/*
  NrrdIO: stand-alone code for basic nrrd functionality
  Copyright (C) 2012, 2011, 2010, 2009  University of Chicago
  Copyright (C) 2008, 2007, 2006, 2005  Gordon Kindlmann
  Copyright (C) 2004, 2003, 2002, 2001, 2000, 1999, 1998  University of Utah

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any
  damages arising from the use of this software.

  Permission is granted to anyone to use this software for any
  purpose, including commercial applications, and to alter it and
  redistribute it freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must
     not claim that you wrote the original software. If you use this
     software in a product, an acknowledgment in the product
     documentation would be appreciated but is not required.

  2. Altered source versions must be plainly marked as such, and must
     not be misrepresented as being the original software.

  3. This notice may not be removed or altered from any source distribution.
*/

#include "NrrdIO.h"

/*
learned: using these functions correctly to manage even simple
memory usage can be very tricky.  

problem 0: even trying to write airMopPrint, I foolishly thought:
"print the string, then free it".  But the print callback clobbered
the free callback, because of the semantics of airMopAdd().  So,
I had to add _airMopAdd().

problem 1: debugging hest with purify, on case of hitting error after
parsing multiple variable parameter option of strings: so, I allocated
an array of strings (arrays), and registered all the strings with
airMopMem(), and registered the array itself also with airMopMem().
Again, got clobbered.  airSetNull(&((*vP)[0])) clobbered 
airFree(*vP).  So, I gave up on using airMopMem() for the individual
elements, and am using simply airMopAdd(airFree).  The alternative
was to change the airMopAdd()s in airMopMem() to _airMopAdd()s, but
I didn't feel confident that this would be safe.

-----------  SO: as a result of all that:

airMopAdd() will no longer over-write a callback based on the pointer
It will only over-write the "when" of a (pointer,callback) pair, so that
you can't register multiple copies of a (pointer,callback) pair (regardless
of differences, if any, in "when").  Therefore, there will be AT MOST ONE
instance of a (pointer,callback) pair in a mop.

_airMopAdd() was nixed.

airMopSub() and airMopUnMem were created

*/

#define AIR_MOP_INCR 10

airArray *
airMopNew() {
  
  return airArrayNew(NULL, NULL, sizeof(airMop), AIR_MOP_INCR);
}

/*
** except for allocation error, this always returns 0,
** to facilitate this weird idiom:
**
**   if (!(nmeasr = nrrdNew())
**       || airMopAdd(mop, nmeasr, (airMopper)nrrdNuke, airMopAlways)
**       || !(nsize = nrrdNew())
**       || airMopAdd(mop, nsize, (airMopper)nrrdNuke, airMopAlways)
**       || !(pair = AIR_CAST(ccpair *, calloc(pctx->CCNum, sizeof(ccpair))))
**       || airMopAdd(mop, pair, airFree, airMopAlways)) {
**
** GLK may regret this.
*/
int
airMopAdd(airArray *arr, void *ptr, airMopper mop, int when) {
  static const char me[]="airMopAdd";
  airMop *mops;
  unsigned int ii;
  
  if (!arr) {
    return 0;
  }

  mops = (airMop *)arr->data;
  /* first see if this is something we already set a callback for */
  for (ii=0; ii<arr->len; ii++) {
    if (mops[ii].ptr == ptr && mops[ii].mop == mop) {
      mops[ii].when = when;
      /* we're done */
      return 0;
    }
  }
  /* this is a new ptr */
  ii = airArrayLenIncr(arr, 1);
  if (!arr->data) {
    fprintf(stderr, "%s: PANIC: can't re-allocate mop array\n", me);
    return 1;
  }
  mops = (airMop *)arr->data;
  mops[ii].ptr = ptr;
  mops[ii].mop = mop;
  mops[ii].when = when;
  return 0;
}

void
airMopSub(airArray *arr, void *ptr, airMopper mop) {
  airMop *mops;
  unsigned int ii;
  
  if (!arr) {
    return;
  }

  mops = (airMop *)arr->data;
  /* first see if this is something we already set a callback for */
  for (ii=0; ii<arr->len; ii++) {
    if (mops[ii].ptr == ptr && mops[ii].mop == mop) {
      mops[ii].ptr = NULL;
      mops[ii].mop = NULL;
      mops[ii].when = airMopNever;
      return;
    }
  }
  /* else we've never seen this before, user is a moron */
  return;
}

void
airMopMem(airArray *arr, void *_ptrP, int when) {
  void **ptrP;

  if (!(arr && _ptrP)) {
    return;
  }

  ptrP = (void **)_ptrP;
  airMopAdd(arr, ptrP, (airMopper)airSetNull, when);
  airMopAdd(arr, *ptrP, airFree, when);
  /*
  printf("airMopMem(0x%p): will free() 0x%p\n", 
         (void*)arr, (void*)(*ptrP));
  printf("airMopMem(0x%p): will set 0x%p to NULL\n", 
         (void*)arr, (void*)ptrP);
  */
  return;
}

void
airMopUnMem(airArray *arr, void *_ptrP) {
  void **ptrP;

  if (!(arr && _ptrP)) {
    return;
  }

  ptrP = (void **)_ptrP;
  airMopSub(arr, ptrP, (airMopper)airSetNull);
  airMopSub(arr, *ptrP, airFree);
  return;
}

static void *
_airMopPrint(void *_str) {
  char *str;

  str = (char *)_str;
  if (str) {
    printf("%s\n", str);
  }
  return NULL;
}

void
airMopPrint(airArray *arr, const void *_str, int when) {
  char *copy;

  if (!(arr && _str))
    return;

  copy = airStrdup(AIR_CAST(const char*, _str));
  airMopAdd(arr, copy, airFree, airMopAlways);
  airMopAdd(arr, copy, _airMopPrint, when);
  return;
}

static const char
_airMopWhenStr[4][128] = {
  " never",
  " error",
  "  okay",
  "always",
};

/*
** This is to overcome the warning about
** "ISO C forbids conversion of function pointer to object pointer type";
** the result here is thus implementation-dependent
*/
typedef union {
  airMopper m;
  void *v;
} mvunion;

void
airMopDebug(airArray *arr) {
  airMop *mops;
  unsigned int ii;
  mvunion mvu;

  if (!arr)
    return;

  mops = (airMop *)arr->data;
  printf("airMopDebug: _________________________ mop stack for 0x%p:\n",
         AIR_VOIDP(arr));
  if (arr->len) {
    ii = arr->len;
    do {
      ii--;
      printf("%4u: ", ii);
      if (NULL == mops[ii].mop && NULL == mops[ii].ptr
          && airMopNever == mops[ii].when) {
        printf("no-op\n");
        continue;
      }
      /* else */
      printf("%s: ", _airMopWhenStr[mops[ii].when]);
      if (airFree == mops[ii].mop) {
        printf("airFree(0x%p)\n", AIR_VOIDP(mops[ii].ptr));
        continue;
      }
      if ((airMopper)airSetNull == mops[ii].mop) {
        printf("airSetNull(0x%p)\n", AIR_VOIDP(mops[ii].ptr));
        continue;
      }
      if (_airMopPrint == mops[ii].mop) {
        printf("_airMopPrint(\"%s\" == 0x%p)\n",
               AIR_CAST(char*, mops[ii].ptr), AIR_VOIDP(mops[ii].ptr));
        continue;
      }
      if ((airMopper)airFclose == mops[ii].mop) {
        printf("airFclose(0x%p)\n", AIR_VOIDP(mops[ii].ptr));
        continue;
      }
      /* else */
      mvu.m = mops[ii].mop;
      printf("0x%p(0x%p)\n", AIR_VOIDP(mvu.v), AIR_VOIDP(mops[ii].ptr));
    } while (ii);
  }
  printf("airMopDebug: ^^^^^^^^^^^^^^^^^^^^^^^^^\n");
}

void
airMopDone(airArray *arr, int error) {
  airMop *mops;
  unsigned int ii;

  /*
  printf("airMopDone(%p): hello, %s\n", (void*)arr, error ? "error" : "okay");
  */
  if (arr) {
    mops = (airMop *)arr->data;
    if (arr->len) {
      ii = arr->len;
      do {
        ii--;
        if (mops[ii].ptr
            && (airMopAlways == mops[ii].when
                || (airMopOnError == mops[ii].when && error)
                || (airMopOnOkay == mops[ii].when && !error))) {
          mops[ii].mop(mops[ii].ptr);
        }
      } while (ii);
    }
    airArrayNuke(arr);
    /*
      printf("airMopDone(%p): done!\n", (void*)arr);
    */
  }
  return;
}

void
airMopError(airArray *arr) {
  
  airMopDone(arr, AIR_TRUE);
}

void
airMopOkay(airArray *arr) {
  
  airMopDone(arr, AIR_FALSE);
}

