nnn/plugins/imgview

#!/usr/bin/env sh

# Description: Open hovered or current directory in image viewer.
#              Supported image viewers open in thumbnail mode when
#              the hovered entry is a directory.
#
# Dependencies:
#   - imv (https://github.com/eXeC64/imv) or,
#   - sxiv (https://github.com/muennich/sxiv) or,
#   - ucollage (https://github.com/ckardaris/ucollage) or,
#   - lsix (https://github.com/hackerb9/lsix), or
#   - viu (https://github.com/atanunq/viu), or
#   - catimg (https://github.com/posva/catimg), or
#   - optional: ffmpeg for audio thumbnails (album art)
#   - optional: ffmpegthumbnailer for video thumbnails
#
# Shell: POSIX compliant
# Author: Arun Prakash Jana, Luuk van Baal

target="$(readlink -f "$1")"

exit_prompt() {
    [ -n "$1" ] && printf "%s\n" "$1"
    printf "%s" "Press any key to exit..."
    cfg=$(stty -g); stty raw -echo; head -c 1; stty "$cfg"
    clear
    exit
}

nthumb_cleanup() {
    [ -n "$!" ] && while [ -e /proc/"$!" ]; do sleep 1; done
    if [ -f "$target" ]; then
        rm -r "$(dirname "$target")"/.nthumbs
    elif [ -d "$target" ]; then
        rm -r "$target"/.nthumbs
    fi &
}

make_thumbs() {
    if [ -d "$target" ]; then
        [ "$1" -eq 4 ] && exit_prompt "$3 can only display a single image"
        cd "$target" || exit_prompt
    fi
    if mkdir .nthumbs >/dev/null; then
        thumbs=1
    else
        exit_prompt
    fi
    if [ "$1" -eq 4 ]; then
      mime="$(file -bL --mime-type -- "$2")"
        case "$mime" in
          audio/*) ffmpeg -i "$2" ".nthumbs/${2%%.*}.jpg" -y >/dev/null 2>&1
              ret=".nthumbs/${2%%.*}.jpg" ;;
          video/*) ffmpegthumbnailer -i "$2" -o .nthumbs/"${2%%.*}".jpg 2> /dev/null
              ret=".nthumbs/${2%%.*}.jpg" ;;
          *) ret="$2" ;;
        esac
    fi
    for file in *; do
        case "$(file -bL --mime-type -- "$file")" in
          audio/*) [ "$1" -ne 0 ] && ffmpeg -i "$file" ".nthumbs/${file%%.*}.jpg" -y >/dev/null 2>&1 ;;
          video/*) [ "$1" -ne 1 ] && ffmpegthumbnailer -i "$file" -o .nthumbs/"${file%%.*}".jpg 2> /dev/null ;;
        esac
    done
}

view_files() {
    find . .nthumbs -maxdepth 1 -type f -print0 | xargs -0 "$@" --
}

if uname | grep -q "Darwin"; then
    [ -f "$1" ] && open "$1" >/dev/null 2>&1 &
elif type lsix >/dev/null 2>&1; then
    if [ -d "$target" ]; then
        cd "$target" || exit_prompt
    fi
    make_thumbs ""
    clear
    lsix
    cd .nthumbs && lsix
    nthumb_cleanup
    exit_prompt
elif type ucollage >/dev/null 2>&1; then
    make_thumbs 1
    if ! UCOLLAGE_EXPAND_DIRS=1 ucollage . .nthumbs; then
      nthumb_cleanup && exit_prompt
    fi
    nthumb_cleanup
    exit
elif type sxiv >/dev/null 2>&1; then
    make_thumbs 0
    if [ -f "$target" ]; then
        view_files sxiv -a >/dev/null 2>&1 &
    elif [ -d "$target" ]; then
        view_files sxiv -aqt >/dev/null 2>&1 &
    fi
elif type imv >/dev/null 2>&1; then
    make_thumbs 3
    view_files imv >/dev/null 2>&1 &
elif type imvr >/dev/null 2>&1; then
    make_thumbs 3
    view_files imvr >/dev/null 2>&1 &
elif type viu >/dev/null 2>&1; then
    clear
    make_thumbs 4 "$1" viu
    viu -n "$ret"
    nthumb_cleanup
    exit_prompt
elif type catimg >/dev/null 2>&1; then
    make_thumbs 4 "$1" catimg
    catimg "$ret"
    nthumb_cleanup
    exit_prompt
else
    exit_prompt "Please install sxiv/imv/viu/catimg/lsix."
fi
[ "$thumbs" -ne 0 ] && nthumb_cleanup &