#include <netinet/tcp.h>
#include <sys/epoll.h>

#include <net/if.h>
#include <ifaddrs.h>

#include "osd.h"

static int extract_port(std::string & host)
{
    int port = 0;
    int pos = 0;
    if ((pos = host.find(':')) >= 0)
    {
        port = strtoull(host.c_str() + pos + 1, NULL, 10);
        if (port >= 0x10000)
        {
            port = 0;
        }
        host = host.substr(0, pos);
    }
    return port;
}

std::vector<std::string> getifaddr_list()
{
    std::vector<std::string> addresses;
    ifaddrs *list, *ifa;
    if (getifaddrs(&list) == -1)
    {
        throw std::runtime_error(std::string("getifaddrs: ") + strerror(errno));
    }
    for (ifa = list; ifa != NULL; ifa = ifa->ifa_next)
    {
        if (!ifa->ifa_addr)
        {
            continue;
        }
        int family = ifa->ifa_addr->sa_family;
        if ((family == AF_INET || family == AF_INET6) &&
            (ifa->ifa_flags & (IFF_UP | IFF_RUNNING | IFF_LOOPBACK)) == (IFF_UP | IFF_RUNNING))
        {
            void *addr_ptr;
            if (family == AF_INET)
                addr_ptr = &((sockaddr_in *)ifa->ifa_addr)->sin_addr;
            else
                addr_ptr = &((sockaddr_in6 *)ifa->ifa_addr)->sin6_addr;
            char addr[INET6_ADDRSTRLEN];
            if (!inet_ntop(family, addr_ptr, addr, INET6_ADDRSTRLEN))
            {
                throw std::runtime_error(std::string("inet_ntop: ") + strerror(errno));
            }
            addresses.push_back(std::string(addr));
        }
    }
    freeifaddrs(list);
    return addresses;
}

json11::Json osd_t::get_status()
{
    json11::Json::object st;
    st["state"] = "up";
    if (bind_address != "0.0.0.0")
        st["addresses"] = { bind_address };
    else
    {
        if (bind_addresses.size() == 0)
            bind_addresses = getifaddr_list();
        st["addresses"] = bind_addresses;
    }
    st["port"] = bind_port;
    st["blockstore_enabled"] = bs ? true : false;
    if (bs)
    {
        st["size"] = bs->get_block_count() * bs->get_block_size();
        st["free"] = bs->get_free_block_count() * bs->get_block_size();
    }
    json11::Json::object pg_status;
    for (auto & p: pgs)
    {
        auto & pg = p.second;
        json11::Json::object pg_st;
        json11::Json::array pg_state;
        for (int i = 0; i < pg_state_bit_count; i++)
            if (pg.state & pg_state_bits[i])
                pg_state.push_back(pg_state_names[i]);
        pg_st["state"] = pg_state;
        pg_st["object_count"] = pg.total_count;
        pg_st["clean_count"] = pg.clean_count;
        pg_st["misplaced_count"] = pg.misplaced_objects.size();
        pg_st["degraded_count"] = pg.degraded_objects.size();
        pg_st["incomplete_count"] = pg.incomplete_objects.size();
        pg_st["write_osd_set"] = pg.cur_set;
        pg_status[std::to_string(pg.pg_num)] = pg_st;
    }
    st["pgs"] = pg_status;
    json11::Json::object op_stats, subop_stats;
    for (int i = 0; i <= OSD_OP_MAX; i++)
    {
        op_stats[osd_op_names[i]] = json11::Json::object {
            { "count", op_stat_count[0][i] },
            { "sum", op_stat_sum[0][i] },
        };
    }
    for (int i = 0; i <= OSD_OP_MAX; i++)
    {
        subop_stats[osd_op_names[i]] = json11::Json::object {
            { "count", subop_stat_count[0][i] },
            { "sum", subop_stat_sum[0][i] },
        };
    }
    st["op_latency"] = op_stats;
    st["subop_latency"] = subop_stats;
    return st;
}

void osd_t::report_status()
{
    if (consul_host == "")
    {
        consul_host = consul_address;
        extract_port(consul_host);
    }
    std::string st = get_status().dump();
    std::string req = "PUT /v1/kv/"+consul_prefix+"/osd/"+std::to_string(osd_num)+" HTTP/1.1\r\n"+
        "Host: "+consul_host+"\r\n"+
        "Content-Length: "+std::to_string(st.size())+"\r\n"+
        "Connection: close\r\n"
        "\r\n"+st;
    http_request(consul_address, req, [this](int err, std::string res)
    {
        int pos = res.find("\r\n\r\n");
        if (pos >= 0)
            res = res.substr(pos+4);
        if (err != 0 || res != "true")
            printf("Error reporting state to Consul: code %d (%s), response text: %s\n", err, strerror(err), res.c_str());
    });
}

struct http_co_t
{
    osd_t *osd;
    std::string host;
    std::string request;
    std::string response;
    std::vector<char> rbuf;

    int st = 0;
    int peer_fd = -1;
    int epoll_events = 0;
    int code = 0;
    int sent = 0, received = 0;
    iovec iov;
    msghdr msg = { 0 };
    int cqe_res = 0;

    std::function<void(int, std::string)> callback;
    std::function<void(int, int)> epoll_handler;

    ~http_co_t();
    void resume();
};

void osd_t::http_request(std::string host, std::string request, std::function<void(int, std::string)> callback)
{
    http_co_t *handler = new http_co_t();
    handler->osd = this;
    handler->host = host;
    handler->request = request;
    handler->callback = callback;
    handler->epoll_handler = [this, handler](int peer_fd, int epoll_events)
    {
        handler->epoll_events |= epoll_events;
        handler->resume();
    };
    handler->resume();
}

http_co_t::~http_co_t()
{
    callback(code, response);
    if (peer_fd >= 0)
    {
        osd->epoll_handlers.erase(peer_fd);
        epoll_ctl(osd->epoll_fd, EPOLL_CTL_DEL, peer_fd, NULL);
        close(peer_fd);
        peer_fd = -1;
    }
}

void http_co_t::resume()
{
    if (st == 0)
    {
        int port = extract_port(host);
        struct sockaddr_in addr;
        int r;
        if ((r = inet_pton(AF_INET, host.c_str(), &addr.sin_addr)) != 1)
        {
            code = ENXIO;
            delete this;
            return;
        }
        addr.sin_family = AF_INET;
        addr.sin_port = htons(port ? port : 80);
        peer_fd = socket(AF_INET, SOCK_STREAM, 0);
        if (peer_fd < 0)
        {
            code = errno;
            delete this;
            return;
        }
        fcntl(peer_fd, F_SETFL, fcntl(peer_fd, F_GETFL, 0) | O_NONBLOCK);
        r = connect(peer_fd, (sockaddr*)&addr, sizeof(addr));
        if (r < 0 && errno != EINPROGRESS)
        {
            code = errno;
            delete this;
            return;
        }
        osd->epoll_handlers[peer_fd] = epoll_handler;
        // Add FD to epoll (EPOLLOUT for tracking connect() result)
        epoll_event ev;
        ev.data.fd = peer_fd;
        ev.events = EPOLLOUT | EPOLLIN | EPOLLRDHUP | EPOLLET;
        if (epoll_ctl(osd->epoll_fd, EPOLL_CTL_ADD, peer_fd, &ev) < 0)
        {
            code = errno;
            delete this;
            return;
        }
        epoll_events = 0;
        st = 1;
        return;
    }
    if (st == 1)
    {
        if (epoll_events & (EPOLLOUT | EPOLLERR))
        {
            int result = 0;
            socklen_t result_len = sizeof(result);
            if (getsockopt(peer_fd, SOL_SOCKET, SO_ERROR, &result, &result_len) < 0)
            {
                result = errno;
            }
            if (result != 0)
            {
                code = result;
                delete this;
                return;
            }
            int one = 1;
            setsockopt(peer_fd, SOL_TCP, TCP_NODELAY, &one, sizeof(one));
            // Disable EPOLLOUT on this fd
            epoll_event ev;
            ev.data.fd = peer_fd;
            ev.events = EPOLLIN | EPOLLRDHUP | EPOLLET;
            if (epoll_ctl(osd->epoll_fd, EPOLL_CTL_MOD, peer_fd, &ev) < 0)
            {
                code = errno;
                delete this;
                return;
            }
            st = 2;
            epoll_events = 0;
            resume();
            return;
        }
        else if (epoll_events & EPOLLRDHUP)
        {
            delete this;
            return;
        }
        else
        {
            return;
        }
    }
    // Write data
    if (st == 2)
    {
        io_uring_sqe *sqe = osd->ringloop->get_sqe();
        if (!sqe)
            return;
        ring_data_t* data = ((ring_data_t*)sqe->user_data);
        iov = (iovec){ .iov_base = (void*)(request.c_str()+sent), .iov_len = request.size()-sent };
        msg.msg_iov = &iov;
        msg.msg_iovlen = 1;
        data->callback = [this](ring_data_t *data)
        {
            st = 4;
            cqe_res = data->res;
            resume();
        };
        my_uring_prep_sendmsg(sqe, peer_fd, &msg, 0);
        st = 3;
        return;
    }
    if (st == 3)
    {
        return;
    }
    if (st == 4)
    {
        if (cqe_res < 0 && cqe_res != -EAGAIN)
        {
            delete this;
            return;
        }
        sent += cqe_res;
        if (sent < request.size())
            st = 2;
        else
            st = 5;
        resume();
        return;
    }
    // Read response
    if (st == 5)
    {
        if (epoll_events & (EPOLLRDHUP|EPOLLERR))
        {
            delete this;
            return;
        }
        else if (epoll_events & EPOLLIN)
        {
            if (rbuf.size() != 9000)
                rbuf.resize(9000);
            io_uring_sqe *sqe = osd->ringloop->get_sqe();
            if (!sqe)
                return;
            ring_data_t* data = ((ring_data_t*)sqe->user_data);
            iov = { .iov_base = rbuf.data(), .iov_len = 9000 };
            msg.msg_iov = &iov;
            msg.msg_iovlen = 1;
            data->callback = [this](ring_data_t *data)
            {
                st = 7;
                cqe_res = data->res;
                resume();
            };
            my_uring_prep_recvmsg(sqe, peer_fd, &msg, 0);
            st = 6;
            epoll_events = 0;
        }
    }
    if (st == 6)
    {
        return;
    }
    if (st == 7)
    {
        if (cqe_res < 0 && cqe_res != -EAGAIN)
        {
            delete this;
            return;
        }
        response += std::string(rbuf.data(), cqe_res);
        received += cqe_res;
        st = 5;
        resume();
        return;
    }
}