using Microsoft.Extensions.Logging;
using Microsoft.Win32;
using PatchProbe.Shared.Contracts;
using PatchProbe.Shared.Models;

namespace PatchProbe.Cli.Collectors;

public sealed class PendingRebootCollector(ILogger<PendingRebootCollector> logger) : ICollector<PendingRebootInfo>
{
    public Task<PendingRebootInfo> CollectAsync(CancellationToken cancellationToken = default)
    {
        logger.LogInformation("Collecting pending reboot indicators");

        var info = new PendingRebootInfo
        {
            CbsRebootPending = KeyExists(@"SOFTWARE\Microsoft\Windows\CurrentVersion\Component Based Servicing\RebootPending")
                            || KeyExists(@"SOFTWARE\Microsoft\Windows\CurrentVersion\Component Based Servicing\RebootInProgress"),
            WindowsUpdateRebootRequired = KeyExists(@"SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update\RebootRequired"),
            SessionManagerRebootRequired = HasPendingFileRenameOperations(),
            ComputerRenameRequired = HasPendingComputerRename(),
        };

        logger.LogInformation("Pending reboot: {AnyPending} (CBS={Cbs}, WU={Wu}, SessionMgr={Sm}, Rename={Rename})",
            info.AnyPending, info.CbsRebootPending, info.WindowsUpdateRebootRequired,
            info.SessionManagerRebootRequired, info.ComputerRenameRequired);

        return Task.FromResult(info);
    }

    private static bool KeyExists(string subKeyPath)
    {
        try
        {
            using var key = Registry.LocalMachine.OpenSubKey(subKeyPath);
            return key != null;
        }
        catch { return false; }
    }

    private static bool HasPendingFileRenameOperations()
    {
        try
        {
            using var key = Registry.LocalMachine.OpenSubKey(@"SYSTEM\CurrentControlSet\Control\Session Manager");
            var value = key?.GetValue("PendingFileRenameOperations");
            if (value is string[] arr) return arr.Length > 0;
        }
        catch { }
        return false;
    }

    private static bool HasPendingComputerRename()
    {
        try
        {
            using var key = Registry.LocalMachine.OpenSubKey(@"SYSTEM\CurrentControlSet\Control\ComputerName\ActiveComputerName");
            using var pendingKey = Registry.LocalMachine.OpenSubKey(@"SYSTEM\CurrentControlSet\Control\ComputerName\ComputerName");
            var active = key?.GetValue("ComputerName")?.ToString();
            var pending = pendingKey?.GetValue("ComputerName")?.ToString();
            return !string.Equals(active, pending, StringComparison.OrdinalIgnoreCase);
        }
        catch { return false; }
    }
}