firmware/src/mesh/RadioLibInterface.h

#pragma once

#include "PeriodicTask.h"
#include "RadioInterface.h"

#include <RadioLib.h>

// ESP32 has special rules about ISR code
#ifdef ARDUINO_ARCH_ESP32
#define INTERRUPT_ATTR IRAM_ATTR
#else
#define INTERRUPT_ATTR
#endif

class RadioLibInterface : public RadioInterface, private PeriodicTask
{
    /// Used as our notification from the ISR
    enum PendingISR { ISR_NONE = 0, ISR_RX, ISR_TX, TRANSMIT_DELAY_COMPLETED };

    volatile PendingISR pending = ISR_NONE;

    /**
     * Raw ISR handler that just calls our polymorphic method
     */
    static void isrTxLevel0(), isrLevel0Common(PendingISR code);

    /**
     * Debugging counts
     */
    uint32_t rxBad = 0, rxGood = 0, txGood = 0;

  protected:
    float bw = 125;
    uint8_t sf = 9;
    uint8_t cr = 7;

    /**
     * FIXME, use a meshtastic sync word, but hashed with the Channel name.  Currently picking the same default
     * the RF95 used (0x14). Note: do not use 0x34 - that is reserved for lorawan
     */
    uint8_t syncWord = SX126X_SYNC_WORD_PRIVATE;

    float currentLimit = 100;     // FIXME
    uint16_t preambleLength = 32; // 8 is default, but FIXME use longer to increase the amount of sleep time when receiving

    Module module; // The HW interface to the radio

    /**
     * provides lowest common denominator RadioLib API
     */
    PhysicalLayer *iface;

    /// are _trying_ to receive a packet currently (note - we might just be waiting for one)
    bool isReceiving;

  public:
    /** Our ISR code currently needs this to find our active instance
     */
    static RadioLibInterface *instance;

    /**
     * Glue functions called from ISR land
     */
    virtual void disableInterrupt() = 0;

    /**
     * Enable a particular ISR callback glue function
     */
    virtual void enableInterrupt(void (*)()) = 0;

  public:
    RadioLibInterface(RADIOLIB_PIN_TYPE cs, RADIOLIB_PIN_TYPE irq, RADIOLIB_PIN_TYPE rst, RADIOLIB_PIN_TYPE busy, SPIClass &spi,
                      PhysicalLayer *iface = NULL);

    virtual ErrorCode send(MeshPacket *p);

    /**
     * Return true if we think the board can go to sleep (i.e. our tx queue is empty, we are not sending or receiving)
     *
     * This method must be used before putting the CPU into deep or light sleep.
     */
    virtual bool canSleep();

    /**
     * Start waiting to receive a message
     *
     * External functions can call this method to wake the device from sleep.
     */
    virtual void startReceive() = 0;

  private:
    /** start an immediate transmit */
    void startSend(MeshPacket *txp);

    /** if we have something waiting to send, start a short random timer so we can come check for collision before actually doing
     * the transmit
     *
     * If the timer was already running, we just wait for that one to occur.
     * */
    void startTransmitTimer(bool withDelay = true);

    void handleTransmitInterrupt();
    void handleReceiveInterrupt();

    static void timerCallback(void *p1, uint32_t p2);

    virtual void doTask();

  protected:
    /// Initialise the Driver transport hardware and software.
    /// Make sure the Driver is properly configured before calling init().
    /// \return true if initialisation succeeded.
    virtual bool init();
    
    /**
     * Convert our modemConfig enum into wf, sf, etc...
     *
     * These paramaters will be pull from the channelSettings global
     */
    virtual void applyModemConfig();

    /** Could we send right now (i.e. either not actively receiving or transmitting)? */
    virtual bool canSendImmediately();

    /** are we actively receiving a packet (only called during receiving state) */
    virtual bool isActivelyReceiving() = 0;

    /**
     * Raw ISR handler that just calls our polymorphic method
     */
    static void isrRxLevel0();

    /**
     * If a send was in progress finish it and return the buffer to the pool */
    void completeSending();

    /**
     * Add SNR data to received messages
     */
    virtual void addReceiveMetadata(MeshPacket *mp) = 0;

    virtual void loop(); // Idle processing

    virtual void setStandby() = 0;
};