#!/bin/bash
set -euo pipefail

##########################
# Color helpers (no tput)
##########################
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[0;33m'
CYAN='\033[0;36m'
GRAY='\033[0;37m'
BOLD='\033[1m'
RESET='\033[0m'

# Disable colors if output is not a terminal
if [ ! -t 1 ]; then
    RED='' GREEN='' YELLOW='' CYAN='' GRAY='' BOLD='' RESET=''
fi

color_red()    { printf '%b' "$RED"; }
color_green()  { printf '%b' "$GREEN"; }
color_yellow() { printf '%b' "$YELLOW"; }
color_cyan()   { printf '%b' "$CYAN"; }
color_gray()   { printf '%b' "$GRAY"; }
color_reset()  { printf '%b' "$RESET"; }

##########################
# Use exported variables from main detection script
##########################
OS="${DETECTED_OS}"
DDE="${DETECTED_DE}"
DE="${SELECTED_DE:-none}"
TWM="${SELECTED_TWM:-none}"
INSTALL_LEVEL="${INSTALL_LEVEL:-minimal}"

##########################
# 4. Desktop Environment installation
##########################
color_yellow
echo "Installing XFCE..."
color_reset

# Detect if XFCE and SDDM are installed and install if needed
if [[ -z "$DDE" ]]; then
    color_cyan
    echo
    echo "No Desktop Environment detected. Installing XFCE (light setup with SDDM)..."
    color_reset

    sudo apt update
    sudo apt install -y --no-install-recommends sddm xfce4 xfce4-goodies

    # Enable SDDM as the display manager
    sudo systemctl enable sddm

    # Enable graphical target
    sudo systemctl set-default graphical.target

    color_green
    echo
    echo "XFCE with SDDM installed successfully."
    echo "You can reboot now to start XFCE."
    color_reset
else
    color_cyan
    echo
    echo "You already have $DE installed."
    color_reset

    # Check if LightDM is installed and active
    if systemctl is-active --quiet lightdm; then
        color_yellow
        echo
        echo "LightDM is currently active. Replacing with SDDM..."
        color_reset

        # Disable and remove LightDM
        sudo systemctl disable lightdm
        sudo apt purge -y lightdm lightdm-gtk-greeter

        # Install and enable SDDM
        sudo apt install -y sddm
        sudo systemctl enable sddm

        color_green
        echo
        echo "LightDM removed and replaced with SDDM."
        color_reset
    else
        color_cyan
        echo
        echo "No LightDM detected, leaving current display manager unchanged."
        color_reset
    fi
fi