#!/bin/bash
set -euo pipefail

##########################
# Color helpers (printf-safe, 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

say_red()    { printf "\n"; printf "%b%s%b\n" "$RED" "$*" "$RESET"; }
say_green()    { printf "\n"; printf "%b%s%b\n" "$GREEN" "$*" "$RESET"; }
say_yellow()   { printf "\n"; printf "%b%s%b\n" "$YELLOW" "$*" "$RESET"; }
say_cyan()     { printf "\n"; printf "%b%s%b\n" "$CYAN" "$*" "$RESET"; }
say_gray()     { printf "\n"; printf "%b%s%b\n" "$GRAY" "$*" "$RESET"; }
say_bold()     { printf "\n"; printf "%b%s%b\n" "$BOLD" "$*" "$RESET"; }

##########################
# Use exported variables from main detection script
##########################
OS="${DETECTED_OS}"
DDE="${DETECTED_DE}"
DE="${SELECTED_DE:-none}"
TWM="${SELECTED_TWM:-none}"
INSTALL_LEVEL="${INSTALL_LEVEL:-minimal}"
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"

##########################
# 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
##########################
say_yellow -e "Starting XFCE installation..."

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

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

    install_packages sddm xfce4 xfce4-goodies
    enable_graphical_target

    say_green -e "XFCE with SDDM installed successfully. You can reboot now to start XFCE."
else
    say_cyan -e "Detected existing Desktop Environment: $CURRENT_DE"

    if [[ "$CURRENT_DM" == "lightdm" ]]; then
        say_yellow -e "LightDM is currently active. Replacing with SDDM..."

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

        install_packages sddm
        enable_graphical_target

        say_green -e "LightDM removed and replaced with SDDM."
    else
        say_cyan -e "Current display manager: ${CURRENT_DM:-none}. Leaving unchanged."
    fi
fi

# End of script
say_green -e "XFCE / SDDM setup completed."