#!/usr/bin/env bash
set -e

# Color definitions
RESET="\033[0m"
BOLD="\033[1m"
RED="\033[1;31m"
GREEN="\033[1;32m"
YELLOW="\033[1;33m"
BLUE="\033[1;34m"
CYAN="\033[1;36m"

# Default shell
LAUNCH_TERMINAL_SHELL="bash"

function usage() {
    # Use echo to output the help message with colors
    echo -e "${BOLD}Usage:${RESET} ${0##*/} [cmd] [options]"
    echo -e ""
    echo -e "${BOLD}Options:${RESET}"
    echo -e "  -s [shell]      Change the shell to [shell]."
    echo -e "  -h              Display this help message."
    echo -e ""
    echo -e "${BOLD}Description:${RESET}"
    echo -e "  This script launches a specified command in an appropriate terminal emulator,"
    echo -e "  automatically detecting the best option based on the desktop environment."
    echo -e ""
    echo -e "${BOLD}Examples:${RESET}"
    echo -e "  ${CYAN}${0##*/} \"echo Hello World\" -s zsh${RESET}"
    exit "${1:-0}"
}

# Parse command-line options
while getopts "s:h" arg; do
    case "${arg}" in
        s) LAUNCH_TERMINAL_SHELL="${OPTARG}" ;;
        h | ?) usage 0 ;;

        *) 
            echo -e "${RED}Invalid argument: '${arg}'${RESET}";
            usage 1
        ;;
    esac
done

shift "$((OPTIND - 1))"

# Validate input command
if [ "$#" -lt 1 ]; then
    echo -e "${RED}Error:${RESET} A command is required to execute."
    usage 1
fi

COMMAND="${1}"

# Detect terminal emulator
declare -A terminals=(["alacritty"]="alacritty -e bash -c"
    ["konsole"]="konsole -e bash -c"
    ["kgx"]="kgx -- bash -c"
    ["gnome-terminal"]="gnome-terminal -- bash -c"
    ["xfce4-terminal"]="xfce4-terminal --disable-server --command"
    ["qterminal"]="qterminal -e bash -c"
    ["lxterminal"]="lxterminal -e bash -c"
    ["mate-terminal"]="mate-terminal --disable-factory -e bash -c"
    ["xterm"]="xterm -e bash -c"
    ["foot"]="foot -T exec-terminal -e bash -c")

term_order=("alacritty"
    "konsole"
    "kgx"
    "gnome-terminal"
    "mate-terminal"
    "xfce4-terminal"
    "qterminal"
    "lxterminal"
    "xterm"
    "foot")

# Desktop environment-specific terminal preference
case "${XDG_CURRENT_DESKTOP}" in
    KDE) terminal="konsole" ;;

    GNOME)
        if command -v "kgx" &>/dev/null; then
            terminal="kgx"
        else
            terminal="gnome-terminal"
        fi
    ;;

    XFCE) terminal="xfce4-terminal" ;;
    LXQt) terminal="qterminal" ;;
    MATE) terminal="mate-terminal" ;;
esac

# Fallback: Check for available terminals
if [ -z "${terminal}" ] || ! command -v "${terminal}" &>/dev/null; then
    for i in "${term_order[@]}"; do
        if command -v "${i}" &>/dev/null; then
            terminal="${i}"
            break
        fi
    done
fi

# Error handling if no terminal is found
if [ -z "${terminal}" ]; then
    echo -e "${RED}Error:${RESET} No terminal emulator found!";
    notify-send -t 1500 --app-name="Terminal Launcher" "No terminal emulator found!";

    exit 1
fi

# Debug detected terminal
echo -e "${YELLOW}Detected terminal:${RESET} ${BOLD}${terminal}${RESET}"

# Launch the command in the terminal
echo -e "${CYAN}Launching command:${RESET} ${BOLD}${COMMAND}${RESET}"

eval "${terminals[${terminal}]} \"${COMMAND}\"" || {
    echo -e "${RED}Failed to launch command!${RESET}";
    exit 2
}

# Success message
echo -e "${GREEN}Command executed successfully in terminal!${RESET}"