#!/bin/bash
#  $HeadURL: https://svn.pasta.freemyip.com/main/miniade/trunk/bin/nop-sh $ $LastChangedRevision: 10133 $

#  Notes to users:
#
#      (C) 2021-2024 Alexis Huxley - distributed under GPL3 - absolutely no warranty!
#
#      BE VERY VERY CAREFUL not to run this script against something other than
#      a container directory! You do not want to change the ownership/groupship
#      of files installed on your actual host!!!
#

#  Modules
. $(miniade) || { echo "${0##*/}: ERROR: miniade failed (hint: run 'miniade' to see error)" >&2; exit 1; }

#  Configurable stuff

#  Other globals

main()
{
    local MY_ARGS
    local MODE RECIPE_TITLE OUTPUT_FILE PROGNAME

    #  Defaults for options
    OUTPUT_FILE=

    #  Process options
    special_opts_handler()
    {
        case $1 in
            -o)     OUTPUT_FILE=$2
                    extra_shift ;;
            --html) MODE=html ;;
            --pdf)  MODE=pdf ;;
            *)      return 1 ;;
        esac
    }
    miniade_process_options --help-handler=help --special-opts-handler=special_opts_handler MY_ARGS "$@" && set -- "${MY_ARGS[@]}"

    #  Process arguments
    [ $# = 3 ] || miniade_bad_usage
    DIR=$1
    UID_OFFSET=$2
    GID_OFFSET=$3

    #  Sanity checks and derivations
    [ -d "$DIR" ] || miniade_error "$DIR: directory not found"
    [[ $UID_OFFSET =~ ^-?[1-9][0-9]*$ ]] || miniade_error "$UID_OFFSET: invalid UID offset"
    [[ $GID_OFFSET =~ ^-?[1-9][0-9]*$ ]] || miniade_error "$GID_OFFSET: invalid GID offset"
    perl -e 'use File::Find;' 2>/dev/null || miniade_error "File::Find: perl module not installed"
    perl -e 'use File::lchown;' 2>/dev/null || miniade_error "File::lchown: perl module not installed"

    #  Guts
    perl -e 'use File::Find; 
             use File::lchown qw( lchown ); 

             ($dir, $uid_offset, $gid_offset) = @ARGV;
             %dev_ino_tuples = ();

             sub wanted { 
                 lstat $_;
                 #  Ignore second hardlinks by ignoring device/inode numbers already encountered.
                 return if defined $dev_ino_tuples[(lstat _)[0] + ";" + (lstat _)[1]];
                 #  chown.
                 lchown ((lstat _)[4]+$uid_offset, (lstat _)[5]+$gid_offset, $_); 
                 #  Note we have seen this device/inode.
                 $dev_ino_tuples[(lstat _)[0] + ";" + (lstat _)[1]] = 1;
             }
     
             find(\&wanted, $dir);' "$DIR" "$UID_OFFSET" "$GID_OFFSET"
}

help()
{
    local PROGNAME

    miniade_get_progname PROGNAME
    echo "Usage: $PROGNAME [ <standard-options> ] <dir> <uid-offset> <gid-offset>"
    exit 0
}

main "$@"