/*
  TwoWire.h - TWI/I2C library for Arduino & Wiring
  Copyright (c) 2006 Nicholas Zambetti.  All right reserved.

  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

  Modified 2012 by Todd Krein (todd@krein.org) to implement repeated starts
  Modified December 2014 by Ivan Grokhotkov (ivan@esp8266.com) - esp8266 support
  Modified April 2015 by Hrsto Gochkov (ficeto@ficeto.com) - alternative esp8266 support
  Modified November 2017 by Chuck Todd <stickbreaker on GitHub> to use ISR and increase stability.
  Modified Nov 2021 by Hristo Gochkov <Me-No-Dev> to support ESP-IDF API
*/

#ifndef TwoWire_h
#define TwoWire_h

#include "soc/soc_caps.h"
#if SOC_I2C_SUPPORTED

#include <esp32-hal.h>
#include <esp32-hal-log.h>
#if !CONFIG_DISABLE_HAL_LOCKS
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"
#endif
#include "HardwareI2C.h"
#include "Stream.h"

// WIRE_HAS_BUFFER_SIZE means Wire has setBufferSize()
#define WIRE_HAS_BUFFER_SIZE    1
// WIRE_HAS_END means Wire has end() 
#define WIRE_HAS_END 1

#ifndef I2C_BUFFER_LENGTH
    #define I2C_BUFFER_LENGTH 128  // Default size, if none is set using Wire::setBuffersize(size_t)
#endif
#if SOC_I2C_SUPPORT_SLAVE
typedef void(*user_onRequest)(void);
typedef void(*user_onReceive)(uint8_t*, int);
#endif /* SOC_I2C_SUPPORT_SLAVE */

class TwoWire: public HardwareI2C
{
protected:
    uint8_t num;
    int8_t sda;
    int8_t scl;

    size_t bufferSize;
    uint8_t *rxBuffer;
    size_t rxIndex;
    size_t rxLength;

    uint8_t *txBuffer;
    size_t txLength;
    uint16_t txAddress;

    uint32_t _timeOutMillis;
    bool nonStop;
#if !CONFIG_DISABLE_HAL_LOCKS
    TaskHandle_t currentTaskHandle;
    SemaphoreHandle_t lock;
#endif
private:
#if SOC_I2C_SUPPORT_SLAVE
    bool is_slave;
    void (*user_onRequest)(void);
    void (*user_onReceive)(int);
    static void onRequestService(uint8_t, void *);
    static void onReceiveService(uint8_t, uint8_t*, size_t, bool, void *);
#endif /* SOC_I2C_SUPPORT_SLAVE */
    bool initPins(int sdaPin, int sclPin);
    bool allocateWireBuffer();
    void freeWireBuffer();

public:
    TwoWire(uint8_t bus_num);
    ~TwoWire();

    bool begin() override final
    {
        return begin(-1, -1);
    }

    bool begin(uint8_t address) override final
    {
#if SOC_I2C_SUPPORT_SLAVE
        return begin(address, -1, -1, 0);
#else
        log_e("I2C slave is not supported on " CONFIG_IDF_TARGET);
        return false;
#endif
    }

    bool end() override;

    bool setClock(uint32_t freq) override;
  
    void beginTransmission(uint8_t address) override;
    uint8_t endTransmission(bool stopBit) override;
    uint8_t endTransmission() override;

    size_t requestFrom(uint8_t address, size_t len, bool stopBit) override;
    size_t requestFrom(uint8_t address, size_t len) override;

    void onReceive(void(*)(int)) override;
    void onRequest(void(*)(void)) override;
    
    //call setPins() first, so that begin() can be called without arguments from libraries
    bool setPins(int sda, int scl);
    
    bool begin(int sda, int scl, uint32_t frequency=0); // returns true, if successful init of i2c bus
#if SOC_I2C_SUPPORT_SLAVE
    bool begin(uint8_t slaveAddr, int sda, int scl, uint32_t frequency);
#endif /* SOC_I2C_SUPPORT_SLAVE */

    size_t setBufferSize(size_t bSize);

    void setTimeOut(uint16_t timeOutMillis); // default timeout of i2c transactions is 50ms
    uint16_t getTimeOut();

    uint32_t getClock();

    size_t write(uint8_t) override;
    size_t write(const uint8_t *, size_t) override;
    int available() override;
    int read() override;
    int peek() override;
    void flush() override;

#if SOC_I2C_SUPPORT_SLAVE
    size_t slaveWrite(const uint8_t *, size_t);
#endif /* SOC_I2C_SUPPORT_SLAVE */
};

extern TwoWire Wire;
extern TwoWire Wire1;

#endif /* SOC_I2C_SUPPORTED */
#endif /* TwoWire_h */
