appId,const QString& channel){m_error.clear();return loadAndVerify(appId,channel);}
bool DeviceIdentityHelper::ensureIssued(const QString& base,const QString& token,const QString& appId,const QString& channel,const QString& licenseKey){
 m_error.clear();if(loadAndVerify(appId,channel)){ConfigHelper::instance().setValue("Update","device_id",m_deviceId);return true;}
 QString installation=ConfigHelper::instance().getValue("Device","installation_id");if(installation.isEmpty()){installation=QUuid::createUuid().toString(QUuid::WithoutBraces);if(!ConfigHelper::instance().setValue("Device","installation_id",installation)){m_error="cannot save installation id";return false;}}
 QByteArray machine=QSysInfo::machineUniqueId()+installation.toUtf8();QString mh=QString::fromLatin1(QCryptographicHash::hash(machine,QCryptographicHash::Sha256).toHex());QJsonObject body{{"app_id",appId},{"channel",channel},{"license_key",licenseKey},{"installation_id",installation},{"machine_hash",mh}};
 QNetworkAccessManager manager;QNetworkRequest req{QUrl(base+"/api/v1/device/issue")};req.setHeader(QNetworkRequest::ContentTypeHeader,"application/json");req.setRawHeader("X-Client-Token",token.toUtf8());QNetworkReply* reply=manager.post(req,QJsonDocument(body).toJson(QJsonDocument::Compact));QEventLoop loop;QObject::connect(reply,&QNetworkReply::finished,&loop,&QEventLoop::quit);loop.exec();int status=reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();QByteArray raw=reply->readAll();reply->deleteLater();if(status!=200){m_error=QString("device issue failed (HTTP %1): %2").arg(status).arg(QString::fromUtf8(raw));return false;}auto response=QJsonDocument::fromJson(raw).object();QJsonObject wrapper{{"identity_text",response.value("identity_text")},{"signature",response.value("signature")}};QString path=QDir(m_installDir).filePath("config/client_identity.dat");QSaveFile out(path);QByteArray bytes=QJsonDocument(wrapper).toJson(QJsonDocument::Compact);if(!out.open(QIODevice::WriteOnly)||out.write(bytes)!=bytes.size()||!out.commit()){m_error="cannot save device credential";return false;}if(!loadAndVerify(appId,channel))return false;if(!ConfigHelper::instance().setValue("Update","device_id",m_deviceId)){m_error="cannot save server device id";return false;}return true;
}