#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <sys/stat.h>
#include <grass/gis.h>
#include "list.h"
#include "mapcalc.h"
#include "map.h"

typedef MAP *(*m_func)(void);
typedef MAP *(*m_func_m)(void *m0);
typedef MAP *(*m_func_mm)(void *m0, void *m1);

typedef struct Mapfunc
{
  char *name;
  void *func;
  char *proto;
}MAPFUNC;

static MAP *testmap (MAP *m);
static MAP *test2map (MAP *m, MAP *n);
static MAP *map_op_func_plus (MAP *m, MAP *n);
static void find_maps (void);
void init_map (void);
void showmap (SYMBOL *map);
void setmap (SYMBOL *var, SYMBOL *map);
SYMBOL *mkmapvar (SYMBOL *var, SYMBOL *map);
SYMBOL *mapfunc (SYMBOL *func, SYMBOL *arglist);
SYMBOL *mapop (int op, SYMBOL *map1, SYMBOL *map2);

static MAPFUNC mf[] =
{
  { "testmap", testmap, "m" },
  { "test2map", test2map, "mm" },
  { "map_op_func_+", map_op_func_plus, "mm" },
  { NULL, NULL, NULL }
};

/*************************************************************************
 * This function represents a built-in map function.
 * Should probably go to another file
 */
static MAP *
testmap (MAP *m)
{
  char namebuf[128];
  /*
   * The map name always exists, as it represents data on disk, but
   * might be a temporary name, when it should not be displayed
   * (should it?).
   */
  printf ("Performing 1 arg map function on map %s\n", m->name);
  sprintf (namebuf, "t-%s", m->name);
  m = (MAP *)listitem (sizeof (MAP));
  m->name = strdup (namebuf);
  return m;
}

static MAP *
test2map (MAP *m, MAP *n)
{
  char namebuf[128];

  printf ("Performing 2 arg map function on maps %s and %s\n", m->name, n->name);
  sprintf (namebuf, "%s.%s", m->name, n->name);
  m = (MAP *)listitem (sizeof (MAP));
  m->name = strdup (namebuf);
  return m;
}

static MAP *
map_op_func_plus (MAP *m, MAP *n)
{
  char namebuf[128];

  printf ("Performing map %s + %s\n", m->name, n->name);
  sprintf (namebuf, "%s.%s", m->name, n->name);
  m = (MAP *)listitem (sizeof (MAP));
  m->name = strdup (namebuf);
  return m;
}

/*
 * end of move to other file
 ***********************************************************************/

static void
find_maps (void)
{
  char *gisdbase, *location, *mapset;
  char basepath[4096], subdirpath[4096], path[4096];
  DIR *dir, *subdir;
  struct dirent *ent, *subent;

  gisdbase = getenv ("GISDBASE");
  if (!gisdbase)
    gisdbase = ".";

  location = getenv ("LOCATION_NAME");
  if (!location)
    location = ".";

  mapset = getenv ("MAPSET");
  if (!mapset)
    mapset = ".";

  /*
   * Now, if I'm not in grass, I can simulate the existence of a vector
   * map creating a directory vector with one subdirectory for each `map'
   * having a file `head'
   */

  sprintf (basepath, "%s/%s/%s/vector", gisdbase, location, mapset);
  dir = opendir (basepath);
  if (!dir)
    return;

  while ((ent = readdir (dir)) != NULL)
  {
    struct stat buf;

    if (!strcmp (ent->d_name, ".") || !strcmp (ent->d_name, ".."))
      continue;

    strcpy (path, basepath);
    strcat (path, "/");
    strcat (path, ent->d_name);

    if (stat (path, &buf))
      continue;
    if (S_ISDIR (buf.st_mode))
    {
      strcpy (subdirpath, path);
      subdir = opendir (subdirpath);
      if (!subdir)
	continue;
      while ((subent = readdir (subdir)) != NULL)
      {
	if (!strcmp (subent->d_name, ".") || !strcmp (subent->d_name, ".."))
	  continue;
	if (!strcmp (subent->d_name, "head"))
	{
	  MAP *map;
	  SYMBOL *sym;

	  map = (MAP *)listitem (sizeof (MAP));
	  map->name = strdup (ent->d_name);
	  map->refcnt++;
	  sym = putsym (map->name);
	  sym->type = sym->itype = st_map;
	  sym->v.p = map;
	}
      }
      closedir (subdir);
    }
  }
  closedir (dir);
}

void
init_map (void)
{
  SYMBOL *sym;
  int i;

  for (i = 0; mf[i].name; i++)
  {
    sym = putsym (mf[i].name);
    sym->type = sym->itype = st_mfunc;
    sym->v.p = mf[i].func;
    sym->proto = mf[i].proto;
    sym->rettype = st_map;
  }

  find_maps ();
}

void
printmap (SYMBOL *sym)
{
  MAP *map;

  map = (MAP *)sym->v.p;
  if (map->name)
    printf ("\t%s\n", map->name);
}

void
showmap (SYMBOL *sym)
{
  MAP *map;

  map = (MAP *)sym->v.p;
  printmap (sym);
  if (--map->refcnt > 0)
    sym->v.p = NULL;
  freesym (sym);
}

MAP *
freemap (MAP *map)
{
  if (map)
  {
    if (map->refcnt > 0)
      return map;
    if (map->name)
      G_free (map->name);
    if (map->mapinfo)
      G_free (map->mapinfo);		/* call grass to handle map */
    G_free (map);
  }
  return NULL;
}

void
setmap (SYMBOL *var, SYMBOL *map)
{
  SYMBOL *sym;

  if (var->name)
  {
    sym = getsym (var->name);
    if (sym)
    {
      sym->v.p = freemap (sym->v.p);
      sym->v.p = map->v.p;
    }
  }

  freemap (var->v.p);
  var->v.p = NULL;
  freesym (var);

  printmap (map);
  map->v.p = NULL;
  freesym (map);
}

SYMBOL *
mkmapvar (SYMBOL *var, SYMBOL *map)
{
  var->type = var->itype = st_map;
  var->name = var->v.p;
  var->v.p = map->v.p;
  map->v.p = NULL;
  freesym (map);

  symtab = (SYMBOL *)listadd ((LIST *)symtab, (LIST *)var, cmpsymsym);

  printmap (var);

  return var;
}

SYMBOL *
mapfunc (SYMBOL *func, SYMBOL *arglist)
{
  SYMBOL *sym;
  MAP *res = NULL;
  int argc = -1;

  if (!func || !func->v.p || func->type != st_mfunc)
  {
    parseerror = 1;
    printf ("Can't call bad map-function\n");
  }
  else
    argc = listcnt ((LIST *)arglist);

  if (argc == 0 && (!func->proto || !*func->proto))
    res = (*(m_func)func->v.p)();
  else if (argc == 1 && !strcmp (func->proto, "m"))
    res = (*(m_func_m)func->v.p)(arglist->v.p);
  else if (argc == 2 && !strcmp (func->proto, "mm"))
    res = (*(m_func_mm)func->v.p)(arglist->v.p,
				  arglist->next->v.p);
  else
  {
    printf ("Bad arguments to mapfunc %s (argc = %d)\n", func->name, argc);
    parseerror = 1;
  }

  listdelall ((LIST *)func, freesym);
  listdelall ((LIST *)arglist, freesym);

  sym = (SYMBOL *)listitem (sizeof (SYMBOL));
  sym->type = st_map;
  sym->v.p = res;

  return sym;
}

SYMBOL *
mapop (int op, SYMBOL *map1, SYMBOL *map2)
{
  SYMBOL *func, *arglist, *res = NULL;
  char buf[32];

  sprintf (buf, "map_op_func_%c", op);

  func = getsym (buf);
  if (!func)
  {
    printf ("No function defined to perform map %c map\n", op);
    parseerror = 1;
  }
  else
  {
    res = (SYMBOL *)listitem (sizeof (SYMBOL));
    symcpy (res, func);
    res->next = NULL;
    func = res;
    arglist = (SYMBOL *)listapp (NULL, (LIST *)map1);
    arglist = (SYMBOL *)listapp ((LIST *)arglist, (LIST *)map2);

    res = mapfunc (func, arglist);
  }

  /* free map1/map2 ?    only if they have no name? */

  return res;
}