using Microsoft.Win32;
using System.Security;

namespace Zcbot.WindowsNode;

internal sealed record OriginRuntimeStatus(
    string Software,
    string? SoftwareVersion,
    string AdapterVersion,
    string Health,
    string Detail);

internal static class OriginRuntimeProbe
{
    private static readonly Lazy<OriginRuntimeStatus> Current = new(DetectCore);
    private const string AutomationProgId = @"Origin.ApplicationSI\CLSID";

    internal static OriginRuntimeStatus Detect() => Current.Value;

    private static OriginRuntimeStatus DetectCore()
    {
        try
        {
            var version = FindInstalledVersion();
            using var automationKey = Registry.ClassesRoot.OpenSubKey(AutomationProgId);
            var automationRegistered = automationKey is not null;
            if (version is null && !automationRegistered)
            {
                return Status(null, "unavailable", "未检测到 Origin/OriginPro 安装");
            }
            if (!automationRegistered)
            {
                return Status(version, "unavailable", "已检测到 Origin，但 COM 自动化组件未注册");
            }
            if (!Environment.UserInteractive)
            {
                return Status(version, "unavailable", "Origin 需要交互式 Windows 桌面会话");
            }
            var interpreter = OriginWorkerRuntime.ResolveInterpreter();
            if (interpreter is null)
            {
                return Status(
                    version,
                    "unavailable",
                    "Origin 可用，但固定 Python 运行时缺失；请配置 ZCBOT_ORIGIN_PYTHON");
            }
            return Status(version, "ready", $"Origin COM 与固定 Python 运行时可用（{interpreter}）");
        }
        catch (Exception exception) when (
            exception is SecurityException or UnauthorizedAccessException or IOException)
        {
            return Status(null, "unavailable", $"Origin 运行时探测失败：{exception.Message}");
        }
    }

    private static OriginRuntimeStatus Status(string? version, string health, string detail) =>
        new("OriginPro", version, "0.4.0", health, detail);

    private static string? FindInstalledVersion()
    {
        var candidates = new List<string>();
        foreach (var hive in new[] { RegistryHive.LocalMachine, RegistryHive.CurrentUser })
        {
            foreach (var view in new[] { RegistryView.Registry64, RegistryView.Registry32 })
            {
                using var baseKey = RegistryKey.OpenBaseKey(hive, view);
                using var uninstall = baseKey.OpenSubKey(
                    @"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall");
                if (uninstall is null)
                {
                    continue;
                }
                foreach (var keyName in uninstall.GetSubKeyNames())
                {
                    using var product = uninstall.OpenSubKey(keyName);
                    var name = product?.GetValue("DisplayName") as string;
                    var publisher = product?.GetValue("Publisher") as string;
                    if (!IsOriginProduct(name, publisher))
                    {
                        continue;
                    }
                    var version = product?.GetValue("DisplayVersion") as string;
                    if (!string.IsNullOrWhiteSpace(version))
                    {
                        candidates.Add(version.Trim());
                    }
                }
            }
        }
        return candidates.OrderByDescending(ParseVersion).ThenByDescending(x => x).FirstOrDefault();
    }

    private static bool IsOriginProduct(string? name, string? publisher) =>
        !string.IsNullOrWhiteSpace(name)
        && (name.Equals("Origin", StringComparison.OrdinalIgnoreCase)
            || name.StartsWith("Origin ", StringComparison.OrdinalIgnoreCase)
            || name.StartsWith("OriginPro", StringComparison.OrdinalIgnoreCase))
        && (publisher?.Contains("OriginLab", StringComparison.OrdinalIgnoreCase) ?? false);

    private static Version ParseVersion(string value) =>
        Version.TryParse(value, out var version) ? version : new Version(0, 0);
}