/**
 * Copyright FunASR (https://github.com/alibaba-damo-academy/FunASR). All Rights
 * Reserved. MIT License  (https://opensource.org/licenses/MIT)
 */
/* 2022-2023 by zhaomingwork */

// websocket server for asr engine
// take some ideas from https://github.com/k2-fsa/sherpa-onnx
// online-websocket-server-impl.cc, thanks. The websocket server has two threads
// pools, one for handle network data and one for asr decoder.
// now only support offline engine.

#include "websocket-server-2pass.h"

#include <thread>
#include <utility>
#include <vector>

context_ptr WebSocketServer::on_tls_init(tls_mode mode,
                                         websocketpp::connection_hdl hdl,
                                         std::string& s_certfile,
                                         std::string& s_keyfile) {
  namespace asio = websocketpp::lib::asio;

  LOG(INFO) << "on_tls_init called with hdl: " << hdl.lock().get();
  LOG(INFO) << "using TLS mode: "
            << (mode == MOZILLA_MODERN ? "Mozilla Modern"
                                       : "Mozilla Intermediate");

  context_ptr ctx = websocketpp::lib::make_shared<asio::ssl::context>(
      asio::ssl::context::sslv23);

  try {
    if (mode == MOZILLA_MODERN) {
      // Modern disables TLSv1
      ctx->set_options(
          asio::ssl::context::default_workarounds |
          asio::ssl::context::no_sslv2 | asio::ssl::context::no_sslv3 |
          asio::ssl::context::no_tlsv1 | asio::ssl::context::single_dh_use);
    } else {
      ctx->set_options(asio::ssl::context::default_workarounds |
                       asio::ssl::context::no_sslv2 |
                       asio::ssl::context::no_sslv3 |
                       asio::ssl::context::single_dh_use);
    }

    ctx->use_certificate_chain_file(s_certfile);
    ctx->use_private_key_file(s_keyfile, asio::ssl::context::pem);

  } catch (std::exception& e) {
    LOG(INFO) << "Exception: " << e.what();
  }
  return ctx;
}

nlohmann::json handle_result(FUNASR_RESULT result, nlohmann::json msg) {

    websocketpp::lib::error_code ec;
    nlohmann::json jsonresult;
    jsonresult["text"]="";

    std::string tmp_online_msg = FunASRGetResult(result, 0);
    if (tmp_online_msg != "") {
      LOG(INFO) << "online_res :" << tmp_online_msg;
      jsonresult["text"] = tmp_online_msg; 
      jsonresult["mode"] = "2pass-online";
    }
    std::string tmp_tpass_msg = FunASRGetTpassResult(result, 0);
    if (tmp_tpass_msg != "") {
      LOG(INFO) << "offline results : " << tmp_tpass_msg;
      jsonresult["text"] = tmp_tpass_msg; 
      jsonresult["mode"] = "2pass-offline";    
    }

    if (msg.contains("wav_name")) {
      jsonresult["wav_name"] = msg["wav_name"];
    }

    return jsonresult;
}
// feed buffer to asr engine for decoder
void WebSocketServer::do_decoder(
    std::vector<char>& buffer, websocketpp::connection_hdl& hdl,
    nlohmann::json& msg, std::vector<std::vector<std::string>>& punc_cache,
    websocketpp::lib::mutex& thread_lock, bool& is_final,
    FUNASR_HANDLE& tpass_online_handle) {
 
  // lock for each connection
  scoped_lock guard(thread_lock);
  FUNASR_RESULT Result = nullptr;
  int asr_mode_ = 2;
  if (msg.contains("mode")) {
    std::string modeltype = msg["mode"];
    if (modeltype == "offline") {
      asr_mode_ = 0;
    } else if (modeltype == "online") {
      asr_mode_ = 1;
    } else if (modeltype == "2pass") {
      asr_mode_ = 2;
    }
  } else {
    // default value
    msg["mode"] = "2pass";
    asr_mode_ = 2;
  }
 
  try {
    // loop to send chunk_size 800*2 data to asr engine.   TODO: chunk_size need get from client 
    while (buffer.size() >= 800 * 2) {
      std::vector<char> subvector = {buffer.begin(),
                                      buffer.begin() + 800 * 2};
      buffer.erase(buffer.begin(), buffer.begin() + 800 * 2);

      try{
        Result =
            FunTpassInferBuffer(tpass_handle, tpass_online_handle,
                                subvector.data(), subvector.size(), punc_cache,
                                false, msg["audio_fs"], msg["wav_format"], (ASR_TYPE)asr_mode_);
      }catch (std::exception const &e)
      {
          LOG(ERROR)<<e.what();
      }
      if (Result) {
        websocketpp::lib::error_code ec;
        nlohmann::json jsonresult =
            handle_result(Result, msg["wav_name"]);
        jsonresult["is_final"] = false;
        if(jsonresult["text"] != "") {
          if (is_ssl) {
            wss_server_->send(hdl, jsonresult.dump(),
                              websocketpp::frame::opcode::text, ec);
          } else {
            server_->send(hdl, jsonresult.dump(),
                          websocketpp::frame::opcode::text, ec);
          }
        }
        FunASRFreeResult(Result);
      }

    }
    if(is_final){

      try{
        Result = FunTpassInferBuffer(tpass_handle, tpass_online_handle,
                                      buffer.data(), buffer.size(), punc_cache,
                                      is_final, msg["audio_fs"], msg["wav_format"], (ASR_TYPE)asr_mode_);
      }catch (std::exception const &e)
      {
          LOG(ERROR)<<e.what();
      }
      for(auto &vec:punc_cache){
        vec.clear();
      }
      if (Result) {
        websocketpp::lib::error_code ec;
        nlohmann::json jsonresult =
            handle_result(Result, msg["wav_name"]);
        jsonresult["is_final"] = true;
        if (is_ssl) {
          wss_server_->send(hdl, jsonresult.dump(),
                            websocketpp::frame::opcode::text, ec);
        } else {
          server_->send(hdl, jsonresult.dump(),
                        websocketpp::frame::opcode::text, ec);
        }
        FunASRFreeResult(Result);
      }
    }

  } catch (std::exception const& e) {
    std::cerr << "Error: " << e.what() << std::endl;
  }
}

void WebSocketServer::on_open(websocketpp::connection_hdl hdl) {
  scoped_lock guard(m_lock);     // for threads safty
  check_and_clean_connection();  // remove closed connection

  std::shared_ptr<FUNASR_MESSAGE> data_msg =
      std::make_shared<FUNASR_MESSAGE>();  // put a new data vector for new
                                           // connection
  data_msg->samples = std::make_shared<std::vector<char>>();
  data_msg->thread_lock = new websocketpp::lib::mutex();
 
  data_msg->msg = nlohmann::json::parse("{}");
  data_msg->msg["wav_format"] = "pcm";
  data_msg->msg["audio_fs"] = 16000;
  data_msg->punc_cache =
      std::make_shared<std::vector<std::vector<std::string>>>(2);
  // std::vector<int> chunk_size = {5, 10, 5};  //TODO, need get from client
  // FUNASR_HANDLE tpass_online_handle =
  //     FunTpassOnlineInit(tpass_handle, chunk_size);
  // data_msg->tpass_online_handle = tpass_online_handle;
  data_map.emplace(hdl, data_msg);
  LOG(INFO) << "on_open, active connections: " << data_map.size();
 
}

void WebSocketServer::on_close(websocketpp::connection_hdl hdl) {
  scoped_lock guard(m_lock);
  std::shared_ptr<FUNASR_MESSAGE> data_msg  = nullptr;
  auto it_data = data_map.find(hdl);
  if (it_data != data_map.end()) {
    data_msg  = it_data->second;
  }
  else
  {
    return;
  }
  scoped_lock guard_decoder(*(data_msg->thread_lock));  //wait for do_decoder finished and avoid access freed tpass_online_handle 
  FunTpassOnlineUninit(data_msg->tpass_online_handle);
  data_map.erase(hdl);  // remove data vector when  connection is closed
  LOG(INFO) << "on_close, active connections: "<< data_map.size();
}

// remove closed connection
void WebSocketServer::check_and_clean_connection() {
  std::vector<websocketpp::connection_hdl> to_remove;  // remove list
  auto iter = data_map.begin();
  while (iter != data_map.end()) {  // loop to find closed connection
    websocketpp::connection_hdl hdl = iter->first;

    if (is_ssl) {
      wss_server::connection_ptr con = wss_server_->get_con_from_hdl(hdl);
      if (con->get_state() != 1) {  // session::state::open ==1
        to_remove.push_back(hdl);
      }
    } else {
      server::connection_ptr con = server_->get_con_from_hdl(hdl);
      if (con->get_state() != 1) {  // session::state::open ==1
        to_remove.push_back(hdl);
      }
    }

    iter++;
  }
  for (auto hdl : to_remove) {
    data_map.erase(hdl);
    LOG(INFO) << "remove one connection ";
  }
}
void WebSocketServer::on_message(websocketpp::connection_hdl hdl,
                                 message_ptr msg) {
  unique_lock lock(m_lock);
  // find the sample data vector according to one connection

  std::shared_ptr<FUNASR_MESSAGE> msg_data = nullptr;

  auto it_data = data_map.find(hdl);
  if (it_data != data_map.end()) {
    msg_data = it_data->second;
  }

  std::shared_ptr<std::vector<char>> sample_data_p = msg_data->samples;
  std::shared_ptr<std::vector<std::vector<std::string>>> punc_cache_p =
      msg_data->punc_cache;
  websocketpp::lib::mutex* thread_lock_p = msg_data->thread_lock;
 
  lock.unlock();

  if (sample_data_p == nullptr) {
    LOG(INFO) << "error when fetch sample data vector";
    return;
  }
 
  const std::string& payload = msg->get_payload();  // get msg type

  switch (msg->get_opcode()) {
    case websocketpp::frame::opcode::text: {
      nlohmann::json jsonresult = nlohmann::json::parse(payload);

      if (jsonresult.contains("wav_name")) {
        msg_data->msg["wav_name"] = jsonresult["wav_name"];
      }
      if (jsonresult.contains("mode")) {
        msg_data->msg["mode"] = jsonresult["mode"];
      }
      if (jsonresult.contains("wav_format")) {
        msg_data->msg["wav_format"] = jsonresult["wav_format"];
      }
      if (jsonresult.contains("audio_fs")) {
        msg_data->msg["audio_fs"] = jsonresult["audio_fs"];
      }
      if (jsonresult.contains("chunk_size")){
        if(msg_data->tpass_online_handle == NULL){
          std::vector<int> chunk_size_vec = jsonresult["chunk_size"].get<std::vector<int>>();
          FUNASR_HANDLE tpass_online_handle =
              FunTpassOnlineInit(tpass_handle, chunk_size_vec);
          msg_data->tpass_online_handle = tpass_online_handle;
        }
      }
      LOG(INFO) << "jsonresult=" << jsonresult << ", msg_data->msg="
                << msg_data->msg;
      if (jsonresult["is_speaking"] == false ||
          jsonresult["is_finished"] == true) {
        LOG(INFO) << "client done";

        // if it is in final message, post the sample_data to decode
        asio::post(
            io_decoder_,
            std::bind(&WebSocketServer::do_decoder, this,
                      std::move(*(sample_data_p.get())), std::move(hdl),
                      std::ref(msg_data->msg), std::ref(*(punc_cache_p.get())),
                      std::ref(*thread_lock_p), std::move(true),
                      std::ref(msg_data->tpass_online_handle)));
      }
      break;
    }
    case websocketpp::frame::opcode::binary: {
      // recived binary data
      const auto* pcm_data = static_cast<const char*>(payload.data());
      int32_t num_samples = payload.size();
 
      if (isonline) {
        sample_data_p->insert(sample_data_p->end(), pcm_data,
                              pcm_data + num_samples);
        int setpsize = 800 * 2;  // TODO, need get from client 
		    // if sample_data size > setpsize, we post data to decode
        if (sample_data_p->size() > setpsize) {
            int chunksize = floor(sample_data_p->size() / setpsize);
            // make sure the subvector size is an integer multiple of setpsize
            std::vector<char> subvector = {
                  sample_data_p->begin(),
                  sample_data_p->begin() + chunksize * setpsize};
            // keep remain in sample_data
            sample_data_p->erase(sample_data_p->begin(),
                                  sample_data_p->begin() + chunksize * setpsize);
            // post to decode
            asio::post(io_decoder_,
                        std::bind(&WebSocketServer::do_decoder, this,
                                  std::move(subvector), std::move(hdl),
                                  std::ref(msg_data->msg),
                                  std::ref(*(punc_cache_p.get())),
                                  std::ref(*thread_lock_p), std::move(false),
                                  std::ref(msg_data->tpass_online_handle)));
        }
      } else {
        sample_data_p->insert(sample_data_p->end(), pcm_data,
                              pcm_data + num_samples);
      }
      break;
    }
    default:
      break;
  }
}

// init asr model
void WebSocketServer::initAsr(std::map<std::string, std::string>& model_path,
                              int thread_num) {
  try {
    tpass_handle = FunTpassInit(model_path, thread_num);
    if (!tpass_handle) {
      LOG(ERROR) << "FunTpassInit init failed";
      exit(-1);
    }

  } catch (const std::exception& e) {
    LOG(INFO) << e.what();
  }
}