#include "nng_wrap.h"
#include "common.h"

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

#include <vector>
using namespace std;

namespace nng_wrap {
//////////////////////////////////////////////
// reply for request

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->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) return;

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

    string msg{(const char*)nng_msg_body(om), nng_msg_len(om)};
    nng_msg_free(om);

    lock_guard<mutex> l{rep->mtx_msg_};
    rep->works_.emplace(rep->work_index_, w);
    rep->msg_.emplace(rep->work_index_, move(msg));
    rep->work_index_++;
    rep->cv_msg_.notify_all();
}

static struct work *alloc_work(nng_socket sock, _rr* rep)
{
    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) {
        return NULL;
    }
    if ((rv = nng_ctx_open(&w->ctx, sock)) != 0) {
        return NULL;
    }
    w->state = INIT;
    return (w);
}

static int create_server(nng_socket* sock, const string& url, const int count, _rr* rep){
    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(work*) * count);
    for (int i = 0; i < count; i++) {
        works[i] = alloc_work(*sock, rep);
    }

    remove_exist(url);
    rv = nng_listen(*sock, url.c_str(), NULL, 0);
    if (rv < 0){
        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) != 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) != 0) return -1;
    }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();
            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) > timeout_req_rep){
                        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{};
    {
        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("subscribe_read timeout");
            return -1;
        }
        auto iter = rep->msg_.begin();
        key = iter->first;
        *msg = move(iter->second);
        rep->msg_.erase(iter);
    }

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

    return 0;
}

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)));

        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;
}

}