#!/usr/bin/env bash
# Generate thumbnails using magick
# https://imagemagick.org/script/download.php
#
# Defaults to current directory creating thumbs with 1000x1000
# images with 200px white borders around the original image.
#
# Defaults can be overridden with ENV variables like this:
# $ THMB_BACKGROUND=black x-thumbgen ~/images/
#
# Created by: Ismo Vuorinen <https://github.com/ivuorinen> 2015

: "${THMB_SOURCE:=$1}"
: "${THMB_BACKGROUND:=white}"
: "${THMB_RESIZE:=800x800}"
: "${THMB_EXTENT:=1000x1000}"

[ $# -eq 0 ] && {
  echo "Usage: $0 /full/path/to/image/folder"
  exit 1
}

if [ "$THMB_SOURCE" == "" ] || [ ! -d "$THMB_SOURCE" ]; then
  THMB_SOURCE=$(pwd)
fi

if command -v magick &> /dev/null; then

  magick \
    "$THMB_SOURCE/*" \
    -resize "$THMB_RESIZE" \
    -background "$THMB_BACKGROUND" \
    -gravity center \
    -extent "$THMB_EXTENT" \
    -set filename:fname '%t_thumb.%e' +adjoin '%[filename:fname]'

else
  echo "magick not found in PATH, https://imagemagick.org/script/download.php"
fi