#!/bin/sh

# Copyright (c) 2021, la-ninpre
#
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
# 
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.


# small script to create page with qr-coded recovery tokens for otp
# uses: qrencode, imagemagick(convert, montage)
#
# file with codes should be in following format:
# - recovery codes should be on separate lines
# - every line beginning with # is ignored

QRENCODE_ERR_CORR_LEVEL=H
CODES_KEEP_PNG=0
CODES_MAKE_PDF=0

usage() {
    echo "create qr-coded recovery tokens for easy printing"
    echo
    echo "USAGE:"
    echo "  $0 [OPTIONS] <text-file>"
    echo
    echo "OPTIONS:"
    echo "  -k  keep png files with qrcodes"
    echo "  -l {L,M,Q,H}"
    echo "      set qrencode error correction level"    
    echo "  -p  produce pdf instead of image"
    echo "  -h  print this help message"
    echo
}

while getopts kl:ph arg
do
    case "$arg" in
        k) CODES_KEEP_PNG=1
            ;;
        l) case $OPTARG in
            [lL]) QRENCODE_ERR_CORR_LEVEL=L ;;
            [mM]) QRENCODE_ERR_CORR_LEVEL=M ;;
            [qQ]) QRENCODE_ERR_CORR_LEVEL=Q ;;
            [hH]) QRENCODE_ERR_CORR_LEVEL=H ;;
            *)  echo "error correction level should be one of L, M, Q or H"
                exit 1 ;;
            esac
            ;;
        p) CODES_MAKE_PDF=1
            ;;
        h|*) usage && exit 1
            ;;
    esac
done

shift $((OPTIND - 1))

[ $# -ne 1 ] && usage && exit 1

CODES_FILE="$1"
CODES_BASENAME="${CODES_FILE%%.*}"
CODES_EXT="${CODES_FILE##*.}"
CODES_DIR="$PWD/${CODES_BASENAME}_${CODES_EXT}_dir"
CODES_DATE="$(date +'%Y-%m-%d %H:%M')"
CODES_OUTPUT="${CODES_BASENAME}_qrcodes"
CODES_OUT_IMG="${CODES_OUTPUT}.png"
CODES_OUT_PDF="${CODES_OUTPUT}.pdf"

rm -f "$CODES_OUT_IMG" "$CODES_OUT_PDF"
[ -d "$CODES_DIR" ] && rm -rf "$CODES_DIR"
mkdir "$CODES_DIR"

sed -e '/^#.*/ d' -e '/^\s*$/ d' < "$CODES_FILE" \
    | xargs -I{} \
    qrencode -l "$QRENCODE_ERR_CORR_LEVEL" -t png -d 150 \
    -o "$CODES_DIR/{}-code.png" {}

montage -title "\n$CODES_FILE\n$CODES_DATE" \
    "$CODES_DIR/*-code.png" -page a4 -geometry 128x128\> "$CODES_OUT_IMG"

[ "$CODES_MAKE_PDF" -ne 0 ] && {
    convert \( -size 1240x1754 xc: \) "$CODES_OUT_IMG" \
        -composite "$CODES_OUT_PDF"
    [ "$CODES_KEEP_PNG" -eq 0 ] && rm -f "$CODES_OUT_IMG"
    }

[ "$CODES_KEEP_PNG" -eq 0 ] && rm -rf "$CODES_DIR" || exit 0