/*

 * Copyright (c) 2016-2023  Moddable Tech, Inc.

 *

 *   This file is part of the Moddable SDK Runtime.

 * 

 *   The Moddable SDK Runtime is free software: you can redistribute it and/or modify

 *   it under the terms of the GNU Lesser General Public License as published by

 *   the Free Software Foundation, either version 3 of the License, or

 *   (at your option) any later version.

 * 

 *   The Moddable SDK Runtime is distributed in the hope that it will be useful,

 *   but WITHOUT ANY WARRANTY; without even the implied warranty of

 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *   GNU Lesser General Public License for more details.

 * 

 *   You should have received a copy of the GNU Lesser General Public License

 *   along with the Moddable SDK Runtime.  If not, see <http://www.gnu.org/licenses/>.

 *

 * This file incorporates work covered by the following copyright and  

 * permission notice:  

 *

 *       Copyright (C) 2010-2016 Marvell International Ltd.

 *       Copyright (C) 2002-2010 Kinoma, Inc.

 *

 *       Licensed under the Apache License, Version 2.0 (the "License");

 *       you may not use this file except in compliance with the License.

 *       You may obtain a copy of the License at

 *

 *        http://www.apache.org/licenses/LICENSE-2.0

 *

 *       Unless required by applicable law or agreed to in writing, software

 *       distributed under the License is distributed on an "AS IS" BASIS,

 *       WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 *       See the License for the specific language governing permissions and

 *       limitations under the License.

 */

#include "xsAll.h"

//#define mxPromisePrint 1

#ifndef mxReportUnhandledRejections

#define mxReportUnhandledRejections 0

#endif

static void fxAddUnhandledRejection(txMachine* the, txSlot* promise);

static void fxCombinePromises(txMachine* the, txInteger which);

static txSlot* fxNewCombinePromisesFunction(txMachine* the, txInteger which, txSlot* already, txSlot* object);

enum {

  XS_PROMISE_COMBINE_NONE = 0,

  XS_PROMISE_COMBINE_FULFILLED = 1,

  XS_PROMISE_COMBINE_REJECTED = 2,

  XS_PROMISE_COMBINE_SETTLED = 4,

};

void fxBuildPromise(txMachine* the)

{

  txSlot* slot;

  mxPush(mxObjectPrototype);

  slot = fxLastProperty(the, fxNewObjectInstance(the));

  slot = fxNextHostFunctionProperty(the, slot, mxCallback(fx_Promise_prototype_catch), 1, mxID(_catch), XS_DONT_ENUM_FLAG);

  slot = fxNextHostFunctionProperty(the, slot, mxCallback(fx_Promise_prototype_finally), 1, mxID(_finally_), XS_DONT_ENUM_FLAG);

  slot = fxNextHostFunctionProperty(the, slot, mxCallback(fx_Promise_prototype_then), 2, mxID(_then), XS_DONT_ENUM_FLAG);

  slot = fxNextStringXProperty(the, slot, "Promise", mxID(_Symbol_toStringTag), XS_DONT_ENUM_FLAG | XS_DONT_SET_FLAG);

  mxPromisePrototype = *the->stack;

  slot = fxBuildHostConstructor(the, mxCallback(fx_Promise), 1, mxID(_Promise));

  mxPromiseConstructor = *the->stack;

  slot = fxLastProperty(the, slot);

  slot = fxNextHostFunctionProperty(the, slot, mxCallback(fx_Promise_all), 1, mxID(_all), XS_DONT_ENUM_FLAG);

  slot = fxNextHostFunctionProperty(the, slot, mxCallback(fx_Promise_allSettled), 1, mxID(_allSettled), XS_DONT_ENUM_FLAG);

  slot = fxNextHostFunctionProperty(the, slot, mxCallback(fx_Promise_any), 1, mxID(_any), XS_DONT_ENUM_FLAG);

  slot = fxNextHostFunctionProperty(the, slot, mxCallback(fx_Promise_race), 1, mxID(_race), XS_DONT_ENUM_FLAG);

  slot = fxNextHostFunctionProperty(the, slot, mxCallback(fx_Promise_reject), 1, mxID(_reject), XS_DONT_ENUM_FLAG);

  slot = fxNextHostFunctionProperty(the, slot, mxCallback(fx_Promise_resolve), 1, mxID(_resolve), XS_DONT_ENUM_FLAG);

#if mxECMAScript2025

  slot = fxNextHostFunctionProperty(the, slot, mxCallback(fx_Promise_try), 1, mxID(_try_), XS_DONT_ENUM_FLAG);

#endif

#if mxECMAScript2024

  slot = fxNextHostFunctionProperty(the, slot, mxCallback(fx_Promise_withResolvers), 0, mxID(_withResolvers), XS_DONT_ENUM_FLAG);

#endif

  slot = fxNextHostAccessorProperty(the, slot, mxCallback(fx_species_get), C_NULL, mxID(_Symbol_species), XS_DONT_ENUM_FLAG);

  mxPop();

  fxNewHostFunction(the, mxCallback(fxOnRejectedPromise), 1, XS_NO_ID, XS_NO_ID);

  mxOnRejectedPromiseFunction = *the->stack;

  mxPop();

  fxNewHostFunction(the, mxCallback(fxOnResolvedPromise), 1, XS_NO_ID, XS_NO_ID);

  mxOnResolvedPromiseFunction = *the->stack;

  mxPop();

  fxNewHostFunction(the, mxCallback(fxOnThenable), 1, XS_NO_ID, XS_NO_ID);

  mxOnThenableFunction = *the->stack;

  mxPop();

}

txSlot* fxNewPromiseInstance(txMachine* the)

{

#ifdef mxPromisePrint

  static txID gID = 0;

#endif

  txSlot* promise;

  txSlot* slot;

  txSlot* instance;

  promise = fxNewSlot(the);

  promise->kind = XS_INSTANCE_KIND;

  promise->value.instance.garbage = C_NULL;

  promise->value.instance.prototype = the->stack->value.reference;

  the->stack->kind = XS_REFERENCE_KIND;

  the->stack->value.reference = promise;

  /* STATUS */

  slot = promise->next = fxNewSlot(the);

  slot->flag = XS_INTERNAL_FLAG;

#ifdef mxPromisePrint

  slot->ID = gID++;

#endif

  slot->kind = XS_PROMISE_KIND;

  slot->value.integer = mxUndefinedStatus;

  /* THENS */

  slot = slot->next = fxNewSlot(the);

  slot->flag = XS_INTERNAL_FLAG;

  slot->value.reference = instance = fxNewSlot(the);

    slot->kind = XS_REFERENCE_KIND;

  instance->kind = XS_INSTANCE_KIND;

  instance->value.instance.garbage = C_NULL;

  instance->value.instance.prototype = C_NULL;

  /* RESULT */

  slot = slot->next = fxNewSlot(the);

  slot->flag = XS_INTERNAL_FLAG;

#if mxReportUnhandledRejections

  /* ENVIRONMENT */

  slot = slot->next = fxNewSlot(the);

  slot->flag = XS_INTERNAL_FLAG;

  instance = the->frame;

  while (instance) {

    txSlot* environment = mxFrameToEnvironment(instance);

    if (environment->ID != XS_NO_ID) {

      slot->ID = environment->ID;

      slot->value.environment.line = environment->value.environment.line;

      break;

    }

    instance = instance->next;

  }

#endif

  return promise;

}

txSlot* fxNewPromiseCapability(txMachine* the, txSlot* resolveFunction, txSlot* rejectFunction)

{

  txSlot* capability;

  txSlot* slot;

  txSlot* function;

  mxNew();

  resolveFunction->value.reference = fxNewHostFunction(the, fxNewPromiseCapabilityCallback, 2, XS_NO_ID, mxNewPromiseCapabilityCallbackProfileID);

  resolveFunction->kind = XS_REFERENCE_KIND;

    mxRunCount(1);

    capability = resolveFunction->value.reference;

  resolveFunction->kind = XS_UNDEFINED_KIND;

  slot = mxFunctionInstanceHome(capability)->value.home.object;

  if (!slot)

    mxTypeError("executor not called");

  slot = slot->next;

  if (!mxIsReference(slot))

    mxTypeError("resolve: not an object");

  function = slot->value.reference; 

  if (!mxIsFunction(function))

    mxTypeError("resolve: not a function");

  resolveFunction->kind = XS_REFERENCE_KIND;

  resolveFunction->value.reference = function;

  slot = slot->next;

  if (!mxIsReference(slot))

    mxTypeError("reject: not an object");

  function = slot->value.reference; 

  if (!mxIsFunction(function))

    mxTypeError("reject: not a function");

  rejectFunction->kind = XS_REFERENCE_KIND;

  rejectFunction->value.reference = function;

  return the->stack->value.reference;

}

void fxNewPromiseCapabilityCallback(txMachine* the)

{

  txSlot* slot = mxFunctionInstanceHome(mxFunction->value.reference);

  txSlot* object = slot->value.home.object;

  txSlot* resolveFunction;

  txSlot* rejectFunction;

  if (object) {

    resolveFunction = object->next;

    rejectFunction = resolveFunction->next;

    if (!mxIsUndefined(resolveFunction) || !mxIsUndefined(rejectFunction))

      mxTypeError("executor already called");

  }

  else {

    object = fxNewInstance(the);

    resolveFunction = object->next = fxNewSlot(the);

    rejectFunction = resolveFunction->next = fxNewSlot(the);

    slot->value.home.object = object;

        mxPop();

  }

  if (mxArgc > 0) {

    resolveFunction->kind = mxArgv(0)->kind;

    resolveFunction->value = mxArgv(0)->value;

  }

  if (mxArgc > 1) {

    rejectFunction->kind = mxArgv(1)->kind;

    rejectFunction->value = mxArgv(1)->value;

  }

}

void fxAddUnhandledRejection(txMachine* the, txSlot* promise)

{

  txSlot* reason = mxPromiseResult(promise);

  txSlot* list = &mxUnhandledPromises;

  txSlot** address = &list->value.reference->next;

  txSlot* slot;

  while ((slot = *address)) {

    if (slot->value.weakRef.target == promise)

      break;

    mxMeterSome(1);

    slot = slot->next;

    address = &slot->next;

  }

  if (!slot) {

#ifdef mxPromisePrint

    fprintf(stderr, "fxAddUnhandledRejection %d\n", promise->next->ID);

#endif

    slot = *address = fxNewSlot(the);

    slot->kind = XS_WEAK_REF_KIND;

    slot->value.weakRef.target = promise;

    slot = slot->next = fxNewSlot(the);

    slot->kind = reason->kind;

    slot->value = reason->value;

  }

}

void fxCheckUnhandledRejections(txMachine* the, txBoolean atExit)

{

  txSlot* list = &mxUnhandledPromises;

  txSlot** address = &list->value.reference->next;

  txSlot* slot;

  if (atExit) {

    txIndex count = 0;

    while ((slot = *address)) {

    #if mxReportUnhandledRejections

      if (slot->value.weakRef.target == C_NULL) {

        fprintf(stderr, "# garbage collected promise\n");

      }

      else {

        txSlot* property = mxPromiseEnvironment(slot->value.weakRef.target);

        if (property && property->ID) {

          fprintf(stderr, "%s:%d\n", fxGetKeyName(the, property->ID), property->value.environment.line);

        }

      }

    #endif

      slot = slot->next;

      *address = slot->next;

      mxException.value = slot->value;

      mxException.kind = slot->kind;

      count++;

    }

    if (count > 0)

      fxAbort(the, XS_UNHANDLED_REJECTION_EXIT);

  }

  else {

    while ((slot = *address)) {

      if (slot->value.weakRef.target == C_NULL) {

        slot = slot->next;

        *address = slot->next;

        mxException.value = slot->value;

        mxException.kind = slot->kind;

        fxAbort(the, XS_UNHANDLED_REJECTION_EXIT);

      }

      else {

        slot = slot->next;

        address = &slot->next;

      }

    }

  }

}

void fxCombinePromises(txMachine* the, txInteger which)

{

  txSlot* stack = the->stack;

  txSlot* resolveFunction;

  txSlot* rejectFunction;

  txSlot* promise;

  txSlot* object;

  txSlot* property;

  txSlot* array;

  txSlot* already;

  txSlot* iterator;

  txSlot* next;

  txSlot* value;

  txInteger index;

  if (!mxIsReference(mxThis))

    mxTypeError("this: not an object");

  mxTemporary(resolveFunction);

  mxTemporary(rejectFunction);

  mxPushSlot(mxThis);

  promise = fxNewPromiseCapability(the, resolveFunction, rejectFunction);

  mxPullSlot(mxResult);

  {

    mxTry(the) {

      txSlot* resolve = C_NULL;

      if (which) {

        object = fxNewInstance(the);

        property = fxNextIntegerProperty(the, object, 0, XS_NO_ID, XS_NO_FLAG);

        property = fxNextReferenceProperty(the, property, promise, XS_NO_ID, XS_NO_FLAG);

        if (which == XS_PROMISE_COMBINE_REJECTED)

          property = fxNextSlotProperty(the, property, rejectFunction, XS_NO_ID, XS_NO_FLAG);

        else

          property = fxNextSlotProperty(the, property, resolveFunction, XS_NO_ID, XS_NO_FLAG);

        mxPush(mxArrayPrototype);

        array = fxNewArrayInstance(the);

        already = array->next;

        property = fxNextReferenceProperty(the, property, array, XS_NO_ID, XS_NO_FLAG);

        mxPop();

      }

      mxPushSlot(mxThis);

      mxGetID(mxID(_resolve)); 

      resolve = the->stack;

      if (!fxIsCallable(the, resolve))

        mxTypeError("resolve: not a function");

      mxTemporary(iterator);

      mxTemporary(next);

      fxGetIterator(the, mxArgv(0), iterator, next, 0);

      index = 0;

      mxTemporary(value);

      while (fxIteratorNext(the, iterator, next, value)) {

        mxTry(the) {

          mxPushSlot(mxThis);

          mxPushSlot(resolve);

          mxCall();

          mxPushSlot(value);

          mxRunCount(1);

          mxDub();

          mxGetID(mxID(_then));

          mxCall();

          if (which) {

            already = already->next = fxNewSlot(the);

            already->kind = XS_UNINITIALIZED_KIND;

            array->next->value.array.length++;

          }

          if (which & XS_PROMISE_COMBINE_SETTLED) {

            fxNewCombinePromisesFunction(the, which | XS_PROMISE_COMBINE_FULFILLED, already, object);

            fxNewCombinePromisesFunction(the, which | XS_PROMISE_COMBINE_REJECTED, already, object);

          }

          else if (which & XS_PROMISE_COMBINE_FULFILLED) {

            fxNewCombinePromisesFunction(the, which, already, object);

            mxPushSlot(rejectFunction);

          }

          else if (which & XS_PROMISE_COMBINE_REJECTED) {

            mxPushSlot(resolveFunction);

            fxNewCombinePromisesFunction(the, which, already, object);

          }

          else {

            mxPushSlot(resolveFunction);

            mxPushSlot(rejectFunction);

          }

          mxRunCount(2);

          mxPop();

          index++;

        }

        mxCatch(the) {

          fxIteratorReturn(the, iterator, 1);

          fxJump(the);

        }

      }

      if (which) {

        property = object->next;

        property->value.integer += index;

        index = property->value.integer;

      }

      if ((index == 0) && (which != XS_PROMISE_COMBINE_NONE)) {

        mxPushUndefined();

        if (which == XS_PROMISE_COMBINE_REJECTED)

          mxPushSlot(rejectFunction);

        else

          mxPushSlot(resolveFunction);

        mxCall();

        if ((which == XS_PROMISE_COMBINE_SETTLED) || (which == XS_PROMISE_COMBINE_FULFILLED)) {

          fxCacheArray(the, array);

          mxPushReference(array);

        }

        else if (which == XS_PROMISE_COMBINE_REJECTED) {

          mxPush(mxAggregateErrorConstructor);

          mxNew();

          fxCacheArray(the, array);

          mxPushReference(array);

          mxRunCount(1);

        }

        else {

          mxPushUndefined();

        }

        mxRunCount(1);

      }

    }

    mxCatch(the) {

      fxRejectException(the, rejectFunction);

    }

  }

  the->stack = stack;

}

void fxCombinePromisesCallback(txMachine* the)

{

  txSlot* slot = mxFunctionInstanceHome(mxFunction->value.reference)->value.home.object->next;

  txInteger which = slot->value.integer;

  txSlot* instance;

  txSlot* property;

  slot = slot->next;

  if (slot->value.closure->kind != XS_UNINITIALIZED_KIND)

    return;

  if (which & XS_PROMISE_COMBINE_SETTLED) {

    mxPush(mxObjectPrototype);

    instance = fxNewObjectInstance(the);

  }

  if (mxArgc > 0)

    mxPushSlot(mxArgv(0));

  else

    mxPushUndefined();

  if (which & XS_PROMISE_COMBINE_SETTLED) {

    property = fxLastProperty(the, instance);

    if (which & XS_PROMISE_COMBINE_FULFILLED) {

      property = fxNextStringXProperty(the, property, "fulfilled", mxID(_status), XS_NO_FLAG);

      property = fxNextSlotProperty(the, property, the->stack, mxID(_value), XS_NO_FLAG);

    }

    else {

      property = fxNextStringXProperty(the, property, "rejected", mxID(_status), XS_NO_FLAG);

      property = fxNextSlotProperty(the, property, the->stack, mxID(_reason), XS_NO_FLAG);

    }

    mxPop();

  }

  mxPullSlot(slot->value.closure);

  slot = slot->next->value.reference->next;

  slot->value.integer--;

  if (slot->value.integer == 0) {

    /* THIS */

    slot = slot->next;

    mxPushSlot(slot);

    /* FUNCTION */

    slot = slot->next;

    mxPushSlot(slot);

    mxCall();

    /* ARGUMENTS */

    slot = slot->next;

    if (which == XS_PROMISE_COMBINE_REJECTED) {

      mxPush(mxAggregateErrorConstructor);

      mxNew();

    }

    fxCacheArray(the, slot->value.reference);

    mxPushSlot(slot);

    if (which == XS_PROMISE_COMBINE_REJECTED) {

      mxRunCount(1);

    }

    /* COUNT */

    mxRunCount(1);

    mxPullSlot(mxResult);

  }

}

txSlot* fxNewCombinePromisesFunction(txMachine* the, txInteger which, txSlot* already, txSlot* object)

{

  txSlot* result;

  txSlot* instance;

  txSlot* property;

  result = fxNewHostFunction(the, fxCombinePromisesCallback, 1, XS_NO_ID, mxCombinePromisesCallbackProfileID);

  instance = fxNewInstance(the);

  property = fxNextIntegerProperty(the, instance, which, XS_NO_ID, XS_NO_FLAG);

  property = property->next = fxNewSlot(the);

  property->kind = XS_CLOSURE_KIND;

  property->value.closure = already;

  property = fxNextReferenceProperty(the, property, object, XS_NO_ID, XS_NO_FLAG);

  property = mxFunctionInstanceHome(result);

  property->value.home.object = instance;

  mxPop();

  return result;

}

void fxOnRejectedPromise(txMachine* the)

{

  txSlot* reaction = mxThis->value.reference;

  txSlot* resolveFunction = reaction->next;

  txSlot* rejectFunction = resolveFunction->next;

  txSlot* resolveHandler = rejectFunction->next;

  txSlot* rejectHandler = resolveHandler->next;

  txSlot* argument = mxArgv(0);

  txSlot* function = rejectFunction;

  if (rejectHandler->kind == XS_REFERENCE_KIND) {

    mxTry(the) {

      /* THIS */

      mxPushUndefined();

      /* FUNCTION */

      mxPushSlot(rejectHandler);

      mxCall();

      /* ARGUMENTS */

      mxPushSlot(argument);

      mxRunCount(1);

      mxPullSlot(argument);

      function = resolveFunction;

    }

    mxCatch(the) {

      *argument = mxException;

      mxException = mxUndefined;

      function = rejectFunction;

    }

  }

    if (function->kind == XS_REFERENCE_KIND) {

    /* THIS */

    mxPushUndefined();

    /* FUNCTION */

    mxPushSlot(function);

    mxCall();

    /* ARGUMENTS */

    mxPushSlot(argument);

    mxRunCount(1);

    mxPop();

  }

}

void fxOnResolvedPromise(txMachine* the)

{

  txSlot* reaction = mxThis->value.reference;

  txSlot* resolveFunction = reaction->next;

  txSlot* rejectFunction = resolveFunction->next;

  txSlot* resolveHandler = rejectFunction->next;

  txSlot* argument = mxArgv(0);

  txSlot* function = resolveFunction;

  if (resolveHandler->kind == XS_REFERENCE_KIND) {

    mxTry(the) {

      /* THIS */

      mxPushUndefined();

      /* FUNCTION */

      mxPushSlot(resolveHandler);

      mxCall();

      /* ARGUMENTS */

      mxPushSlot(argument);

      mxRunCount(1);

      mxPullSlot(argument);

    }

    mxCatch(the) {

      *argument = mxException;

      mxException = mxUndefined;

      function = rejectFunction;

    }

  }

    if (function->kind == XS_REFERENCE_KIND) {

    /* THIS */

    mxPushUndefined();

    /* FUNCTION */

    mxPushSlot(function);

    mxCall();

    /* ARGUMENTS */

    mxPushSlot(argument);

    mxRunCount(1);

    mxPop();

    }

}

void fxOnThenable(txMachine* the)

{

  txSlot* resolveFunction = mxArgv(0);

  txSlot* rejectFunction = mxArgv(1);

  txSlot* thenFunction = mxArgv(2);

  mxTry(the) {

    /* THIS */

    mxPushSlot(mxThis);

    /* FUNCTION */

    mxPushSlot(thenFunction);

    mxCall();

    /* ARGUMENTS */

    mxPushSlot(resolveFunction);

    mxPushSlot(rejectFunction);

    mxRunCount(2);

    mxPop();

  }

  mxCatch(the) {

    fxRejectException(the, rejectFunction);

  }

}

void fxPromiseThen(txMachine* the, txSlot* promise, txSlot* onFullfilled, txSlot* onRejected, txSlot* resolveFunction, txSlot* rejectFunction)

{

  txSlot* reaction;

  txSlot* slot;

  txSlot* status;

  reaction = fxNewInstance(the);

  slot = reaction->next = fxNewSlot(the);

  slot->flag = XS_INTERNAL_FLAG;

  if (resolveFunction) {

    slot->kind = resolveFunction->kind;

    slot->value = resolveFunction->value;

  }

  slot = slot->next = fxNewSlot(the);

  slot->flag = XS_INTERNAL_FLAG;

  if (rejectFunction) {

    slot->kind = rejectFunction->kind;

    slot->value = rejectFunction->value;

  }

  slot = slot->next = fxNewSlot(the);

  slot->ID = mxID(__onFullfilled_);

  if (onFullfilled) {

    slot->kind = onFullfilled->kind;

    slot->value = onFullfilled->value;

  }

  slot = slot->next = fxNewSlot(the);

  slot->ID = mxID(__onRejected_);

  if (onRejected) {

    slot->kind = onRejected->kind;

    slot->value = onRejected->value;

  }

  if (resolveFunction) {

    slot = slot->next = fxNewSlot(the);

    slot->ID = mxID(__result_);

    slot->kind = mxResult->kind;

    slot->value = mxResult->value;

  }

  status = mxPromiseStatus(promise);

  if (status->value.integer == mxPendingStatus) {

    txSlot** address = &(mxPromiseThens(promise)->value.reference->next);

    while ((slot = *address)) 

      address = &(slot->next);

    slot = *address = fxNewSlot(the);

    slot->kind = XS_REFERENCE_KIND;

    slot->value.reference = reaction;

  }

  else {

    mxPushReference(reaction);

    if (status->value.integer == mxFulfilledStatus)

      mxPush(mxOnResolvedPromiseFunction);

    else

      mxPush(mxOnRejectedPromiseFunction);

    mxCall();

    slot = mxPromiseResult(promise);

    mxPushSlot(slot);

    fxQueueJob(the, 1, promise);

  }

  mxPop(); // reaction

}

void fxPushPromiseFunctions(txMachine* the, txSlot* promise)

{

  txSlot* resolve;

  txSlot* reject;

  txSlot* object;

  txSlot* slot;

  resolve = fxNewHostFunction(the, fxResolvePromise, 1, XS_NO_ID, mxResolvePromiseProfileID);

  reject = fxNewHostFunction(the, fxRejectPromise, 1, XS_NO_ID, mxRejectPromiseProfileID);

  slot = object = fxNewInstance(the);

  slot = object->next = fxNewSlot(the);

  slot->kind = XS_BOOLEAN_KIND;

  slot->value.boolean = 0;

  slot = slot->next = fxNewSlot(the);

  slot->kind = XS_REFERENCE_KIND;

  slot->value.reference = promise;

  slot = mxFunctionInstanceHome(resolve);

  slot->value.home.object = object;

  slot = mxFunctionInstanceHome(reject);

  slot->value.home.object = object;

  mxPop();

}

void fxRejectException(txMachine* the, txSlot* rejectFunction)

{

  /* THIS */

  mxPushUndefined();

  /* FUNCTION */

  mxPushSlot(rejectFunction);

  mxCall();

  /* ARGUMENTS */

  mxPush(mxException);

  mxException = mxUndefined;

  mxRunCount(1);

  mxPop();

}

void fxRejectPromise(txMachine* the)

{

  txSlot* slot;

  txSlot* promise;

  txSlot* argument;

  txSlot* result;

  slot = mxFunctionInstanceHome(mxFunction->value.reference)->value.home.object->next;

  if (slot->value.boolean)

    return;

  slot->value.boolean = 1;

  mxPushSlot(slot->next);

  promise = the->stack->value.reference;

  slot->next = C_NULL;

  if (mxArgc > 0)

    mxPushSlot(mxArgv(0));

  else

    mxPushUndefined();

  argument = the->stack;

#ifdef mxPromisePrint

  fprintf(stderr, "fxRejectPromise %d\n", promise->next->ID);

#endif

  result = mxPromiseResult(promise);

  result->kind = argument->kind;

  result->value = argument->value;

  slot = mxPromiseThens(promise)->value.reference->next;

  if (slot) {

    while (slot) {

      mxPushReference(slot->value.reference);

      mxPush(mxOnRejectedPromiseFunction);

      mxCall();

      mxPushSlot(argument);

      fxQueueJob(the, 1, promise);

      slot = slot->next;

    }

    mxPromiseThens(promise)->value.reference->next = C_NULL;

  }

  else {

    fxAddUnhandledRejection(the, promise);

  }

  slot = mxPromiseStatus(promise);

  slot->value.integer = mxRejectedStatus;

}

void fxResolvePromise(txMachine* the)

{

  txSlot* slot;

  txSlot* promise;

  txSlot* argument;

  txSlot* result;

  slot = mxFunctionInstanceHome(mxFunction->value.reference)->value.home.object->next;

  if (slot->value.boolean)

    return;

  slot->value.boolean = 1;

  mxPushSlot(slot->next);

  promise = the->stack->value.reference;

  slot->next = C_NULL;

  if (mxArgc > 0)

    mxPushSlot(mxArgv(0));

  else

    mxPushUndefined();

  argument = the->stack;  

#ifdef mxPromisePrint

  fprintf(stderr, "fxResolvePromise %d\n", promise->next->ID);

#endif

  mxTry(the) {

    if (mxIsReference(argument)) {

      if (argument->value.reference == promise)

        mxTypeError("promise resolves itself");

      mxPushSlot(argument);

      mxGetID(mxID(_then));

      slot = the->stack;

      if (fxIsCallable(the, slot)) {

#ifdef mxPromisePrint

  fprintf(stderr, "fxResolvePromise then %d\n", promise->next->ID);

#endif

        mxPushSlot(argument);

        mxPush(mxOnThenableFunction);

        mxCall();

        fxPushPromiseFunctions(the, promise);

        mxPushSlot(slot);

        fxQueueJob(the, 3, promise);

        goto bail;

      }

      mxPop();

    }

    result = mxPromiseResult(promise);

    result->kind = argument->kind;

    result->value = argument->value;

    slot = mxPromiseThens(promise)->value.reference->next;

    while (slot) {

      mxPushReference(slot->value.reference);

      mxPush(mxOnResolvedPromiseFunction);

      mxCall();

      mxPushSlot(result);

      fxQueueJob(the, 1, promise);

      slot = slot->next;

    }

    mxPromiseThens(promise)->value.reference->next = C_NULL;

    slot = mxPromiseStatus(promise);

    slot->value.integer = mxFulfilledStatus;

  }

bail:

  mxCatch(the) {

    result = mxPromiseResult(promise);

    result->kind = mxException.kind;

    result->value = mxException.value;

    mxException = mxUndefined;

    slot = mxPromiseThens(promise)->value.reference->next;

    if (slot) {

      while (slot) {

        mxPushReference(slot->value.reference);

        mxPush(mxOnRejectedPromiseFunction);

        mxCall();

        mxPushSlot(result);

        fxQueueJob(the, 1, promise);

        slot = slot->next;

      }

      mxPromiseThens(promise)->value.reference->next = C_NULL;

    }

    else {

      fxAddUnhandledRejection(the, promise);

    }

    slot = mxPromiseStatus(promise);

    slot->value.integer = mxRejectedStatus;

  }

}

void fx_Promise(txMachine* the)

{

  txSlot* stack = the->stack;

  txSlot* promise;

  txSlot* argument;

  txSlot* status;

  txSlot* resolveFunction;

  txSlot* rejectFunction;

  if (mxIsUndefined(mxTarget))

    mxTypeError("call: Promise");

  if (mxArgc < 1)

    mxTypeError("no executor");

  argument = mxArgv(0);

  if (!fxIsCallable(the, argument))

    mxTypeError("executor: not a function");

  mxPushSlot(mxTarget);

  fxGetPrototypeFromConstructor(the, &mxPromisePrototype);

  promise = fxNewPromiseInstance(the);

#ifdef mxPromisePrint

  fprintf(stderr, "fx_Promise %d\n", promise->next->ID);

#endif

  mxPullSlot(mxResult);

  status = mxPromiseStatus(promise);

  status->value.integer = mxPendingStatus;

  fxPushPromiseFunctions(the, promise);

  resolveFunction = the->stack + 1;

  rejectFunction = the->stack;

  {

    mxTry(the) {

      /* THIS */

      mxPushUndefined();

      /* FUNCTION */

      mxPushSlot(argument);

      mxCall();

      /* ARGUMENTS */

      mxPushSlot(resolveFunction);

      mxPushSlot(rejectFunction);

      mxRunCount(2);

    }

    mxCatch(the) {

      fxRejectException(the, rejectFunction);