#!/bin/bash
# 20190811-19 | tatze
#   crawl through the current and its subdirectories and create
#   smaller pictures by reducing height/width and quality;
#   save them as a copy inside "./reduced" with subfolder structure;
#   reduced files have the original's modified date
# ------------------------------------------
width=2220
quality=90
# ------------------------------------------
global_path=~/Pictures/_reduced/
local_path='reduced/'
# ------------------------------------------

# bold or normal?
bold=$(tput bold)
normal=$(tput sgr0)

printf "\n${bold}Where shall the reduced images be created? ${normal}
1. locally ($local_path) ${bold}[default]${normal}
2. globaly ($global_path)\n${bold}
[?] : ${normal}"
read RP

case $RP in
  2)
    printf "using $global_path ${normal}\n\n"
    path=$global_path
    pth=$(basename $PWD)/
    path+=$pth
    ;;
  *)
    printf "using $local_path ${normal}\n\n"
    path=$local_path
    ;;
esac

if [ ! -d $path ]
  then
  printf "${bold}creating folder $path ${normal}\n"
  mkdir -p -- $path
  if [ ! -d $path ]
    then
    printf "${bold}creating folder $path FAILED, aborting script.${normal}\n"
    exit 1
  fi
fi

# find all jp[e]g s, recursively, excluding the "*_reduced"
find . -iregex '.*\.jpe?g$' -not -iregex '.*_reduced\.jpe?g$' -not -path "$path/*" -print0 | sort -z |
while IFS= read -rd '' file; do
  dn=$(dirname "$file")
  rd="$path"
  # get rid of that ./
  rd+=$(sed 's|^./||' <<< $dn)
  if [ ! -d "$rd" ]
    then
    printf "\n${bold}creating folder $rd ${normal}\n"
    mkdir "$rd"
  fi

  bn=$(basename "$file")
  bn="${bn%.*}_reduced.${bn##*.}"
  if [ ! -f "$rd/$bn" ]
  then
    convert "$file" -resize $width -verbose -quality $quality "$rd"/"$bn"
    # preserve modified timestamp
    touch -r "$file" "$rd"/"$bn"
  else
    printf "$rd/$bn already exists, skipping.\n"
  fi
done