#!/bin/bash

# Created By: srdusr
# Created On: Tue 07 Mar 2023 15:06:47 PM CAT
# Project: Agnostic scratchpad/dropdown terminal that works on most window managers

# Dependencies: wmctrl, xprop, xdo, xdotool
# NOTE: Ensure script is included in system's path and can therefore be invoked with the command 'scratchpad'.
#       Furthermore make sure the terminal is using x11 as a backend in wayland to allow this to work.
#       Example: wezterm.lua: enable_wayland = false,
#                 kitty.conf: linux_display_server x11

# Set the environment variables to x11 to allow working in Wayland
export GDK_BACKEND=x11
export QT_QPA_PLATFORM=xcb
export WAYLAND_DISPLAY=""
export WINIT_UNIX_BACKEND=x11

# Supported terminals and dropdown class
supported_terminals=("wezterm" "kitty" "alacritty")

# Check if any supported terminal with scratchpad class is running
for term in "${supported_terminals[@]}"; do
    if pgrep -f "$term.*--class scratchpad" >/dev/null; then
        my_term="$term"
        break
    fi
done

# If no supported terminal is running, start the first available one
if [ "$my_term" = "" ]; then
    for term in "${supported_terminals[@]}"; do
        if command -v "$term" >/dev/null 2>&1; then
            my_term="$term"
            break
        fi
    done
    if [ "$my_term" = "" ]; then
        echo "No supported terminal found." && exit 1
    fi

    # Start terminal with scratchpad class
    case "$my_term" in
    "wezterm") wezterm start --class scratchpad -e tmux new-session -A -s tmux -e bash & ;;
    "kitty") kitty --class scratchpad tmux new-session -A -s tmux -e bash & ;;
    "alacritty") alacritty --class scratchpad -e tmux new-session -A -s tmux -e bash & ;;
    esac
fi

# Get the window ID of the scratchpad terminal
id="$(xdo id -N scratchpad)"

# Toggle scratchpad terminal visibility
if [ "$id" != "" ]; then
    if xwininfo -id "$id" | grep "Map State: IsViewable" >/dev/null; then
        # Scratchpad is visible, hide it
        dimensions="$(xwininfo -id "$id" | awk '/Width:|Height:/ { printf("%s=%s;", tolower($1), $2) }')"
        xdo hide "$id" 2>/dev/null
    else
        # Scratchpad is hidden, show it and restore dimensions
        xdo show "$id"
        xdotool windowsize "$id" "$(echo "$dimensions" | tr ';' ' ')" 2>/dev/null
        xdotool windowactivate "$id"
        xdotool windowfocus "$id"
    fi
fi