#!/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'

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"; }

##########################
# Paths and variables
##########################
OS="${DETECTED_OS:-debian}"
DDE="${DETECTED_DE:-}"
DE="${SELECTED_DE:-none}"
TWM="${SELECTED_TWM:-none}"
INSTALL_LEVEL="${INSTALL_LEVEL:-minimal}"

##########################
# Helper functions
##########################
install_packages() {
    local packages=("$@")
    sudo apt update
    sudo apt install -y --no-install-recommends "${packages[@]}"
}

is_package_installed() {
    dpkg -s "$1" &>/dev/null
}

detect_de() {
    if command -v xfce4-session >/dev/null 2>&1; then
        echo "xfce"
    else
        echo ""
    fi
}

detect_display_manager() {
    if [ -f /etc/X11/default-display-manager ]; then
        basename "$(cat /etc/X11/default-display-manager)"
    else
        echo ""
    fi
}

enable_graphical_target() {
    sudo systemctl enable sddm
    sudo systemctl set-default graphical.target
}

##########################
# Start installation
##########################
echo -e "${YELLOW}Starting XFCE installation...${RESET}"

CURRENT_DE="$(detect_de)"
CURRENT_DM="$(detect_display_manager)"

if [[ -z "$CURRENT_DE" ]]; then
    echo -e "${CYAN}No Desktop Environment detected. Installing XFCE (light setup with SDDM)...${RESET}"

    install_packages sddm xfce4 xfce4-goodies
    enable_graphical_target

    echo -e "${GREEN}XFCE with SDDM installed successfully. You can reboot now to start XFCE.${RESET}"
else
    echo -e "${CYAN}Detected existing Desktop Environment: $CURRENT_DE${RESET}"

    if [[ "$CURRENT_DM" == "lightdm" ]]; then
        echo -e "${YELLOW}LightDM is currently active. Replacing with SDDM...${RESET}"

        sudo systemctl disable lightdm
        sudo apt purge -y lightdm lightdm-gtk-greeter

        install_packages sddm
        enable_graphical_target

        echo -e "${GREEN}LightDM removed and replaced with SDDM.${RESET}"
    else
        echo -e "${CYAN}Current display manager: ${CURRENT_DM:-none}. Leaving unchanged.${RESET}"
    fi
fi

# Force SDDM to use X11 session
sudo mkdir -p /etc/sddm.conf.d
echo -e "[Autologin]\nSession=xfce.desktop" | sudo tee /etc/sddm.conf.d/10-xfce.conf >/dev/null
echo -e "[General]\nSession=xfce.desktop" | sudo tee /etc/sddm.conf.d/10-xfce-session.conf >/dev/null

# End of script
echo -e "${GREEN}XFCE / SDDM setup completed.${RESET}"