AsyncWebSocket.h

/*
  Asynchronous WebServer library for Espressif MCUs

  Copyright (c) 2016 Hristo Gochkov. All rights reserved.
  This file is part of the esp8266 core for Arduino environment.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library 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
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/
#ifndef ASYNCWEBSOCKET_H_
#define ASYNCWEBSOCKET_H_

#include <Arduino.h>
#ifdef ESP32
#include <AsyncTCP.h>
#define WS_MAX_QUEUED_MESSAGES 16
#else
#include <ESPAsyncTCP.h>
#define WS_MAX_QUEUED_MESSAGES 8
#endif
#include <ESPAsyncWebServer.h>

#include "AsyncWebSynchronization.h"

#include <list>
#include <deque>
#include <memory>

#ifdef ESP8266
#include <Hash.h>
#ifdef CRYPTO_HASH_h // include Hash.h from espressif framework if the first include was from the crypto library
#include <../src/Hash.h>
#endif
#endif

#ifdef ESP32
#define DEFAULT_MAX_WS_CLIENTS 8
#else
#define DEFAULT_MAX_WS_CLIENTS 4
#endif

using AsyncWebSocketMessageBuffer = std::shared_ptr<std::vector<uint8_t>>;

class AsyncWebSocket;
class AsyncWebSocketResponse;
class AsyncWebSocketClient;
class AsyncWebSocketControl;

typedef struct {
    /** Message type as defined by enum AwsFrameType.
     * Note: Applications will only see WS_TEXT and WS_BINARY.
     * All other types are handled by the library. */
    uint8_t message_opcode;
    /** Frame number of a fragmented message. */
    uint32_t num;
    /** Is this the last frame in a fragmented message ?*/
    uint8_t final;
    /** Is this frame masked? */
    uint8_t masked;
    /** Message type as defined by enum AwsFrameType.
     * This value is the same as message_opcode for non-fragmented
     * messages, but may also be WS_CONTINUATION in a fragmented message. */
    uint8_t opcode;
    /** Length of the current frame.
     * This equals the total length of the message if num == 0 && final == true */
    uint64_t len;
    /** Mask key */
    uint8_t mask[4];
    /** Offset of the data inside the current frame. */
    uint64_t index;
} AwsFrameInfo;

typedef enum { WS_DISCONNECTED, WS_CONNECTED, WS_DISCONNECTING } AwsClientStatus;
typedef enum { WS_CONTINUATION, WS_TEXT, WS_BINARY, WS_DISCONNECT = 0x08, WS_PING, WS_PONG } AwsFrameType;
typedef enum { WS_MSG_SENDING, WS_MSG_SENT, WS_MSG_ERROR } AwsMessageStatus;
typedef enum { WS_EVT_CONNECT, WS_EVT_DISCONNECT, WS_EVT_PONG, WS_EVT_ERROR, WS_EVT_DATA } AwsEventType;


class AsyncWebSocketMessage
{
private:
    std::shared_ptr<std::vector<uint8_t>> _WSbuffer;
    uint8_t _opcode{WS_TEXT};
    bool _mask{false};
    AwsMessageStatus _status{WS_MSG_ERROR};
    size_t _sent{};
    size_t _ack{};
    size_t _acked{};

public:
    AsyncWebSocketMessage(std::shared_ptr<std::vector<uint8_t>> buffer, uint8_t opcode=WS_TEXT, bool mask=false);

    bool finished() const { return _status != WS_MSG_SENDING; }
    bool betweenFrames() const { return _acked == _ack; }

    void ack(size_t len, uint32_t time);
    size_t send(AsyncClient *client);
};

class AsyncWebSocketClient {
  private:
    AsyncClient *_client;
    AsyncWebSocket *_server;
    uint32_t _clientId;
    AwsClientStatus _status;

    AsyncWebLock _lock;

    std::deque<AsyncWebSocketControl> _controlQueue;
    std::deque<AsyncWebSocketMessage> _messageQueue;

    uint8_t _pstate;
    AwsFrameInfo _pinfo;

    uint32_t _lastMessageTime;
    uint32_t _keepAlivePeriod;

    void _queueControl(uint8_t opcode, const uint8_t *data=NULL, size_t len=0, bool mask=false);
    void _queueMessage(std::shared_ptr<std::vector<uint8_t>> buffer, uint8_t opcode=WS_TEXT, bool mask=false);
    void _runQueue();
    void _clearQueue();

  public:
    void *_tempObject;

    AsyncWebSocketClient(AsyncWebServerRequest *request, AsyncWebSocket *server);
    ~AsyncWebSocketClient();

    //client id increments for the given server
    uint32_t id() const { return _clientId; }
    AwsClientStatus status() const { return _status; }
    AsyncClient* client() { return _client; }
    const AsyncClient* client() const { return _client; }
    AsyncWebSocket *server(){ return _server; }
    const AsyncWebSocket *server() const { return _server; }
    AwsFrameInfo const &pinfo() const { return _pinfo; }

    IPAddress remoteIP() const;
    uint16_t  remotePort() const;

    bool shouldBeDeleted() const { return !_client; }

    //control frames
    void close(uint16_t code=0, const char * message=NULL);
    void ping(const uint8_t *data=NULL, size_t len=0);

    //set auto-ping period in seconds. disabled if zero (default)
    void keepAlivePeriod(uint16_t seconds){
      _keepAlivePeriod = seconds * 1000;
    }
    uint16_t keepAlivePeriod(){
      return (uint16_t)(_keepAlivePeriod / 1000);
    }

    //data packets
    /**
     * @brief allocate memory buffer owned by shared-pointer and copy provided data
     * used to keep the data untill websocket send is complete for single/multiple clients
     * 
     * @param message 
     * @param len 
     * @return AsyncWebSocketMessageBuffer 
     */
    AsyncWebSocketMessageBuffer makeBuffer(const uint8_t *message, size_t len);

    /**
     * @brief allocate empty memory buffer owned by shared-pointer
     * used to keep the data untill websocket send is complete for single/multiple clients
     * 
     * @param len 
     * @return AsyncWebSocketMessageBuffer 
     */
    inline AsyncWebSocketMessageBuffer makeBuffer(size_t len){ return std::make_shared<std::vector<uint8_t>>(len); };

    void message(AsyncWebSocketMessageBuffer buffer, uint8_t opcode=WS_TEXT, bool mask=false) { _queueMessage(buffer, opcode, mask); }
    bool queueIsFull() const;
    size_t queueLen() const;

    size_t printf(const char *format, ...)  __attribute__ ((format (printf, 2, 3)));
#ifndef ESP32
    size_t printf_P(PGM_P formatP, ...)  __attribute__ ((format (printf, 2, 3)));
#endif

    inline void text(AsyncWebSocketMessageBuffer buffer){ _queueMessage(buffer); };
    inline void text(const uint8_t *message, size_t len){ text(makeBuffer(message, len)); };
    inline void text(const char *message, size_t len){ text((const uint8_t *)message, len); };
    inline void text(const char *message){ text(message, strlen(message)); };
    inline void text(const String &message){ text(message.c_str(), message.length()); };
    void text(const __FlashStringHelper *message);

    inline void binary(AsyncWebSocketMessageBuffer buffer){ _queueMessage(buffer, WS_BINARY); };
    inline void binary(const uint8_t *message, size_t len){ binary(makeBuffer(message, len)); };
    inline void binary(const char * message, size_t len){ binary((const uint8_t *)message, len); };
    inline void binary(const char * message){ binary(message, strlen(message)); };
    inline void binary(const String &message){ binary(message.c_str(), message.length()); };
    void binary(const __FlashStringHelper *message, size_t len);

    bool canSend() const;

    //system callbacks (do not call)
    void _onAck(size_t len, uint32_t time);
    void _onError(int8_t);
    void _onPoll();
    void _onTimeout(uint32_t time);
    void _onDisconnect();
    void _onData(void *pbuf, size_t plen);
};

typedef std::function<bool(AsyncWebServerRequest *request)> AwsHandshakeHandler;
typedef std::function<void(AsyncWebSocket * server, AsyncWebSocketClient * client, AwsEventType type, void * arg, uint8_t *data, size_t len)> AwsEventHandler;

//WebServer Handler implementation that plays the role of a socket server
class AsyncWebSocket: public AsyncWebHandler {
  private:
    String _url;
    std::list<AsyncWebSocketClient> _clients;
    uint32_t _cNextId;
    AwsEventHandler _eventHandler;
	  AwsHandshakeHandler _handshakeHandler;
    bool _enabled;
    AsyncWebLock _lock;

  public:
    AsyncWebSocket(const String& url);
    ~AsyncWebSocket();
    const char * url() const { return _url.c_str(); }
    void enable(bool e){ _enabled = e; }
    bool enabled() const { return _enabled; }
    bool availableForWriteAll();
    bool availableForWrite(uint32_t id);

    size_t count() const;
    AsyncWebSocketClient * client(uint32_t id);
    bool hasClient(uint32_t id){ return client(id) != NULL; }

    void close(uint32_t id, uint16_t code=0, const char * message=NULL);
    void closeAll(uint16_t code=0, const char * message=NULL);
    void cleanupClients(uint16_t maxClients = DEFAULT_MAX_WS_CLIENTS);

    void ping(uint32_t id, const uint8_t *data=NULL, size_t len=0);
    void pingAll(const uint8_t *data=NULL, size_t len=0); //  done

    //data packets
    /**
     * @brief allocate memory buffer owned by shared-pointer and copy provided data
     * used to keep the data untill websocket send is complete for single/multiple clients
     * 
     * @param message 
     * @param len 
     * @return AsyncWebSocketMessageBuffer 
     */
    AsyncWebSocketMessageBuffer makeBuffer(const uint8_t *message, size_t len);

    /**
     * @brief allocate empty memory buffer owned by shared-pointer
     * used to keep the data untill websocket send is complete for single/multiple clients
     * 
     * @param len 
     * @return AsyncWebSocketMessageBuffer 
     */
    inline AsyncWebSocketMessageBuffer makeBuffer(size_t len){ return std::make_shared<std::vector<uint8_t>>(len); };

    void text(uint32_t id, AsyncWebSocketMessageBuffer message);
    void text(uint32_t id, const uint8_t * message, size_t len);
    inline void text(uint32_t id, const char *message, size_t len){ text(id, (const uint8_t *)message, len); };
    inline void text(uint32_t id, const char *message){ text(id, message, strlen(message)); };
    inline void text(uint32_t id, const String &message){ text(id, message.c_str(), message.length()); };
    void text(uint32_t id, const __FlashStringHelper *message);

    void textAll(AsyncWebSocketMessageBuffer buffer);
    void textAll(const uint8_t *message, size_t len);
    void textAll(const char * message, size_t len);
    void textAll(const char * message);
    void textAll(const String &message);
    void textAll(const __FlashStringHelper *message); //  need to convert

    void binary(uint32_t id, AsyncWebSocketMessageBuffer message);
    void binary(uint32_t id, const uint8_t *message, size_t len);
    void binary(uint32_t id, const char *message, size_t len);
    void binary(uint32_t id, const char *message);
    void binary(uint32_t id, const String &message);
    void binary(uint32_t id, const __FlashStringHelper *message, size_t len);

    void binaryAll(AsyncWebSocketMessageBuffer buffer);
    void binaryAll(const uint8_t *message, size_t len);
    void binaryAll(const char *message, size_t len);
    void binaryAll(const char *message);
    void binaryAll(const String &message);
    void binaryAll(const __FlashStringHelper *message, size_t len);

    size_t printf(uint32_t id, const char *format, ...)  __attribute__ ((format (printf, 3, 4)));
    size_t printfAll(const char *format, ...)  __attribute__ ((format (printf, 2, 3)));
#ifndef ESP32
    size_t printf_P(uint32_t id, PGM_P formatP, ...)  __attribute__ ((format (printf, 3, 4)));
#endif
    size_t printfAll_P(PGM_P formatP, ...)  __attribute__ ((format (printf, 2, 3)));

    //event listener
    void onEvent(AwsEventHandler handler){
      _eventHandler = handler;
    }

    // Handshake Handler
    void handleHandshake(AwsHandshakeHandler handler){
      _handshakeHandler = handler; 
    }
	
    //system callbacks (do not call)
    uint32_t _getNextId(){ return _cNextId++; }
    AsyncWebSocketClient *_newClient(AsyncWebServerRequest *request);
    void _handleEvent(AsyncWebSocketClient * client, AwsEventType type, void * arg, uint8_t *data, size_t len);
    virtual bool canHandle(AsyncWebServerRequest *request) override final;
    virtual void handleRequest(AsyncWebServerRequest *request) override final;

    const std::list<AsyncWebSocketClient> &getClients() const { return _clients; }
};

//WebServer response to authenticate the socket and detach the tcp client from the web server request
class AsyncWebSocketResponse: public AsyncWebServerResponse {
  private:
    String _content;
    AsyncWebSocket *_server;
  public:
    AsyncWebSocketResponse(const String& key, AsyncWebSocket *server);
    void _respond(AsyncWebServerRequest *request);
    size_t _ack(AsyncWebServerRequest *request, size_t len, uint32_t time);
    bool _sourceValid() const { return true; }
};


#endif /* ASYNCWEBSOCKET_H_ */