#!/usr/bin/sh
# @author nate zhou
# @since 2025,2026
# @depends gpg wmenu dmenu(xorg, with password patch)
# Decrypt the gpg encrypted file and pipe to a viewer without writting to disk.
# @TODO: fix piping to mpv in tty

file="$1"

if [ "$XDG_SESSION_TYPE" = "wayland" ]; then
    menu="${HOME}/.local/bin/wmenu-color"
elif [ -n "$XAUTHORITY" ]; then
    menu="dmenu"
fi

usage() {
cat << _EOF_
DESCRIPTIOIN
        Decrypt the gpg encrypted file and pipe to a viewer without writting to
        disk. Which viewer will be passed to depends totally on the file
        extension, e.g. `webm.gpg` will be viewed with mpv.
USAGE
        $(basename "$0") FILE
_EOF_
}
[ $# -eq 0 ] && (usage; exit 0)

decrypt() {
    local pass=""

    if [ "$XDG_SESSION_TYPE" != "tty" ]; then
        pass="$($menu -P -p "[$(basename $0)] passphrase:" < /dev/null)"
    else
        read -p "[$(basename) $0 passphrase: ]" -r pass
    fi

    echo "$pass" | gpg --no-symkey-cache --batch --passphrase-fd 0 -d "$file"
}

rifle() {
    case "$file" in
        *.gif.gpg|*.mkv.gpg|*.mov.gpg|*.flv.gpg|*.mp4.gpg|*.webm.gpg|*.mp3.gpg|*.ogg.gpg|*.opus.gpg|*.oga.gpg|*.acc.gpg|*.flac.gpg|*.wav.gpg)
            mpv - --loop --no-resume-playback
            ;;
        *.jpg.gpg|*.jpeg.gpg|*.png.gpg|*.svg.gpg|*.webp.gpg|*.tiff.gpg|*.heic.gpg)
            [ "$XDG_SESSION_TYPE" != "tty" ] && swayimg - || mpv -
            ;;
        *.epub.gpg|*.pdf.gpg)
            zathura -
            ;;
        *.gpg)
            less
            ;;
    esac
}

warn() {
    notify-send -r 404 "${basename $0}" "failed"
}

decrypt "$file" | rifle || warn