#include <engine.h>   /* Matlab include file */
#include <petscsys.h>
#include <petscmatlab.h>               /*I   "petscmatlab.h"  I*/
#include <petsc/private/petscimpl.h>

struct  _p_PetscMatlabEngine {
  PETSCHEADER(int);
  Engine *ep;
  char   buffer[1024];
};

PetscClassId MATLABENGINE_CLASSID = -1;

/*@C
    PetscMatlabEngineCreate - Creates a MATLAB engine object

    Not Collective

    Input Parameters:
+   comm - a separate MATLAB engine is started for each process in the communicator
-   machine - name of machine where MATLAB engine is to be run (usually NULL)

    Output Parameter:
.   mengine - the resulting object

   Options Database:
.    -matlab_engine_graphics - allow the MATLAB engine to display graphics

   Level: advanced

.seealso: PetscMatlabEngineDestroy(), PetscMatlabEnginePut(), PetscMatlabEngineGet(),
          PetscMatlabEngineEvaluate(), PetscMatlabEngineGetOutput(), PetscMatlabEnginePrintOutput(),
          PETSC_MATLAB_ENGINE_(), PetscMatlabEnginePutArray(), PetscMatlabEngineGetArray(), PetscMatlabEngine
@*/
PetscErrorCode  PetscMatlabEngineCreate(MPI_Comm comm,const char machine[],PetscMatlabEngine *mengine)
{
  PetscErrorCode    ierr;
  PetscMPIInt       rank,size;
  char              buffer[256];
  PetscMatlabEngine e;
  PetscBool         flg = PETSC_FALSE,mgiven = PETSC_TRUE;

  PetscFunctionBegin;
  if (MATLABENGINE_CLASSID == -1) {
    ierr = PetscClassIdRegister("MATLAB Engine",&MATLABENGINE_CLASSID);CHKERRQ(ierr);
  }
  ierr = PetscOptionsGetBool(NULL,NULL,"-matlab_engine_graphics",&flg,NULL);CHKERRQ(ierr);

  ierr = PetscHeaderCreate(e,MATLABENGINE_CLASSID,"MatlabEngine","MATLAB Engine","Sys",comm,PetscMatlabEngineDestroy,NULL);CHKERRQ(ierr);

  if (!machine) {
    machine = "\0";
    mgiven  = PETSC_FALSE;
  }
  ierr = PetscStrncpy(buffer,PETSC_MATLAB_COMMAND,sizeof(buffer));CHKERRQ(ierr);
  if (!flg) {
    ierr = PetscStrlcat(buffer," -nodisplay ",sizeof(buffer));CHKERRQ(ierr);
  }
  ierr  = PetscStrlcat(buffer," -nosplash ",sizeof(buffer));CHKERRQ(ierr);
  if (mgiven) {
    ierr  = PetscInfo2(0,"Starting MATLAB engine on %s with command %s\n",machine,buffer);CHKERRQ(ierr);
  } else {
    ierr  = PetscInfo1(0,"Starting MATLAB engine with command %s\n",buffer);CHKERRQ(ierr);
  }
  e->ep = engOpen(buffer);
  if (!e->ep) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Unable to start MATLAB engine on %s",machine);
  engOutputBuffer(e->ep,e->buffer,1024);

  ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
  ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
  sprintf(buffer,"MPI_Comm_rank = %d; MPI_Comm_size = %d;\n",rank,size);
  engEvalString(e->ep, buffer);
  if (mgiven) {
    ierr = PetscInfo1(0,"Started MATLAB engine on %s\n",machine);CHKERRQ(ierr);
  } else {
    ierr = PetscInfo(0,"Started MATLAB engine\n");CHKERRQ(ierr);
  }
  *mengine = e;
  PetscFunctionReturn(0);
}

/*@
   PetscMatlabEngineDestroy - Shuts down a Matlab engine.

   Collective on PetscMatlabEngine

   Input Parameters:
.  e  - the engine

   Level: advanced

.seealso: PetscMatlabEnginCreate(), PetscMatlabEnginePut(), PetscMatlabEngineGet(),
          PetscMatlabEngineEvaluate(), PetscMatlabEngineGetOutput(), PetscMatlabEnginePrintOutput(),
          PETSC_MATLAB_ENGINE_(), PetscMatlabEnginePutArray(), PetscMatlabEngineGetArray(), PetscMatlabEngine
@*/
PetscErrorCode  PetscMatlabEngineDestroy(PetscMatlabEngine *v)
{
  PetscErrorCode ierr;

  PetscFunctionBegin;
  if (!*v) PetscFunctionReturn(0);
  PetscValidHeaderSpecific(*v,MATLABENGINE_CLASSID,1);
  if (--((PetscObject)(*v))->refct > 0) PetscFunctionReturn(0);
  ierr = PetscInfo(0,"Stopping MATLAB engine\n");CHKERRQ(ierr);
  ierr = engClose((*v)->ep);
  if (ierr) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error closing Matlab engine");
  ierr = PetscInfo(0,"MATLAB engine stopped\n");CHKERRQ(ierr);
  ierr = PetscHeaderDestroy(v);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

/*@C
    PetscMatlabEngineEvaluate - Evaluates a string in MATLAB

    Not Collective

    Input Parameters:
+   mengine - the MATLAB engine
-   string - format as in a printf()

   Level: advanced

.seealso: PetscMatlabEngineDestroy(), PetscMatlabEnginePut(), PetscMatlabEngineGet(),
          PetscMatlabEngineCreate(), PetscMatlabEngineGetOutput(), PetscMatlabEnginePrintOutput(),
          PETSC_MATLAB_ENGINE_(), PetscMatlabEnginePutArray(), PetscMatlabEngineGetArray(), PetscMatlabEngine
@*/
PetscErrorCode  PetscMatlabEngineEvaluate(PetscMatlabEngine mengine,const char string[],...)
{
  va_list        Argp;
  char           buffer[1024];
  PetscErrorCode ierr;
  size_t         fullLength;

  PetscFunctionBegin;
  va_start(Argp,string);
  ierr = PetscVSNPrintf(buffer,1024-9-5,string,&fullLength,Argp);CHKERRQ(ierr);
  va_end(Argp);

  ierr = PetscInfo1(0,"Evaluating MATLAB string: %s\n",buffer);CHKERRQ(ierr);
  engEvalString(mengine->ep, buffer);

  /*
     Check for error in MATLAB: indicated by ? as first character in engine->buffer
  */
  if (mengine->buffer[4] == '?') SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB,"Error in evaluating MATLAB command:%s\n%s",string,mengine->buffer);

  ierr = PetscInfo1(0,"Done evaluating Matlab string: %s\n",buffer);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

/*@C
    PetscMatlabEngineGetOutput - Gets a string buffer where the MATLAB output is
          printed

    Not Collective

    Input Parameter:
.   mengine - the MATLAB engine

    Output Parameter:
.   string - buffer where MATLAB output is printed

   Level: advanced

.seealso: PetscMatlabEngineDestroy(), PetscMatlabEnginePut(), PetscMatlabEngineGet(),
          PetscMatlabEngineEvaluate(), PetscMatlabEngineCreate(), PetscMatlabEnginePrintOutput(),
          PETSC_MATLAB_ENGINE_(), PetscMatlabEnginePutArray(), PetscMatlabEngineGetArray(), PetscMatlabEngine
@*/
PetscErrorCode  PetscMatlabEngineGetOutput(PetscMatlabEngine mengine,char **string)
{
  PetscFunctionBegin;
  *string = mengine->buffer;
  PetscFunctionReturn(0);
}

/*@C
    PetscMatlabEnginePrintOutput - prints the output from MATLAB

    Collective on PetscMatlabEngine

    Input Parameters:
.    mengine - the Matlab engine

   Level: advanced

.seealso: PetscMatlabEngineDestroy(), PetscMatlabEnginePut(), PetscMatlabEngineGet(),
          PetscMatlabEngineEvaluate(), PetscMatlabEngineGetOutput(), PetscMatlabEngineCreate(),
          PETSC_MATLAB_ENGINE_(), PetscMatlabEnginePutArray(), PetscMatlabEngineGetArray(), PetscMatlabEngine
@*/
PetscErrorCode  PetscMatlabEnginePrintOutput(PetscMatlabEngine mengine,FILE *fd)
{
  PetscErrorCode ierr;
  PetscMPIInt    rank;

  PetscFunctionBegin;
  ierr = MPI_Comm_rank(PetscObjectComm((PetscObject)mengine),&rank);CHKERRQ(ierr);
  ierr = PetscSynchronizedFPrintf(PetscObjectComm((PetscObject)mengine),fd,"[%d]%s",rank,mengine->buffer);CHKERRQ(ierr);
  ierr = PetscSynchronizedFlush(PetscObjectComm((PetscObject)mengine),fd);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

/*@
    PetscMatlabEnginePut - Puts a Petsc object into the MATLAB space. For parallel objects,
      each processors part is put in a separate  MATLAB process.

    Collective on PetscObject

    Input Parameters:
+    mengine - the MATLAB engine
-    object - the PETSc object, for example Vec

   Level: advanced

   Note: Mats transfered between PETSc and MATLAB and vis versa are transposed in the other space
         (this is because MATLAB uses compressed column format and PETSc uses compressed row format)

.seealso: PetscMatlabEngineDestroy(), PetscMatlabEngineCreate(), PetscMatlabEngineGet(),
          PetscMatlabEngineEvaluate(), PetscMatlabEngineGetOutput(), PetscMatlabEnginePrintOutput(),
          PETSC_MATLAB_ENGINE_(), PetscMatlabEnginePutArray(), MatlabEngineGetArray(), PetscMatlabEngine
@*/
PetscErrorCode  PetscMatlabEnginePut(PetscMatlabEngine mengine,PetscObject obj)
{
  PetscErrorCode ierr,(*put)(PetscObject,void*);

  PetscFunctionBegin;
  ierr = PetscObjectQueryFunction(obj,"PetscMatlabEnginePut_C",&put);CHKERRQ(ierr);
  if (!put) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Object %s cannot be put into MATLAB engine",obj->class_name);
  ierr = PetscInfo(0,"Putting MATLAB object\n");CHKERRQ(ierr);
  ierr = (*put)(obj,mengine->ep);CHKERRQ(ierr);
  ierr = PetscInfo1(0,"Put MATLAB object: %s\n",obj->name);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

/*@
    PetscMatlabEngineGet - Gets a variable from MATLAB into a PETSc object.

    Collective on PetscObject

    Input Parameters:
+    mengine - the MATLAB engine
-    object - the PETSc object, for example Vec

   Level: advanced

   Note: Mats transfered between PETSc and MATLAB and vis versa are transposed in the other space
         (this is because MATLAB uses compressed column format and PETSc uses compressed row format)

.seealso: PetscMatlabEngineDestroy(), PetscMatlabEnginePut(), PetscMatlabEngineCreate(),
          PetscMatlabEngineEvaluate(), PetscMatlabEngineGetOutput(), PetscMatlabEnginePrintOutput(),
          PETSC_MATLAB_ENGINE_(), PetscMatlabEnginePutArray(), MatlabEngineGetArray(), PetscMatlabEngine
@*/
PetscErrorCode  PetscMatlabEngineGet(PetscMatlabEngine mengine,PetscObject obj)
{
  PetscErrorCode ierr,(*get)(PetscObject,void*);

  PetscFunctionBegin;
  if (!obj->name) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Cannot get object that has no name");
  ierr = PetscObjectQueryFunction(obj,"PetscMatlabEngineGet_C",&get);CHKERRQ(ierr);
  if (!get) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Object %s cannot be gotten from MATLAB engine",obj->class_name);
  ierr = PetscInfo(0,"Getting MATLAB object\n");CHKERRQ(ierr);
  ierr = (*get)(obj,mengine->ep);CHKERRQ(ierr);
  ierr = PetscInfo1(0,"Got MATLAB object: %s\n",obj->name);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

/*
    The variable Petsc_Matlab_Engine_keyval is used to indicate an MPI attribute that
  is attached to a communicator, in this case the attribute is a PetscMatlabEngine
*/
static PetscMPIInt Petsc_Matlab_Engine_keyval = MPI_KEYVAL_INVALID;


/*@C
   PETSC_MATLAB_ENGINE_ - Creates a matlab engine shared by all processors
                    in a communicator.

   Not Collective

   Input Parameter:
.  comm - the MPI communicator to share the engine

   Level: developer

   Notes:
   Unlike almost all other PETSc routines, this does not return
   an error code. Usually used in the form
$      PetscMatlabEngineYYY(XXX object,PETSC_MATLAB_ENGINE_(comm));

.seealso: PetscMatlabEngineDestroy(), PetscMatlabEnginePut(), PetscMatlabEngineGet(),
          PetscMatlabEngineEvaluate(), PetscMatlabEngineGetOutput(), PetscMatlabEnginePrintOutput(),
          PetscMatlabEngineCreate(), PetscMatlabEnginePutArray(), PetscMatlabEngineGetArray(), PetscMatlabEngine,
          PETSC_MATLAB_ENGINE_WORLD, PETSC_MATLAB_ENGINE_SELF

@*/
PetscMatlabEngine  PETSC_MATLAB_ENGINE_(MPI_Comm comm)
{
  PetscErrorCode    ierr;
  PetscBool         flg;
  PetscMatlabEngine mengine;

  PetscFunctionBegin;
  if (Petsc_Matlab_Engine_keyval == MPI_KEYVAL_INVALID) {
    ierr = MPI_Comm_create_keyval(MPI_COMM_NULL_COPY_FN,MPI_COMM_NULL_DELETE_FN,&Petsc_Matlab_Engine_keyval,0);
    if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_MATLAB_ENGINE_",__FILE__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," "); mengine = 0;}
  }
  ierr = MPI_Comm_get_attr(comm,Petsc_Matlab_Engine_keyval,(void**)&mengine,(int*)&flg);
  if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_MATLAB_ENGINE_",__FILE__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," "); mengine = 0;}
  if (!flg) { /* viewer not yet created */
    char *machinename = 0,machine[64];

    ierr = PetscOptionsGetString(NULL,NULL,"-matlab_engine_machine",machine,64,&flg);
    if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_MATLAB_ENGINE_",__FILE__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," "); mengine = 0;}
    if (flg) machinename = machine;
    ierr = PetscMatlabEngineCreate(comm,machinename,&mengine);
    if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_MATLAB_ENGINE_",__FILE__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," "); mengine = 0;}
    ierr = PetscObjectRegisterDestroy((PetscObject)mengine);
    if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_MATLAB_ENGINE_",__FILE__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," "); mengine = 0;}
    ierr = MPI_Comm_set_attr(comm,Petsc_Matlab_Engine_keyval,mengine);
    if (ierr) {PetscError(PETSC_COMM_SELF,__LINE__,"PETSC_MATLAB_ENGINE_",__FILE__,PETSC_ERR_PLIB,PETSC_ERROR_INITIAL," "); mengine = 0;}
  }
  PetscFunctionReturn(mengine);
}

/*@C
    PetscMatlabEnginePutArray - Puts an array into the MATLAB space, treating it as a Fortran style (column major ordering) array. For parallel objects,
      each processors part is put in a separate  MATLAB process.

    Collective on PetscObject

    Input Parameters:
+    mengine - the MATLAB engine
.    m,n - the dimensions of the array
.    array - the array (represented in one dimension)
-    name - the name of the array

   Level: advanced

.seealso: PetscMatlabEngineDestroy(), PetscMatlabEngineCreate(), PetscMatlabEngineGet(),
          PetscMatlabEngineEvaluate(), PetscMatlabEngineGetOutput(), PetscMatlabEnginePrintOutput(),
          PETSC_MATLAB_ENGINE_(), PetscMatlabEnginePut(), MatlabEngineGetArray(), PetscMatlabEngine
@*/
PetscErrorCode  PetscMatlabEnginePutArray(PetscMatlabEngine mengine,int m,int n,const PetscScalar *array,const char name[])
{
  PetscErrorCode ierr;
  mxArray        *mat;

  PetscFunctionBegin;
  ierr = PetscInfo1(0,"Putting MATLAB array %s\n",name);CHKERRQ(ierr);
#if !defined(PETSC_USE_COMPLEX)
  mat = mxCreateDoubleMatrix(m,n,mxREAL);
#else
  mat = mxCreateDoubleMatrix(m,n,mxCOMPLEX);
#endif
  ierr = PetscArraycpy(mxGetPr(mat),array,m*n);CHKERRQ(ierr);
  engPutVariable(mengine->ep,name,mat);

  ierr = PetscInfo1(0,"Put MATLAB array %s\n",name);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

/*@C
    PetscMatlabEngineGetArray - Gets a variable from Matlab into an array

    Not Collective

    Input Parameters:
+    mengine - the Matlab engine
.    m,n - the dimensions of the array
.    array - the array (represented in one dimension)
-    name - the name of the array

   Level: advanced

.seealso: PetscMatlabEngineDestroy(), PetscMatlabEnginePut(), PetscMatlabEngineCreate(),
          PetscMatlabEngineEvaluate(), PetscMatlabEngineGetOutput(), PetscMatlabEnginePrintOutput(),
          PETSC_MATLAB_ENGINE_(), PetscMatlabEnginePutArray(), PetscMatlabEngineGet(), PetscMatlabEngine
@*/
PetscErrorCode  PetscMatlabEngineGetArray(PetscMatlabEngine mengine,int m,int n,PetscScalar *array,const char name[])
{
  PetscErrorCode ierr;
  mxArray        *mat;

  PetscFunctionBegin;
  ierr = PetscInfo1(0,"Getting MATLAB array %s\n",name);CHKERRQ(ierr);
  mat  = engGetVariable(mengine->ep,name);
  if (!mat) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_LIB,"Unable to get array %s from matlab",name);
  ierr = PetscArraycpy(array,mxGetPr(mat),m*n);CHKERRQ(ierr);
  ierr = PetscInfo1(0,"Got MATLAB array %s\n",name);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}