#!/usr/bin/env sh
# Description: Open a Drag and drop window, to drop files onto other programs.
#              Also provides drag and drop window for files.
#
# Dependencies:
# 	- dragon (https://github.com/mwh/dragon), or
# 	- kitty (https://github.com/kovidgoyal/kitty)
#
# Notes if using dragon:
#   1. Files that are dropped will be added to nnn's selection
#      Some web-based files will be downloaded to current dir
#      with curl and it may overwrite some existing files
#   2. The user has to mm to clear nnn's selection first
#
# Shell: POSIX compliant
# Author: 0xACE

# If you want system notification, put this equal to 1
notify=0

selection=${NNN_SEL:-${XDG_CONFIG_HOME:-$HOME/.config}/nnn/.selection}
resp=f
all=
if type dragon-drag-and-drop >/dev/null 2>&1; then
    dnd="dragon-drag-and-drop"
elif type dragon-drop >/dev/null 2>&1; then
    dnd="dragon-drop"
elif [ "$TERM" = "xterm-kitty" ]; then
    dnd="kitten dnd"
else
    dnd="dragon"
fi

add_file()
{
    printf '%s\0' "$@" >>"$selection"
}

use_all()
{
    printf "mark --all (a) [default=none]: "
    read -r resp
    if [ "$resp" = "a" ]; then
        all="--all"
    else
        all=""
    fi
}

if [ -s "$selection" ]; then
    printf "Drop file (r). Drag selection (s), Drag current directory (d) or drag current file (f) [default=f]: "
    read -r resp
else
    printf "Drop file (r). Drag current directory (d) or drag current file (f) [default=f]: "
    read -r resp
    if [ "$resp" = "s" ]; then
        resp=f
    fi
fi

clear_tui()
{
    pid=$!
    reset # nnn to dnd
    wait $pid
    reset # dnd to nnn
}

if [ "$dnd" = "kitten dnd" ]; then
    if [ "$resp" = "s" ]; then
        # shellcheck disable=SC2086
        xargs -0 $dnd 2>/dev/null <"$selection" &
    elif [ "$resp" = "d" ]; then
        $dnd "$PWD/"* 2>/dev/null &
    else # send one or receive
        $dnd "$1" 2>/dev/null &
    fi

    clear_tui

    if [ "$resp" = "s" ]; then
        [ -p "$NNN_PIPE" ] && printf "-" >"$NNN_PIPE" # clear selection
    fi
else
    if [ "$resp" = "s" ]; then
        use_all
        sed -z 's|'"$PWD/"'||g' <"$selection" | xargs -0 "$dnd" "$all" 2>/dev/null &
    elif [ "$resp" = "d" ]; then
        use_all
        "$dnd" "$all" "$PWD/"* 2>/dev/null &
    elif [ "$resp" = "r" ]; then
        true >"$selection"
        "$dnd" --print-path --target 2>/dev/null | while read -r f; do
            if printf "%s" "$f" | grep -q '^\(https\?\|ftps\?\|s\?ftp\)://'; then
                if output=$(curl -fsLJOS "$f" 2>&1); then
                    filename="$(basename "${f%%\?*}")"
                    add_file "$PWD/$filename"
                    if [ $notify = 1 ]; then
                        notify-send "Download Complete" "Finished downloading $filename"
                    fi
                else
                    if [ $notify = 1 ]; then
                        notify-send "Download Failed" "$output"
                    else
                        echo "Download Failed: $output"
                    fi
                fi
            elif [ -e "$f" ]; then
                add_file "$f"
            fi
        done &
    elif [ -n "$1" ] && [ -e "$1" ]; then
        "$dnd" "$1" 2>/dev/null &
    fi
fi