/* Copyright (c) 2017-2020 The Linux Foundation. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials provided
 *       with the distribution.
 *     * Neither the name of The Linux Foundation, nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <netinet/in.h>
#include <netdb.h>
#include <loc_misc_utils.h>
#include <log_util.h>
#include <LocIpc.h>
#include <algorithm>

using namespace std;

namespace loc_util {

#ifdef LOG_TAG
#undef LOG_TAG
#endif
#define LOG_TAG "LocSvc_LocIpc"

#define SOCK_OP_AND_LOG(buf, length, opable, rtv, exe)  \
    if (nullptr == (buf) || 0 == (length)) { \
        LOC_LOGe("Invalid inputs: buf - %p, length - %u", (buf), (length)); \
    } else if (!(opable)) {                                             \
        LOC_LOGe("Invalid object: operable - %d", (opable));            \
    } else { \
        rtv = (exe); \
        if (-1 == rtv) { \
            LOC_LOGw("failed reason: %s", strerror(errno)); \
        } \
    }

const char Sock::MSG_ABORT[] = "LocIpc::Sock::ABORT";
const char Sock::LOC_IPC_HEAD[] = "$MSGLEN$";
ssize_t Sock::send(const void *buf, uint32_t len, int flags, const struct sockaddr *destAddr,
                          socklen_t addrlen) const {
    ssize_t rtv = -1;
    SOCK_OP_AND_LOG(buf, len, isValid(), rtv, sendto(buf, len, flags, destAddr, addrlen));
    return rtv;
}
ssize_t Sock::recv(const LocIpcRecver& recver, const shared_ptr<ILocIpcListener>& dataCb, int flags,
                   struct sockaddr *srcAddr, socklen_t *addrlen, int sid) const {
    ssize_t rtv = -1;
    if (-1 == sid) {
        sid = mSid;
    } // else it sid would be connection based socket id for recv
    SOCK_OP_AND_LOG(dataCb.get(), mMaxTxSize, isValid(), rtv,
                    recvfrom(recver, dataCb, sid, flags, srcAddr, addrlen));
    return rtv;
}
ssize_t Sock::sendto(const void *buf, size_t len, int flags, const struct sockaddr *destAddr,
                     socklen_t addrlen) const {
    ssize_t rtv = -1;
    if (len <= mMaxTxSize) {
        rtv = ::sendto(mSid, buf, len, flags, destAddr, addrlen);
    } else {
        std::string head(LOC_IPC_HEAD + to_string(len));
        rtv = ::sendto(mSid, head.c_str(), head.length(), flags, destAddr, addrlen);
        if (rtv > 0) {
            for (size_t offset = 0; offset < len && rtv > 0; offset += rtv) {
                rtv = ::sendto(mSid, (char*)buf + offset, min(len - offset, (size_t)mMaxTxSize),
                               flags, destAddr, addrlen);
            }
            rtv = (rtv > 0) ? (head.length() + len) : -1;
        }
    }
    return rtv;
}
ssize_t Sock::recvfrom(const LocIpcRecver& recver, const shared_ptr<ILocIpcListener>& dataCb,
                       int sid, int flags, struct sockaddr *srcAddr, socklen_t *addrlen) const  {
    std::string msg(mMaxTxSize, 0);
    ssize_t nBytes = ::recvfrom(sid, (void*)msg.data(), msg.size(), flags, srcAddr, addrlen);
    if (nBytes > 0) {
        if (strncmp(msg.data(), MSG_ABORT, sizeof(MSG_ABORT)) == 0) {
            LOC_LOGi("recvd abort msg.data %s", msg.data());
            nBytes = 0;
        } else if (strncmp(msg.data(), LOC_IPC_HEAD, sizeof(LOC_IPC_HEAD) - 1)) {
            // short message
            msg.resize(nBytes);
            dataCb->onReceive(msg.data(), nBytes, &recver);
        } else {
            // long message
            size_t msgLen = 0;
            sscanf(msg.data() + sizeof(LOC_IPC_HEAD) - 1, "%zu", &msgLen);
            msg.resize(msgLen);
            for (size_t msgLenReceived = 0; (msgLenReceived < msgLen) && (nBytes > 0);
                 msgLenReceived += nBytes) {
                nBytes = ::recvfrom(sid, &(msg[msgLenReceived]), msg.size() - msgLenReceived,
                                    flags, srcAddr, addrlen);
            }
            if (nBytes > 0) {
                nBytes = msgLen;
                dataCb->onReceive(msg.data(), nBytes, &recver);
            }
        }
    }

    return nBytes;
}
ssize_t Sock::sendAbort(int flags, const struct sockaddr *destAddr, socklen_t addrlen) {
    return send(MSG_ABORT, sizeof(MSG_ABORT), flags, destAddr, addrlen);
}

class LocIpcLocalSender : public LocIpcSender {
protected:
    shared_ptr<Sock> mSock;
    struct sockaddr_un mAddr;
    inline virtual bool isOperable() const override { return mSock != nullptr && mSock->isValid(); }
    inline virtual ssize_t send(const uint8_t data[], uint32_t length, int32_t /* msgId */) const {
        return mSock->send(data, length, 0, (struct sockaddr*)&mAddr, sizeof(mAddr));
    }
public:
    inline LocIpcLocalSender(const char* name) : LocIpcSender(),
            mSock(nullptr),
            mAddr({.sun_family = AF_UNIX, {}}) {

        int fd = -1;
        if (nullptr != name) {
            fd = ::socket(AF_UNIX, SOCK_DGRAM, 0);
            if (fd >= 0) {
                timeval timeout;
                timeout.tv_sec = 2;
                timeout.tv_usec = 0;
                setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(timeout));
            }
        }
        mSock.reset(new Sock(fd));
        if (mSock != nullptr && mSock->isValid()) {
            snprintf(mAddr.sun_path, sizeof(mAddr.sun_path), "%s", name);
        }
    }
};

class LocIpcLocalRecver : public LocIpcLocalSender, public LocIpcRecver {
protected:
    inline virtual ssize_t recv() const override {
        socklen_t size = sizeof(mAddr);
        return mSock->recv(*this, mDataCb, 0, (struct sockaddr*)&mAddr, &size);
    }
public:
    inline LocIpcLocalRecver(const shared_ptr<ILocIpcListener>& listener, const char* name) :
            LocIpcLocalSender(name), LocIpcRecver(listener, *this) {

        if ((unlink(mAddr.sun_path) < 0) && (errno != ENOENT)) {
            LOC_LOGw("unlink socket error. reason:%s", strerror(errno));
        }

        umask(0157);
        if (mSock->isValid() && ::bind(mSock->mSid, (struct sockaddr*)&mAddr, sizeof(mAddr)) < 0) {
            LOC_LOGe("bind socket error. sock fd: %d: %s, reason: %s", mSock->mSid,
                    mAddr.sun_path, strerror(errno));
            mSock->close();
        }
    }
    inline virtual ~LocIpcLocalRecver() { unlink(mAddr.sun_path); }
    inline virtual const char* getName() const override { return mAddr.sun_path; };
    inline virtual void abort() const override {
        if (isSendable()) {
            mSock->sendAbort(0, (struct sockaddr*)&mAddr, sizeof(mAddr));
        }
    }
};

class LocIpcInetSender : public LocIpcSender {
protected:
    int mSockType;
    shared_ptr<Sock> mSock;
    const string mName;
    sockaddr_in mAddr;
    inline virtual bool isOperable() const override { return mSock != nullptr && mSock->isValid(); }
    virtual ssize_t send(const uint8_t data[], uint32_t length, int32_t /* msgId */) const {
        return mSock->send(data, length, 0, (struct sockaddr*)&mAddr, sizeof(mAddr));
    }
public:
    inline LocIpcInetSender(const LocIpcInetSender& sender) :
            mSockType(sender.mSockType), mSock(sender.mSock),
            mName(sender.mName), mAddr(sender.mAddr) {
    }
    inline LocIpcInetSender(const char* name, int32_t port, int sockType) : LocIpcSender(),
            mSockType(sockType),
            mSock(make_shared<Sock>((nullptr == name) ? -1 : (::socket(AF_INET, mSockType, 0)))),
            mName((nullptr == name) ? "" : name),
            mAddr({.sin_family = AF_INET, .sin_port = htons(port),
                    .sin_addr = {htonl(INADDR_ANY)}}) {
        if (mSock != nullptr && mSock->isValid() && nullptr != name) {
            struct hostent* hp = gethostbyname(name);
            if (nullptr != hp) {
                memcpy((char*)&(mAddr.sin_addr.s_addr), hp->h_addr_list[0], hp->h_length);
            }
        }
    }

    unique_ptr<LocIpcRecver> getRecver(const shared_ptr<ILocIpcListener>& listener) override {
        return make_unique<SockRecver>(listener, *this, mSock);
    }
};

class LocIpcInetTcpSender : public LocIpcInetSender {
protected:
    mutable bool mFirstTime;

    virtual ssize_t send(const uint8_t data[], uint32_t length, int32_t /* msgId */) const {
        if (mFirstTime) {
            mFirstTime = false;
            ::connect(mSock->mSid, (const struct sockaddr*)&mAddr, sizeof(mAddr));
        }
        return mSock->send(data, length, 0, (struct sockaddr*)&mAddr, sizeof(mAddr));
    }

public:
    inline LocIpcInetTcpSender(const char* name, int32_t port) :
            LocIpcInetSender(name, port, SOCK_STREAM),
            mFirstTime(true) {}
};

class LocIpcInetRecver : public LocIpcInetSender, public LocIpcRecver {
     int32_t mPort;
protected:
     virtual ssize_t recv() const = 0;
public:
    inline LocIpcInetRecver(const shared_ptr<ILocIpcListener>& listener, const char* name,
                               int32_t port, int sockType) :
            LocIpcInetSender(name, port, sockType), LocIpcRecver(listener, *this),
            mPort(port) {
        if (mSock->isValid() && ::bind(mSock->mSid, (struct sockaddr*)&mAddr, sizeof(mAddr)) < 0) {
            LOC_LOGe("bind socket error. sock fd: %d, reason: %s", mSock->mSid, strerror(errno));
            mSock->close();
        }
    }
    inline virtual ~LocIpcInetRecver() {}
    inline virtual const char* getName() const override { return mName.data(); };
    inline virtual void abort() const override {
        if (isSendable()) {
            sockaddr_in loopBackAddr = {.sin_family = AF_INET, .sin_port = htons(mPort),
                    .sin_addr = {htonl(INADDR_LOOPBACK)}};
            mSock->sendAbort(0, (struct sockaddr*)&loopBackAddr, sizeof(loopBackAddr));
        }
    }
    inline virtual unique_ptr<LocIpcSender> getLastSender() const override {
        return make_unique<LocIpcInetSender>(static_cast<const LocIpcInetSender&>(*this));
    }
};

class LocIpcInetTcpRecver : public LocIpcInetRecver {
    mutable int32_t mConnFd;
protected:
    inline virtual ssize_t recv() const override {
        socklen_t size = sizeof(mAddr);
        if (-1 == mConnFd && mSock->isValid()) {
            if (::listen(mSock->mSid, 3) < 0 ||
                (mConnFd = accept(mSock->mSid, (struct sockaddr*)&mAddr, &size)) < 0) {
                mSock->close();
                mConnFd = -1;
            }
        }
        return mSock->recv(*this, mDataCb, 0, (struct sockaddr*)&mAddr, &size, mConnFd);
    }
public:
    inline LocIpcInetTcpRecver(const shared_ptr<ILocIpcListener>& listener, const char* name,
                               int32_t port) :
            LocIpcInetRecver(listener, name, port, SOCK_STREAM), mConnFd(-1) {}
    inline virtual ~LocIpcInetTcpRecver() { if (-1 != mConnFd) ::close(mConnFd);}
};

class LocIpcInetUdpRecver : public LocIpcInetRecver {
protected:
    inline virtual ssize_t recv() const override {
        socklen_t size = sizeof(mAddr);
        return mSock->recv(*this, mDataCb, 0, (struct sockaddr*)&mAddr, &size);
    }
public:
    inline LocIpcInetUdpRecver(const shared_ptr<ILocIpcListener>& listener, const char* name,
                                int32_t port) :
            LocIpcInetRecver(listener, name, port, SOCK_DGRAM) {}

    inline virtual ~LocIpcInetUdpRecver() {}
};

class LocIpcRunnable : public LocRunnable {
    bool mAbortCalled;
    LocIpc& mLocIpc;
    unique_ptr<LocIpcRecver> mIpcRecver;
public:
    inline LocIpcRunnable(LocIpc& locIpc, unique_ptr<LocIpcRecver>& ipcRecver) :
            mAbortCalled(false),
            mLocIpc(locIpc),
            mIpcRecver(move(ipcRecver)) {}
    inline bool run() override {
        if (mIpcRecver != nullptr) {
            mLocIpc.startBlockingListening(*(mIpcRecver.get()));
            if (!mAbortCalled) {
                LOC_LOGw("startListeningBlocking() returned w/o stopBlockingListening() called");
            }
        }
        // return false so the calling thread exits while loop
        return false;
    }
    inline void abort() {
        mAbortCalled = true;
        if (mIpcRecver != nullptr) {
            mIpcRecver->abort();
        }
    }
};

bool LocIpc::startNonBlockingListening(unique_ptr<LocIpcRecver>& ipcRecver) {
    if (ipcRecver != nullptr && ipcRecver->isRecvable()) {
        std::string threadName("LocIpc-");
        threadName.append(ipcRecver->getName());
        mRunnable = new LocIpcRunnable(*this, ipcRecver);
        return mThread.start(threadName.c_str(), mRunnable);
    } else {
        LOC_LOGe("ipcRecver is null OR ipcRecver->recvable() is fasle");
        return false;
    }
}

bool LocIpc::startBlockingListening(LocIpcRecver& ipcRecver) {
    if (ipcRecver.isRecvable()) {
        // inform that the socket is ready to receive message
        ipcRecver.onListenerReady();
        while (ipcRecver.recvData());
        return true;
    } else  {
        LOC_LOGe("ipcRecver is null OR ipcRecver->recvable() is fasle");
        return false;
    }
}

void LocIpc::stopNonBlockingListening() {
    if (mRunnable) {
        mRunnable->abort();
        mRunnable = nullptr;
    }
}

void LocIpc::stopBlockingListening(LocIpcRecver& ipcRecver) {
    if (ipcRecver.isRecvable()) {
        ipcRecver.abort();
    }
}

bool LocIpc::send(LocIpcSender& sender, const uint8_t data[], uint32_t length, int32_t msgId) {
    return sender.sendData(data, length, msgId);
}

shared_ptr<LocIpcSender> LocIpc::getLocIpcLocalSender(const char* localSockName) {
    return make_shared<LocIpcLocalSender>(localSockName);
}
unique_ptr<LocIpcRecver> LocIpc::getLocIpcLocalRecver(const shared_ptr<ILocIpcListener>& listener,
                                                      const char* localSockName) {
    return make_unique<LocIpcLocalRecver>(listener, localSockName);
}
static void* sLibQrtrHandle = nullptr;
static const char* sLibQrtrName = "libloc_socket.so";
shared_ptr<LocIpcSender> LocIpc::getLocIpcQrtrSender(int service, int instance) {
    typedef shared_ptr<LocIpcSender> (*creator_t) (int, int);
    static creator_t creator = (creator_t)dlGetSymFromLib(sLibQrtrHandle, sLibQrtrName,
            "_ZN8loc_util22createLocIpcQrtrSenderEii");
    return (nullptr == creator) ? nullptr : creator(service, instance);
}
unique_ptr<LocIpcRecver> LocIpc::getLocIpcQrtrRecver(const shared_ptr<ILocIpcListener>& listener,
                                                     int service, int instance) {
    typedef unique_ptr<LocIpcRecver> (*creator_t)(const shared_ptr<ILocIpcListener>&, int, int);
    static creator_t creator = (creator_t)dlGetSymFromLib(sLibQrtrHandle, sLibQrtrName,
#ifdef USE_GLIB
            "_ZN8loc_util22createLocIpcQrtrRecverERKSt10shared_ptrINS_15ILocIpcListenerEEii");
#else
            "_ZN8loc_util22createLocIpcQrtrRecverERKNSt3__110shared_ptrINS_15ILocIpcListenerEEEii");
#endif
    return (nullptr == creator) ? nullptr : creator(listener, service, instance);
}
shared_ptr<LocIpcSender> LocIpc::getLocIpcInetTcpSender(const char* serverName, int32_t port) {
    return make_shared<LocIpcInetTcpSender>(serverName, port);
}
unique_ptr<LocIpcRecver> LocIpc::getLocIpcInetTcpRecver(const shared_ptr<ILocIpcListener>& listener,
                                                            const char* serverName, int32_t port) {
    return make_unique<LocIpcInetTcpRecver>(listener, serverName, port);
}
shared_ptr<LocIpcSender> LocIpc::getLocIpcInetUdpSender(const char* serverName, int32_t port) {
    return make_shared<LocIpcInetSender>(serverName, port, SOCK_DGRAM);
}
unique_ptr<LocIpcRecver> LocIpc::getLocIpcInetUdpRecver(const shared_ptr<ILocIpcListener>& listener,
                                                             const char* serverName, int32_t port) {
    return make_unique<LocIpcInetUdpRecver>(listener, serverName, port);
}
pair<shared_ptr<LocIpcSender>, unique_ptr<LocIpcRecver>>
        LocIpc::getLocIpcQmiLocServiceSenderRecverPair(const shared_ptr<ILocIpcListener>& listener, int instance) {
    typedef pair<shared_ptr<LocIpcSender>, unique_ptr<LocIpcRecver>> (*creator_t)(const shared_ptr<ILocIpcListener>&, int);
    static void* sLibEmuHandle = nullptr;
    static creator_t creator = (creator_t)dlGetSymFromLib(sLibEmuHandle, "libloc_emu.so",
            "_ZN13QmiLocService41createLocIpcQmiLocServiceSenderRecverPairERKNSt3__110shared_ptrIN8loc_util15ILocIpcListenerEEEi");
    return (nullptr == creator) ?
            make_pair<shared_ptr<LocIpcSender>, unique_ptr<LocIpcRecver>>(nullptr, nullptr) :
            creator(listener, instance);
}

}