InventoryAgent/Inventory.Core/UpdateChecker.cs

using System;
using System.Diagnostics;
using System.IO;
using System.Reflection;
using System.Text.Json;

namespace Inventory.Core
{
    public class VersionManifest
    {
        public string Version { get; set; }
        public string MsiPath { get; set; }
    }

    public static class UpdateChecker
    {
        public static bool CheckForUpdate(string manifestPath, out string newMsiPath)
        {
            newMsiPath = null;
            try
            {
                // 1. Get local assembly version
                var localVersion = Assembly.GetExecutingAssembly().GetName().Version;

                if (!File.Exists(manifestPath))
                {
                    // Manifest not found, cannot check for update.
                    return false;
                }

                // 2. Read and deserialize the version.json
                var manifestContent = File.ReadAllText(manifestPath);
                var manifest = JsonSerializer.Deserialize<VersionManifest>(manifestContent, new JsonSerializerOptions { PropertyNameCaseInsensitive = true });

                if (manifest == null || !Version.TryParse(manifest.Version, out var manifestVersion))
                {
                    // Invalid manifest file
                    return false;
                }

                // 3. Compare versions
                if (manifestVersion > localVersion)
                {
                    // 4. If newer, construct the full MSI path
                    var manifestDir = Path.GetDirectoryName(manifestPath);
                    newMsiPath = Path.Combine(manifestDir, manifest.MsiPath);
                    return true;
                }
            }
            catch (Exception)
            {
                // Log this exception in a real application
                return false;
            }

            return false;
        }
    }
}