enum asmStatementIndex {
  asmObjProcIdx,
  asmEvalIdx,
  asmDuplicateObjIdx,
  asmIncrIntIdx,
  asmIncrObjIdx,
  asmIntegerIdx,
  asmJumpIdx,
  asmJumpTrueIdx,
  asmLeIntIdx,
  asmLeIntObjIdx,
  asmMethodDelegateDispatchIdx,
  asmMethodSelfDispatchIdx,
  asmNoopIdx,
  asmObjIdx,
  asmSelfIdx,
  asmSetIntIdx,
  asmSetObjIdx,
  asmSetObjToResultIdx,
  asmSetResultIdx,
  asmSetResultIntIdx,
  asmStoreResultIdx,
  asmVarIdx
};

static CONST char *asmStatementNames[] = {
  "cmd",
  "eval",
  "duplicateObj",
  "incrInt",
  "incrObj",
  "integer",
  "jump",
  "jumpTrue",
  "leInt",
  "leIntObj",
  "methodDelegateDispatch",
  "methodSelfDispatch",
  "noop",
  "obj",
  "self",
  "setInt",
  "setObj",
  "setObjToResult",
  "setResult",
  "setResultInt",
  "storeResult",
  "var",
  NULL
};

enum asmStatementArgTypeIndex {
  asmStatementArgTypeArgIdx,
  asmStatementArgTypeArgvIdx,
  asmStatementArgTypeInstructionIdx,
  asmStatementArgTypeIntIdx,
  asmStatementArgTypeObjIdx,
  asmStatementArgTypeResultIdx,
  asmStatementArgTypeSlotIdx,
  asmStatementArgTypeVarIdx
};

static CONST char *asmStatementArgType[] = {
  "arg",
  "argv",
  "instruction",
  "int",
  "obj",
  "result",
  "slot",
  "var",
  NULL};

static CONST char *asmStatementCmdType[]         = {"arg", "obj", "result", "var", NULL};
static CONST char *asmStatementInstructionType[] = {"instruction", NULL};
static CONST char *asmStatementIntType[]         = {"int", NULL};
static CONST char *asmStatementObjType[]         = {"obj", NULL};
static CONST char *asmStatementSlotObjArgType[]  = {"slot", "obj", "arg", NULL};
static CONST char *asmStatementSlotType[]        = {"slot", NULL};
static CONST char *asmStatementSlotIntType[]     = {"slot", "int", NULL};
static CONST char *asmStatementStoreType[]       = {"instruction", "argv", NULL};

static AsmStatementInfo asmStatementInfo[] = {
  /* asmObjProcIdx, */
  {ASM_INFO_PAIRS|ASM_INFO_SKIP1, NULL, 2, -1, NR_PAIRS1},
  /* asmEval */
  {0|ASM_INFO_PAIRS, asmStatementCmdType, 3, -1, NR_PAIRS},
  /* asmDuplicateObj */
  {0|ASM_INFO_PAIRS, asmStatementSlotObjArgType, 5, 5, 2},
  /* asmIncrInt */
  {0|ASM_INFO_PAIRS, asmStatementSlotType, 5, 5, 2},
  /* asmIncrObj */
  {0|ASM_INFO_PAIRS, asmStatementSlotType, 5, 5, 2},
  /* asmInteger */
  {0|ASM_INFO_DECL|ASM_INFO_PAIRS, asmStatementIntType, 3, 3, 0},
  /* asmJump */
  {0|ASM_INFO_PAIRS, asmStatementInstructionType, 3, 3, 1},
  /* asmJumpTrue */
  {0|ASM_INFO_PAIRS, asmStatementInstructionType, 3, 3, 1},
  /* asmLeInt */
  {0|ASM_INFO_PAIRS, asmStatementSlotType, 5, 5, 2},
  /* asmLeIntObj */
  {0|ASM_INFO_PAIRS, asmStatementSlotType, 5, 5, 2},
  /* asmMethodDelegateDispatch */
  {0|ASM_INFO_PAIRS, asmStatementCmdType, 5, -1, NR_PAIRS},
  /* asmMethodSelfDispatch */
  {0|ASM_INFO_PAIRS, asmStatementCmdType, 3, -1, NR_PAIRS},
  /* asmNoop */
  {0, NULL, 1, 1, 0},
  /* asmObj */
  {0|ASM_INFO_DECL, NULL, 2, 2, 0},
  /* asmSelf */
  {0|ASM_INFO_PAIRS, NULL, 1, 1, 0},
  /* asmSetInt */
  {0|ASM_INFO_PAIRS, asmStatementSlotIntType, 5, 5, 2},
  /* asmSetObj */
  {0|ASM_INFO_PAIRS, asmStatementSlotObjArgType, 5, 5, 2},
  /* asmSetObjToResult */
  {0|ASM_INFO_PAIRS, asmStatementSlotType, 3, 3, 2},
  /* asmSetResult */
  {0|ASM_INFO_PAIRS, asmStatementSlotType, 3, 3, 1},
  /* asmSetResultInt */
  {0|ASM_INFO_PAIRS, asmStatementSlotType, 3, 3, 1},
  /* asmStoreResult */
  {0|ASM_INFO_PAIRS, asmStatementStoreType, 5, 5, 0},
  /* asmVar */
  {0|ASM_INFO_DECL|ASM_INFO_PAIRS, asmStatementObjType, 3, 3, 0}
};


/*
 *----------------------------------------------------------------------
 * AsmAssemble --
 *
 *    The assmbler, takes an assembly script in the form of a nested
 *    list and emits the internal representation for the execution
 *    enigine.
 *
 *----------------------------------------------------------------------
 */

static int
AsmAssemble(ClientData cd, Tcl_Interp *interp, Tcl_Obj *nameObj,
	      int nrArgs, Tcl_Obj *asmObj, AsmCompiledProc **retAsmProc) {
  AsmPatches patchArray[100], *patches = &patchArray[0], *patchPtr; // TODO: make me dynamic
  Tcl_Command cmd;
  AsmCompiledProc *proc;
  AsmInstruction *inst;
  int i, result, nrAsmInstructions, nrLocalObjs, totalArgvArgs;
  int oc, currentAsmInstruction, currentSlot;
  Tcl_Obj **ov;
  CONST char *procName;

  assert(nameObj != NULL);
  procName = ObjStr(nameObj);

  if (Tcl_ListObjGetElements(interp, asmObj, &oc, &ov) != TCL_OK) {
    return NsfPrintError(interp, "Asm code is not a valid list");
  }

  /*
   * First Iteration: check wellformedness, determine sizes
   */
  nrAsmInstructions = 0;
  nrLocalObjs = 0;
  totalArgvArgs = 0;

  for (i = 0; i < oc; i++) {
    int index, offset, wordOc;
    Tcl_Obj *lineObj = ov[i], **wordOv;

    if (Tcl_ListObjGetElements(interp, lineObj, &wordOc, &wordOv) != TCL_OK) {
      return NsfPrintError(interp,
			   "Asm: line is not a well-formed asm instruction: %s",
			   ObjStr(lineObj));
    }

    result = Tcl_GetIndexFromObj(interp, wordOv[0], asmStatementNames, "asm instruction", 0, &index);
    if (result != TCL_OK) {
      return NsfPrintError(interp,
			   "Asm: line is not a valid asm instruction: word %s, line %s",
			   ObjStr(wordOv[0]), ObjStr(lineObj));
    }

    offset = (asmStatementInfo[index].flags & ASM_INFO_SKIP1) ? 2 : 1;

    if ((asmStatementInfo[index].flags & ASM_INFO_PAIRS) && (wordOc-offset) % 2 == 1) {
      return NsfPrintError(interp, "Asm: argument list of cmd must contain pairs: %s",
			   ObjStr(lineObj));
    }

    if (asmStatementInfo[index].minArgs > -1
	&& wordOc < asmStatementInfo[index].minArgs) {
      return NsfPrintError(interp, "Asm: statement must contain at least %d words: %s",
			   asmStatementInfo[index].minArgs, ObjStr(lineObj));
    }

    if (asmStatementInfo[index].maxArgs > -1
	&& wordOc > asmStatementInfo[index].maxArgs) {
      return NsfPrintError(interp, "Asm: statement must contain at most %d words: %s",
			   asmStatementInfo[index].maxArgs, ObjStr(lineObj));
    }

    if (asmStatementInfo[index].argTypes) {
      result = AsmInstructionArgvCheck(interp, offset, wordOc,
				       asmStatementInfo[index].argTypes,
				       nrLocalObjs, oc, wordOv, lineObj);
      if (unlikely(result != TCL_OK)) {return result;}
    }

    if ((asmStatementInfo[index].flags & ASM_INFO_DECL) == 0) {
      int cArgs = asmStatementInfo[index].cArgs;
      /*
       * Determine the actual number of arguments passed to the
       * emitted instruction. This number might be determine by the
       * instruction type, or by the actual instruction being
       * processed (and later maybe for {*} etc.).
       */
      if (cArgs == NR_PAIRS) {
	cArgs = (wordOc-offset) / 2;
      } else if (cArgs == NR_PAIRS1) {
	cArgs = 1 + (wordOc-offset) / 2;
      }
      //fprintf(stderr, "instruction %s need argvargs %d\n", ObjStr(lineObj), cArgs);
      totalArgvArgs += cArgs;

      nrAsmInstructions++;
    } else {
      /* currently obj and var from the same pool, will change... */
      nrLocalObjs ++;
    }

    /*
     * optional, per-statement check operations
     */
    switch (index) {
    case asmObjProcIdx:
      /* {cmd ::set slot 0 slot 2} */
      cmd = Tcl_GetCommandFromObj(interp, wordOv[1]);
      if (cmd == NULL) {
	return NsfPrintError(interp,
			     "Asm: cmd is not a valid Tcl command: %s\n",
			     Tcl_GetString( wordOv[1]));
      }
      break;

   /* begin generated code */

   /* end generated code */

    default:
      break;
    }
  }

  nrAsmInstructions ++;
  fprintf(stderr, "%s: nrAsmInstructions %d nrLocalObjs %d nrArgs %d argvArgs %d => data %d\n",
	  procName, nrAsmInstructions, nrLocalObjs, nrArgs, totalArgvArgs,
	  nrLocalObjs + nrArgs + totalArgvArgs );

  /*
   * Allocate structures
   */

  proc = (AsmCompiledProc *)ckalloc(sizeof(AsmCompiledProc));
  proc->code = (AsmInstruction *)ckalloc(sizeof(AsmInstruction) * nrAsmInstructions);
  memset(proc->slotFlags, 0, sizeof(int) * NSF_ASM_NR_STATIC_SLOTS);

  proc->ip = proc->code;  /* points to the first writable instructon */
  proc->firstObj = proc->staticObjs;  /* point to the first free obj */
  proc->locals = proc->staticObjs;    /* locals is just an alias     */
  proc->nrAsmArgReferences = 0;
  proc->slots = proc->locals + nrArgs;
  //fprintf(stderr, "args = %ld\n", proc->slots - proc->locals);

  AsmLocalsAlloc(proc, nrArgs + nrLocalObjs);
  /* when freeing, we need something like
    for (i=0; i < nrArgs + nrLocalObjs; i++) {
      if (proc->slotFlags[i] & ASM_SLOT_MUST_DECR) {Tcl_DecrRefCount(proc->slots[i]); }
    }
  */

  /*
   * Second Iteration: emit code
   */
  currentSlot = 0;
  currentAsmInstruction = 0;

  for (i = 0; i < oc; i++) {
    int index, offset, cArgs, argc, codeIndex, argvIndex, j;
    Tcl_Obj *lineObj = ov[i], **argv;

    Tcl_ListObjGetElements(interp, lineObj, &argc, &argv);
    Tcl_GetIndexFromObj(interp, argv[0], asmStatementNames, "asm instruction", 0, &index);

    offset = (asmStatementInfo[index].flags & ASM_INFO_SKIP1) ? 2 : 1;

    cArgs = asmStatementInfo[index].cArgs;
    if (cArgs == NR_PAIRS) {
      cArgs = (argc-offset) / 2;
    } else if (cArgs == NR_PAIRS1) {
      cArgs = 1 + (argc-offset) / 2;
    }

    switch (index) {

    case asmObjProcIdx:
      /* {cmd ::set slot 0 slot 2} */
      cmd = Tcl_GetCommandFromObj(interp, argv[1]);
#if defined(LABEL_THREADING)
      inst = AsmInstructionNew(proc, objProc, cArgs);
      inst->cmd = ((Command *)cmd)->objProc;
#else
      inst = AsmInstructionNew(proc, ((Command *)cmd)->objProc, cArgs);
#endif
      inst->clientData = ((Command *)cmd)->objClientData;
      /* use the assembly word as cmd name; should be ok when we keep assembly around */
      inst->argv[0] = argv[1];
      /*fprintf(stderr, "[%d] %s/%d\n", currentAsmInstruction, Tcl_GetString(argv[1]), 1+((argc-offset)/2));*/

      AsmInstructionArgvSet(interp, offset, argc, 1, inst, proc, argv, 0);
      break;

      /* begin generated code */
   case asmEvalIdx:

	inst = AsmInstructionNew(proc, asmEval, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
      break;

   case asmDuplicateObjIdx:

	inst = AsmInstructionNew(proc, asmDuplicateObj, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	inst->clientData = proc;

      break;

   case asmIncrIntIdx:

	inst = AsmInstructionNew(proc, asmIncrInt, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	inst->clientData = proc;

      break;

   case asmIncrObjIdx:

	inst = AsmInstructionNew(proc, asmIncrObj, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	inst->clientData = proc;

      break;

   case asmIntegerIdx:

	{
	  int intValue;
	  Tcl_GetIntFromObj(interp, argv[2], &intValue);
	  proc->slots[currentSlot] = INT2PTR(intValue);
	  //fprintf(stderr, "setting slots [%d] = %d\n", currentSlot, intValue);
	  proc->slotFlags[currentSlot] |= ASM_SLOT_IS_INTEGER;
	  currentSlot ++;
	}

      break;

   case asmJumpIdx:

	inst = AsmInstructionNew(proc, asmJump, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	inst->clientData = proc;

      break;

   case asmJumpTrueIdx:

	inst = AsmInstructionNew(proc, asmJumpTrue, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	inst->clientData = proc;

      break;

   case asmLeIntIdx:

	inst = AsmInstructionNew(proc, asmLeInt, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	inst->clientData = proc;

      break;

   case asmLeIntObjIdx:

	inst = AsmInstructionNew(proc, asmLeIntObj, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	inst->clientData = proc;

      break;

   case asmMethodDelegateDispatchIdx:

	inst = AsmInstructionNew(proc, asmMethodDelegateDispatch, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	{ Tcl_Command cmd = NULL;
	  NsfObject *object = NULL;
	  AsmResolverInfo *resInfo;
	
	  if (strncmp(ObjStr(inst->argv[1]), "::nsf::methods::", 16) == 0) {
	    cmd = Tcl_GetCommandFromObj(interp, inst->argv[1]);
	    //fprintf(stderr, "%s: asmMethod cmd '%s' => %p\n", procName, ObjStr(inst->argv[1]), cmd);
	  }
	  if (strncmp(ObjStr(inst->argv[0]), "::nx::", 6) == 0) {
	    GetObjectFromObj(interp, inst->argv[0], &object);
	    //fprintf(stderr, "%s: asmMethod object '%s' => %p\n", procName, ObjStr(inst->argv[0]), object);
	  }
	  if (cmd && object) {
	    // experimental: bind obj and method
	    resInfo = NEW(AsmResolverInfo); // TODO: LEAK
	    resInfo->cmd = cmd;
	    resInfo->object = object;
	    inst->clientData = resInfo;
	    AsmInstructionSetCmd(inst, asmMethodDelegateDispatch11);
	  } else if (cmd != 0) {
	    inst->clientData = cmd;
	  } else {	
	    inst->clientData = NULL;
	  }
	}

      break;

   case asmMethodSelfDispatchIdx:

	inst = AsmInstructionNew(proc, asmMethodSelfDispatch, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	{ Tcl_Command cmd = NULL;	
	  AsmResolverInfo *resInfo;
	
	  if (strncmp(ObjStr(inst->argv[0]), "::nsf::methods::", 16) == 0) {
	    cmd = Tcl_GetCommandFromObj(interp, inst->argv[0]);
	    if (cmd != 0) {
	      //fprintf(stderr, "%s: asmMethodSelfCmdDispatch cmd '%s' => %p\n", procName, ObjStr(inst->argv[0]), cmd);
	      AsmInstructionSetCmd(inst, asmMethodSelfCmdDispatch);
	    }
	  } else {
	    //fprintf(stderr, "%s: asmMethodSelfDispatch cmd '%s'\n", procName, ObjStr(inst->argv[0]));
	  }
	  resInfo = NEW(AsmResolverInfo); // TODO: LEAK
	  resInfo->cmd = cmd;
	  resInfo->proc = proc;
	  inst->clientData = resInfo;
	}

      break;

   case asmNoopIdx:

	inst = AsmInstructionNew(proc, asmNoop, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
      break;

   case asmObjIdx:

	proc->slots[currentSlot] = argv[1];
	Tcl_IncrRefCount(proc->slots[currentSlot]);
	proc->slotFlags[currentSlot] |= ASM_SLOT_MUST_DECR;
	currentSlot ++;

      break;

   case asmSelfIdx:

	inst = AsmInstructionNew(proc, asmSelf, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	inst->clientData = proc;

      break;

   case asmSetIntIdx:

	inst = AsmInstructionNew(proc, asmSetInt, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	inst->clientData = proc;

      break;

   case asmSetObjIdx:

	inst = AsmInstructionNew(proc, asmSetObj, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	inst->clientData = proc;

      break;

   case asmSetObjToResultIdx:

	inst = AsmInstructionNew(proc, asmSetObjToResult, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	inst->clientData = proc;

      break;

   case asmSetResultIdx:

	inst = AsmInstructionNew(proc, asmSetResult, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	inst->clientData = proc;

      break;

   case asmSetResultIntIdx:

	inst = AsmInstructionNew(proc, asmSetResultInt, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	inst->clientData = proc;

      break;

   case asmStoreResultIdx:

	inst = AsmInstructionNew(proc, asmStoreResult, cArgs);
	if (cArgs > 0) {AsmInstructionArgvSet(interp, offset, argc, 0, inst, proc, argv, 0);}
	codeIndex = -1;
	argvIndex = -1;
	for (j = offset; j < argc; j += 2) {
	    int argIndex, intValue;
	    Tcl_GetIndexFromObj(interp, argv[j], asmStatementArgType, "asm internal arg type", 0, &argIndex);
	    Tcl_GetIntFromObj(interp, argv[j+1], &intValue);
	    switch (argIndex) {
	      case asmStatementArgTypeInstructionIdx: codeIndex = intValue; break;
	      case asmStatementArgTypeArgvIdx: argvIndex = intValue; break;
	    }
	  }
	// TODO: CHECK codeIndex, argvIndex (>0, reasonable values)
	//fprintf(stderr, "%p setting instruction %d => %d %d\n", patches, currentAsmInstruction, codeIndex, argvIndex);
	patches->targetAsmInstruction = currentAsmInstruction;
	patches->sourceAsmInstruction = codeIndex;
	patches->argvIndex = argvIndex;
	patches++;

      break;

   case asmVarIdx:

	proc->slots[currentSlot] = NULL;
	currentSlot ++;

      break;


      /* end generated code */
  }

    if ((asmStatementInfo[index].flags & ASM_INFO_DECL) == 0) {
      currentAsmInstruction ++;
    }
  }

  /*
   * add END instruction
   */
  inst = AsmInstructionNew(proc, NULL, 0);

  /*
   * All addresses are determined, apply the argv patches triggered
   * from above.
   */

  for (patchPtr = &patchArray[0]; patchPtr < patches; patchPtr++) {
    fprintf(stderr, "want to patch code[%d]->argv = code[%d]->argv[%d]\n",
	    patchPtr->targetAsmInstruction, patchPtr->sourceAsmInstruction, patchPtr->argvIndex);
    /* set the argument vector of code[1] to the address of code[4]->argv[1] */
    (&proc->code[patchPtr->targetAsmInstruction])->argv =
      &(&proc->code[patchPtr->sourceAsmInstruction])->argv[patchPtr->argvIndex];
  }

  *retAsmProc = proc;

  return TCL_OK;
}
