/*
 * Authors:
 * Dmitriy A. Gearasimov <naeper@demlabs.net>
 * DeM Labs Inc.   https://demlabs.net

 This file is part of DAP (Deus Applications Prototypes) the open source project

 DAP (Deus Applicaions Prototypes) is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 DAP is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with any DAP based project.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdint.h>
#include <errno.h>
#include <assert.h>
#include <string.h>

#ifdef WIN32
#undef _WIN32_WINNT
#define _WIN32_WINNT 0x0600
#include <winsock2.h>
#include <windows.h>
#include <mswsock.h>
#include <ws2tcpip.h>
#include <io.h>
#include <wepoll.h>
#include <pthread.h>
#endif

#include "dap_common.h"
#include "dap_client.h"
#include "dap_config.h"
#include "dap_events.h"
#include "dap_http_client_simple.h"
#include "dap_client_pvt.h"
#include "dap_stream_ch_pkt.h"
#include "dap_stream_ch_chain.h"
#include "dap_stream_ch_chain_pkt.h"
#include "dap_stream_ch_chain_net.h"
#include "dap_stream_ch_chain_net_pkt.h"
#include "dap_stream_pkt.h"
#include "dap_chain_node_client.h"

#define LOG_TAG "dap_chain_node_client"

#define DAP_APP_NAME NODE_NETNAME"-node"
#define SYSTEM_PREFIX "/opt/"DAP_APP_NAME
#define SYSTEM_CONFIGS_DIR SYSTEM_PREFIX"/etc"

static int listen_port_tcp = 8079;

static void s_stage_connected_callback(dap_client_t *a_client, void *a_arg);
static void s_ch_chain_callback_notify_packet_out(dap_stream_ch_chain_t*, uint8_t a_pkt_type,
                                                      dap_stream_ch_chain_pkt_t *a_pkt, size_t a_pkt_data_size,
                                                      void * a_arg);
static void s_ch_chain_callback_notify_packet_in(dap_stream_ch_chain_t* a_ch_chain, uint8_t a_pkt_type,
                                                      dap_stream_ch_chain_pkt_t *a_pkt, size_t a_pkt_data_size,
                                                      void * a_arg);

/**
 * @brief dap_chain_node_client_init
 * @return
 */
int dap_chain_node_client_init(void)
{
    dap_config_t *g_config;
    // read listen_port_tcp from settings
    dap_config_init(SYSTEM_CONFIGS_DIR);
    if((g_config = dap_config_open(DAP_APP_NAME)) == NULL) {
        return -1;
    }
    else {
        const char *port_str = dap_config_get_item_str(g_config, "server", "listen_port_tcp");
        listen_port_tcp = (port_str) ? atoi(port_str) : 8079;
    }
    if(g_config)
        dap_config_close(g_config);
    return 0;
}

/**
 * @brief dap_chain_node_client_deinit
 */
void dap_chain_node_client_deinit()
{
    dap_http_client_simple_deinit();
    dap_client_deinit();
}

/**
 * @brief stage_status_callback
 * @param a_client
 * @param a_arg
 */
static void stage_status_callback(dap_client_t *a_client, void *a_arg)
{
    (void) a_client;
    (void) a_arg;

    //printf("* stage_status_callback client=%x data=%x\n", a_client, a_arg);
}

/**
 * @brief s_stage_status_error_callback
 * @param a_client
 * @param a_arg
 */
static void s_stage_status_error_callback(dap_client_t *a_client, void *a_arg)
{
    (void) a_arg;
    dap_chain_node_client_t *l_node_client = DAP_CHAIN_NODE_CLIENT(a_client);
    if ( l_node_client && l_node_client->keep_connection &&
         ( ( dap_client_get_stage(a_client) != STAGE_STREAM_STREAMING )||
           ( dap_client_get_stage_status(a_client) == STAGE_STATUS_ERROR  ) ) ){
        log_it(L_NOTICE,"Some errors happends, current state is %s but we need to return back to STAGE_STREAM_STREAMING",
                 dap_client_get_stage_str(a_client) ) ;

        pthread_mutex_unlock(&l_node_client->wait_mutex);
        log_it(L_DEBUG,"Wakeup all who waits");
        l_node_client->state = NODE_CLIENT_STATE_ERROR;

#ifndef _WIN32
        pthread_cond_signal(&l_node_client->wait_cond);
#else
        SetEvent( l_node_client->wait_cond );
#endif
        //dap_client_go_stage( a_client , STAGE_STREAM_STREAMING, s_stage_end_callback );
    }
    //printf("* tage_status_error_callback client=%x data=%x\n", a_client, a_arg);
}

/**
 * @brief a_stage_end_callback
 * @param a_client
 * @param a_arg
 */
static void s_stage_connected_callback(dap_client_t *a_client, void *a_arg)
{
    dap_chain_node_client_t *l_node_client = a_client->_inheritor;
    //assert(l_node_client);
    if(l_node_client) {
        log_it(L_NOTICE,"Stream connection with node " NODE_ADDR_FP_STR " established",
               NODE_ADDR_FP_ARGS_S( l_node_client->remote_node_addr) );
        pthread_mutex_lock(&l_node_client->wait_mutex);
        l_node_client->state = NODE_CLIENT_STATE_CONNECTED;

        dap_stream_ch_t * l_ch = dap_client_get_stream_ch( a_client , dap_stream_ch_chain_get_id() );
        if (l_ch){
            dap_stream_ch_chain_t * l_ch_chain = DAP_STREAM_CH_CHAIN(l_ch);
            l_ch_chain->callback_notify_packet_out = s_ch_chain_callback_notify_packet_out;
            l_ch_chain->callback_notify_packet_in = s_ch_chain_callback_notify_packet_in;
            l_ch_chain->callback_notify_arg = l_node_client;
        }else {
            log_it(L_WARNING,"No ch_chain channel, can't init notify callback for pkt type CH_CHAIN");
        }

        pthread_mutex_unlock(&l_node_client->wait_mutex);
        if ( l_node_client->callback_connected )
            l_node_client->callback_connected(l_node_client,a_arg);
        l_node_client->keep_connection = true;
        log_it(L_DEBUG,"Wakeup all who waits");

#ifndef _WIN32
        pthread_cond_signal(&l_node_client->wait_cond);
#else
        SetEvent( l_node_client->wait_cond );
#endif

    }
}

/**
 * @brief s_ch_chain_callback_notify_packet
 * @param a_pkt_type
 * @param a_pkt
 * @param a_pkt_data_size
 * @param a_arg
 */
static void s_ch_chain_callback_notify_packet_in(dap_stream_ch_chain_t* a_ch_chain, uint8_t a_pkt_type,
                                                      dap_stream_ch_chain_pkt_t *a_pkt, size_t a_pkt_data_size,
                                                      void * a_arg)
{
    dap_chain_node_client_t * l_node_client = (dap_chain_node_client_t *) a_arg;
    switch (a_pkt_type) {
        case DAP_STREAM_CH_CHAIN_NET_PKT_TYPE_ERROR:
            pthread_mutex_lock(&l_node_client->wait_mutex);
            l_node_client->state = NODE_CLIENT_STATE_ERROR ;
            dap_snprintf(l_node_client->last_error,sizeof (l_node_client->last_error),
                     "%s", (char*) a_pkt->data );
            log_it(L_WARNING,"Received packet DAP_STREAM_CH_CHAIN_NET_PKT_TYPE_ERROR with error \"%s\"",
                   l_node_client->last_error);
            pthread_mutex_unlock(&l_node_client->wait_mutex);

#ifndef _WIN32
            pthread_cond_signal(&l_node_client->wait_cond);
#else
            SetEvent( l_node_client->wait_cond );
#endif

        case DAP_STREAM_CH_CHAIN_NET_PKT_TYPE_NODE_ADDR_LEASE:
            pthread_mutex_lock(&l_node_client->wait_mutex);
            l_node_client->state = NODE_CLIENT_STATE_NODE_ADDR_LEASED;
            pthread_mutex_unlock(&l_node_client->wait_mutex);
#ifndef _WIN32
            pthread_cond_signal(&l_node_client->wait_cond);
#else
            SetEvent( l_node_client->wait_cond );
#endif
        break;
        case DAP_STREAM_CH_CHAIN_PKT_TYPE_SYNCED_ALL:
        case DAP_STREAM_CH_CHAIN_PKT_TYPE_SYNCED_GLOBAL_DB:
        case DAP_STREAM_CH_CHAIN_PKT_TYPE_SYNCED_CHAINS:{
            dap_stream_ch_chain_sync_request_t * l_request = NULL;
            if ( a_pkt_data_size == sizeof ( *l_request))
                l_request = (dap_stream_ch_chain_sync_request_t* ) a_pkt->data;

            if ( l_request ){
                if ( l_request->id_start < (uint64_t) dap_db_log_get_last_id() ){
                    log_it(L_INFO, "Remote is synced but we have updates for it");
                    // Get log diff
                    a_ch_chain->request_last_ts = dap_db_log_get_last_id();
                    dap_list_t *l_list = dap_db_log_get_list((time_t) l_request->id_start);

                    if ( l_list ) {
                        // Add it to outgoing list
                        l_list->prev = a_ch_chain->request_global_db_trs;
                        a_ch_chain->request_global_db_trs = l_list;
                        a_ch_chain->request_net_id.uint64 = a_pkt->hdr.net_id.uint64;
                        a_ch_chain->request_cell_id.uint64 = a_pkt->hdr.cell_id.uint64;
                        a_ch_chain->request_chain_id.uint64 = a_pkt->hdr.chain_id.uint64;
                        a_ch_chain->state = CHAIN_STATE_SYNC_GLOBAL_DB ;

                        dap_chain_node_addr_t l_node_addr = { 0 };
                        l_node_addr.uint64 = dap_db_get_cur_node_addr();
                        dap_stream_ch_chain_pkt_write(a_ch_chain->ch, DAP_STREAM_CH_CHAIN_PKT_TYPE_FIRST_GLOBAL_DB,
                                a_ch_chain->request_net_id, a_ch_chain->request_chain_id,
                                a_ch_chain->request_cell_id, &l_node_addr, sizeof(dap_chain_node_addr_t));

                        log_it(L_INFO, "Sync for remote tr_count=%d",dap_list_length(l_list));
                        dap_stream_ch_set_ready_to_write(a_ch_chain->ch, true);
                    }
                }else {
                    log_it(L_INFO, "Remote node has lastes ts for us");
                    pthread_mutex_lock(&l_node_client->wait_mutex);
                    l_node_client->state = NODE_CLIENT_STATE_SYNCED;
                    pthread_mutex_unlock(&l_node_client->wait_mutex);
#ifndef _WIN32
                    pthread_cond_signal(&l_node_client->wait_cond);
#else
                    SetEvent( l_node_client->wait_cond );
#endif

                }
            }else {
                log_it(L_INFO, "Sync notify without request to sync back, stay in SYNCED state");
                pthread_mutex_lock(&l_node_client->wait_mutex);
                l_node_client->state = NODE_CLIENT_STATE_SYNCED;
                pthread_mutex_unlock(&l_node_client->wait_mutex);
#ifndef _WIN32
                pthread_cond_signal(&l_node_client->wait_cond);
#else
                SetEvent( l_node_client->wait_cond );
#endif
            }

        }
        default:{}
    }
}

/**
 * @brief s_ch_chain_callback_notify_packet_in
 * @param a_ch_chain
 * @param a_pkt_type
 * @param a_pkt
 * @param a_pkt_data_size
 * @param a_arg
 */
static void s_ch_chain_callback_notify_packet_out(dap_stream_ch_chain_t* a_ch_chain, uint8_t a_pkt_type,
                                                      dap_stream_ch_chain_pkt_t *a_pkt, size_t a_pkt_data_size,
                                                      void * a_arg)
{
    (void) a_pkt;
    (void) a_pkt_data_size;
    (void) a_ch_chain;
    dap_chain_node_client_t * l_node_client = (dap_chain_node_client_t *) a_arg;
    switch (a_pkt_type) {
        case DAP_STREAM_CH_CHAIN_PKT_TYPE_SYNCED_ALL:
        case DAP_STREAM_CH_CHAIN_PKT_TYPE_SYNCED_GLOBAL_DB:
        case DAP_STREAM_CH_CHAIN_PKT_TYPE_SYNCED_CHAINS:{
            pthread_mutex_lock(&l_node_client->wait_mutex);
            l_node_client->state = NODE_CLIENT_STATE_SYNCED;
            pthread_mutex_unlock(&l_node_client->wait_mutex);
#ifndef _WIN32
            pthread_cond_signal(&l_node_client->wait_cond);
#else
            SetEvent( l_node_client->wait_cond );
#endif
        }break;
        default:{}
    }
}

/**
 * Create connection to server
 *
 * return a connection handle, or NULL, if an error
 */
dap_chain_node_client_t* dap_chain_node_client_connect(dap_chain_node_info_t *a_node_info)
{
    if(!a_node_info){
        log_it(L_ERROR,"Can't connect to the node: null object node_info");
        return NULL;
    }
    dap_chain_node_client_t *l_node_client = DAP_NEW_Z(dap_chain_node_client_t);
    l_node_client->state = NODE_CLIENT_STATE_DISCONNECTED;

#ifndef _WIN32
    pthread_condattr_t attr;
    pthread_condattr_init(&attr);
    pthread_condattr_setclock(&attr, CLOCK_MONOTONIC);
    pthread_cond_init(&l_node_client->wait_cond, &attr);
#else
    l_node_client->wait_cond = CreateEventA( NULL, FALSE, FALSE, NULL );
#endif

    pthread_mutex_init(&l_node_client->wait_mutex, NULL);
    l_node_client->events = NULL; //dap_events_new();
    l_node_client->client = dap_client_new(l_node_client->events, stage_status_callback, s_stage_status_error_callback);
    l_node_client->client->_inheritor = l_node_client;
    l_node_client->remote_node_addr.uint64 = a_node_info->hdr.address.uint64;
    dap_client_set_active_channels(l_node_client->client,"CN");

    int hostlen = 128;
    char host[hostlen];
    if(a_node_info->hdr.ext_addr_v4.s_addr)
    {
        struct sockaddr_in sa4 = { .sin_family = AF_INET, .sin_addr = a_node_info->hdr.ext_addr_v4 };
        inet_ntop(AF_INET, &(((struct sockaddr_in *) &sa4)->sin_addr), host, hostlen);
    }
    else
    {
        struct sockaddr_in6 sa6 = { .sin6_family = AF_INET6, .sin6_addr = a_node_info->hdr.ext_addr_v6 };
        inet_ntop(AF_INET6, &(((struct sockaddr_in6 *) &sa6)->sin6_addr), host, hostlen);
    }
    // address not defined
    if(!strcmp(host, "::")) {
        dap_chain_node_client_close(l_node_client);
        return NULL;
    }
    dap_client_set_uplink(l_node_client->client, strdup(host), listen_port_tcp);
//    dap_client_stage_t a_stage_target = STAGE_ENC_INIT;
    dap_client_stage_t l_stage_target = STAGE_STREAM_STREAMING;

    l_node_client->state = NODE_CLIENT_STATE_CONNECT;
    // Handshake & connect
    dap_client_go_stage(l_node_client->client, l_stage_target, s_stage_connected_callback);
    return l_node_client;
}

/**
 * Close connection to server, delete chain_node_client_t *client
 */
void dap_chain_node_client_close(dap_chain_node_client_t *a_client)
{
    if(a_client) {

        pthread_mutex_lock(&a_client->wait_mutex);
        a_client->client->_inheritor = NULL;// because client->_inheritor == a_client
        pthread_mutex_unlock(&a_client->wait_mutex);

        // clean client
        //dap_client_delete(a_client->client);
        //a_client->client = NULL;

#ifndef _WIN32
        pthread_cond_destroy(&a_client->wait_cond);
#else
        CloseHandle( a_client->wait_cond );
#endif
        pthread_mutex_destroy(&a_client->wait_mutex);
        DAP_DELETE(a_client);
    }
}


/**
 * Send stream request to server
 */
int dap_chain_node_client_send_ch_pkt(dap_chain_node_client_t *a_client, uint8_t a_ch_id, uint8_t a_type,
        const void *a_pkt_data, size_t a_pkt_data_size)
{
    if(!a_client || a_client->state < NODE_CLIENT_STATE_CONNECTED)
        return -1;

//    dap_stream_t *l_stream = dap_client_get_stream(a_client->client);
    dap_stream_ch_t * l_ch = dap_client_get_stream_ch(a_client->client, a_ch_id);
    if(l_ch){
//        dap_stream_ch_chain_net_t * l_ch_chain = DAP_STREAM_CH_CHAIN_NET(l_ch);

        dap_stream_ch_pkt_write(l_ch, a_type, a_pkt_data, a_pkt_data_size);
        dap_stream_ch_set_ready_to_write(l_ch, true);
        return 0;
    }else
        return -1;
}


/**
 * wait for the complete of request
 *
 * timeout_ms timeout in milliseconds
 * waited_state state which we will wait, sample NODE_CLIENT_STATE_CONNECT or NODE_CLIENT_STATE_SENDED
 * return -2 false, -1 timeout, 0 end of connection or sending data
 */
int dap_chain_node_client_wait( dap_chain_node_client_t *a_client, int a_waited_state, int a_timeout_ms )
{
    int ret = -1;
    if( !a_client )
        return -3;

    pthread_mutex_lock( &a_client->wait_mutex );
    // have waited
    if ( a_client->state == a_waited_state ) {
        pthread_mutex_unlock( &a_client->wait_mutex );
        return 0;
    }

#ifndef _WIN32
    // prepare for signal waiting
    struct timespec to;
    clock_gettime( CLOCK_MONOTONIC, &to );
    int64_t nsec_new = to.tv_nsec + a_timeout_ms * 1000000ll;
    // if the new number of nanoseconds is more than a second

    if ( nsec_new > (long) 1e9 ) {
        to.tv_sec += nsec_new / (long) 1e9;
        to.tv_nsec = nsec_new % (long) 1e9;
    }
    else
        to.tv_nsec = (long) nsec_new;
#else
    pthread_mutex_unlock( &a_client->wait_mutex );
#endif

    // signal waiting
    do {

#ifndef _WIN32
        int wait = pthread_cond_timedwait( &a_client->wait_cond, &a_client->wait_mutex, &to);
        if(wait == 0 && (
                    a_client->state == a_waited_state ||
                    a_client->state == NODE_CLIENT_STATE_ERROR )
          ) {
            ret = a_client->state == a_waited_state ? 0 : -2;
            break;
        }
        else if(wait == ETIMEDOUT) { // 110 260
            ret = -1;
            break;
        }
#else
        int wait = WaitForSingleObject( a_client->wait_cond, (uint32_t)a_timeout_ms );
        pthread_mutex_lock( &a_client->wait_mutex );

        if ( wait == WAIT_OBJECT_0 && (
                    a_client->state == a_waited_state ||
                    a_client->state == NODE_CLIENT_STATE_ERROR )
          ) {
            ret = a_client->state == a_waited_state ? 0 : -2;
            break;
        }
        else if ( wait == WAIT_TIMEOUT || wait == WAIT_FAILED ) {
            ret = -1;
            break;
        }
#endif

    } while( 1 );

    pthread_mutex_unlock( &a_client->wait_mutex );
    return ret;
}