#!/bin/bash
#
# This script will manually generate thumbnails for MediaWiki. It's useful for memory-constrained
# environments such as shared hosting where you might have to resort to generating the thumbnails
# on a another machine and then uploading them manually. See also:
# https://www.mediawiki.org/wiki/Manual:Errors_and_symptoms#Manually_adding_thumbnail_files
#

USAGE="Usage: "$(basename $0)" <sourcefile> <width>"

if [ ! -f "$1" ]; then
  echo "Error: first parameter must be a file path." >&2
  echo $USAGE
  exit 1
fi
if ! [[ "$2" =~ ^[0-9]+$ ]]; then
  echo "Error: second parameter must be an integer." >&2
  echo $USAGE
  exit 1
fi

SRC="$1"
WIDTH=$2
RELSRC=$(echo $SRC | rev | cut -d/ -f1-3 | rev )
DEST=$(dirname $(dirname $(dirname $SRC)))"/thumb/"$RELSRC"/"$WIDTH"px-"$(basename "$SRC")

echo "Create this file?"
echo $DEST
echo -n "[y/N]: "
read
if [[ $REPLY =~ ^[Yy]$ ]]
then
    mkdir -p $(dirname "$DEST")
    convert -resize $WIDTH "$SRC" "$DEST"
fi