#!/bin/bash
# Show me the (monospace) fonts ;-)
# --
# altblue 2005.11.22
#

set -eu

[ -v TRACE ] && set -x

INPUT_FILE='unicode-extras.txt'
FONT_SIZE=12

CHECK_REQUIRES=0

bail () { echo "$*. Bailing out." >&2; exit 1; }

requires () {
  [[ "$CHECK_REQUIRES" == "" || $CHECK_REQUIRES -lt 1 ]] && return
  which which &>/dev/null || bail 'No "which"?! No cookies for you.'
  echo 'Checking required programs:'
  for prog in "$@" ; do
    printf '  - %s ... ' "$prog"
    which "$prog" 2>/dev/null || bail 'NOT FOUND!'
  done
}

requires fc-list ppmtojpeg sed xterm xwd xwdtopnm

trap -- 'kill %%' INT
trap -- 'kill %% &>/dev/null || :' EXIT

ssdir=screenshots

mkdir -p "$ssdir"
[ -d screenshots ] || bail "I really want my "$ssdir" folder!"

idx=0
echo "Generating screenshots into $ssdir:"

# maybe useful/applicable filters:
#   scalable=True/False
#   style=Regular/Roman
# lang=something is really useful, to be able to easy drop "dingbat" fonts
# … but some lousy fonters forgot to set it up :(
# … while some dingbat fonts do declare lang=, … and not decorative &al!
#
# • much shorter list w/o these variants! ~300 vs. ~1500!
#  | grep -viE -- '-(Black|Bold|Condensed|Expanded|Ext[A-Z]|Extra|Heavy|Italic|Light|Oblique|Retina|Semi|SmBld|Thin|Ultra)' \
#  | grep -viE -- '(Black|Bold|Heavy|It|Ita|Italic|Light|Oblique)$' \
{
  for pattern in \
    :lang=en:scalable=false:pixelsize=${FONT_SIZE} \
    :lang=en:scalable=true:spacing=dual \
    :lang=en:scalable=true:spacing=mono
  do
    fc-list "$pattern" postscriptname fullname
  done
    # no shit, "M+1m" doesn't support "en"… but supports "ie"!
    #fc-list :lang=ie:scalable=true:spacing=dual postscriptname
    #fc-list :lang=ie:scalable=true:spacing=mono postscriptname
    # missing spacing?! htf would you be able to select this?!
    #fc-list :postscriptname=CodeNewRoman postscriptname
    #fc-list : postscriptname | grep -E ':postscriptname=((Roboto|NotoSans)Mono|NotCourierSans|saxMono)'
} \
  | sort -s \
  | uniq \
  | while read -r pat
do
  [[ -z $pat ]] && continue
  # pat=":fullname=Arimo Italic Nerd Font Complete Mono:postscriptname=ArimoNerdFontCompleteM-Italic"
  idx=$((idx+1))
  psn="${pat##*:postscriptname=}"
  psn="${psn//[^a-zA-Z0-9-]/}"
  file="$ssdir"/"$psn".jpg
  fn="${pat##*:fullname=}"
  fn="${fn%%:postscriptname=*}"
  echo -n "  $idx. $fn ($psn) … "
  if [[ -e $file ]] ; then
    if [[ -s $file ]] ; then
      echo "“$file” already exists: skipped."
      continue
    else
      echo "“$file” already exists, but it is empty: replacing."
      rm -vf "$file"
    fi
  fi
  xterm \
    -fs $FONT_SIZE \
    -fa "$pat" \
    -u8 \
    -title "$fn" \
    -class floating \
    -hold \
    -geometry 80x25+0+0 \
    -e "echo -e \\\\033[1m${fn}\\\\033[0m\\\\n ; cat $INPUT_FILE" &
  sleep 2
  xwd -name "$fn" | xwdtopnm 2>/dev/null | ppmtojpeg >"$file"
  kill %%
  echo 'done.'
  ls -l "$file"
done