#!/bin/bash

# 00-system-prep.sh
# Updates system and sets up Flathub.
# Relies on DISTRO and PACKAGE_MANAGER being set by the caller.
# Supports NixOS, Fedora (dnf), and Debian/Ubuntu (apt).

echo "--- Starting System Preparation ---"

if [ -z "$DISTRO" ] || [ -z "$PACKAGE_MANAGER" ]; then
    echo "ERROR: DISTRO and PACKAGE_MANAGER must be set in the environment."
    exit 1
fi

# ── NixOS path: system updates are declarative via flake ──
if [ "$DISTRO" == "nixos" ]; then
    echo "NixOS detected: system updates are managed declaratively via flake.nix."
    echo "Run 'nixos-rebuild switch --flake ~/dotfiles/nixos#nixos' to apply changes."
    echo "Skipping imperative system update."
fi

# ── Traditional distro path ────────────────────────────────
if [ "$DISTRO" != "nixos" ]; then
    echo "Updating system packages..."
    if [ "$PACKAGE_MANAGER" == "dnf" ]; then
        sudo dnf update -y && sudo dnf upgrade -y
    elif [ "$PACKAGE_MANAGER" == "apt" ]; then
        sudo apt update && sudo apt upgrade -y
    else
        echo "WARNING: Unknown package manager '$PACKAGE_MANAGER'. Skipping system update."
    fi
fi

# Setup Flatpak (works on NixOS too if enabled in flake.nix)
echo "Setting up Flathub repository..."
if command -v flatpak &> /dev/null; then
    flatpak remote-add --if-not-exists flathub https://dl.flathub.org/repo/flathub.flatpakrepo
else
    echo "WARNING: flatpak command not found. Skipping Flathub setup."
    echo "Ensure Flatpak is installed via your package manager or flake.nix."
fi

echo "--- System Preparation Finished ---"