#!/bin/sh
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     | Website:  https://openfoam.org
#   \\  /    A nd           | Copyright (C) 2015-2025 OpenFOAM Foundation
#    \\/     M anipulation  |
#------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM.
#
#     OpenFOAM is free software: you can redistribute it and/or modify it
#     under the terms of the GNU General Public License as published by
#     the Free Software Foundation, either version 3 of the License, or
#     (at your option) any later version.
#
#     OpenFOAM 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 General Public License
#     for more details.
#
#     You should have received a copy of the GNU General Public License
#     along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
#
# Script
#     foamVTKSeries
#
# Description
#     For post-processed VTK files that form a series, foamVTKSeries writes a
#     '.vtk.series' file with filenames and corresponding times, which can be
#     opened in ParaView.
#
#     ParaView then interprets the files as a sequence which can be played with
#     video controls.
#------------------------------------------------------------------------------
error() {
    exec 1>&2
    while [ "$#" -ge 1 ]; do echo "$1"; shift; done
    usage
    exit 1
}

usage() {
        cat <<USAGE

Usage: ${0##*/} [OPTIONS] ...
options:
  -case | -c <dir>   specify case directory (default = local dir)
  -dir  | -d <dir>   post-processing directory <dir> (default = postProcessing)
  -help | -h         print the usage

For post-processed VTK files that form a series, foamVTKSeries writes a
'.vtk.series' file with filenames and corresponding times, which can be opened
in ParaView.  ParaView then interprets the files as a sequence which can be
played with video controls.

VTK files are typically written into time directories within a named "function"
sub-directory of the case 'postProcessing' directory, e.g.
'postProcessing/patchSurface/0.1/patch.vtk', where 'patchSurface' is the
function sub-directory and '0.1' is the time directory.

Series files use the same prefix as the VTK files and are written into the
function sub-directory, i.e. 'postProcessing/patchSurface/patch.vtk.series' in
our example.
USAGE
}

seriesFileHead () {
    cat<<EOF
{
    "file-series-version": "1.0",
    "files": [
EOF
}

seriesFileFoot () {
    cat<<EOF

    ]
}
EOF
}

dir=postProcessing

while [ "$#" -gt 0 ]
do
   case "$1" in
   -c | -case)
      [ "$#" -ge 2 ] || error "'$1' option requires an argument"
      cd "$2" 2>/dev/null || error "directory does not exist:  '$2'"
      shift 2
      ;;
   -d | -dir)
      [ "$#" -ge 2 ] || error "'$1' option requires an argument"
      dir=$2
      shift 2
      ;;
   -h | -help)
      usage && exit 0
      ;;
   -*)
      error "invalid option '$1'"
      ;;
   *)
      break
      ;;
    esac
done

[ ! -d "$dir" ] && error "Cannot find postProcessing directory, exiting."

subDirs=$(find "$dir" -maxdepth 1 -mindepth 1 -type d)

for s in $subDirs
do
    # Create list of subdirectories containing VTK files
    subDir_files=$(find "$s" -type f -name "*vtk")

    [ "$subDir_files" ] || continue

    printf "Sequencing all VTK files in %s\n" "$s"

    # Get the names of VTK files in this category
    names=$(for f in $subDir_files; do basename "$f" .vtk; done | sort -u)

    for n in $names
    do
        series_file="$s/$n.vtk.series"
        seriesFileHead > "$series_file"

        # Create list of VTK files of a given name, ordered by time step
        files=$(echo "$subDir_files" | \
            grep "$n\.vtk" | \
            awk -F'/' '{print($(NF-1)" "$0)}' | \
            LC_ALL=C  sort -k 1 -g | \
            cut -d' ' -f2)

        unset comma

        for f in $files
        do
            # Write series file
            [ "$comma" ] && printf ",\n" >> "$series_file"
            [ "$comma" ] || comma=yes
            time="$(dirname "$f" | awk -F/ '{print $NF}')"
            printf "%17s\"%s\", \"time\": %s }" \
                   '{"name": ' \
                   "$time/$n.vtk" \
                   "$time" >> "$series_file"
        done

        seriesFileFoot >> "$series_file"
    done
done
