using System;
using System.IO;

namespace Deploymentcenter.Client;

public static class LicenseConfig
{
    private static string? _storageDirectoryOverride;
    private static string? _hardwareIdOverride;

    public static string? HardwareIdOverride
    {
        get
        {
            if (!string.IsNullOrWhiteSpace(_hardwareIdOverride))
                return _hardwareIdOverride;

            var envHwid = Environment.GetEnvironmentVariable("DEPLOYMENTCENTER_HWID") 
                       ?? Environment.GetEnvironmentVariable("LICENSELABRADOR_HWID");
            if (!string.IsNullOrWhiteSpace(envHwid))
                return envHwid;

            return null;
        }
        set => _hardwareIdOverride = value;
    }

    public static string GetStorageDirectory(string productSlug)
    {
        if (string.IsNullOrWhiteSpace(productSlug))
            productSlug = "default_app";

        // 1. Explicitly set property
        if (!string.IsNullOrWhiteSpace(_storageDirectoryOverride))
            return ValidateNonEmpty(_storageDirectoryOverride!);

        // 2. Environment Variable
        var envDir = Environment.GetEnvironmentVariable("DEPLOYMENTCENTER_STORAGE_DIR")
                  ?? Environment.GetEnvironmentVariable("LICENSELABRADOR_STORAGE_DIR");
        if (!string.IsNullOrWhiteSpace(envDir))
            return ValidateNonEmpty(Path.Combine(envDir!, productSlug, "license"));

        // 3. Platform specific resolution
        if (OperatingSystemHelpers.IsLinux() || OperatingSystemHelpers.IsMacOS())
        {
            var xdg = Environment.GetEnvironmentVariable("XDG_CONFIG_HOME");
            if (!string.IsNullOrWhiteSpace(xdg))
                return ValidateNonEmpty(Path.Combine(xdg!, productSlug, "license"));

            var home = Environment.GetEnvironmentVariable("HOME");
            if (!string.IsNullOrWhiteSpace(home))
                return ValidateNonEmpty(Path.Combine(home!, ".config", productSlug, "license"));
        }
        else if (OperatingSystemHelpers.IsWindows())
        {
            var appData = Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData);
            if (!string.IsNullOrWhiteSpace(appData))
                return ValidateNonEmpty(Path.Combine(appData, productSlug, "license"));
        }

        // 4. Fallback to AppContext.BaseDirectory
        var baseDir = AppContext.BaseDirectory;
        if (!string.IsNullOrWhiteSpace(baseDir))
            return ValidateNonEmpty(Path.Combine(baseDir, "license"));

        throw new InvalidOperationException("Could not resolve valid non-empty StorageDirectory for licensing.");
    }

    public static void SetStorageDirectory(string path)
    {
        _storageDirectoryOverride = path;
    }

    private static string ValidateNonEmpty(string path)
    {
        if (string.IsNullOrWhiteSpace(path))
            throw new InvalidOperationException("StorageDirectory resolved to an empty or invalid path.");
        return path;
    }
}