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

static const struct option long_options[] = {
  {"framebuffer", required_argument, 0, 'F'},
  {"help",        no_argument,       0, 'h'},
  { NULL,         0,                 0,  0 }
};

static const char *short_options = "F:h";

static const char *helptext =
  "UPIWIN - Micro Pi Windows server program\n\n"
  "Usage: upiwin [options] scriptname [scriptargs]\n\n"
  "Available options:\n"
  "  -F,--framebuffer [devname] - Specifies the framebuffer device name\n"
  "  -h,--help - Displays this help message.\n"
  "";

#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;
}

static HRESULT parse_cmdline(int argc, char *argv[], GLOBAL_CONFIG *parsed)
{
  int c;
  PSTR pstr;
  BOOL help = FALSE;

  memset(parsed, 0, sizeof(GLOBAL_CONFIG));
  for (;;)
  {
    c = getopt_long(argc, argv, short_options, long_options, NULL);
    if (c==-1)
      break;
    switch (c)
    {
      case 'F':
	pstr = strdup(optarg);
	if (!pstr)
	{
	  Log(LERROR, "Out of memory in parse_cmdline");
	  return E_OUTOFMEMORY;
	}
	if (parsed->framebuffer_device)
	  free(parsed->framebuffer_device);
	parsed->framebuffer_device = pstr;
	break;

      case 'h':
	help = TRUE;
	break;

      default:
	fprintf(stderr, "%s: unexpected option -%c\n", argv[0], c);
	return E_UNEXPECTED;
    }
  }
  if (help)
  {
    fputs(helptext, stdout);
    return S_FALSE;
  }
  return S_OK;
}

static void overlay_config(GLOBAL_CONFIG *p)
{
  if (p->framebuffer_device)
    Gconfig.framebuffer_device = p->framebuffer_device;
}

HRESULT Config_setup(int argc, char *argv[])
{
  HRESULT hr;
  GLOBAL_CONFIG from_commandline;
  
  if (atexit(run_exit_funcs))
  {
    Log(LFATAL, "Unable to set up exit function mechanism");
    return E_FAIL;
  }
  init_defaults();
  hr = parse_cmdline(argc, argv, &from_commandline);
  if (hr != S_OK)
    return hr;
  overlay_config(&from_commandline)
  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;
}