#include <stddef.h>
#include <signal.h>
#include <string.h>
#include <pthread.h>
#include "scode.h"
#include "log.h"
#include "msg_queue.h"
#include "gpio.h"
#include "time_func.h"

#define DEBOUNCE_BUTTON_MSEC  350

PMSG_QUEUE Sys_Queue = NULL;

static pthread_t ithread;
static volatile sig_atomic_t running = 1;
static UINT32 last_bstate = 0;

static void *input_thread(void *arg)
{
  UINT32 st, down, up, mask;
  UINT_PTR attr;
  TIMESTAMP now;
  TIMESTAMP button_event_ok[GPIO_BUTTON_COUNT];

  memset(button_event_ok, 0, GPIO_BUTTON_COUNT * sizeof(TIMESTAMP));
  
  while (running)
  {
    /* poll hardware buttons */
    st = Gpio_read_buttons();
    if (st != last_bstate)
    {
      now = Time_since_start();
      up = last_bstate & ~st;
      down = st & ~last_bstate;
      for (attr = 1, mask = GRB_STATE_BUTTON1; attr <= GPIO_BUTTON_COUNT; attr++, mask <<= 1)
      {
	if (now < button_event_ok[attr - 1])
	  continue;
	if (up & mask)
	{
	  button_event_ok[attr - 1] = now + DEBOUNCE_BUTTON_MSEC;
	  Mq_post1(Sys_Queue, 0, WM_HWBUTTONUP, attr);
	}
	else if (down & mask)
	  Mq_post1(Sys_Queue, 0, WM_HWBUTTONDOWN, attr);
      }
      last_bstate = st;
    }

    /* additional poll activity here */
  }
  return NULL;
}

HRESULT Sys_enable_input(void)
{
  HRESULT rc = S_OK;
  int threadrc;
  
  Sys_Queue = Mq_alloc(64);
  if (!Sys_Queue)
  {
    Log(LFATAL, "Unable to allocate system message queue.");
    return E_OUTOFMEMORY;
  }
  running = 1;
  threadrc = pthread_create(&ithread, NULL, input_thread, NULL);
  if (threadrc != 0)
  {
    rc = SCODE_FROM_ERRNO(threadrc);
    Log(LFATAL, "Unable to start system input thread (%08X).", rc);
  }
  return rc;
}

void Sys_disable_input(void)
{
  running = 0;
  pthread_join(ithread, NULL);
  Mq_destroy(Sys_Queue);
  Sys_Queue = NULL;
}