#!/bin/bash
#------------------------------------------------------------------------------
# =========                 |
# \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
#  \\    /   O peration     |
#   \\  /    A nd           | www.openfoam.com
#    \\/     M anipulation  |
#------------------------------------------------------------------------------
#     Copyright (C) 2023-2024 OpenCFD Ltd.
#------------------------------------------------------------------------------
# License
#     This file is part of OpenFOAM, distributed under GPL-3.0-or-later.
#
# Script
#     foamUpgradeFiniteArea
#
# Description
#     Relocate finite-area files to new sub-directory locations
#
#------------------------------------------------------------------------------
printHelp() {
    cat <<USAGE

Usage: ${0##*/} [OPTION]
options:
  -case=DIR         Specify starting directory, default is cwd
  -dry-run | -n     Test without performing actions
  -verbose | -v     Additional verbosity
  -force            (currently ignored)
  -link-back        Link back from new finite-area/ to old locations
  -no-mesh          Do not move system/faMeshDefinition
  -git              Use 'git mv' when making changes
  -help             Print help and exit

Relocate finite-area files to new sub-directory locations

Equivalent options:
  | -case=DIR  | -case DIR |

USAGE
   exit 0  # A clean exit
}

# Report error and exit
die()
{
    exec 1>&2
    echo
    echo "Error encountered:"
    while [ "$#" -ge 1 ]; do echo "    $1"; shift; done
    echo
    echo "See '${0##*/} -help' for usage"
    echo
    exit 1
}

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

# Parse options
unset caseDir optDryRun optGit optVerbose optLink optMeshDef hadError

while [ "$#" -gt 0 ]
do
    case "$1" in
    (- | --)
        shift
        break   # Stop option parsing
        ;;
    (-h | -help*) printHelp ;;

    (-n | -dry-run)  optDryRun="(dry-run) " ;;
    (-v | -verbose)  optVerbose=true ;;
    (-f | -force)    echo "Ignored option: ${1%%=*}" 1>&2 ;;
    (-link-back)     optLink=back ;;
#    (-link-only)     optLink=forward ;;
    (-no-mesh)       optMeshDef=false ;;
    (-git)           optGit=true ;;

    (-case=*)
        caseDir="${1#*=}"
        ;;
    (-case)
        caseDir="$2"
        [ "$#" -ge 2 ] || die "'$1' option requires an argument"
        shift
        ;;

    (-*) die "unknown option: $1" ;;
    (*)  die "unknown argument: $1" ;;

    esac
    shift
done

if [ -n "$caseDir" ]
then
    cd "$caseDir" 2>/dev/null || {
        echo "${0##*/}: No such directory $caseDir" 1>&2
        exit 2
    }
fi

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

# Proper umask
umask 022

# The commands
copy_cmd="cp -a${optVerbose:+ -v}"
move_cmd="mv${optVerbose:+ -v}"
link_cmd="ln -sf${optVerbose:+ -v}"
mkdir_cmd="mkdir -p"

if [ -n "$optDryRun" ]
then
    if [ -n "$optVerbose" ]
    then
        copy_cmd="echo cp -a"
        move_cmd="echo mv"
        link_cmd="echo ln -sf"
        mkdir_cmd="echo mkdir -p"
    else
        copy_cmd=true
        move_cmd=true
        link_cmd=true
        mkdir_cmd=true
    fi
elif [ -n "$optGit" ]
then
    move_cmd="git mv"
    link_cmd="echo no symlink for git:"
fi

regionDir="finite-area"

#------------------------------------------------------------------------------
# Various script parts
#
# awk : scan file for FoamFile { ... class NAME; }

read -d '' getClass_awk << 'AWK_CONTENT'
BEGIN { state = 0 }  # 0=begin, 1=header, 2=done

/FoamFile/ { if (!state) { state = 1; next; } exit; }

# FoamFile begin contents
/\{/ { if (state == 1) state = 2; next; }

# FoamFile end contents
/\}/ { if (state == 2) exit; next; }

/^[ ]*class[ ]/ {
    if (state == 2)
    {
        sub("^[ ]*class[ ]+", "")
        sub("[ ;]*$", "")
        print
        exit
    }
    next
}
AWK_CONTENT


# Check for FoamFile and return extracted 'class'
getFoamFile_class()
{
    local file="$1"
    local class

    if grep -q FoamFile "$file" 2>/dev/null
    then
        # class="$(foamDictionary -disableFunctionEntries -entry FoamFile/class -value "$file" 2> stderr)"
        class="$(awk -- "$getClass_awk" "$file")"
    fi
    echo "$class"
}


# Check if class corresponds to an finite-area field
# eg, areaScalarField, ... edgeVectorField
isAreaFieldClass()
{
    case "$1" in
    (area*Field | edge*Field) return 0 ;;
    esac

    return 1
}


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

#Debug# getFoamFile_class "system/faSchemes"

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

# Link back from the local finite-area/ directory to the current directory
# variables
#   - regionDir = "finite-area"
#
performLinkBack()
{
    local file

    if [ -d "$regionDir" ]
    then
        find "$regionDir" -maxdepth 1 -type f 2>/dev/null | while read file
        do
            file="${file#*/}"

            if [ -f "$regionDir/$file" ] && [ ! -f "$file" ]
            then
                echo "${optDryRun}  ln -s $regionDir/$file $file" 1>&2
                $link_cmd "$regionDir/$file" "$file"
            fi
        done
    fi
}


# Move from current directory to local finite-area/ directory
# variables
#   - regionDir = "finite-area"
#
performMove()
{
    local file="$1"

    if [ -f "$regionDir/$file" ]
    then
        echo "${optDryRun}  already: $regionDir/$file" 1>&2
    elif [ -f "$file" ]
    then
        $mkdir_cmd "$regionDir"
        echo "${optDryRun}  mv $file -> $regionDir/" 1>&2
        $move_cmd "$file" "$regionDir/$file"
    elif [ -n "$file" ]
    then
        echo "${optDryRun}  no $file" 1>&2
    fi
}


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

# system
# ----
if [ -d system ]
then
(
    cd system || exit
    currDir="system"

    echo "${optDryRun}Examining files in $currDir/" 1>&2

    performMove faSchemes
    performMove faSolution

    if [ "$optMeshDef" = false ]
    then
        echo "${optDryRun}  ignore: faMeshDefinition" 1>&2
    else
        performMove faMeshDefinition
    fi

    if [ -d "$regionDir" ] && [ "$optLink" = back ]
    then
        performLinkBack
    fi
)
else
    echo "${optDryRun}No system/ directory..." 1>&2
fi


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

# time dirs (initial conditions)
# ----

for timeDir in 0 0.orig
do
    if [ -d "$timeDir" ]
    then
    (
        cd "$timeDir" || exit
        currDir="$timeDir"

        echo "${optDryRun}Examining $currDir/" 1>&2

        find . -maxdepth 1 -type f | while read file
        do
            file="${file#*/}"

            case "$file" in
            (*.gz)
                echo "${optDryRun}  ignoring compressed file: $file" 1>&2
                continue
                ;;
            esac

            className="$(getFoamFile_class "$file")"

            if isAreaFieldClass "$className"
            then
                performMove "$file"
            fi
        done

        if [ -d "$regionDir" ] && [ "$optLink" = back ]
        then
            performLinkBack
        fi
    )
    else
        echo "${optDryRun}No $timeDir/ directory..." 1>&2
    fi
done


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