#include "nng_wrap.h"

#include <string.h>

#include <vector>
#include "common.h"
using namespace std;

#include <nng/protocol/reqrep0/rep.h>
#include <nng/supplemental/util/platform.h>

#include "nng/compat/nanomsg/reqrep.h"
#include "nng/compat/nanomsg/pubsub.h"
#include "nng/compat/nanomsg/survey.h"

namespace nng_wrap {

static int client_socket(const string& url, const int protocol, int family=AF_SP){
    int sock = nn_socket(family, protocol);
    if (sock < 0) return sock;
    int rc = nn_connect(sock, url.c_str());
    if (rc < 0) {
        nn_close(sock);
        return rc;
    }
    return sock;
}

static void set_socket_timeout(int sock, const int to_ms){
    nn_setsockopt(sock, NN_SOL_SOCKET, NN_SNDTIMEO, &to_ms, sizeof(to_ms));
    nn_setsockopt(sock, NN_SOL_SOCKET, NN_RCVTIMEO, &to_ms, sizeof(to_ms));
}

static int send_and_recv(int sock,
    const void* in, const int in_len,
    void** out, int *out_len)
{
    int rc = nn_send(sock, in, in_len, 0);
    if (rc != in_len) {
        nn_close(sock);
        return -1;
    }
    char *msg = NULL;
    rc = nn_recv(sock, &msg, NN_MSG, 0);
    if (rc < 0) {
        nn_close(sock);
        return rc;
    }
    nn_close(sock);
    copy_memory(out, out_len, msg, rc);
    nn_freemsg(msg);
    return 0;
}

/////////////////////////////////////////////////
// simple interface

void free_nng(void* data, const int data_len){
    free(data);
}

void copy_memory(void** dest, int *dest_len, const void* src, const int src_len){
    char* tmp = (char*)malloc(src_len);
    memcpy(tmp, src, src_len);
    *dest = tmp;
    if(dest_len)
        *dest_len = src_len;
}

void set_last_error(const std::string& emsg){
    // verbose_info += emsg;
}

void get_last_error(int* ec, void** emsg, int* emsg_len){
    *emsg = NULL;
    *emsg_len = 0;

    *ec = nn_errno();
    const char* msg = nn_strerror(*ec);
    // string strMsg(msg);
    // strMsg = strMsg + "{" + verbose_info + "}";
    // copy_memory(emsg, emsg_len, strMsg.data(), strMsg.size());
    // verbose_info.clear();

    copy_memory(emsg, emsg_len, msg, strlen(msg));
}

///////////////////////////////////////////////////////
// simple request waiting reply

int simple_request(const std::string& url,
    const void* in, const int in_len,
    void** out, int *out_len, const int to_ms){

    TAG;
    *out = NULL;
    *out_len = 0;

    // printf("------>> simple_request url %s\n", (char*)url.data);
    int sock = client_socket(url, NN_REQ);
    if (sock < 0) {
        PRNTVITAG("client_socket faild");
        return false;
    }

    int tm = to_ms < timeout_req_rep ? timeout_req_rep : to_ms;
    set_socket_timeout(sock, tm);

    auto ret = send_and_recv(sock, in, in_len, out, out_len);
    // printf("------>> simple_request out data address %p len %d\n", out->data, out->data_len);
    if (ret < 0) {
        PRNTVITAG("send_and_recv faild");
        return false;
    }
    return true;
}

/////////////////////////////////////////////////////
// publish

static int pub_connect_to_center(const string& topic, _ps* pub){
    if (pub->socket_ > 0) return pub->socket_;
    pub->url_ = topic;

    TAG;
    int sock = client_socket(topic, NN_REQ);
    if (sock < 0){
        PRNTVITAG("client_socket faild");
        return -1;
    }
    set_socket_timeout(sock, timeout_req_rep);
    pub->socket_ = sock;
    pub->t_ = get_thread([](const auto pub){
        while (!pub->t_quit_.load()) {
            _ps::psmsg *msg{NULL};
            {
                unique_lock<mutex> l{pub->mtx_msg_};
                pub->cv_msg_.wait(l, [pub]{
                    return !pub->msg_.empty() || pub->t_quit_.load();
                });
                if(pub->t_quit_.load()) break;
                msg = &pub->msg_.front();
                if (msg->topic_.empty()) {pub->msg_.pop_front(); continue;}
            }
            string sndmsg = (string{msg->topic_}+='\0')+=msg->data_;
            int rc = nn_send(pub->socket_, sndmsg.data(), sndmsg.size(), 0);
            if (rc == (int)sndmsg.size()){
                char* tmp{};
                rc = nn_recv(pub->socket_, &tmp, NN_MSG, 0);
                if (rc > 0){
                    nn_freemsg(tmp);
                    // printf("======>> publish topic %s data length %lu\n", msg->topic_.c_str(), msg->data_.size());
                    lock_guard<mutex> l{pub->mtx_msg_};
                    pub->msg_.pop_front();
                    continue;
                }else{
                    PRNTVITAG("publish req-rep thread nn_recv faild");
                }
            }else{
                PRNTVITAG("publish req-rep thread nn_send faild");
            }

        }
    }, pub);
    return sock;
}

int publish(const std::string& topic, const void* data, const int data_len, void* arg/*=NULL*/){
    // printf("======>> publish topic %s\n", topic.c_str());
    _ps* pub = (_ps*)arg;
    if (!pub) pub = singleton<_ps>();

    if (!data && data_len == 0){
        // printf("======>> publish start url %s\n", topic.c_str());
        return pub_connect_to_center(topic, pub);
    }
    if (pub->socket_ < 0){
        pub_connect_to_center(pub->url_, pub);
    }
    if(pub->socket_ < 0) {
        PRNTVITAG("publish socket_ < 0");
        return -1;
    }

    // printf("======>> publish topic %s\n", topic.c_str());
    lock_guard<mutex> l{pub->mtx_msg_};
    pub->msg_.emplace_back(topic, string{(const char*)data, (const size_t)data_len});
    pub->cv_msg_.notify_one();
    return (*pub)();
}

///////////////////////////////////////////////
// subscribe

int subscribe_center(const std::string& url, void* arg/*=NULL*/){
    _ps_sub* sub = (_ps_sub*)arg;
    if (!sub) sub = singleton<_ps_sub>();

    if (sub->socket_ > 0) return 0;
    sub->url_ = url;

    TAG;
    int sock = client_socket(url, NN_SUB);
    if (sock < 0){
        PRNTVITAG("client_socket faild\n");
        return -1;
    }
    // set_socket_timeout(sock, timeout_req_rep);
    sub->socket_ = sock;
    sub->t_ = get_thread([](const auto sub){
        while (!sub->t_quit_.load()) {
            char* m{};
            int m_len = nn_recv(sub->socket_, &m, NN_MSG, NN_DONTWAIT);
            if (m_len > 0){
                string tmp_msg{m, (size_t)m_len};
                nn_freemsg(m);
                string topic{tmp_msg.c_str()};
                string msg{};
                {
                    lock_guard<mutex> l{sub->operator()()};
                    for(auto && i : sub->topics_){
                        if (!!!i.compare(topic)){
                            msg = move(tmp_msg.substr(i.size()+1));
                            break;
                        }
                    }
                }
                // printf("======>> subscribe recv topic %s msg length %lu\n", topic, msg.length());
                if (!msg.empty()){
                    lock_guard<mutex> l(sub->mtx_msg_);
                    sub->msg_.emplace_back(move(topic), move(msg));
                    sub->cv_msg_.notify_all();
                }

            }else {
                {
                    lock_guard<mutex> l{sub->mtx_failed_topics_};
                    if (!sub->failed_topics_.empty()){
                        for(auto iter = sub->failed_topics_.begin(); iter != sub->failed_topics_.end();){
                            if (nn_setsockopt(sub->socket_, NN_SUB, NN_SUB_SUBSCRIBE, iter->c_str(), iter->length()) >= 0){
                                iter = sub->failed_topics_.erase(iter);
                            }else{
                                iter++;
                            }
                        }
                    }
                }
                this_thread::sleep_for(chrono::milliseconds{6});
                // printf("======>> subscribe nn_recv failed %s\n", nn_strerror(nn_errno()));
            }
        }
    }, sub);
    return 0;
}

int subscribe_topic(const std::string& topic, void* arg/*=NULL*/){
    _ps_sub* sub = (_ps_sub*)arg;
    if (!sub) sub = singleton<_ps_sub>();

    TAG;
    if (sub->socket_ < 0){
        subscribe_center(sub->url_, sub);
    }
    if (sub->socket_ < 0) {
        PRNTVITAG("socket_ < 0");
        return -1;
    }

    auto ret = nn_setsockopt(sub->socket_, NN_SUB, NN_SUB_SUBSCRIBE, topic.c_str(), topic.length());
    // printf("set NN_SUB_SUBSCRIBE topic %s ret %d\n", topic.c_str(), ret);
    if (ret < 0){
        PRNTVITAG("nn_setsockopt failed");
        lock_guard<mutex> l{sub->mtx_failed_topics_};
        sub->failed_topics_.insert(topic);
    }
    lock_guard<mutex> l{(*sub)()};
    sub->topics_.insert(topic);

    return 0;
}

int unsubscribe_topic(const std::string& topic, void* arg/*=NULL*/){
    _ps_sub* sub = (_ps_sub*)arg;
    if (!sub) sub = singleton<_ps_sub>();

    lock_guard<mutex> l{(*sub)()};
    auto iter = sub->topics_.find(topic);
    if (iter != sub->topics_.end()){
        nn_setsockopt(sub->socket_, NN_SUB, NN_SUB_UNSUBSCRIBE, topic.c_str(), topic.length());
        sub->topics_.erase(iter);
    }

    return 0;
}

int subscribe_read(std::string* topic, std::string* msg, const int to_ms, void* arg/*=NULL*/){
    _ps_sub* sub = (_ps_sub*)arg;
    if (!sub) sub = singleton<_ps_sub>();

    TAG;

    int tm = to_ms > 0 ? to_ms : 30;

    unique_lock<mutex> l(sub->mtx_msg_);
    auto status = sub->cv_msg_.wait_for(l, chrono::milliseconds{tm}, [sub]{
        return !sub->msg_.empty();
    });
    if (!status){
        PRNTVITAG("subscribe_read timeout");
        return -1;
    }
    auto& tmp = sub->msg_.front();
    *topic = std::move(tmp.topic_);
    *msg = std::move(tmp.data_);
    sub->msg_.pop_front();

    return 0;
}

///////////////////////////////////////////////////////////
// survey respondent for heartbeat

int respond_survey(const std::string& url, std::string&& fixed_msg, void* arg/*=NULL*/){
    _sv* sv = (_sv*)arg;
    if (!sv) sv = singleton<_sv>();

    sv->url_ = url;
    sv->fixed_msg_ = move(fixed_msg);
    sv->t_ = get_thread([](const auto sv){

        TAG;

        int& sock = sv->socket_;

        while (!sv->t_quit_.load()) {
            if (sock < 0){
                sock = client_socket(sv->url_, NN_RESPONDENT);
                if (sock > 0) set_socket_timeout(sock, 126);
            }
            if (sock < 0) continue;

            char* tmp{};
            int rc = nn_recv(sock, &tmp, NN_MSG, 0);
            if (rc > 0){
                nn_freemsg(tmp);
                rc = nn_send(sock, (*sv)().front().data(), (*sv)().front().size(), 0);
                if (rc < 0){
                    PRNTVITAG("heartbeat survey failed");
                    PRNTVITAG(nn_strerror(nn_errno()));
                }
            }
        }
    }, sv);

    return 0;
}

int request2(const std::string &ipc, const void* r, const int r_len,
    void** reply, int* reply_len, const int to_ms, void* arg/*=NULL*/)
{
    const auto suc = simple_request(ipc, r, r_len, reply, reply_len, to_ms);
    if (suc){
        const size_t sl = rr_unblocking_msg_.size();
        const size_t rl = *reply_len;
        if (sl != rl) return true;

        const auto& s = rr_unblocking_msg_;
        auto r = (const char*)(*reply);
        if (s.compare(0, sl, r, rl) == 0){
            free(*reply);
            *reply = NULL;
            *reply_len = 0;
            return false;
        }
    }
    return suc;
}

static void server_cb(void *arg)
{
    if (!arg) return;

    struct work *work = (struct work*)arg;
    nng_msg *    msg;
    int          rv;
    // uint32_t     when{0};

    switch (work->state) {
    case INIT:
        work->state = RECV;
        nng_ctx_recv(work->ctx, work->aio);
        break;
    case RECV:
        if ((rv = nng_aio_result(work->aio)) != 0) {
            break;
        }
        msg = nng_aio_get_msg(work->aio);

        work->msg   = msg;
        work->state = WAIT;
        if (work->cb_recv) work->cb_recv(work);
        // nng_sleep_aio(when, work->aio);
        break;
    case WAIT:
        // We could add more data to the message here.
        nng_aio_set_msg(work->aio, work->msg);
        work->msg   = NULL;
        work->state = SEND;
        nng_ctx_send(work->ctx, work->aio);
        break;
    case SEND:
        if ((rv = nng_aio_result(work->aio)) != 0) {
            nng_msg_free(work->msg);
            work->msg = NULL;
        }
        work->state = RECV;
        nng_ctx_recv(work->ctx, work->aio);
        break;
    default:
        break;
    }
}

static void cb_recv_for_aio(work* w){
    nng_msg *om = w->msg;
    if (!om) {nng_sleep_aio(0, w->aio); return;}

    _rr* rep = (_rr*)w->user_data;

    auto t = (*rep)();
    lock_guard<mutex> l{rep->mtx_msg_};
    rep->works_.emplace(get<0>(t), w);
    get<1>(t).emplace(get<0>(t), string{(const char*)nng_msg_body(om), nng_msg_len(om)});
    get<0>(t)++;
    rep->cv_msg_.notify_all();

    nng_msg_free(om);
}

static struct work *alloc_work(nng_socket sock, _rr* rep, const int mode)
{
    struct work *w;
    int          rv;

    if ((w = (struct work*)nng_alloc(sizeof(*w))) == NULL) {
        return NULL;;
    }
    w->cb_recv = cb_recv_for_aio;
    w->user_data = rep;

    if ((rv = nng_aio_alloc(&w->aio, server_cb, w)) != 0) {
        nng_free(w, sizeof(*w));
        return NULL;
    }
    if ((rv = nng_ctx_open(&w->ctx, sock)) != 0) {
        nng_free(w, sizeof(*w));
        return NULL;
    }
    w->state = INIT;
    w->mode = mode;

    return (w);
}

static int create_server(nng_socket* sock, const string& url, const int count, _rr* rep, const int mode){
    TAG;
    if (sock->id > 0) return 0;

    int rv = nng_rep0_open(sock);
    if (rv < 0){
        PRNTVITAG("create_server nng_rep0_open faild");
        PRNTVITAG(url);
        return rv;
    }

    work** works = (work**)malloc(sizeof(void*) * count);
    for (int i = 0; i < count; i++) {
        works[i] = alloc_work(*sock, rep, mode);
    }

    remove_exist(url);
    rv = nng_listen(*sock, url.c_str(), NULL, 0);
    if (rv < 0){
        for(int i = 0; i < count; i++) if(works[i]) nng_free(works[i], sizeof(work));
        free(works);
        PRNTVITAG("create_server nng_listen failed");
        PRNTVITAG(url);
        return rv;
    }

    for (int i = 0; i < count; i++) {
        server_cb(works[i]); // this starts them going (INIT state)
    }

    free(works);
    return 0;
}

static void aio_unblock(work* w, const void* msg, const int msg_len){
    nng_msg_alloc(&w->msg, 0);
    nng_msg_append(w->msg, msg, msg_len);

    nng_sleep_aio(0, w->aio);
}

int start_reply(const std::string& url, const int port, void* arg/*=NULL*/){
    _rr* rep = (_rr*)arg;
    if (!rep) rep = singleton<_rr>();

    string ipc = "ipc:///tmp/" + url;
    if (url.find("ipc://") == 0){
        ipc = url;
    }
    rep->url_ = ipc;
    if(create_server(&get<0>(rep->socks_), ipc, 62, rep, REPLY_IPC) != 0) return -1;

    if (port > 0){
        get<1>(get<1>(rep->socks_)) = port;
        ipc = "tcp://0.0.0.0:" + to_string(port);
        if(create_server(&get<0>(get<1>(rep->socks_)), ipc, 62, rep, REPLY_TCP) != 0) return -1;
        // printf("======>> create server for remote port %d\n", port);
    }else {
        get<0>(get<1>(rep->socks_)).id = numeric_limits<int32_t>::max();
    }

    if (!rep->t_unblock_){
        rep->t_unblock_.reset(new thread(get_thread([](const auto rep){
            constexpr int idle = 10;
            const auto data = rr_unblocking_msg_.data();
            const auto data_size = rr_unblocking_msg_.size();
            constexpr int life_span = timeout_req_rep*10;

            auto f = [rep]{
                vector<struct work*> tmp{};
                lock_guard<mutex> l{rep->mtx_msg_};
                for(auto iter = rep->works_.begin(); iter != rep->works_.end();){
                    if ((iter->second+=idle) > life_span){
                        tmp.push_back(iter->second.w_);
                        iter = rep->works_.erase(iter);
                    }else {
                        ++iter;
                    }
                }
                return tmp;
            };
            while (!rep->t_quit_.load()) {
                this_thread::sleep_for(chrono::milliseconds{10});
                vector<struct work*> tmp = f();
                for(auto && w : tmp){
                    aio_unblock(w, data, data_size);
                }
            }
        }, rep)));
    }

    return 0;
}

int read_request(void** src, std::string* msg, const int to_ms, void* arg/*=NULL*/){
    _rr* rep = (_rr*)arg;
    if (!rep) rep = singleton<_rr>();

    if (get<0>(rep->socks_).id == 0 || get<0>(get<1>(rep->socks_)).id == 0)
        if (start_reply(rep->url_, get<1>(get<1>(rep->socks_))) != 0)
            return -1;

    int tm = to_ms > 0 ? to_ms : 30;

    uint64_t key{};
    work* w{};
    {
        unique_lock<mutex> l(rep->mtx_msg_);
        auto status = rep->cv_msg_.wait_for(l, chrono::milliseconds{tm}, [rep]{
            return !rep->msg_.empty();
        });
        if (!status){
            PRNTVITAG("read_request timeout");
            return -1;
        }
        auto iter = rep->msg_.begin();
        key = iter->first;
        *msg = move(iter->second);
        rep->msg_.erase(iter);
        auto witer = rep->works_.find(key);
        if (witer != rep->works_.end()){
            w = witer->second;
        }
    }

    if (!w) return -1;

    *src = malloc(sizeof(uint64_t));
    *(uint64_t*)(*src) = key;

    return w->mode;
}

int send_reply(const void* src, const void* msg, const int msg_len, void* arg/*=NULL*/){
    _rr* rep = (_rr*)arg;
    if (!rep) rep = singleton<_rr>();

    struct work* w{};
    {
        auto key = *(static_cast<uint64_t*>(const_cast<void*>(src)));
        free(const_cast<void*>(src));

        lock_guard<mutex> l{rep->mtx_msg_};
        auto iter = rep->works_.find(key);
        if (iter == rep->works_.end()) return -1;
        w = iter->second;
        rep->works_.erase(iter);
    }

    aio_unblock(w, msg, msg_len);

    return 0;
}

}