#nullable enable
using IPA.AntiMalware.ComAPI;
using IPA.Logging;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace IPA.AntiMalware
{
    internal class WindowsCOMAntiMalware : IAntiMalware
    {
        internal static WindowsCOMAntiMalware? TryInitialize()
        {
            try
            {
                return new();
            }
            catch (Exception e)
            {
                Logger.AntiMalware.Warn("Could not initialize COM-based antimalware engine:");
                Logger.AntiMalware.Warn(e);
                return null;
            }
        }

        private readonly IAntimalware amInterface;

        private WindowsCOMAntiMalware()
        {
            var amType = Type.GetTypeFromCLSID(AmsiConstants.CAntimalwareGuid, true);
            amInterface = (IAntimalware)Activator.CreateInstance(amType);
        }

        private static ScanResult ScanResultFromAmsiResult(AmsiResult result)
            => result switch
            {
                AmsiResult.Clean => ScanResult.KnownSafe,
                AmsiResult.NotDetected => ScanResult.NotDetected,
                AmsiResult.Detected => ScanResult.Detected,
                _ => ScanResult.MaybeMalware
            };

        public ScanResult ScanFile(FileInfo file)
        {
            using var stream = new AmsiFileStream(file, IntPtr.Zero);
            amInterface.Scan(stream, out var result, out var provider);
            Logger.AntiMalware.Trace($"Scanned file '{file}' with {provider.DisplayName()}, and got '{result}'");
            return ScanResultFromAmsiResult(result);
        }

        public ScanResult ScanData(byte[] data, string? contentName = null)
        {
            contentName ??= $"unknown_data_{Guid.NewGuid()}";
            using var stream = new AmsiMemoryStream(contentName, data, IntPtr.Zero);
            amInterface.Scan(stream, out var result, out var provider);
            Logger.AntiMalware.Trace($"Scanned data named '{contentName}' with {provider.DisplayName()}, and got '{result}'");
            return ScanResultFromAmsiResult(result);
        }
    }
}