#include <petsc/private/dmnetworkimpl.h> /*I  "petscdmnetwork.h"  I*/

static PetscErrorCode DMView_Network_CSV(DM dm, PetscViewer viewer)
{
  DM              dmcoords;
  PetscInt        nsubnets, i, subnet, nvertices, nedges, vertex, edge;
  PetscInt        vertexOffsets[2], globalEdgeVertices[2];
  PetscScalar     vertexCoords[2];
  const PetscInt *vertices, *edges, *edgeVertices;
  Vec             allVertexCoords;
  PetscMPIInt     rank;
  MPI_Comm        comm;

  PetscFunctionBegin;
  // Get the network containing coordinate information
  PetscCall(DMGetCoordinateDM(dm, &dmcoords));
  // Get the coordinate vector for the network
  PetscCall(DMGetCoordinatesLocal(dm, &allVertexCoords));
  // Get the MPI communicator and this process' rank
  PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
  PetscCallMPI(MPI_Comm_rank(comm, &rank));
  // Start synchronized printing
  PetscCall(PetscViewerASCIIPushSynchronized(viewer));

  // Write the header
  PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "Type,Rank,ID,X,Y,Z,Name,Color\n"));

  // Iterate each subnetwork (Note: We need to get the global number of subnets apparently)
  PetscCall(DMNetworkGetNumSubNetworks(dm, NULL, &nsubnets));
  for (subnet = 0; subnet < nsubnets; subnet++) {
    // Get the subnetwork's vertices and edges
    PetscCall(DMNetworkGetSubnetwork(dm, subnet, &nvertices, &nedges, &vertices, &edges));

    // Write out each vertex
    for (i = 0; i < nvertices; i++) {
      vertex = vertices[i];
      // Get the offset into the coordinate vector for the vertex
      PetscCall(DMNetworkGetLocalVecOffset(dmcoords, vertex, ALL_COMPONENTS, vertexOffsets));
      vertexOffsets[1] = vertexOffsets[0] + 1;
      // Remap vertex to the global value
      PetscCall(DMNetworkGetGlobalVertexIndex(dm, vertex, &vertex));
      // Get the vertex position from the coordinate vector
      PetscCall(VecGetValues(allVertexCoords, 2, vertexOffsets, vertexCoords));

      // TODO: Determine vertex color/name
      PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "Node,%" PetscInt_FMT ",%" PetscInt_FMT ",%lf,%lf,0,%" PetscInt_FMT "\n", (PetscInt)rank, vertex, (double)PetscRealPart(vertexCoords[0]), (double)PetscRealPart(vertexCoords[1]), vertex));
    }

    // Write out each edge
    for (i = 0; i < nedges; i++) {
      edge = edges[i];
      PetscCall(DMNetworkGetConnectedVertices(dm, edge, &edgeVertices));
      PetscCall(DMNetworkGetGlobalVertexIndex(dm, edgeVertices[0], &globalEdgeVertices[0]));
      PetscCall(DMNetworkGetGlobalVertexIndex(dm, edgeVertices[1], &globalEdgeVertices[1]));
      PetscCall(DMNetworkGetGlobalEdgeIndex(dm, edge, &edge));

      // TODO: Determine edge color/name
      PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "Edge,%" PetscInt_FMT ",%" PetscInt_FMT ",%" PetscInt_FMT ",%" PetscInt_FMT ",0,%" PetscInt_FMT "\n", (PetscInt)rank, edge, globalEdgeVertices[0], globalEdgeVertices[1], edge));
    }
  }
  // End synchronized printing
  PetscCall(PetscViewerFlush(viewer));
  PetscCall(PetscViewerASCIIPopSynchronized(viewer));
  PetscFunctionReturn(PETSC_SUCCESS);
}

#include <petscdraw.h>
static PetscErrorCode DMView_Network_Matplotlib(DM dm, PetscViewer viewer)
{
  PetscMPIInt rank, size, rank2;
  MPI_Comm    comm;
  char        filename[PETSC_MAX_PATH_LEN + 1], proccall[PETSC_MAX_PATH_LEN + 500], scriptFile[PETSC_MAX_PATH_LEN + 1], streamBuffer[256];
  PetscViewer csvViewer;
  FILE       *processFile = NULL;
  PetscBool   isnull;
  PetscDraw   draw;

  PetscFunctionBegin;
  // Deal with the PetscDraw we are given
  PetscCall(PetscViewerDrawGetDraw(viewer, 1, &draw));
  PetscCall(PetscDrawIsNull(draw, &isnull));
  PetscCall(PetscDrawSetVisible(draw, PETSC_FALSE));

  // Clear the file name buffer so all communicated bytes are well-defined
  PetscCall(PetscMemzero(filename, sizeof(filename)));

  // Get the MPI communicator and this process' rank
  PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
  PetscCallMPI(MPI_Comm_rank(comm, &rank));
  PetscCallMPI(MPI_Comm_size(comm, &size));

  // Generate and broadcast the temporary file name from rank 0
  if (rank == 0) {
#if defined(PETSC_HAVE_TMPNAM_S)
    // Acquire a temporary file to write to and open an ASCII/CSV viewer
    PetscCheck(tmpnam_s(filename, sizeof(filename)) == 0, comm, PETSC_ERR_SYS, "Could not acquire temporary file");
#elif defined(PETSC_HAVE_MKSTEMP) && __STDC_VERSION__ > 199901L
    size_t numChars;
    // Same thing, but for POSIX systems on which tmpnam is deprecated
    // Note: Configure may detect mkstemp but it will not be defined if compiling for C99, so check additional defines to see if we can use it
    PetscCall(PetscStrcpy(filename, "/tmp/"));
    // Mkstemp requires us to explicitly specify part of the path, but some systems may not like putting files in /tmp/ so have an option for it
    PetscCall(PetscOptionsGetString(NULL, NULL, "-dmnetwork_view_tmpdir", filename, sizeof(filename), NULL));
    // Make sure the filename ends with a '/'
    PetscCall(PetscStrlen(filename, &numChars));
    if (filename[numChars - 1] != '/') {
      filename[numChars]     = '/';
      filename[numChars + 1] = 0;
    }
    // Perform the actual temporary file creation
    PetscCall(PetscStrcat(filename, "XXXXXX"));
    PetscCheck(mkstemp(filename) != -1, comm, PETSC_ERR_SYS, "Could not acquire temporary file");
#else
    // Same thing, but for older C versions which don't have the safe form
    PetscCheck(tmpnam(filename) != NULL, comm, PETSC_ERR_SYS, "Could not acquire temporary file");
#endif
    // Broadcast the filename to all other MPI ranks
    for (rank2 = 1; rank2 < size; rank2++) PetscCallMPI(MPI_Send(filename, PETSC_MAX_PATH_LEN, MPI_BYTE, rank2, 0, comm));
  } else {
    // Receive the file name
    PetscCallMPI(MPI_Recv(filename, PETSC_MAX_PATH_LEN, MPI_BYTE, 0, 0, comm, MPI_STATUS_IGNORE));
  }

  PetscCall(PetscViewerASCIIOpen(PETSC_COMM_WORLD, filename, &csvViewer));
  PetscCall(PetscViewerPushFormat(csvViewer, PETSC_VIEWER_ASCII_CSV));

  // Use the CSV viewer to write out the local network
  PetscCall(DMView_Network_CSV(dm, csvViewer));

  // Close the viewer
  PetscCall(PetscViewerDestroy(&csvViewer));

  // Get the value of $PETSC_DIR
  PetscCall(PetscStrreplace(PETSC_COMM_WORLD, "${PETSC_DIR}/share/petsc/bin/dmnetwork_view.py", scriptFile, sizeof(scriptFile)));
  PetscCall(PetscFixFilename(scriptFile, scriptFile));
  // Generate the system call for 'python3 $PETSC_DIR/share/petsc/dmnetwork_view.py <file>'
  PetscCall(PetscArrayzero(proccall, sizeof(proccall)));
  PetscCall(PetscSNPrintf(proccall, sizeof(proccall), "%s %s %s %s", PETSC_PYTHON_EXE, scriptFile, (isnull ? "-tx" : ""), filename));

#if defined(PETSC_HAVE_POPEN)
  // Perform the call to run the python script (Note: while this is called on all ranks POpen will only run on rank 0)
  PetscCall(PetscPOpen(PETSC_COMM_WORLD, NULL, proccall, "r", &processFile));
  if (processFile != NULL) {
    while (fgets(streamBuffer, sizeof(streamBuffer), processFile) != NULL) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%s", streamBuffer));
  }
  PetscCall(PetscPClose(PETSC_COMM_WORLD, processFile));
#else
  // Same thing, but using the standard library for systems that don't have POpen/PClose (only run on rank 0)
  if (rank == 0) {
    PetscCheck(system(proccall) == 0, comm, PETSC_ERR_SYS, "Failed to call viewer script");
    // Barrier so that all ranks wait until the call completes
    PetscCallMPI(MPI_Barrier(PETSC_COMM_WORLD));
  }
#endif
  // Clean up the temporary file we used using rank 0
  if (rank == 0) PetscCheck(remove(filename) == 0, comm, PETSC_ERR_SYS, "Failed to delete temporary file");
  PetscFunctionReturn(PETSC_SUCCESS);
}

PetscErrorCode DMView_Network(DM dm, PetscViewer viewer)
{
  PetscBool         iascii, isdraw;
  PetscViewerFormat format;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
  PetscValidHeaderSpecific(viewer, PETSC_VIEWER_CLASSID, 2);
  PetscCall(PetscViewerGetFormat(viewer, &format));

  PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERDRAW, &isdraw));
  if (isdraw) {
    PetscCall(DMView_Network_Matplotlib(dm, viewer));
    PetscFunctionReturn(PETSC_SUCCESS);
  }

  PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
  if (iascii) {
    const PetscInt *cone, *vtx, *edges;
    PetscInt        vfrom, vto, i, j, nv, ne, nsv, p, nsubnet;
    DM_Network     *network = (DM_Network *)dm->data;
    PetscMPIInt     rank;

    PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
    if (format == PETSC_VIEWER_ASCII_CSV) {
      PetscCall(DMView_Network_CSV(dm, viewer));
      PetscFunctionReturn(PETSC_SUCCESS);
    }

    nsubnet = network->cloneshared->Nsubnet; /* num of subnetworks */
    if (!rank) {
      PetscCall(PetscPrintf(PETSC_COMM_SELF, "  NSubnets: %" PetscInt_FMT "; NEdges: %" PetscInt_FMT "; NVertices: %" PetscInt_FMT "; NSharedVertices: %" PetscInt_FMT ".\n", nsubnet, network->cloneshared->NEdges, network->cloneshared->NVertices,
                            network->cloneshared->Nsvtx));
    }

    PetscCall(DMNetworkGetSharedVertices(dm, &nsv, NULL));
    PetscCall(PetscViewerASCIIPushSynchronized(viewer));
    PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "  [%d] nEdges: %" PetscInt_FMT "; nVertices: %" PetscInt_FMT "; nSharedVertices: %" PetscInt_FMT "\n", rank, network->cloneshared->nEdges, network->cloneshared->nVertices, nsv));

    for (i = 0; i < nsubnet; i++) {
      PetscCall(DMNetworkGetSubnetwork(dm, i, &nv, &ne, &vtx, &edges));
      if (ne) {
        PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "     Subnet %" PetscInt_FMT ": nEdges %" PetscInt_FMT ", nVertices(include shared vertices) %" PetscInt_FMT "\n", i, ne, nv));
        for (j = 0; j < ne; j++) {
          p = edges[j];
          PetscCall(DMNetworkGetConnectedVertices(dm, p, &cone));
          PetscCall(DMNetworkGetGlobalVertexIndex(dm, cone[0], &vfrom));
          PetscCall(DMNetworkGetGlobalVertexIndex(dm, cone[1], &vto));
          PetscCall(DMNetworkGetGlobalEdgeIndex(dm, edges[j], &p));
          PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "       edge %" PetscInt_FMT ": %" PetscInt_FMT " ----> %" PetscInt_FMT "\n", p, vfrom, vto));
        }
      }
    }

    /* Shared vertices */
    PetscCall(DMNetworkGetSharedVertices(dm, NULL, &vtx));
    if (nsv) {
      PetscInt        gidx;
      PetscBool       ghost;
      const PetscInt *sv = NULL;

      PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "     SharedVertices:\n"));
      for (i = 0; i < nsv; i++) {
        PetscCall(DMNetworkIsGhostVertex(dm, vtx[i], &ghost));
        if (ghost) continue;

        PetscCall(DMNetworkSharedVertexGetInfo(dm, vtx[i], &gidx, &nv, &sv));
        PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "       svtx %" PetscInt_FMT ": global index %" PetscInt_FMT ", subnet[%" PetscInt_FMT "].%" PetscInt_FMT " ---->\n", i, gidx, sv[0], sv[1]));
        for (j = 1; j < nv; j++) PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "                                           ----> subnet[%" PetscInt_FMT "].%" PetscInt_FMT "\n", sv[2 * j], sv[2 * j + 1]));
      }
    }
    PetscCall(PetscViewerFlush(viewer));
    PetscCall(PetscViewerASCIIPopSynchronized(viewer));
  } else PetscCheck(iascii, PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Viewer type %s not yet supported for DMNetwork writing", ((PetscObject)viewer)->type_name);
  PetscFunctionReturn(PETSC_SUCCESS);
}