#!/bin/bash
#
# generate a Plasma5 Wallpaper collection from a single image

# Parameter '-b': bitmap file of JPG or PNG format.
#   Aspect ratio of the image *must* be 16:9 (1920x1080 px or higher res).
# Parameter 2: name of the wallpaper directory (single word)
# Parameter 3: descriptive long name for the wallpaper (between quotes)
#
# Example:
#  ./gen_wallpaper_from_bitmap.sh -p sample.png -d LivingFlame -n "The living flame" -a "John Doe" -e "foo@fum.info"
# ---------------------------------------------------------------------------

CWD=$(cd $(dirname $0); pwd)

# Attribution - this will be used in the wallpaper metadata file:
WP_AUTHOR=${WP_AUTHOR:-"Eric Hameleers"}
WP_EMAIL=${WP_EMAIL:-"alien@slackware.com"}

# More default values:
WP_ROOT=${WP_ROOT:-"$CWD"}

BN=$(basename $0)
SHOWHELP=0

# ---------------------------------------------------------------------------
while getopts "a:b:d:e:hn:r:" Option
do
  case $Option in
    a ) WP_AUTHOR="${OPTARG}"
        ;;
    b ) WP_BITMAP="${OPTARG}"
        ;;
    d ) WP_DIR="${OPTARG}"
        ;;
    e ) WP_EMAIL="${OPTARG}"
        ;;
    h ) SHOWHELP=1
        ;;
    n ) WP_NAME="${OPTARG}"
        ;;
    r ) WP_ROOT="${OPTARG}"
        ;;
    * ) ;;   # DEFAULT
  esac
done

# End of option parsing.
shift $(($OPTIND - 1))

#  $1 now references the first non option item supplied on the command line
#  if one exists.
# ---------------------------------------------------------------------------

if [ $SHOWHELP -eq 1 ]; then
  echo "[$BN:] Parameters are:"
  echo "  -a <author>   Name of the wallpaper author, put inbetween quotes."
  echo "  -b <bitmap>   Bitmap file in JPG or PNG format."
  echo "                Aspect ratio of the image *must* be 16:9"
  echo "                (1920x1080 px or higher res)."
  echo "  -d <dirname>  Directory name for the wallpaper."
  echo "  -e <email>    Email address of the wallpaper author."
  echo "  -h            This help."
  echo "  -n <name>     Descriptive name for the wallpaper, inbetween quotes."
  echo "  -r <rootdir>  Root directory to create the wallpaper"
  echo "                directory structure in."
  exit 0
fi

# Some house-keeping with regard to the supplied image:
WP_REALBITMAP="$(readlink -f ${WP_BITMAP} 2>&1)"
WP_REALBASE="$(echo $(basename ${WP_REALBITMAP}) |rev |cut -d. -f2- |rev)"
WP_BITMBASE="$(echo $(basename ${WP_BITMAP}) |rev |cut -d. -f2- |rev)"

# If wallpaper name / description were not given, we use the bitmap basename:
WP_DIR=${WP_DIR:-"$WP_REALBASE"}
WP_NAME=${WP_NAME:-"$WP_BITMBASE"}

# Exit immediately if the image file is not found:
if ! readlink -f "${WP_BITMAP}" 1>/dev/null 2>&1 1>/dev/null 2>&1 || ! file "${WP_REALBITMAP}" | grep -q "image data" ; then
  echo "-- No wallpaper image found."
  exit 1
fi

# Exit if the target directory does not exist or is not writable:
if [ ! -d "${WP_ROOT}" ]; then
  echo "-- '${WP_ROOT}' not a directory."
  exit 2
fi
# Get the full path:
WP_ROOT="$(cd ${WP_ROOT}; pwd)"
if [ ! -w "${WP_ROOT}" ]; then
  echo "-- Directory '${WP_ROOT}' not writable."
  exit 2
fi

# Exit if the wallpaper already exists:
if [ -d "${WP_ROOT}/${WP_DIR}" ]; then
  echo "-- Wallpaper '${WP_ROOT}/${WP_DIR}' already exists."
  exit 3
fi

# Create the wallpaper for Plasma5;
echo "-- Normalizing background image."
# First convert our image into a JPG with known filename:
TMPDIR=$(mktemp -d -t wp_img.XXXXXX)
convert "${WP_REALBITMAP}" ${TMPDIR}/background.jpg

# The toplevel directory WP_DIR is your wallpaper!
# It needs to be placed in /usr/share/wallpapers/ on the target system:
mkdir -p ${WP_ROOT}/${WP_DIR}/contents/images

# Create set of images for common aspect ratios like 16:9, 16:10 and 4:3:
# Aspect Ratio 16:9 :
convert ${TMPDIR}/background.jpg \
  -resize 1920x1080 \
  ${WP_ROOT}/${WP_DIR}/contents/images/1920x1080.jpg
convert ${TMPDIR}/background.jpg \
  -resize 5120x2880 \
  ${WP_ROOT}/${WP_DIR}/contents/images/5120x2880.jpg
# Aspect Ratio 16:10 :
convert  ${TMPDIR}/background.jpg \
  -resize 5120x - | \
  convert - -geometry 1920x1200^ -gravity center -crop 1920x1200+0+0 \
  ${WP_ROOT}/${WP_DIR}/contents/images/1920x1200.jpg
convert  ${TMPDIR}/background.jpg \
  -resize 5120x - | \
  convert - -geometry 1280x800^ -gravity center -crop 1280x800+0+0 \
  ${WP_ROOT}/${WP_DIR}/contents/images/1280x800.jpg
# Aspect Ratio 4:3 :
convert  ${TMPDIR}/background.jpg \
  -resize 5120x - | \
  convert - -geometry 1024x768^ -gravity center -crop 1024x768+0+0 \
  ${WP_ROOT}/${WP_DIR}/contents/images/1024x768.jpg

# Create the required wallpaper screenshot of 400x225 px (16:9 aspect ratio):
convert ${TMPDIR}/background.jpg \
  -resize 400x225 \
  ${WP_ROOT}/${WP_DIR}/contents/screenshot.png

# Add wallpaper description:
cat <<EOT >${WP_ROOT}/${WP_DIR}/metadata.desktop
[Desktop Entry]
Name=${WP_NAME}

X-KDE-PluginInfo-Name=${WP_DIR}
X-KDE-PluginInfo-Author=${WP_AUTHOR}
X-KDE-PluginInfo-Email=${WP_EMAIL}
X-KDE-PluginInfo-License=CC-BY-SA-4.0
EOT

# Inform user:
echo "-- Wallpaper '${WP_NAME}' created in '${WP_ROOT}/${WP_DIR}'."

# Cleanup:
rm -fr $TMPDIR