/*
 * Author: Sven Gothel <sgothel@jausoft.com>
 * Copyright (c) 2020 Gothel Software e.K.
 * Copyright (c) 2020 ZAFENA AB
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#include <cstring>
#include <string>
#include <memory>
#include <cstdint>
#include <cstdio>

#include <algorithm>

// #define PERF_PRINT_ON 1
#include <jau/debug.hpp>

#include <jau/environment.hpp>
#include <jau/basic_algos.hpp>
#include <jau/packed_attribute.hpp>

#include "BTIoctl.hpp"

#include "HCIIoctl.hpp"
#include "HCIComm.hpp"
#include "HCIHandler.hpp"
#include "DBTTypes.hpp"

extern "C" {
    #include <inttypes.h>
    #include <unistd.h>
    #include <poll.h>
    #include <signal.h>
    #ifdef __linux__
        #include <sys/ioctl.h>
    #endif
}

using namespace direct_bt;

HCIEnv::HCIEnv() noexcept
: exploding( jau::environment::getExplodingProperties("direct_bt.hci") ),
  HCI_READER_THREAD_POLL_TIMEOUT( jau::environment::getInt32Property("direct_bt.hci.reader.timeout", 10000, 1500 /* min */, INT32_MAX /* max */) ),
  HCI_COMMAND_STATUS_REPLY_TIMEOUT( jau::environment::getInt32Property("direct_bt.hci.cmd.status.timeout", 3000, 1500 /* min */, INT32_MAX /* max */) ),
  HCI_COMMAND_COMPLETE_REPLY_TIMEOUT( jau::environment::getInt32Property("direct_bt.hci.cmd.complete.timeout", 10000, 1500 /* min */, INT32_MAX /* max */) ),
  HCI_COMMAND_POLL_PERIOD( jau::environment::getInt32Property("direct_bt.hci.cmd.poll.period", 125, 50 /* min */, INT32_MAX /* max */) ),
  HCI_EVT_RING_CAPACITY( jau::environment::getInt32Property("direct_bt.hci.ringsize", 64, 64 /* min */, 1024 /* max */) ),
  DEBUG_EVENT( jau::environment::getBooleanProperty("direct_bt.debug.hci.event", false) ),
  HCI_READ_PACKET_MAX_RETRY( HCI_EVT_RING_CAPACITY )
{
}

const pid_t HCIHandler::pidSelf = getpid();

__pack( struct hci_rp_status {
    __u8    status;
} );

HCIHandler::HCIConnectionRef HCIHandler::addOrUpdateHCIConnection(jau::darray<HCIConnectionRef> &list,
                                                      const BDAddressAndType& addressAndType, const uint16_t handle) noexcept {
    const std::lock_guard<std::recursive_mutex> lock(mtx_connectionList); // RAII-style acquire and relinquish via destructor
    // remove all old entry with given address first
    auto end = list.end();
    for (auto it = list.begin(); it != end; ++it) {
        HCIConnectionRef conn = *it;
        if ( conn->equals(addressAndType) ) {
            // reuse same entry
            WORDY_PRINT("HCIHandler::addTrackerConnection: address%s, handle %s: reuse entry %s - %s",
               addressAndType.toString().c_str(), jau::uint16HexString(handle).c_str(),
               conn->toString().c_str(), toString().c_str());
            // Overwrite tracked connection handle with given _valid_ handle only, i.e. non zero!
            if( 0 != handle ) {
                if( 0 != conn->getHandle() && handle != conn->getHandle() ) {
                    WARN_PRINT("HCIHandler::addTrackerConnection: address%s, handle %s: reusing entry %s, overwriting non-zero handle - %s",
                       addressAndType.toString().c_str(), jau::uint16HexString(handle).c_str(),
                       conn->toString().c_str(), toString().c_str());
                }
                conn->setHandle( handle );
            }
            return conn; // done
        }
    }
    HCIConnectionRef res( new HCIConnection(addressAndType, handle) );
    list.push_back( res );
    return res;
}

HCIHandler::HCIConnectionRef HCIHandler::findHCIConnection(jau::darray<HCIConnectionRef> &list, const BDAddressAndType& addressAndType) noexcept {
    const std::lock_guard<std::recursive_mutex> lock(mtx_connectionList); // RAII-style acquire and relinquish via destructor
    const jau::nsize_t size = list.size();
    for (jau::nsize_t i = 0; i < size; i++) {
        HCIConnectionRef & e = list[i];
        if( e->equals(addressAndType) ) {
            return e;
        }
    }
    return nullptr;
}

HCIHandler::HCIConnectionRef HCIHandler::findTrackerConnection(const uint16_t handle) noexcept {
    const std::lock_guard<std::recursive_mutex> lock(mtx_connectionList); // RAII-style acquire and relinquish via destructor
    const jau::nsize_t size = connectionList.size();
    for (jau::nsize_t i = 0; i < size; i++) {
        HCIConnectionRef & e = connectionList[i];
        if ( handle == e->getHandle() ) {
            return e;
        }
    }
    return nullptr;
}

HCIHandler::HCIConnectionRef HCIHandler::removeTrackerConnection(const HCIConnectionRef conn) noexcept {
    const std::lock_guard<std::recursive_mutex> lock(mtx_connectionList); // RAII-style acquire and relinquish via destructor
    auto end = connectionList.end();
    for (auto it = connectionList.begin(); it != end; ++it) {
        HCIConnectionRef e = *it;
        if ( *e == *conn ) {
            connectionList.erase(it);
            return e; // done
        }
    }
    return nullptr;
}
int HCIHandler::countPendingTrackerConnections() noexcept {
    const std::lock_guard<std::recursive_mutex> lock(mtx_connectionList); // RAII-style acquire and relinquish via destructor
    int count = 0;
    for (auto it = connectionList.begin(); it != connectionList.end(); it++) {
        HCIConnectionRef e = *it;
        if ( e->getHandle() == 0 ) {
            count++;
        }
    }
    return count;
}
HCIHandler::HCIConnectionRef HCIHandler::removeHCIConnection(jau::darray<HCIConnectionRef> &list, const uint16_t handle) noexcept {
    const std::lock_guard<std::recursive_mutex> lock(mtx_connectionList); // RAII-style acquire and relinquish via destructor
    auto end = list.end();
    for (auto it = list.begin(); it != end; ++it) {
        HCIConnectionRef e = *it;
        if ( e->getHandle() == handle ) {
            list.erase(it);
            return e; // done
        }
    }
    return nullptr;
}

void HCIHandler::clearAllStates() noexcept {
    const std::lock_guard<std::recursive_mutex> lock(mtx_connectionList); // RAII-style acquire and relinquish via destructor
    connectionList.clear();
    disconnectCmdList.clear();
    currentScanType = ScanType::NONE;
}

MgmtEvent::Opcode HCIHandler::translate(HCIEventType evt, HCIMetaEventType met) noexcept {
    if( HCIEventType::LE_META == evt ) {
        switch( met ) {
            case HCIMetaEventType::LE_CONN_COMPLETE: return MgmtEvent::Opcode::DEVICE_CONNECTED;
            default: return MgmtEvent::Opcode::INVALID;
        }
    }
    switch( evt ) {
        case HCIEventType::CONN_COMPLETE: return MgmtEvent::Opcode::DEVICE_CONNECTED;
        case HCIEventType::DISCONN_COMPLETE: return MgmtEvent::Opcode::DEVICE_DISCONNECTED;
        case HCIEventType::CMD_COMPLETE: return MgmtEvent::Opcode::CMD_COMPLETE;
        case HCIEventType::CMD_STATUS: return MgmtEvent::Opcode::CMD_STATUS;
        default: return MgmtEvent::Opcode::INVALID;
    }
}

std::unique_ptr<MgmtEvent> HCIHandler::translate(HCIEvent& ev) noexcept {
    const HCIEventType evt = ev.getEventType();
    const HCIMetaEventType mevt = ev.getMetaEventType();

    if( HCIEventType::LE_META == evt ) {
        switch( mevt ) {
            case HCIMetaEventType::LE_CONN_COMPLETE: {
                HCIStatusCode status;
                const hci_ev_le_conn_complete * ev_cc = getMetaReplyStruct<hci_ev_le_conn_complete>(ev, mevt, &status);
                if( nullptr == ev_cc ) {
                    ERR_PRINT("HCIHandler::translate(reader): LE_CONN_COMPLETE: Null reply-struct: %s - %s",
                            ev.toString().c_str(), toString().c_str());
                    return nullptr;
                }
                const HCILEPeerAddressType hciAddrType = static_cast<HCILEPeerAddressType>(ev_cc->bdaddr_type);
                const BDAddressAndType addressAndType(ev_cc->bdaddr, getBDAddressType(hciAddrType));
                const uint16_t handle = jau::le_to_cpu(ev_cc->handle);
                const HCIConnectionRef conn = addOrUpdateTrackerConnection(addressAndType, handle);
                if( HCIStatusCode::SUCCESS == status ) {
                    return std::make_unique<MgmtEvtDeviceConnected>(dev_id, addressAndType, handle);
                } else {
                    removeTrackerConnection(conn);
                    return std::make_unique<MgmtEvtDeviceConnectFailed>(dev_id, addressAndType, status);
                }
            }
            case HCIMetaEventType::LE_REMOTE_FEAT_COMPLETE: {
                HCIStatusCode status;
                const hci_ev_le_remote_feat_complete * ev_cc = getMetaReplyStruct<hci_ev_le_remote_feat_complete>(ev, mevt, &status);
                if( nullptr == ev_cc ) {
                    ERR_PRINT("HCIHandler::translate(reader): LE_REMOTE_FEAT_COMPLETE: Null reply-struct: %s - %s",
                            ev.toString().c_str(), toString().c_str());
                    return nullptr;
                }
                const uint16_t handle = jau::le_to_cpu(ev_cc->handle);
                const LEFeatures features = static_cast<LEFeatures>(jau::get_uint64(ev_cc->features, 0, true /* littleEndian */));
                const HCIConnectionRef conn = findTrackerConnection(handle);
                if( nullptr == conn ) {
                    WARN_PRINT("HCIHandler::translate(reader): LE_REMOTE_FEAT_COMPLETE: Not tracked conn_handle %s: %s",
                            jau::uint16HexString(handle).c_str(), conn->toString().c_str());
                    return nullptr;
                }
                if( HCIStatusCode::SUCCESS != status ) {
                    WARN_PRINT("HCIHandler::translate(reader): LE_REMOTE_FEAT_COMPLETE: Failed: Status %s, Handle %s: %s",
                            getHCIStatusCodeString(status).c_str(), jau::uint16HexString(handle).c_str(), conn->toString().c_str());
                    return nullptr;
                }
                return std::make_unique<MgmtEvtHCILERemoteUserFeatures>(dev_id, conn->getAddressAndType(), features);
            }
            default:
                return nullptr;
        }
    }
    switch( evt ) {
        case HCIEventType::CONN_COMPLETE: {
            HCIStatusCode status;
            const hci_ev_conn_complete * ev_cc = getReplyStruct<hci_ev_conn_complete>(ev, evt, &status);
            if( nullptr == ev_cc ) {
                ERR_PRINT("HCIHandler::translate(reader): CONN_COMPLETE: Null reply-struct: %s - %s",
                        ev.toString().c_str(), toString().c_str());
                return nullptr;
            }
            const BDAddressAndType addressAndType(ev_cc->bdaddr, BDAddressType::BDADDR_BREDR);
            HCIConnectionRef conn = addOrUpdateTrackerConnection(addressAndType, ev_cc->handle);
            if( HCIStatusCode::SUCCESS == status ) {
                return std::make_unique<MgmtEvtDeviceConnected>(dev_id, conn->getAddressAndType(), conn->getHandle());
            } else {
                std::unique_ptr<MgmtEvent> res( new MgmtEvtDeviceConnectFailed(dev_id, conn->getAddressAndType(),status) );
                removeTrackerConnection(conn);
                return res;
            }
        }
        case HCIEventType::DISCONN_COMPLETE: {
            HCIStatusCode status;
            const hci_ev_disconn_complete * ev_cc = getReplyStruct<hci_ev_disconn_complete>(ev, evt, &status);
            if( nullptr == ev_cc ) {
                ERR_PRINT("HCIHandler::translate(reader): DISCONN_COMPLETE: Null reply-struct: %s - %s",
                        ev.toString().c_str(), toString().c_str());
                return nullptr;
            }
            removeDisconnectCmd(ev_cc->handle);
            HCIConnectionRef conn = removeTrackerConnection(ev_cc->handle);
            if( nullptr == conn ) {
                WORDY_PRINT("HCIHandler::translate(reader): DISCONN_COMPLETE: Not tracked handle %s: %s - %s",
                        jau::uint16HexString(ev_cc->handle).c_str(), ev.toString().c_str(), toString().c_str());
                return nullptr;
            } else {
                if( HCIStatusCode::SUCCESS != status ) {
                    // FIXME: Ever occuring? Still sending out essential disconnect event!
                    ERR_PRINT("HCIHandler::translate(reader): DISCONN_COMPLETE: !SUCCESS[%s, %s], %s: %s - %s",
                            jau::uint8HexString(static_cast<uint8_t>(status)).c_str(), getHCIStatusCodeString(status).c_str(),
                            conn->toString().c_str(), ev.toString().c_str(), toString().c_str());
                }
                const HCIStatusCode hciRootReason = static_cast<HCIStatusCode>(ev_cc->reason);
                return std::make_unique<MgmtEvtDeviceDisconnected>(dev_id, conn->getAddressAndType(), hciRootReason, conn->getHandle());
            }
        }
        case HCIEventType::ENCRYPT_CHANGE: {
            HCIStatusCode status;
            const hci_ev_encrypt_change * ev_cc = getReplyStruct<hci_ev_encrypt_change>(ev, evt, &status);
            if( nullptr == ev_cc ) {
                ERR_PRINT("HCIHandler::translate(reader): ENCRYPT_CHANGE: Null reply-struct: %s - %s",
                        ev.toString().c_str(), toString().c_str());
                return nullptr;
            }
            const uint16_t handle = jau::le_to_cpu(ev_cc->handle);
            const HCIConnectionRef conn = findTrackerConnection(handle);
            if( nullptr == conn ) {
                WARN_PRINT("HCIHandler::translate(reader): ENCRYPT_CHANGE: Not tracked conn_handle %s: %s",
                        jau::uint16HexString(handle).c_str(), conn->toString().c_str());
                return nullptr;
            }
            return std::make_unique<MgmtEvtHCIEncryptionChanged>(dev_id, conn->getAddressAndType(), status, ev_cc->encrypt);
        }
        case HCIEventType::ENCRYPT_KEY_REFRESH_COMPLETE: {
            HCIStatusCode status;
            const hci_ev_key_refresh_complete * ev_cc = getReplyStruct<hci_ev_key_refresh_complete>(ev, evt, &status);
            if( nullptr == ev_cc ) {
                ERR_PRINT("HCIHandler::translate(reader): ENCRYPT_KEY_REFRESH_COMPLETE: Null reply-struct: %s - %s",
                        ev.toString().c_str(), toString().c_str());
                return nullptr;
            }
            const uint16_t handle = jau::le_to_cpu(ev_cc->handle);
            const HCIConnectionRef conn = findTrackerConnection(handle);
            if( nullptr == conn ) {
                WARN_PRINT("HCIHandler::translate(reader): ENCRYPT_KEY_REFRESH_COMPLETE: Not tracked conn_handle %s: %s",
                        jau::uint16HexString(handle).c_str(), conn->toString().c_str());
                return nullptr;
            }
            return std::make_unique<MgmtEvtHCIEncryptionKeyRefreshComplete>(dev_id, conn->getAddressAndType(), status);
        }
        // TODO: AUTH_COMPLETE
        // 7.7.6 AUTH_COMPLETE 0x06

        default:
            return nullptr;
    }
}

std::unique_ptr<const SMPPDUMsg> HCIHandler::getSMPPDUMsg(const HCIACLData::l2cap_frame & l2cap, const uint8_t * l2cap_data) const noexcept {
    if( nullptr != l2cap_data && 0 < l2cap.len && l2cap.isSMP() ) {
        return SMPPDUMsg::getSpecialized(l2cap_data, l2cap.len);
    }
    return nullptr;
}

void HCIHandler::hciReaderThreadImpl() noexcept {
    {
        const std::lock_guard<std::mutex> lock(mtx_hciReaderLifecycle); // RAII-style acquire and relinquish via destructor
        hciReaderShallStop = false;
        hciReaderRunning = true;
        DBG_PRINT("HCIHandler::reader: Started - %s", toString().c_str());
        cv_hciReaderInit.notify_all();
    }
    thread_local jau::call_on_release thread_cleanup([&]() {
        DBG_PRINT("HCIHandler::hciReaderThreadCleanup: hciReaderRunning %d -> 0", hciReaderRunning.load());
        hciReaderRunning = false;
    });

    while( !hciReaderShallStop ) {
        jau::snsize_t len;
        if( !isOpen() ) {
            // not open
            ERR_PRINT("HCIHandler::reader: Not connected %s", toString().c_str());
            hciReaderShallStop = true;
            break;
        }

        len = comm.read(rbuffer.get_wptr(), rbuffer.getSize(), env.HCI_READER_THREAD_POLL_TIMEOUT);
        if( 0 < len ) {
            const jau::nsize_t len2 = static_cast<jau::nsize_t>(len);
            const HCIPacketType pc = static_cast<HCIPacketType>( rbuffer.get_uint8_nc(0) );

            if( HCIPacketType::ACLDATA == pc ) {
                std::unique_ptr<HCIACLData> acldata = HCIACLData::getSpecialized(rbuffer.get_ptr(), len2);
                if( nullptr == acldata ) {
                    // not valid acl-data ...
                    WARN_PRINT("HCIHandler-IO RECV Drop (non-acl-data) %s - %s",
                            jau::bytesHexString(rbuffer.get_ptr(), 0, len2, true /* lsbFirst*/).c_str(), toString().c_str());
                    continue;
                }
                const uint8_t* l2cap_data = nullptr; // owned by acldata
                HCIACLData::l2cap_frame l2cap = acldata->getL2CAPFrame(l2cap_data);
                std::unique_ptr<const SMPPDUMsg> smpPDU = getSMPPDUMsg(l2cap, l2cap_data);
                if( nullptr != smpPDU ) {
                    HCIConnectionRef conn = findTrackerConnection(l2cap.handle);

                    if( nullptr != conn ) {
                        COND_PRINT(env.DEBUG_EVENT, "HCIHandler-IO RECV (ACL.SMP) %s for %s",
                                smpPDU->toString().c_str(), conn->toString().c_str());
                        jau::for_each_fidelity(hciSMPMsgCallbackList, [&](HCISMPMsgCallback &cb) {
                           cb.invoke(conn->getAddressAndType(), *smpPDU, l2cap);
                        });
                    } else {
                        WARN_PRINT("HCIHandler-IO RECV Drop (ACL.SMP): Not tracked conn_handle %s: %s; %s, %s",
                                jau::uint16HexString(l2cap.handle).c_str(), conn->toString().c_str(),
                                l2cap.toString().c_str(), smpPDU->toString().c_str());
                    }
                } else {
                    COND_PRINT(env.DEBUG_EVENT, "HCIHandler-IO RECV Drop (ACL.L2CAP): %s, data %s", l2cap.toString().c_str());

                }
                continue;
            }
            if( HCIPacketType::EVENT != pc ) {
                WARN_PRINT("HCIHandler-IO RECV Drop (not event, nor acl-data) %s - %s",
                        jau::bytesHexString(rbuffer.get_ptr(), 0, len2, true /* lsbFirst*/).c_str(), toString().c_str());
                continue;
            }

            // EVENT
            std::unique_ptr<HCIEvent> event = HCIEvent::getSpecialized(rbuffer.get_ptr(), len2);
            if( nullptr == event ) {
                // not a valid event ...
                ERR_PRINT("HCIHandler-IO RECV Drop (non-event) %s - %s",
                        jau::bytesHexString(rbuffer.get_ptr(), 0, len2, true /* lsbFirst*/).c_str(), toString().c_str());
                continue;
            }

            const HCIMetaEventType mec = event->getMetaEventType();
            if( HCIMetaEventType::INVALID != mec && !filter_test_metaev(mec) ) {
                // DROP
                COND_PRINT(env.DEBUG_EVENT, "HCIHandler-IO RECV Drop (meta filter) %s", event->toString().c_str());
                continue; // next packet
            }

            if( event->isEvent(HCIEventType::CMD_STATUS) || event->isEvent(HCIEventType::CMD_COMPLETE) )
            {
                COND_PRINT(env.DEBUG_EVENT, "HCIHandler-IO RECV (CMD) %s", event->toString().c_str());
                if( hciEventRing.isFull() ) {
                    const jau::nsize_t dropCount = hciEventRing.capacity()/4;
                    hciEventRing.drop(dropCount);
                    WARN_PRINT("HCIHandler-IO RECV Drop (%u oldest elements of %u capacity, ring full) - %s",
                            dropCount, hciEventRing.capacity(), toString().c_str());
                }
                hciEventRing.putBlocking( std::move( event ) );
            } else if( event->isMetaEvent(HCIMetaEventType::LE_ADVERTISING_REPORT) ) {
                // issue callbacks for the translated AD events
                jau::darray<std::shared_ptr<EInfoReport>> eirlist = EInfoReport::read_ad_reports(event->getParam(), event->getParamSize());
                jau::for_each_idx(eirlist, [&](std::shared_ptr<EInfoReport> & eir) {
                    // COND_PRINT(env.DEBUG_EVENT, "HCIHandler-IO RECV (AD EIR) %s", eir->toString().c_str());
                    const MgmtEvtDeviceFound e(dev_id, eir);
                    sendMgmtEvent( e );
                });
            } else {
                // issue a callback for the translated event
                std::unique_ptr<MgmtEvent> mevent = translate(*event);
                if( nullptr != mevent ) {
                    COND_PRINT(env.DEBUG_EVENT, "HCIHandler-IO RECV (CB) %s", event->toString().c_str());
                    sendMgmtEvent( *mevent );
                } else {
                    COND_PRINT(env.DEBUG_EVENT, "HCIHandler-IO RECV Drop (no translation) %s", event->toString().c_str());
                }
            }
        } else if( ETIMEDOUT != errno && !hciReaderShallStop ) { // expected exits
            ERR_PRINT("HCIHandler::reader: HCIComm read error %s", toString().c_str());
        }
    }
    {
        const std::lock_guard<std::mutex> lock(mtx_hciReaderLifecycle); // RAII-style acquire and relinquish via destructor
        WORDY_PRINT("HCIHandler::reader: Ended. Ring has %u entries flushed - %s", hciEventRing.getSize(), toString().c_str());
        hciEventRing.clear();
        hciReaderRunning = false;
        cv_hciReaderInit.notify_all();
    }
}

void HCIHandler::sendMgmtEvent(const MgmtEvent& event) noexcept {
    MgmtEventCallbackList & mgmtEventCallbackList = mgmtEventCallbackLists[static_cast<uint16_t>(event.getOpcode())];
    int invokeCount = 0;

    jau::for_each_fidelity(mgmtEventCallbackList, [&](MgmtEventCallback &cb) {
        try {
            cb.invoke(event);
        } catch (std::exception &e) {
            ERR_PRINT("HCIHandler::sendMgmtEvent-CBs %d/%zd: MgmtEventCallback %s : Caught exception %s - %s",
                    invokeCount+1, mgmtEventCallbackList.size(),
                    cb.toString().c_str(), e.what(), toString().c_str());
        }
        invokeCount++;
    });

    COND_PRINT(env.DEBUG_EVENT, "HCIHandler::sendMgmtEvent: Event %s -> %d/%zd callbacks", event.toString().c_str(), invokeCount, mgmtEventCallbackList.size());
    (void)invokeCount;
}

bool HCIHandler::sendCommand(HCICommand &req) noexcept {
    COND_PRINT(env.DEBUG_EVENT, "HCIHandler-IO SENT %s", req.toString().c_str());

    TROOctets & pdu = req.getPDU();
    if ( comm.write( pdu.get_ptr(), pdu.getSize() ) < 0 ) {
        ERR_PRINT("HCIHandler::sendCommand: HCIComm write error, req %s - %s", req.toString().c_str(), toString().c_str());
        return false;
    }
    return true;
}

std::unique_ptr<HCIEvent> HCIHandler::getNextReply(HCICommand &req, int32_t & retryCount, const int32_t replyTimeoutMS) noexcept
{
    // Ringbuffer read is thread safe
    while( retryCount < env.HCI_READ_PACKET_MAX_RETRY ) {
        std::unique_ptr<HCIEvent> ev = hciEventRing.getBlocking(replyTimeoutMS);
        if( nullptr == ev ) {
            errno = ETIMEDOUT;
            ERR_PRINT("HCIHandler::getNextReply: nullptr result (timeout %d ms -> abort): req %s - %s",
                    replyTimeoutMS, req.toString().c_str(), toString().c_str());
            return nullptr;
        } else if( !ev->validate(req) ) {
            // This could occur due to an earlier timeout w/ a nullptr == res (see above),
            // i.e. the pending reply processed here and naturally not-matching.
            retryCount++;
            COND_PRINT(env.DEBUG_EVENT, "HCIHandler-IO RECV getNextReply: res mismatch (drop, retry %d): res %s; req %s",
                       retryCount, ev->toString().c_str(), req.toString().c_str());
        } else {
            COND_PRINT(env.DEBUG_EVENT, "HCIHandler-IO RECV getNextReply: res %s; req %s", ev->toString().c_str(), req.toString().c_str());
            return ev;
        }
    }
    return nullptr;
}

std::unique_ptr<HCIEvent> HCIHandler::getNextCmdCompleteReply(HCICommand &req, HCICommandCompleteEvent **res) noexcept {
    const std::lock_guard<std::recursive_mutex> lock(mtx_sendReply); // RAII-style acquire and relinquish via destructor

    *res = nullptr;

    int32_t retryCount = 0;
    std::unique_ptr<HCIEvent> ev = nullptr;

    while( retryCount < env.HCI_READ_PACKET_MAX_RETRY ) {
        ev = getNextReply(req, retryCount, env.HCI_COMMAND_COMPLETE_REPLY_TIMEOUT);
        if( nullptr == ev ) {
            break;  // timeout, leave loop
        } else if( ev->isEvent(HCIEventType::CMD_COMPLETE) ) {
            // gotcha, leave loop
            *res = static_cast<HCICommandCompleteEvent*>(ev.get());
            break;
        } else if( ev->isEvent(HCIEventType::CMD_STATUS) ) {
            // pending command .. wait for result
            HCICommandStatusEvent * ev_cs = static_cast<HCICommandStatusEvent*>(ev.get());
            HCIStatusCode status = ev_cs->getStatus();
            if( HCIStatusCode::SUCCESS != status ) {
                WARN_PRINT("HCIHandler::getNextCmdCompleteReply: CMD_STATUS 0x%2.2X (%s), errno %d %s: res %s, req %s - %s",
                        number(status), getHCIStatusCodeString(status).c_str(), errno, strerror(errno),
                        ev_cs->toString().c_str(), req.toString().c_str(), toString().c_str());
                break; // error status, leave loop
            } else {
                DBG_PRINT("HCIHandler::getNextCmdCompleteReply: CMD_STATUS 0x%2.2X (%s, retryCount %d), errno %d %s: res %s, req %s - %s",
                        number(status), getHCIStatusCodeString(status).c_str(), retryCount, errno, strerror(errno),
                        ev_cs->toString().c_str(), req.toString().c_str(), toString().c_str());
            }
            retryCount++;
            continue; // next packet
        } else {
            retryCount++;
            DBG_PRINT("HCIHandler::getNextCmdCompleteReply: !(CMD_COMPLETE, CMD_STATUS) (drop, retry %d): res %s; req %s - %s",
                       retryCount, ev->toString().c_str(), req.toString().c_str(), toString().c_str());
            continue; // next packet
        }
    }
    return ev;
}

HCIHandler::HCIHandler(const uint16_t dev_id_, const BTMode btMode_) noexcept
: env(HCIEnv::get()),
  dev_id(dev_id_),
  rbuffer(HCI_MAX_MTU),
  comm(dev_id_, HCI_CHANNEL_RAW),
  hciEventRing(env.HCI_EVT_RING_CAPACITY), hciReaderShallStop(false),
  hciReaderThreadId(0), hciReaderRunning(false),
  allowClose( comm.isOpen() ),
  btMode(btMode_),
  currentScanType(ScanType::NONE)
{
    WORDY_PRINT("HCIHandler.ctor: Start pid %d - %s", HCIHandler::pidSelf, toString().c_str());
    if( !allowClose ) {
        ERR_PRINT("HCIHandler::ctor: Could not open hci control channel %s", toString().c_str());
        return;
    }

    {
        std::unique_lock<std::mutex> lock(mtx_hciReaderLifecycle); // RAII-style acquire and relinquish via destructor

        std::thread hciReaderThread(&HCIHandler::hciReaderThreadImpl, this); // @suppress("Invalid arguments")
        hciReaderThreadId = hciReaderThread.native_handle();
        // Avoid 'terminate called without an active exception'
        // as hciReaderThreadImpl may end due to I/O errors.
        hciReaderThread.detach();

        while( false == hciReaderRunning ) {
            cv_hciReaderInit.wait(lock);
        }
    }

    PERF_TS_T0();

#if 0
    {
        int opt = 1;
        if (setsockopt(comm.getSocketDescriptor(), SOL_SOCKET, SO_TIMESTAMP, &opt, sizeof(opt)) < 0) {
            ERR_PRINT("HCIHandler::ctor: setsockopt SO_TIMESTAMP %s", toString().c_str());
            goto fail;
        }

        if (setsockopt(comm.getSocketDescriptor(), SOL_SOCKET, SO_PASSCRED, &opt, sizeof(opt)) < 0) {
            ERR_PRINT("HCIHandler::ctor: setsockopt SO_PASSCRED %s", toString().c_str());
            goto fail;
        }
    }
#endif

#define FILTER_ALL_EVENTS 0

    // Mandatory socket filter (not adapter filter!)
    {
#if 0
        // No use for pre-existing hci_ufilter
        hci_ufilter of;
        socklen_t olen;

        olen = sizeof(of);
        if (getsockopt(comm.getSocketDescriptor(), SOL_HCI, HCI_FILTER, &of, &olen) < 0) {
            ERR_PRINT("HCIHandler::ctor: getsockopt %s", toString().c_str());
            goto fail;
        }
#endif
        HCIComm::filter_clear(&filter_mask);
        // HCIComm::filter_set_ptype(number(HCIPacketType::COMMAND), &filter_mask); // COMMANDs
        HCIComm::filter_set_ptype(number(HCIPacketType::EVENT),  &filter_mask); // EVENTs
        HCIComm::filter_set_ptype(number(HCIPacketType::ACLDATA),  &filter_mask); // SMP via ACL DATA

        // Setup generic filter mask for all events, this is also required for
#if FILTER_ALL_EVENTS
        HCIComm::filter_all_events(&filter_mask); // all events
#else
        HCIComm::filter_set_event(number(HCIEventType::CONN_COMPLETE), &filter_mask);
        HCIComm::filter_set_event(number(HCIEventType::DISCONN_COMPLETE), &filter_mask);
        HCIComm::filter_set_event(number(HCIEventType::AUTH_COMPLETE), &filter_mask);
        HCIComm::filter_set_event(number(HCIEventType::ENCRYPT_CHANGE), &filter_mask);
        HCIComm::filter_set_event(number(HCIEventType::CMD_COMPLETE), &filter_mask);
        HCIComm::filter_set_event(number(HCIEventType::CMD_STATUS), &filter_mask);
        HCIComm::filter_set_event(number(HCIEventType::HARDWARE_ERROR), &filter_mask);
        HCIComm::filter_set_event(number(HCIEventType::ENCRYPT_KEY_REFRESH_COMPLETE), &filter_mask);
        // HCIComm::filter_set_event(number(HCIEventType::IO_CAPABILITY_REQUEST), &filter_mask);
        // HCIComm::filter_set_event(number(HCIEventType::IO_CAPABILITY_RESPONSE), &filter_mask);
        HCIComm::filter_set_event(number(HCIEventType::LE_META), &filter_mask);
        // HCIComm::filter_set_event(number(HCIEventType::DISCONN_PHY_LINK_COMPLETE), &filter_mask);
        // HCIComm::filter_set_event(number(HCIEventType::DISCONN_LOGICAL_LINK_COMPLETE), &filter_mask);
#endif
        HCIComm::filter_set_opcode(0, &filter_mask); // all opcode

        if (setsockopt(comm.getSocketDescriptor(), SOL_HCI, HCI_FILTER, &filter_mask, sizeof(filter_mask)) < 0) {
            ERR_PRINT("HCIHandler::ctor: setsockopt HCI_FILTER %s", toString().c_str());
            goto fail;
        }
    }
    // Mandatory own LE_META filter
    {
        uint32_t mask = 0;
#if FILTER_ALL_EVENTS
        filter_all_metaevs(mask);
#else
        filter_set_metaev(HCIMetaEventType::LE_CONN_COMPLETE, mask);
        filter_set_metaev(HCIMetaEventType::LE_ADVERTISING_REPORT, mask);
        filter_set_metaev(HCIMetaEventType::LE_REMOTE_FEAT_COMPLETE, mask);
#endif
        filter_put_metaevs(mask);
    }
    // Mandatory own HCIOpcodeBit/HCIOpcode filter
    {
        uint64_t mask = 0;
#if FILTER_ALL_EVENTS
        filter_all_opcbit(mask);
#else
        filter_set_opcbit(HCIOpcodeBit::CREATE_CONN, mask);
        filter_set_opcbit(HCIOpcodeBit::DISCONNECT, mask);
        // filter_set_opcbit(HCIOpcodeBit::IO_CAPABILITY_REQ_REPLY, mask);
        // filter_set_opcbit(HCIOpcodeBit::IO_CAPABILITY_REQ_NEG_REPLY, mask);
        filter_set_opcbit(HCIOpcodeBit::RESET, mask);
        filter_set_opcbit(HCIOpcodeBit::READ_LOCAL_VERSION, mask);
        filter_set_opcbit(HCIOpcodeBit::LE_SET_SCAN_PARAM, mask);
        filter_set_opcbit(HCIOpcodeBit::LE_SET_SCAN_ENABLE, mask);
        filter_set_opcbit(HCIOpcodeBit::LE_CREATE_CONN, mask);
        filter_set_opcbit(HCIOpcodeBit::LE_ENABLE_ENC, mask);
#endif
        filter_put_opcbit(mask);
    }

    PERF_TS_TD("HCIHandler::ctor.ok");
    WORDY_PRINT("HCIHandler.ctor: End OK - %s", toString().c_str());
    return;

fail:
    close();
    PERF_TS_TD("HCIHandler::ctor.fail");
    WORDY_PRINT("HCIHandler.ctor: End failure - %s", toString().c_str());
    return;
}

void HCIHandler::close() noexcept {
    // Avoid disconnect re-entry -> potential deadlock
    bool expConn = true; // C++11, exp as value since C++20
    if( !allowClose.compare_exchange_strong(expConn, false) ) {
        // not open
        DBG_PRINT("HCIHandler::close: Not connected %s", toString().c_str());
        clearAllCallbacks();
        clearAllStates();
        comm.close();
        return;
    }
    PERF_TS_T0();
    const std::lock_guard<std::recursive_mutex> lock(mtx_sendReply); // RAII-style acquire and relinquish via destructor
    DBG_PRINT("HCIHandler::close: Start %s", toString().c_str());
    clearAllCallbacks();
    clearAllStates();

    // Interrupt HCIHandler's HCIComm::read(..), avoiding prolonged hang
    // and pull all underlying hci read operations!
    comm.close();

    PERF_TS_TD("HCIHandler::close.1");
    {
        std::unique_lock<std::mutex> lockReader(mtx_hciReaderLifecycle); // RAII-style acquire and relinquish via destructor
        const pthread_t tid_self = pthread_self();
        const pthread_t tid_reader = hciReaderThreadId;
        hciReaderThreadId = 0;
        const bool is_reader = tid_reader == tid_self;
        DBG_PRINT("HCIHandler::close: hciReader[running %d, shallStop %d, isReader %d, tid %p) - %s",
                hciReaderRunning.load(), hciReaderShallStop.load(), is_reader, (void*)tid_reader, toString().c_str());
        if( hciReaderRunning ) {
            hciReaderShallStop = true;
            if( !is_reader && 0 != tid_reader ) {
                int kerr;
                if( 0 != ( kerr = pthread_kill(tid_reader, SIGALRM) ) ) {
                    ERR_PRINT("HCIHandler::close: pthread_kill %p FAILED: %d - %s", (void*)tid_reader, kerr, toString().c_str());
                }
            }
            // Ensure the reader thread has ended, no runaway-thread using *this instance after destruction
            while( true == hciReaderRunning ) {
                cv_hciReaderInit.wait(lockReader);
            }
        }
    }
    PERF_TS_TD("HCIHandler::close.X");
    DBG_PRINT("HCIHandler::close: End %s", toString().c_str());
}

std::string HCIHandler::toString() const noexcept {
    return "HCIHandler[dev_id "+std::to_string(dev_id)+", BTMode "+getBTModeString(btMode)+", open "+std::to_string(isOpen())+
            ", scan "+getScanTypeString(currentScanType)+", ring[entries "+std::to_string(hciEventRing.getSize())+"]]";
}

HCIStatusCode HCIHandler::startAdapter() {
    if( !isOpen() ) {
        ERR_PRINT("HCIHandler::startAdapter: Not connected %s", toString().c_str());
        return HCIStatusCode::INTERNAL_FAILURE;
    }
    const std::lock_guard<std::recursive_mutex> lock(mtx_sendReply); // RAII-style acquire and relinquish via destructor
    #ifdef __linux__
        int res;
        if( ( res = ioctl(comm.getSocketDescriptor(), HCIDEVUP, dev_id) ) < 0 ) {
            if (errno != EALREADY) {
                ERR_PRINT("HCIHandler::startAdapter(dev_id %d): FAILED: %d - %s", dev_id, res, toString().c_str());
                return HCIStatusCode::INTERNAL_FAILURE;
            }
        }
        return HCIStatusCode::SUCCESS;
    #else
        #warning add implementation
    #endif
    return HCIStatusCode::INTERNAL_FAILURE;
}

HCIStatusCode HCIHandler::stopAdapter() {
    if( !isOpen() ) {
        ERR_PRINT("HCIHandler::stopAdapter: Not connected %s", toString().c_str());
        return HCIStatusCode::INTERNAL_FAILURE;
    }
    const std::lock_guard<std::recursive_mutex> lock(mtx_sendReply); // RAII-style acquire and relinquish via destructor
    HCIStatusCode status;
    #ifdef __linux__
        int res;
        if( ( res = ioctl(comm.getSocketDescriptor(), HCIDEVDOWN, dev_id) ) < 0) {
            ERR_PRINT("HCIHandler::stopAdapter(dev_id %d): FAILED: %d - %s", dev_id, res, toString().c_str());
            status = HCIStatusCode::INTERNAL_FAILURE;
        } else {
            status = HCIStatusCode::SUCCESS;
        }
    #else
        #warning add implementation
        status = HCIStatusCode::INTERNAL_FAILURE;
    #endif
    if( HCIStatusCode::SUCCESS == status ) {
        clearAllStates();
    }
    return status;
}

HCIStatusCode HCIHandler::resetAdapter() {
    if( !isOpen() ) {
        ERR_PRINT("HCIHandler::resetAdapter: Not connected %s", toString().c_str());
        return HCIStatusCode::INTERNAL_FAILURE;
    }
    const std::lock_guard<std::recursive_mutex> lock(mtx_sendReply); // RAII-style acquire and relinquish via destructor
    #ifdef __linux__
        if( HCIStatusCode::SUCCESS == stopAdapter() && HCIStatusCode::SUCCESS == startAdapter() ) {
            return HCIStatusCode::SUCCESS;
        }
    #else
        #warning add implementation
    #endif
    return HCIStatusCode::INTERNAL_FAILURE;
}

HCIStatusCode HCIHandler::reset() noexcept {
    if( !isOpen() ) {
        ERR_PRINT("HCIHandler::reset: Not connected %s", toString().c_str());
        return HCIStatusCode::INTERNAL_FAILURE;
    }
    const std::lock_guard<std::recursive_mutex> lock(mtx_sendReply); // RAII-style acquire and relinquish via destructor
    HCICommand req0(HCIOpcode::RESET, 0);

    const hci_rp_status * ev_status;
    HCIStatusCode status;
    std::unique_ptr<HCIEvent> ev = processCommandComplete(req0, &ev_status, &status);
    if( nullptr == ev ) {
        return HCIStatusCode::INTERNAL_TIMEOUT; // timeout
    }
    if( HCIStatusCode::SUCCESS == status ) {
        clearAllStates();
    }
    return status;
}

HCIStatusCode HCIHandler::getLocalVersion(HCILocalVersion &version) noexcept {
    if( !isOpen() ) {
        ERR_PRINT("HCIHandler::getLocalVersion: Not connected %s", toString().c_str());
        return HCIStatusCode::INTERNAL_FAILURE;
    }
    HCICommand req0(HCIOpcode::READ_LOCAL_VERSION, 0);
    const hci_rp_read_local_version * ev_lv;
    HCIStatusCode status;
    std::unique_ptr<HCIEvent> ev = processCommandComplete(req0, &ev_lv, &status);
    if( nullptr == ev || nullptr == ev_lv || HCIStatusCode::SUCCESS != status ) {
        ERR_PRINT("HCIHandler::getLocalVersion: READ_LOCAL_VERSION: 0x%x (%s) - %s",
                number(status), getHCIStatusCodeString(status).c_str(), toString().c_str());
        bzero(&version, sizeof(version));
    } else {
        version.hci_ver = ev_lv->hci_ver;
        version.hci_rev = jau::le_to_cpu(ev_lv->hci_rev);
        version.manufacturer = jau::le_to_cpu(ev_lv->manufacturer);
        version.lmp_ver = ev_lv->lmp_ver;
        version.lmp_subver = jau::le_to_cpu(ev_lv->lmp_subver);
    }
    return status;
}

HCIStatusCode HCIHandler::le_set_scan_param(const HCILEOwnAddressType own_mac_type,
                                            const uint16_t le_scan_interval, const uint16_t le_scan_window,
                                            const uint8_t filter_policy, const bool le_scan_active) noexcept {
    if( !isOpen() ) {
        ERR_PRINT("HCIHandler::le_set_scan_param: Not connected %s", toString().c_str());
        return HCIStatusCode::INTERNAL_FAILURE;
    }
    if( hasScanType(currentScanType, ScanType::LE) ) {
        WARN_PRINT("HCIHandler::le_set_scan_param: Not allowed: LE Scan Enabled: %s - tried scan [interval %.3f ms, window %.3f ms]",
                toString().c_str(), 0.625f * (float)le_scan_interval, 0.625f * (float)le_scan_window);
        return HCIStatusCode::COMMAND_DISALLOWED;
    }
    DBG_PRINT("HCI Scan Param: scan [interval %.3f ms, window %.3f ms] - %s",
            0.625f * (float)le_scan_interval, 0.625f * (float)le_scan_window, toString().c_str());

    HCIStructCommand<hci_cp_le_set_scan_param> req0(HCIOpcode::LE_SET_SCAN_PARAM);
    hci_cp_le_set_scan_param * cp = req0.getWStruct();
    cp->type = le_scan_active ? LE_SCAN_ACTIVE : LE_SCAN_PASSIVE;
    cp->interval = jau::cpu_to_le(le_scan_interval);
    cp->window = jau::cpu_to_le(le_scan_window);
    cp->own_address_type = static_cast<uint8_t>(own_mac_type);
    cp->filter_policy = filter_policy;

    const hci_rp_status * ev_status;
    HCIStatusCode status;
    std::unique_ptr<HCIEvent> ev = processCommandComplete(req0, &ev_status, &status);
    return status;
}

HCIStatusCode HCIHandler::le_enable_scan(const bool enable, const bool filter_dup) noexcept {
    if( !isOpen() ) {
        ERR_PRINT("HCIHandler::le_enable_scan: Not connected %s", toString().c_str());
        return HCIStatusCode::INTERNAL_FAILURE;
    }
    const std::lock_guard<std::recursive_mutex> lock(mtx_sendReply); // RAII-style acquire and relinquish via destructor

    ScanType nextScanType = changeScanType(currentScanType, ScanType::LE, enable);
    DBG_PRINT("HCI Enable Scan: enable %s -> %s, filter_dup %d - %s",
            getScanTypeString(currentScanType).c_str(), getScanTypeString(nextScanType).c_str(), filter_dup, toString().c_str());

    HCIStatusCode status;
    if( currentScanType != nextScanType ) {
        HCIStructCommand<hci_cp_le_set_scan_enable> req0(HCIOpcode::LE_SET_SCAN_ENABLE);
        hci_cp_le_set_scan_enable * cp = req0.getWStruct();
        cp->enable = enable ? LE_SCAN_ENABLE : LE_SCAN_DISABLE;
        cp->filter_dup = filter_dup ? LE_SCAN_FILTER_DUP_ENABLE : LE_SCAN_FILTER_DUP_DISABLE;

        const hci_rp_status * ev_status;
        std::unique_ptr<HCIEvent> evComplete = processCommandComplete(req0, &ev_status, &status);
    } else {
        status = HCIStatusCode::SUCCESS;
        WARN_PRINT("HCI Enable Scan: current %s == next %s, OK, skip command - %s",
                getScanTypeString(currentScanType).c_str(), getScanTypeString(nextScanType).c_str(), toString().c_str());
    }

    if( HCIStatusCode::SUCCESS == status ) {
        currentScanType = nextScanType;
        const MgmtEvtDiscovering e(dev_id, ScanType::LE, enable);
        sendMgmtEvent( e );
    }
    return status;
}

HCIStatusCode HCIHandler::le_start_scan(const bool filter_dup,
                                        const HCILEOwnAddressType own_mac_type,
                                        const uint16_t le_scan_interval, const uint16_t le_scan_window,
                                        const uint8_t filter_policy, const bool le_scan_active) noexcept {
    if( !isOpen() ) {
        ERR_PRINT("HCIHandler::le_start_scan: Not connected %s", toString().c_str());
        return HCIStatusCode::INTERNAL_FAILURE;
    }
    const std::lock_guard<std::recursive_mutex> lock(mtx_sendReply); // RAII-style acquire and relinquish via destructor

    if( hasScanType(currentScanType, ScanType::LE) ) {
        WARN_PRINT("HCIHandler::le_start_scan: Not allowed: LE Scan Enabled: %s", toString().c_str());
        return HCIStatusCode::COMMAND_DISALLOWED;
    }
    HCIStatusCode status = le_set_scan_param(own_mac_type, le_scan_interval, le_scan_window, filter_policy, le_scan_active);
    if( HCIStatusCode::SUCCESS != status ) {
        WARN_PRINT("HCIHandler::le_start_scan: le_set_scan_param failed: %s - %s",
                getHCIStatusCodeString(status).c_str(), toString().c_str());
    } else {
        status = le_enable_scan(true /* enable */, filter_dup);
        if( HCIStatusCode::SUCCESS != status ) {
            WARN_PRINT("HCIHandler::le_start_scan: le_enable_scan failed: %s - %s",
                    getHCIStatusCodeString(status).c_str(), toString().c_str());
        }
    }
    return status;
}

HCIStatusCode HCIHandler::le_create_conn(const EUI48 &peer_bdaddr,
                            const HCILEPeerAddressType peer_mac_type,
                            const HCILEOwnAddressType own_mac_type,
                            const uint16_t le_scan_interval, const uint16_t le_scan_window,
                            const uint16_t conn_interval_min, const uint16_t conn_interval_max,
                            const uint16_t conn_latency, const uint16_t supervision_timeout) noexcept {
    /**
     * As we rely on consistent 'pending tracker connections',
     * i.e. avoid a race condition on issuing connections via this command,
     * we need to synchronize this method.
     */
    const std::lock_guard<std::mutex> lock(mtx_connect_cmd); // RAII-style acquire and relinquish via destructor

    if( !isOpen() ) {
        ERR_PRINT("HCIHandler::le_create_conn: Not connected %s", toString().c_str());
        return HCIStatusCode::INTERNAL_FAILURE;
    }

    const uint16_t min_ce_length = 0x0000;
    const uint16_t max_ce_length = 0x0000;
    const uint8_t initiator_filter = 0x00; // whitelist not used but peer_bdaddr*

    DBG_PRINT("HCI Conn Param: scan [interval %.3f ms, window %.3f ms]", 0.625f *
            (float)le_scan_interval, 0.625f * (float)le_scan_window);
    DBG_PRINT("HCI Conn Param: conn [interval [%.3f ms - %.3f ms], latency %d, sup_timeout %d ms] - %s",
            1.25f * (float)conn_interval_min, 1.25f * (float)conn_interval_max,
            conn_latency, supervision_timeout*10, toString().c_str());

    HCIStructCommand<hci_cp_le_create_conn> req0(HCIOpcode::LE_CREATE_CONN);
    hci_cp_le_create_conn * cp = req0.getWStruct();
    cp->scan_interval = jau::cpu_to_le(le_scan_interval);
    cp->scan_window = jau::cpu_to_le(le_scan_window);
    cp->filter_policy = initiator_filter;
    cp->peer_addr_type = static_cast<uint8_t>(peer_mac_type);
    cp->peer_addr = peer_bdaddr;
    cp->own_address_type = static_cast<uint8_t>(own_mac_type);
    cp->conn_interval_min = jau::cpu_to_le(conn_interval_min);
    cp->conn_interval_max = jau::cpu_to_le(conn_interval_max);
    cp->conn_latency = jau::cpu_to_le(conn_latency);
    cp->supervision_timeout = jau::cpu_to_le(supervision_timeout);
    cp->min_ce_len = jau::cpu_to_le(min_ce_length);
    cp->max_ce_len = jau::cpu_to_le(max_ce_length);
    const BDAddressAndType addressAndType(peer_bdaddr, getBDAddressType(peer_mac_type));

    int pendingConnections = countPendingTrackerConnections();
    if( 0 < pendingConnections ) {
        DBG_PRINT("HCIHandler::le_create_conn: %d connections pending - %s", pendingConnections, toString().c_str());
        int32_t td = 0;
        while( env.HCI_COMMAND_COMPLETE_REPLY_TIMEOUT > td && 0 < pendingConnections ) {
            std::this_thread::sleep_for(std::chrono::milliseconds(env.HCI_COMMAND_POLL_PERIOD));
            td += env.HCI_COMMAND_POLL_PERIOD;
            pendingConnections = countPendingTrackerConnections();
        }
        if( 0 < pendingConnections ) {
            WARN_PRINT("HCIHandler::le_create_conn: %d connections pending after %d ms - %s", pendingConnections, td, toString().c_str());
        } else {
            DBG_PRINT("HCIHandler::le_create_conn: pending connections resolved after %d ms - %s", td, toString().c_str());
        }
    }
    HCIConnectionRef disconn = findDisconnectCmd(addressAndType);
    if( nullptr != disconn ) {
        DBG_PRINT("HCIHandler::le_create_conn: disconnect pending %s - %s",
                disconn->toString().c_str(), toString().c_str());
        int32_t td = 0;
        while( env.HCI_COMMAND_COMPLETE_REPLY_TIMEOUT > td && nullptr != disconn ) {
            std::this_thread::sleep_for(std::chrono::milliseconds(env.HCI_COMMAND_POLL_PERIOD));
            td += env.HCI_COMMAND_POLL_PERIOD;
            disconn = findDisconnectCmd(addressAndType);
        }
        if( nullptr != disconn ) {
            WARN_PRINT("HCIHandler::le_create_conn: disconnect persisting after %d ms: %s - %s",
                    td, disconn->toString().c_str(), toString().c_str());
        } else {
            DBG_PRINT("HCIHandler::le_create_conn: disconnect resolved after %d ms - %s", td, toString().c_str());
        }
    }
    HCIConnectionRef conn = addOrUpdateTrackerConnection(addressAndType, 0);
    HCIStatusCode status;
    std::unique_ptr<HCIEvent> ev = processCommandStatus(req0, &status);
    if( HCIStatusCode::SUCCESS != status ) {
        removeTrackerConnection(conn);

        if( HCIStatusCode::CONNECTION_ALREADY_EXISTS == status ) {
            const std::string s0 = nullptr != disconn ? disconn->toString() : "null";
            WARN_PRINT("HCIHandler::le_create_conn: %s: disconnect pending: %s - %s",
                    getHCIStatusCodeString(status).c_str(), s0.c_str(), toString().c_str());
        }
    }
    return status;
}

HCIStatusCode HCIHandler::create_conn(const EUI48 &bdaddr,
                                     const uint16_t pkt_type,
                                     const uint16_t clock_offset, const uint8_t role_switch) noexcept {
    /**
     * As we rely on consistent 'pending tracker connections',
     * i.e. avoid a race condition on issuing connections via this command,
     * we need to synchronize this method.
     */
    const std::lock_guard<std::mutex> lock(mtx_connect_cmd); // RAII-style acquire and relinquish via destructor

    if( !isOpen() ) {
        ERR_PRINT("HCIHandler::create_conn: Not connected %s", toString().c_str());
        return HCIStatusCode::INTERNAL_FAILURE;
    }

    HCIStructCommand<hci_cp_create_conn> req0(HCIOpcode::CREATE_CONN);
    hci_cp_create_conn * cp = req0.getWStruct();
    cp->bdaddr = bdaddr;
    cp->pkt_type = jau::cpu_to_le((uint16_t)(pkt_type & (uint16_t)ACL_PTYPE_MASK)); /* TODO OK excluding SCO_PTYPE_MASK   (HCI_HV1 | HCI_HV2 | HCI_HV3) ? */
    cp->pscan_rep_mode = 0x02; /* TODO magic? */
    cp->pscan_mode = 0x00; /* TODO magic? */
    cp->clock_offset = jau::cpu_to_le(clock_offset);
    cp->role_switch = role_switch;

    int pendingConnections = countPendingTrackerConnections();
    if( 0 < pendingConnections ) {
        DBG_PRINT("HCIHandler::create_conn: %d connections pending - %s", pendingConnections, toString().c_str());
        int32_t td = 0;
        while( env.HCI_COMMAND_COMPLETE_REPLY_TIMEOUT > td && 0 < pendingConnections ) {
            std::this_thread::sleep_for(std::chrono::milliseconds(env.HCI_COMMAND_POLL_PERIOD));
            td += env.HCI_COMMAND_POLL_PERIOD;
            pendingConnections = countPendingTrackerConnections();
        }
        if( 0 < pendingConnections ) {
            WARN_PRINT("HCIHandler::create_conn: %d connections pending after %d ms - %s", pendingConnections, td, toString().c_str());
        } else {
            DBG_PRINT("HCIHandler::create_conn: pending connections resolved after %d ms - %s", td, toString().c_str());
        }
    }
    const BDAddressAndType addressAndType(bdaddr, BDAddressType::BDADDR_BREDR);
    HCIConnectionRef disconn = findDisconnectCmd(addressAndType);
    if( nullptr != disconn ) {
        DBG_PRINT("HCIHandler::create_conn: disconnect pending %s - %s",
                disconn->toString().c_str(), toString().c_str());
        int32_t td = 0;
        while( env.HCI_COMMAND_COMPLETE_REPLY_TIMEOUT > td && nullptr != disconn ) {
            std::this_thread::sleep_for(std::chrono::milliseconds(env.HCI_COMMAND_POLL_PERIOD));
            td += env.HCI_COMMAND_POLL_PERIOD;
            disconn = findDisconnectCmd(addressAndType);
        }
        if( nullptr != disconn ) {
            WARN_PRINT("HCIHandler::create_conn: disconnect persisting after %d ms: %s - %s",
                    td, disconn->toString().c_str(), toString().c_str());
        } else {
            DBG_PRINT("HCIHandler::create_conn: disconnect resolved after %d ms - %s", td, toString().c_str());
        }
    }
    HCIConnectionRef conn = addOrUpdateTrackerConnection(addressAndType, 0);
    HCIStatusCode status;
    std::unique_ptr<HCIEvent> ev = processCommandStatus(req0, &status);
    if( HCIStatusCode::SUCCESS != status ) {
        removeTrackerConnection(conn);

        if( HCIStatusCode::CONNECTION_ALREADY_EXISTS == status ) {
            const std::string s0 = nullptr != disconn ? disconn->toString() : "null";
            WARN_PRINT("HCIHandler::create_conn: %s: disconnect pending: %s - %s",
                    getHCIStatusCodeString(status).c_str(), s0.c_str(), toString().c_str());
        }
    }
    return status;
}

HCIStatusCode HCIHandler::disconnect(const uint16_t conn_handle, const BDAddressAndType& peerAddressAndType,
                                     const HCIStatusCode reason) noexcept
{
    if( !isOpen() ) {
        ERR_PRINT("HCIHandler::create_conn: Not connected %s", toString().c_str());
        return HCIStatusCode::INTERNAL_FAILURE;
    }
    if( 0 == conn_handle ) {
        ERR_PRINT("HCIHandler::disconnect: Null conn_handle given address%s (drop) - %s",
                  peerAddressAndType.toString().c_str(), toString().c_str());
        return HCIStatusCode::INVALID_HCI_COMMAND_PARAMETERS;
    }
    {
        const std::lock_guard<std::recursive_mutex> lock(mtx_connectionList); // RAII-style acquire and relinquish via destructor
        HCIConnectionRef conn = findTrackerConnection(conn_handle);
        if( nullptr == conn ) {
            // disconnect called w/o being connected through this HCIHandler
            conn = addOrUpdateTrackerConnection(peerAddressAndType, conn_handle);
            WORDY_PRINT("HCIHandler::disconnect: Not tracked address%s, added %s - %s",
                       peerAddressAndType.toString().c_str(),
                       conn->toString().c_str(), toString().c_str());
        } else if( !conn->equals(peerAddressAndType) ) {
            ERR_PRINT("HCIHandler::disconnect: Mismatch given address%s and tracked %s (drop) - %s",
                       peerAddressAndType.toString().c_str(),
                       conn->toString().c_str(), toString().c_str());
            return HCIStatusCode::INVALID_HCI_COMMAND_PARAMETERS;
        }
        DBG_PRINT("HCIHandler::disconnect: address%s, handle %s, %s - %s",
                   peerAddressAndType.toString().c_str(),
                   jau::uint16HexString(conn_handle).c_str(),
                   conn->toString().c_str(), toString().c_str());
    }

    HCIStatusCode status;

    // Always issue DISCONNECT command, even in case of an ioError (lost-connection),
    // see Issue #124 fast re-connect on CSR adapter.
    // This will always notify the adapter of a disconnected device.
    {
        HCIStructCommand<hci_cp_disconnect> req0(HCIOpcode::DISCONNECT);
        hci_cp_disconnect * cp = req0.getWStruct();
        cp->handle = jau::cpu_to_le(conn_handle);
        cp->reason = number(reason);

        std::unique_ptr<HCIEvent> ev = processCommandStatus(req0, &status);
    }
    if( HCIStatusCode::SUCCESS == status ) {
        addOrUpdateDisconnectCmd(peerAddressAndType, conn_handle);
    }
    return status;
}

std::unique_ptr<HCIEvent> HCIHandler::processCommandStatus(HCICommand &req, HCIStatusCode *status) noexcept
{
    const std::lock_guard<std::recursive_mutex> lock(mtx_sendReply); // RAII-style acquire and relinquish via destructor

    *status = HCIStatusCode::INTERNAL_FAILURE;

    int32_t retryCount = 0;
    std::unique_ptr<HCIEvent> ev = nullptr;

    if( !sendCommand(req) ) {
        goto exit;
    }

    while( retryCount < env.HCI_READ_PACKET_MAX_RETRY ) {
        ev = getNextReply(req, retryCount, env.HCI_COMMAND_STATUS_REPLY_TIMEOUT);
        if( nullptr == ev ) {
            *status = HCIStatusCode::INTERNAL_TIMEOUT;
            break; // timeout, leave loop
        } else if( ev->isEvent(HCIEventType::CMD_STATUS) ) {
            HCICommandStatusEvent * ev_cs = static_cast<HCICommandStatusEvent*>(ev.get());
            *status = ev_cs->getStatus();
            DBG_PRINT("HCIHandler::processCommandStatus %s -> Status 0x%2.2X (%s), errno %d %s: res %s, req %s - %s",
                    getHCIOpcodeString(req.getOpcode()).c_str(),
                    number(*status), getHCIStatusCodeString(*status).c_str(), errno, strerror(errno),
                    ev_cs->toString().c_str(), req.toString().c_str(), toString().c_str());
            break; // gotcha, leave loop - pending completion result handled via callback
        } else {
            retryCount++;
            DBG_PRINT("HCIHandler::processCommandStatus: !CMD_STATUS (drop, retry %d): res %s; req %s - %s",
                       retryCount, ev->toString().c_str(), req.toString().c_str(), toString().c_str());
            continue; // next packet
        }
    }
    if( nullptr == ev ) {
        // timeout exit
        WARN_PRINT("HCIHandler::processCommandStatus %s -> Status 0x%2.2X (%s), errno %d %s: res nullptr, req %s - %s",
                getHCIOpcodeString(req.getOpcode()).c_str(),
                number(*status), getHCIStatusCodeString(*status).c_str(), errno, strerror(errno),
                req.toString().c_str(), toString().c_str());
    }

exit:
    return ev;
}

template<typename hci_cmd_event_struct>
std::unique_ptr<HCIEvent> HCIHandler::processCommandComplete(HCICommand &req,
                                                             const hci_cmd_event_struct **res, HCIStatusCode *status) noexcept
{
    const std::lock_guard<std::recursive_mutex> lock(mtx_sendReply); // RAII-style acquire and relinquish via destructor

    *res = nullptr;
    *status = HCIStatusCode::INTERNAL_FAILURE;

    if( !sendCommand(req) ) {
        WARN_PRINT("HCIHandler::processCommandComplete Send failed: Status 0x%2.2X (%s), errno %d %s: res nullptr, req %s - %s",
                number(*status), getHCIStatusCodeString(*status).c_str(), errno, strerror(errno),
                req.toString().c_str(), toString().c_str());
        return nullptr; // timeout
    }

    return receiveCommandComplete(req, res, status);
}

template<typename hci_cmd_event_struct>
std::unique_ptr<HCIEvent> HCIHandler::receiveCommandComplete(HCICommand &req,
                                                             const hci_cmd_event_struct **res, HCIStatusCode *status) noexcept
{
    *res = nullptr;
    *status = HCIStatusCode::INTERNAL_FAILURE;

    const HCIEventType evc = HCIEventType::CMD_COMPLETE;
    HCICommandCompleteEvent * ev_cc;
    std::unique_ptr<HCIEvent> ev = getNextCmdCompleteReply(req, &ev_cc);
    if( nullptr == ev ) {
        *status = HCIStatusCode::INTERNAL_TIMEOUT;
        WARN_PRINT("HCIHandler::processCommandComplete %s -> %s: Status 0x%2.2X (%s), errno %d %s: res nullptr, req %s - %s",
                getHCIOpcodeString(req.getOpcode()).c_str(), getHCIEventTypeString(evc).c_str(),
                number(*status), getHCIStatusCodeString(*status).c_str(), errno, strerror(errno),
                req.toString().c_str(), toString().c_str());
        return nullptr; // timeout
    } else if( nullptr == ev_cc ) {
        WARN_PRINT("HCIHandler::processCommandComplete %s -> %s: Status 0x%2.2X (%s), errno %d %s: res %s, req %s - %s",
                getHCIOpcodeString(req.getOpcode()).c_str(), getHCIEventTypeString(evc).c_str(),
                number(*status), getHCIStatusCodeString(*status).c_str(), errno, strerror(errno),
                ev->toString().c_str(), req.toString().c_str(), toString().c_str());
        return ev;
    }
    const uint8_t returnParamSize = ev_cc->getReturnParamSize();
    if( returnParamSize < sizeof(hci_cmd_event_struct) ) {
        WARN_PRINT("HCIHandler::processCommandComplete %s -> %s: Status 0x%2.2X (%s), errno %d %s: res %s, req %s - %s",
                getHCIOpcodeString(req.getOpcode()).c_str(), getHCIEventTypeString(evc).c_str(),
                number(*status), getHCIStatusCodeString(*status).c_str(), errno, strerror(errno),
                ev_cc->toString().c_str(), req.toString().c_str(), toString().c_str());
        return ev;
    }
    *res = (const hci_cmd_event_struct*)(ev_cc->getReturnParam());
    *status = static_cast<HCIStatusCode>((*res)->status);
    DBG_PRINT("HCIHandler::processCommandComplete %s -> %s: Status 0x%2.2X (%s): res %s, req %s - %s",
            getHCIOpcodeString(req.getOpcode()).c_str(), getHCIEventTypeString(evc).c_str(),
            number(*status), getHCIStatusCodeString(*status).c_str(),
            ev_cc->toString().c_str(), req.toString().c_str(), toString().c_str());
    return ev;
}

template<typename hci_cmd_event_struct>
const hci_cmd_event_struct* HCIHandler::getReplyStruct(HCIEvent& event, HCIEventType evc, HCIStatusCode *status) noexcept
{
    const hci_cmd_event_struct* res = nullptr;
    *status = HCIStatusCode::INTERNAL_FAILURE;

    typedef HCIStructCmdCompleteEvtWrap<hci_cmd_event_struct> HCITypeCmdCompleteEvtWrap;
    HCITypeCmdCompleteEvtWrap ev_cc( event );
    if( ev_cc.isTypeAndSizeValid(evc) ) {
        *status = ev_cc.getStatus();
        res = ev_cc.getStruct();
    } else {
        WARN_PRINT("HCIHandler::getReplyStruct: %s: Type or size mismatch: Status 0x%2.2X (%s), errno %d %s: res %s - %s",
                getHCIEventTypeString(evc).c_str(),
                number(*status), getHCIStatusCodeString(*status).c_str(), errno, strerror(errno),
                ev_cc.toString().c_str(), toString().c_str());
    }
    return res;
}

template<typename hci_cmd_event_struct>
const hci_cmd_event_struct* HCIHandler::getMetaReplyStruct(HCIEvent& event, HCIMetaEventType mec, HCIStatusCode *status) noexcept
{
    const hci_cmd_event_struct* res = nullptr;
    *status = HCIStatusCode::INTERNAL_FAILURE;

    typedef HCIStructCmdCompleteMetaEvtWrap<hci_cmd_event_struct> HCITypeCmdCompleteMetaEvtWrap;
    const HCITypeCmdCompleteMetaEvtWrap ev_cc( *static_cast<HCIMetaEvent*>( &event ) );
    if( ev_cc.isTypeAndSizeValid(mec) ) {
        *status = ev_cc.getStatus();
        res = ev_cc.getStruct();
    } else {
        WARN_PRINT("HCIHandler::getMetaReplyStruct: %s: Type or size mismatch: Status 0x%2.2X (%s), errno %d %s: res %s - %s",
                  getHCIMetaEventTypeString(mec).c_str(),
                  number(*status), getHCIStatusCodeString(*status).c_str(), errno, strerror(errno),
                  ev_cc.toString().c_str(), toString().c_str());
    }
    return res;
}

/***
 *
 * MgmtEventCallback section
 *
 */

static MgmtEventCallbackList::equal_comparator _mgmtEventCallbackEqComparator =
        [](const MgmtEventCallback &a, const MgmtEventCallback &b) -> bool { return a == b; };

bool HCIHandler::addMgmtEventCallback(const MgmtEvent::Opcode opc, const MgmtEventCallback &cb) noexcept {
    if( !isValidMgmtEventCallbackListsIndex(opc) ) {
        ERR_PRINT("Opcode %s >= %d - %s", MgmtEvent::getOpcodeString(opc).c_str(), mgmtEventCallbackLists.size(), toString().c_str());
        return false;
    }
    MgmtEventCallbackList &l = mgmtEventCallbackLists[static_cast<uint16_t>(opc)];
    /* const bool added = */ l.push_back_unique(cb, _mgmtEventCallbackEqComparator);
    return true;
}
int HCIHandler::removeMgmtEventCallback(const MgmtEvent::Opcode opc, const MgmtEventCallback &cb) noexcept {
    if( !isValidMgmtEventCallbackListsIndex(opc) ) {
        ERR_PRINT("Opcode %s >= %d - %s", MgmtEvent::getOpcodeString(opc).c_str(), mgmtEventCallbackLists.size(), toString().c_str());
        return 0;
    }
    MgmtEventCallbackList &l = mgmtEventCallbackLists[static_cast<uint16_t>(opc)];
    return l.erase_matching(cb, true /* all_matching */, _mgmtEventCallbackEqComparator);
}
void HCIHandler::clearMgmtEventCallbacks(const MgmtEvent::Opcode opc) noexcept {
    if( !isValidMgmtEventCallbackListsIndex(opc) ) {
        ERR_PRINT("Opcode %s >= %d - %s", MgmtEvent::getOpcodeString(opc).c_str(), mgmtEventCallbackLists.size(), toString().c_str());
        return;
    }
    mgmtEventCallbackLists[static_cast<uint16_t>(opc)].clear();
}
void HCIHandler::clearAllCallbacks() noexcept {
    for(size_t i=0; i<mgmtEventCallbackLists.size(); i++) {
        mgmtEventCallbackLists[i].clear();
    }
    hciSMPMsgCallbackList.clear();
}

/**
 * SMPMsgCallback handling
 */

static HCISMPMsgCallbackList::equal_comparator _changedHCISMPMsgCallbackEqComp =
        [](const HCISMPMsgCallback& a, const HCISMPMsgCallback& b) -> bool { return a == b; };


void HCIHandler::addSMPMsgCallback(const HCISMPMsgCallback & l) {
    hciSMPMsgCallbackList.push_back(l);
}
int HCIHandler::removeSMPMsgCallback(const HCISMPMsgCallback & l) {
    return hciSMPMsgCallbackList.erase_matching(l, true /* all_matching */, _changedHCISMPMsgCallbackEqComp);
}