#!/bin/bash

###############################################################################
# Script Name: add-gnome-shortcut.sh
#
# Description:
#   Creates a new custom keyboard shortcut in GNOME by automatically finding
#   the next available custom-keybinding slot and registering the shortcut.
#
#   The script:
#     1. Reads existing GNOME custom keyboard shortcuts.
#     2. Finds the first unused custom<N> entry.
#     3. Adds the new shortcut to the GNOME keybinding list.
#     4. Sets the shortcut name.
#     5. Sets the command to execute.
#     6. Sets the keyboard shortcut combination.
#
# Requirements:
#   - GNOME Desktop Environment
#   - gsettings
#
# Usage:
#   ./add-gnome-shortcut.sh <name> <command> <key_combo>
#
# Arguments:
#   <name>
#       Display name shown in GNOME Settings.
#
#   <command>
#       Command that will be executed when the shortcut is pressed.
#
#   <key_combo>
#       GNOME keybinding string.
#
# Examples:
#
#   Open Terminal:
#   ./add-gnome-shortcut.sh \
#       "Terminal" \
#       "gnome-terminal" \
#       "<Ctrl><Alt>T"
#
#   Launch Firefox:
#   ./add-gnome-shortcut.sh \
#       "Firefox" \
#       "firefox" \
#       "<Super>F"
#
# Notes:
#   - Existing shortcuts are preserved.
#   - The next available custom-keybinding ID is selected automatically.
#   - Shortcut configuration can be viewed in:
#       Settings → Keyboard → Keyboard Shortcuts → Custom Shortcuts
#
###############################################################################

if [ $# -lt 3 ]; then
    echo "Usage: $0 <new_name> <new_cmd> <key_combo>"
    exit 1
fi

counter=0
list="["
num=0

# Find next available custom keybinding slot
while read -r line; do
    list="$list$(echo "$line" | sed 's/\]//g' | sed 's/\[//g'), "

    ret="$(printf "%s\n" "$line" | grep "custom$counter")"

    if [ -z "$ret" ]; then
        num=$counter
        break
    else
        ((counter++))
        num=$counter
    fi
done < <(
    gsettings get \
        org.gnome.settings-daemon.plugins.media-keys \
        custom-keybindings \
    | sed 's/, /\n/g'
)

key="org.gnome.settings-daemon.plugins.media-keys.custom-keybinding:"
custom="/org/gnome/settings-daemon/plugins/media-keys/custom-keybindings/custom$num/"

if [[ $list = *"@as"* ]]; then
    list="['$custom']"
else
    list="$list'$custom']"
fi

echo "$list"

new_name=$1
new_cmd=$2
key_combo=$3

echo "$key$custom $new_name $new_cmd $key_combo"

# Optional helper for determining key names:
#
# key_str="$(xev)"
# echo "$key_str" \
#   | sed 's/KeyRelease/\nKeyRelease/g' \
#   | sed 's/KeyPress/\nKeyPress/g' \
#   | grep KeyPress \
#   | sed 's/keysym/\nkeysym/g' \
#   | sed 's/same_screen/\nsame_screen/g' \
#   | grep keysym \
#   | grep -o -P '(?<=, ).*(?=\),)' \
#   | sed 's/_L//g' \
#   | sed 's/_R//g'

gsettings set \
    org.gnome.settings-daemon.plugins.media-keys \
    custom-keybindings \
    "$list"

gsettings set "$key$custom" name "$new_name"
gsettings set "$key$custom" command "$new_cmd"
gsettings set "$key$custom" binding "$key_combo"