#include <inttypes.h>
#include "mik32_hal_irq.h" 

#include "pins_arduino.h"
#include "wiring_digital.h"
#include "WInterrupts.h"

extern void ErrorMsgHandler(const char * msg);

typedef void (*voidFuncPtr)(void);

// empty irq handler
static void nothing(void) 
{
  ;
}

// enable global interrupts
void interrupts(void)
{
  HAL_IRQ_EnableInterrupts();
}

// disable global interrupts
void noInterrupts(void)
{
  HAL_IRQ_DisableInterrupts();
}

// we can provide no more than 8 interrupts on gpio at the same time
static volatile voidFuncPtr intFunc[EXTERNAL_NUM_INTERRUPTS] = 
{
#if EXTERNAL_NUM_INTERRUPTS > 7
  nothing,
#endif
#if EXTERNAL_NUM_INTERRUPTS > 6
  nothing,
#endif
#if EXTERNAL_NUM_INTERRUPTS > 5
  nothing,
#endif
#if EXTERNAL_NUM_INTERRUPTS > 4
  nothing,
#endif
#if EXTERNAL_NUM_INTERRUPTS > 3
  nothing,
#endif
#if EXTERNAL_NUM_INTERRUPTS > 2
  nothing,
#endif
  nothing,
  nothing,
};

void attachInterrupt(uint8_t interruptNum, void (*userFunc)(void), int mode) 
{
  // if the interrupt number does not exceed the total number
  if(interruptNum < EXTERNAL_NUM_INTERRUPTS) 
  {
    intFunc[interruptNum] = userFunc; // save pointer to irq handler
    
    // init pin as input without pullups
    pinMode(interruptToDigitalPin(interruptNum), INPUT);
    
    // interrupt line initialization
    HAL_GPIO_InterruptMode halMode;
    if      (mode == LOW)     halMode = GPIO_INT_MODE_LOW;
    else if (mode == HIGH)    halMode = GPIO_INT_MODE_HIGH;
    else if (mode == CHANGE)  halMode = GPIO_INT_MODE_CHANGE;
    else if (mode == FALLING) halMode = GPIO_INT_MODE_FALLING;
    else if (mode == RISING)  halMode = GPIO_INT_MODE_RISING;
    else  return;
    HAL_GPIO_InitInterruptLine(interruptToGpioIntMux(interruptNum), halMode);
    
    // turn on the mask in EPIC
    if ((halMode == GPIO_INT_MODE_LOW) || (halMode == GPIO_INT_MODE_HIGH))
      // by level
      HAL_EPIC_MaskLevelSet(HAL_EPIC_GPIO_IRQ_MASK);
    else
      // by edge
      HAL_EPIC_MaskEdgeSet(HAL_EPIC_GPIO_IRQ_MASK);
  }
  else
    ErrorMsgHandler("attachInterrupt(): incorrect interrupt number\n\r");
}

void detachInterrupt(uint8_t interruptNum) 
{
  if(interruptNum < EXTERNAL_NUM_INTERRUPTS) 
  {
    // disable the interrupt in line
    HAL_GPIO_DeInitInterruptLine(interruptToGpioIntLine(interruptNum));
    intFunc[interruptNum] = nothing;

    // we don't change anything in the EPIC controller, in case there are still configured lines left
  }
}

// disable single interrupt
void disableInterrupt(uint8_t interruptNum)
{
  if(interruptNum < EXTERNAL_NUM_INTERRUPTS) 
  {
    int irq_line_num = interruptToGpioIntLine(interruptNum) >> GPIO_IRQ_LINE_S;
    // disable gpio interrupt line
    GPIO_IRQ->ENABLE_CLEAR = (1 << irq_line_num);
  }
}

// enable single interrupt
void enableInterrupt(uint8_t interruptNum)
{
  if(interruptNum < EXTERNAL_NUM_INTERRUPTS) 
  {
    int irq_line_num = interruptToGpioIntLine(interruptNum) >> GPIO_IRQ_LINE_S;
    // enable gpio interrupt line
    GPIO_IRQ->ENABLE_SET = (1 << irq_line_num);
  }
}

// common gpio interrupt handler 
void gpio_interrupts_handler(void)
{
  // go through all the interrupts and call the handler for the triggered line
  for (uint8_t i = 0; i < EXTERNAL_NUM_INTERRUPTS; i++)
  {
    if (HAL_GPIO_LineInterruptState(interruptToGpioIntLine(i)))
      intFunc[i]();
  }
  
  HAL_GPIO_ClearInterrupts();
}