#!/bin/bash

# Source .env file
if [ -f ".env" ]; then
    source .env
else
    echo "Error: No .env file found. Copy example.env to .env and set your NIXOS_HOST"
    exit 1
fi

if [ -z "$NIXOS_HOST" ]; then
    echo "Error: NIXOS_HOST not set in .env file"
    exit 1
fi

# Validate that the host configuration exists
AVAILABLE_HOSTS=$(nix flake show --json 2>/dev/null | jq -r '.nixosConfigurations | keys[]' 2>/dev/null)
if [ $? -ne 0 ] || [ -z "$AVAILABLE_HOSTS" ]; then
    echo "Warning: Could not validate host configuration. Proceeding anyway..."
else
    if ! echo "$AVAILABLE_HOSTS" | grep -q "^$NIXOS_HOST$"; then
        echo "Error: Host '$NIXOS_HOST' not found in flake.nix"
        echo "Available hosts: $(echo $AVAILABLE_HOSTS | tr '\n' ' ')"
        exit 1
    fi
fi

echo "Building configuration for host: $NIXOS_HOST"

# First, run a check to see if the flake is valid
nix flake check

# Rebuild the system
sudo nixos-rebuild switch --flake ./#$NIXOS_HOST

# Clean up old generations older than 180 days
sudo nix-collect-garbage --delete-older-than 180d