#include <stdlib.h>
#include "config.h"
#include "log.h"

#define EXITFUNCBLOCK_FUNCCOUNT 64

typedef struct tagEXITFUNCBLOCK
{
  struct tagEXITFUNCBLOCK *next;
  int num_funcs;
  PEXITFUNC funcs[EXITFUNCBLOCK_FUNCCOUNT];
} EXITFUNCBLOCK, *PEXITFUNCBLOCK;

/* The global configuration data */
GLOBAL_CONFIG Gconfig;

static PEXITFUNCBLOCK exitfuncs = NULL;

static void run_exit_funcs(void)
{
  int i;
  PEXITFUNCBLOCK p;
  
  while (exitfuncs)
  {
    p = exitfuncs;
    exitfuncs = p->next;
    for (i = p->num_funcs - 1; i >= 0; i++)
      (*(p->funcs[i]))();
    free(p);
  }
}

static void init_defaults(void)
{
  Gconfig.framebuffer_device = "/dev/fb1";
  Gconfig.button_debounce = 100;
  Gconfig.sys_mq_length = 64;
}

HRESULT Config_setup(void)
{
  if (atexit(run_exit_funcs))
  {
    Log(LFATAL, "Unable to set up exit function mechanism");
    return E_FAIL;
  }
  init_defaults();
  return S_OK;
}

HRESULT Config_exitfunc(PEXITFUNC pfn)
{
  PEXITFUNCBLOCK p;
  
  if (!exitfuncs || (exitfuncs->num_funcs == EXITFUNCBLOCK_FUNCCOUNT))
  {
    p = (PEXITFUNCBLOCK)malloc(sizeof(EXITFUNCBLOCK));
    if (!p)
    {
      Log(LERROR, "unable to allocate another exit function block");
      return E_OUTOFMEMORY;
    }
    p->next = exitfuncs;
    p->num_funcs = 0;
    exitfuncs = p;
  }
  exitfuncs->funcs[exitfuncs->num_funcs++] = pfn;
  return S_OK;
}