#!/bin/sh
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | www.openfoam.com
#    \\/     M anipulation  |
#-------------------------------------------------------------------------------
#     Copyright (C) 2015 OpenFOAM Foundation
#     Copyright (C) 2020 DLR
#------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
#
# Script
#     foamSequenceVTKFiles
#
# Description
#     Creates symbolic links to all VTK files in a post-processing directory
#     Links form a sequence like name.0000.vtk, name.0001.vtk, etc.
#     Paraview recognises link names as a sequence which can be animated.
#     The sequence of links can be used to create a video from the images.
#     - Default directory name for VTK files is postProcessing
#
#------------------------------------------------------------------------------
usage () {
    exec 1>&2
    while [ "$#" -ge 1 ]; do echo "$1"; shift; done
    cat <<USAGE

Usage: ${0##*/} [OPTIONS] ...
options:
  -c | -case <dir>    specify case directory (default = local dir)
  -d | -dir <dir>     post-processing directory <dir> (default = postProcessing)
  -o | -out <dir>     output links directory <dir> (default = sequencedVTK)
  -vtk                create sequence of vtk files (default)
  -vtp                create sequence of vtp files
  -vtu                create sequence of vtu files
  -h | -help          help

Creates symbolic links to all VTK files in a post-processing directory
Links form a sequence like name.0000.vtk, name.0001.vtk, etc.
Paraview recognises the link names as a sequence which can be opened and played.
The sequence of links to images can be used to create a video from the images.
- Default directory name for VTK files is postProcessing

USAGE
    exit 1
}

# Set defaults
DIR=postProcessing
OUT=sequencedVTK
fileType=vtk

while [ "$#" -gt 0 ]
do
   case "$1" in
   -h | -help*)
      usage
      ;;
   -c | -case)
      [ "$#" -ge 2 ] || usage "'$1' option requires an argument"
      cd "$2" 2>/dev/null || usage "directory does not exist:  '$2'"
      shift
      ;;
   -d | -dir)
      [ "$#" -ge 2 ] || usage "'$1' option requires an argument"
      DIR=$2
      shift
      ;;
   -o | -out)
      [ "$#" -ge 2 ] || usage "'$1' option requires an argument"
      OUT=$2
      shift 2
      ;;
   -vtk | -vtp | -vtu)
      fileType="${1#-}"
      ;;
   -*)
      usage "invalid option '$1'"
      ;;
   *)
      break
      ;;
    esac
    shift
done

if [ ! -d $DIR ]; then
    echo "Cannot find postProcessing directory, exiting."
    exit 0
fi

FILES=$(find $DIR -name "*.$fileType" -type f)
NAMES=$(for f in $FILES; do basename $f .$fileType; done | sort -u)

if [ -d $OUT ]; then
    echo "$OUT directory already exists.  Deleting links within it..."
    rm -rf $OUT/*
else
    echo "Creating $OUT directory..."
    mkdir $OUT
fi

for N in $NAMES
do
    echo "Sequencing all $fileType files named $N.$fileType"

    # Create list of VTK (vtk, vtp, vtu) files, ordered by time step
    FILE_LIST=$(echo $FILES | \
        tr " " "\n" | \
        grep $N.$fileType | \
        awk -F'/' '{print($(NF-1)" "$0)}' | \
        sort -k 1 -g | \
        cut -d' ' -f2)

    i=0
    for F in $FILE_LIST
    do
        i=$(expr $i + 1) # Relies on ordered list of $sourceFiles
        LINK=$(printf "${N}.%04d.$fileType" $i)
        ln -s ../$F $OUT/$LINK
    done
done

# -----------------------------------------------------------------------------