Sesame-Device/include/server.h

#pragma once

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

/**
 * An event signaled from the device
 */
enum class SesameEvent {
    TextReceived = 1,
    UnexpectedSocketEvent = 2,
    InvalidPayloadSize = 3,
    MessageAuthenticationFailed = 4,
    MessageTimeMismatch = 5,
    MessageCounterInvalid = 6,
    MessageAccepted = 7,
    InfoMessage = 8,
};

/**
 * @brief A callback for messages received over the socket
 * 
 * The first parameter is the received message.
 * The second parameter is the response to the remote.
 * The return value is the type of event to respond with.
 */
typedef SesameEvent (*MessageCallback)(AuthenticatedMessage*, AuthenticatedMessage*);

class ServerConnection {

public:

    ServerConnection(const char* url, int port, const char* path);

    void connect(const char* key, uint32_t reconnectTime = 5000);

    void connectSSL(const char* key, uint32_t reconnectTime = 5000);

    void loop();

    void onMessage(MessageCallback callback);

    // Indicator that the socket is connected.
    bool socketIsConnected = false;

private:

    const char* url;

    int port;

    const char* path;

    const char* key = NULL;

    MessageCallback messageCallback = NULL;

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

    void reconnectAfter(uint32_t reconnectTime);

    void registerEventCallback();

    /**
     * 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);

    /**
     * Process received binary data.
     *
     * Checks whether the received data is a valid and unused key,
     * and then signals that the motor should move.
     * Sends the event id to the server as a response to the request.
     *
     * If the key is valid, then `shouldStartOpening` is set to true.
     *
     * @param payload The pointer to the received data.
     * @param length The number of bytes received.
     */
    void processReceivedBytes(uint8_t* payload, size_t length);

    /**
     * Send a response event to the server and include the next key index.
     *
     * Sends the event type as three byte.
     * @param event The event type
     */
    void sendFailureResponse(SesameEvent event);

    /**
     * Send a response event to the server and include the next key index.
     *
     * Sends the event type as three byte.
     * @param event The event type
     */
    void sendResponse(SesameEvent event, AuthenticatedMessage* message);

};