Sesame-Device/include/controller.h

#pragma once

#include "server.h"
#include "servo.h"
#include "message.h"
#include <ESPAsyncWebServer.h>

struct EthernetConfiguration {

    // The MAC address of the ethernet connection
    uint8_t macAddress[6];

    // The master-in slave-out pin of the SPI connection for the Ethernet module
    int8_t spiPinMiso;

    // The master-out slave-in pin of the SPI connection for the Ethernet module
    int8_t spiPinMosi;

    // The slave clock pin of the SPI connection for the Ethernet module
    int8_t spiPinSclk;

    // The slave-select pin of the SPI connection for the Ethernet module
    int8_t spiPinSS;

    unsigned long dhcpLeaseTimeoutMs;
    unsigned long dhcpLeaseResponseTimeoutMs;

    // The static IP address to assign if DHCP fails
    uint8_t manualIp[4];

    // The IP address of the DNS server, if DHCP fails
    uint8_t manualDnsAddress[4];

    uint32_t socketHeartbeatIntervalMs;
    uint32_t socketHeartbeatTimeoutMs;
    uint8_t socketHeartbeatFailureReconnectCount;
};

struct KeyConfiguration {

    const uint8_t* remoteKey;

    const uint8_t* localKey;

    uint32_t challengeExpiryMs;
};

class SesameController: public ServerConnectionCallbacks {

public:
    SesameController(uint16_t localWebServerPort);

    void configure(ServoConfiguration servoConfig, ServerConfiguration serverConfig, EthernetConfiguration ethernetConfig, KeyConfiguration keyConfig);

    void loop(uint32_t millis);

private:

    uint32_t currentTime = 0;

    ServerConnection server;
    ServoController servo;
    AsyncWebServer localWebServer;

    EthernetConfiguration ethernetConfig;
    bool ethernetIsConfigured = false;

    KeyConfiguration keyConfig;

    bool isReconnecting = false;

    // Buffer to get local message
    SignedMessage receivedLocalMessage;

    uint32_t currentClientChallenge;
    uint32_t currentChallengeExpiry = 0;
    uint32_t currentServerChallenge;

    SignedMessage outgoingMessage;
    
    bool hasCurrentChallenge() {
        return currentChallengeExpiry > currentTime;
    }

    void clearCurrentChallenge() {
        currentClientChallenge = 0;
        currentServerChallenge = 0;
        currentChallengeExpiry = 0;
    }

    /**
     * @brief Send an error Response over the web socket.
     * 
     * @param result The error result to send
     * @param discardMessage Indicate if the stored message should be cleared.
     * 
     * Note: Only clear the message if no other operation is in progress.
     */
    void sendErrorResponseToServer(MessageResult result, bool discardMessage = true);

    void ensureWebSocketConnection();

    void handleLocalMessage(AsyncWebServerRequest *request);
    
    bool convertHexMessageToBinary(const char* str);

    void handleServerMessage(uint8_t* payload, size_t length);

    /**
     * @brief Callback to send an error back to the server via the web socket.
     * 
     * This function is called when the socket get's an error.
     * 
     * @param event The error to report back
     */
    void sendServerError(MessageResult event);

    void processMessage(SignedMessage* message);
    MessageResult verifyAndProcessReceivedMessage(SignedMessage* message);

    void prepareResponseBuffer(MessageResult event, Message* message = NULL);
    void sendPreparedLocalResponse(AsyncWebServerRequest *request);
    void sendPreparedResponseToServer();

    void prepareChallenge(Message* message);
    void completeUnlockRequest(Message* message);
};