Sesame-Device/include/server.h

#pragma once

#include "message.h"
#include "crypto.h"
#include <WebSocketsClient.h>

struct ServerConfiguration {

    /**
     * @brief The url of the remote server to connect to
     */
    const char* url; 
    
    /**
     * @brief The server port
     */
    int port;

    /**
     * @brief The path on the server
     */
    const char* path;

    /**
     * @brief The authentication key for the server
     */
    const char* key;
    
    uint32_t reconnectTime;

    uint32_t socketHeartbeatIntervalMs;
    uint32_t socketHeartbeatTimeoutMs;
    uint8_t socketHeartbeatFailureReconnectCount;

};

class ServerConnectionCallbacks {

public:

    virtual void sendServerError(MessageResult event) = 0;
    virtual void handleServerMessage(uint8_t* payload, size_t length) = 0;
};

class ServerConnection {

public:

    ServerConnection();

    /**
     * @brief Set the configuration and the callback handler
     * 
     * @param callback The handler to handle messages and errors
     */
    void configure(ServerConfiguration configuration, ServerConnectionCallbacks* callbacks);

    /**
     * @brief Call this function regularly to handle socket operations.
     * 
     * Connecting and disconnecting is done automatically.
     * 
     */
    void loop(uint32_t millis);

    /**
     * @brief Send a response message over the socket
     * 
     * @param buffer The data buffer
     * @param length The number of bytes to send
     */
    void sendResponse(uint8_t* buffer, uint16_t length);

private:

    uint32_t currentTime;

    bool socketIsConnected() {
        return webSocket.isConnected();
    }

    void connect();

    void disconnect();

    bool shouldReconnect = true;
    bool isConnecting = false;
    uint32_t connectionTimeout = 0;
    uint32_t nextReconnectAttemptMs = 0;

    void didDisconnect();
    void didConnect();


    ServerConfiguration configuration;

    ServerConnectionCallbacks* controller = NULL;

    // WebSocket to connect to the control server
    WebSocketsClient webSocket;

    /**
     * Callback for WebSocket events.
     *
     * Updates the connection state and processes received keys.
     *
     * @param payload The pointer to received data
     * @param length The number of bytes received
     */
    void webSocketEventHandler(WStype_t type, uint8_t * payload, size_t length);
};