#ifndef LINUX_GPIO_GPIODEFINITIONS_H_
#define LINUX_GPIO_GPIODEFINITIONS_H_

#include <string>
#include <unordered_map>

using gpioId_t = uint16_t;

namespace gpio {
enum Direction {
    IN = 0,
    OUT = 1
};

enum GpioOperation {
    READ,
    WRITE
};

enum GpioTypes {
    NONE,
    GPIOD_REGULAR,
    CALLBACK
};

static constexpr gpioId_t NO_GPIO = -1;
}

/**
 * @brief   Struct containing information about the GPIO to use. This is
 *          required by the libgpiod to access and drive a GPIO.
 * @param chipname      String of the chipname specifying the group which contains the GPIO to
 *                      access. E.g. gpiochip0. To detect names of GPIO groups run gpiodetect on
 *                      the linux command line.
 * @param lineNum       The offset of the GPIO within the GPIO group.
 * @param consumer      Name of the consumer. Simply a description of the GPIO configuration.
 * @param direction     Specifies whether the GPIO should be used as in- or output.
 * @param initValue     Defines the initial state of the GPIO when configured as output.
 *                      Only required for output GPIOs.
 * @param lineHandle    The handle returned by gpiod_chip_get_line will be later written to this
 *                      pointer.
 */
class GpioBase {
public:

    GpioBase() = default;

    GpioBase(gpio::GpioTypes gpioType, std::string consumer, gpio::Direction direction,
            int initValue):
            gpioType(gpioType), consumer(consumer),direction(direction), initValue(initValue) {}

    virtual~ GpioBase() {};

    /* Can be used to cast GpioBase to a concrete child implementation */
    gpio::GpioTypes gpioType = gpio::GpioTypes::NONE;
    std::string consumer;
    gpio::Direction direction = gpio::Direction::IN;
    int initValue = 0;
};

class GpiodRegular: public GpioBase {
public:
    GpiodRegular(): GpioBase() {};

    GpiodRegular(std::string chipname_, int lineNum_, std::string consumer_,
            gpio::Direction direction_, int initValue_):
            GpioBase(gpio::GpioTypes::GPIOD_REGULAR, consumer_, direction_, initValue_),
            chipname(chipname_), lineNum(lineNum_) {}
    std::string chipname;
    int lineNum = 0;
    struct gpiod_line* lineHandle = nullptr;
};

class GpioCallback: public GpioBase {
public:
    GpioCallback(std::string consumer, gpio::Direction direction_, int initValue_,
            void (* callback) (gpioId_t gpioId, gpio::GpioOperation gpioOp, int value, void* args),
            void* callbackArgs):
            GpioBase(gpio::GpioTypes::CALLBACK, consumer, direction_, initValue_),
            callback(callback), callbackArgs(callbackArgs) {}

    void (* callback) (gpioId_t gpioId, gpio::GpioOperation gpioOp,
            int value, void* args) = nullptr;
    void* callbackArgs = nullptr;
};


using GpioMap = std::unordered_map<gpioId_t, GpioBase*>;
using GpioMapIter = GpioMap::iterator;

#endif /* LINUX_GPIO_GPIODEFINITIONS_H_ */