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

DRY_RUN=false

# Check for dry-run flag
if [[ "$1" == "--dry-run" ]]; then
    DRY_RUN=true
    echo "Running in dry-run mode. No changes will be made."
fi

run_cmd() {
    # Run the command or just print it if dry-run
    if [ "$DRY_RUN" = true ]; then
        echo "[DRY-RUN] $*"
    else
        eval "$@"
    fi
}

echo "Detecting Linux distribution..."

# Detect distro
if [ -f /etc/os-release ]; then
    . /etc/os-release
    DISTRO=$ID
    VERSION=$VERSION_ID
else
    echo "Cannot detect Linux distribution."
    exit 1
fi

# Detect if immutable (rpm-ostree or SteamOS readonly)
IMMUTABLE=false
IS_STEAMOS=false
if command -v rpm-ostree &>/dev/null; then
    IMMUTABLE=true
elif command -v steamos-readonly &>/dev/null; then
    IMMUTABLE=true
    IS_STEAMOS=true
fi

echo "Distribution detected: $DISTRO $VERSION"
echo "Immutable system: $IMMUTABLE"

# -----------------------------
# Debian/Ubuntu installer
# -----------------------------
install_debian() {
    echo "Adding i386 architecture..."
    run_cmd "sudo dpkg --add-architecture i386"
    run_cmd "sudo apt update"

    echo "Installing 32-bit runtime libraries..."
    run_cmd "sudo apt install -y libc6:i386 libncurses5:i386 libstdc++6:i386 zlib1g:i386"

}

# -----------------------------
# Fedora/Bazzite installer (immutable-aware)
# -----------------------------
install_fedora() {
    if [ "$IMMUTABLE" = true ]; then
        echo "Immutable Fedora/Bazzite detected."

        # List of 32-bit packages we want
        PKGS=("glibc.i686" "libstdc++.i686" "ncurses-libs.i686" "zlib-ng-compat.i686")


        # Filter out packages that are already installed
        TO_INSTALL=()
        for pkg in "${PKGS[@]}"; do
            if rpm -q "$pkg" &>/dev/null; then
                echo "$pkg is already installed, skipping."
            else
                TO_INSTALL+=("$pkg")
            fi
        done

        if [ ${#TO_INSTALL[@]} -eq 0 ]; then
            echo "All required 32-bit packages are already installed. Nothing to do."
        else
            echo "Layering 32-bit libraries via rpm-ostree: ${TO_INSTALL[*]}"
            run_cmd "sudo rpm-ostree install ${TO_INSTALL[*]}"
            echo "Reboot required for layered packages to take effect."
        fi
    else
        echo "Installing 32-bit libraries via dnf..."
        run_cmd "sudo dnf install -y glibc.i686 libstdc++.i686 ncurses-libs.i686 zlib-ng-compat.i686"
    fi
}

# -----------------------------
# Arch/Manjaro/SteamOS 3+ installer
# -----------------------------
install_arch() {
    if [ "$IS_STEAMOS" = true ]; then
        echo "Immutable SteamOS 3+ detected."

        read -p "Do you want to temporarily disable read-only mode to install 32-bit libraries? (y/N): " RESP
        if [[ "$RESP" =~ ^[Yy]$ ]]; then
            echo "Disabling read-only mode..."
            run_cmd "sudo steamos-readonly disable"

            echo "Installing 32-bit libraries..."
            run_cmd "sudo pacman -S --noconfirm lib32-glibc lib32-gcc-libs lib32-ncurses lib32-zlib"

            echo "Re-enabling read-only mode..."
            run_cmd "sudo steamos-readonly enable"

            echo "32-bit libraries installed successfully!"
        else
            echo "Operation canceled. You can manually disable read-only mode later and rerun the script."
        fi
        return
    fi

    # Regular Arch / Manjaro
    if ! grep -q '^\[multilib\]' /etc/pacman.conf; then
        echo "Enabling multilib repository..."
        run_cmd "sudo sed -i '/\[multilib\]/,/Include/s/^#//' /etc/pacman.conf"
        run_cmd "sudo pacman -Syu --noconfirm"
    fi

    echo "Installing 32-bit runtime libraries..."
    run_cmd "sudo pacman -S --noconfirm  lib32-glibc lib32-gcc-libs lib32-ncurses lib32-zlib"
}

# -----------------------------
# Execute per detected distro
# -----------------------------
case "$DISTRO" in
    ubuntu|debian)
        echo "Installing 32-bit libraries for Debian/Ubuntu..."
        install_debian
        ;;
    fedora|bazzite)
        echo "Installing 32-bit libraries for Fedora/Bazzite..."
        install_fedora
        ;;
    arch|manjaro|cachyos)
        echo "Installing 32-bit libraries for Arch/Manjaro/SteamOS 3+..."
        install_arch
        ;;
    *)
        echo "Unsupported distribution: $DISTRO"
        exit 1
        ;;
esac

echo "32-bit multilib support installation complete!"