using System.Diagnostics;
using System.Text.Json.Nodes;
using QVPN.Core;

public static class XrayConfigTests
{
    public static async Task RunAsync(Func<string, Action, Task> test)
    {
        await test("Xray accepts only local SOCKS traffic and has no direct fallback", () =>
        {
            var config = XrayConfigBuilder.Build(Fixture());
            var inbound = config["inbounds"]!.AsArray().Single()!;
            Check(inbound["protocol"]!.GetValue<string>() == "socks" && inbound["listen"]!.GetValue<string>() == "127.0.0.1");
            Check(inbound["port"]!.GetValue<int>() == Constants.XrayPort);
            Check(inbound["settings"]!["auth"]!.GetValue<string>() == "noauth" && inbound["settings"]!["udp"]!.GetValue<bool>());
            Check(inbound["settings"]!["ip"]!.GetValue<string>() == "127.0.0.1" && !inbound["sniffing"]!["enabled"]!.GetValue<bool>());
            var outbound = config["outbounds"]!.AsArray().Single()!;
            Check(outbound["protocol"]!.GetValue<string>() == "vless" && !outbound["mux"]!["enabled"]!.GetValue<bool>());
            Check(config["routing"]!["rules"]!.AsArray().Single()!["outboundTag"]!.GetValue<string>() == outbound["tag"]!.GetValue<string>());
            Check(config["dns"] is null && config["log"]!["loglevel"]!.GetValue<string>() == "error");
        });
        await test("Xray retains every VLESS and Reality connection field", () =>
        {
            foreach (var flow in new[] { "xtls-rprx-vision", "" })
            {
                var node = Fixture() with { Flow = flow };
                var outbound = XrayConfigBuilder.Build(node)["outbounds"]!.AsArray().Single()!;
                var endpoint = outbound["settings"]!["vnext"]!.AsArray().Single()!;
                var user = endpoint["users"]!.AsArray().Single()!;
                Check(endpoint["address"]!.GetValue<string>() == node.Host && endpoint["port"]!.GetValue<int>() == node.Port);
                Check(user["id"]!.GetValue<string>() == node.Uuid && user["flow"]!.GetValue<string>() == node.Flow && user["encryption"]!.GetValue<string>() == "none");
                var stream = outbound["streamSettings"]!;
                Check(stream["network"]!.GetValue<string>() == "raw" && stream["security"]!.GetValue<string>() == "reality");
                var reality = stream["realitySettings"]!;
                Check(reality["serverName"]!.GetValue<string>() == node.ServerName && reality["fingerprint"]!.GetValue<string>() == node.Fingerprint);
                Check(reality["password"]!.GetValue<string>() == node.PublicKey && reality["shortId"]!.GetValue<string>() == node.ShortId);
                Check(reality["show"]!.GetValue<bool>() == false && reality["spiderX"]!.GetValue<string>() == "/");
            }
        });
        await test("Xray optional Windows binding uses the requested adapter and port", () =>
        {
            var bound = XrayConfigBuilder.Build(Fixture(), 17902, "Беспроводная сеть");
            Check(bound["inbounds"]!.AsArray().Single()!["port"]!.GetValue<int>() == 17902);
            Check(bound["outbounds"]!.AsArray().Single()!["streamSettings"]!["sockopt"]!["interface"]!.GetValue<string>() == "Беспроводная сеть");
            Check(XrayConfigBuilder.Build(Fixture())["outbounds"]!.AsArray().Single()!["streamSettings"]!["sockopt"] is null);
            foreach (var port in new[] { 0, -1, 65536 }) Throws<ArgumentOutOfRangeException>(() => XrayConfigBuilder.Build(Fixture(), port));
            foreach (var name in new[] { "", "  ", "adapter\nname", new string('a', 257) }) Throws<ArgumentException>(() => XrayConfigBuilder.Build(Fixture(), bindInterface: name));
        });
    }

    // Checks the exact packaged engine using synthetic credentials only. Raw
    // process output is drained, since future checks may include private data.
    public static async Task<int> CheckEngineAsync(string executable, CancellationToken token = default)
    {
        string directory = Path.Combine(Path.GetTempPath(), "QVPN.XrayConfigTests-" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(directory);
        try
        {
            foreach (var flow in new[] { "xtls-rprx-vision", "" })
            foreach (var bound in new[] { false, true })
            {
                var config = XrayConfigBuilder.Build(Fixture() with { Flow = flow }, 17902, bound ? "Ethernet" : null);
                string path = Path.Combine(directory, "synthetic-config.json");
                await File.WriteAllTextAsync(path, config.ToJsonString(), token);
                var start = new ProcessStartInfo(Path.GetFullPath(executable))
                {
                    UseShellExecute = false, CreateNoWindow = true, RedirectStandardOutput = true, RedirectStandardError = true,
                    WorkingDirectory = Path.GetDirectoryName(Path.GetFullPath(executable))!
                };
                start.ArgumentList.Add("run"); start.ArgumentList.Add("-test"); start.ArgumentList.Add("-config"); start.ArgumentList.Add(path);
                using var process = Process.Start(start) ?? throw new InvalidOperationException("Xray test process did not start.");
                var stdout = process.StandardOutput.ReadToEndAsync(); var stderr = process.StandardError.ReadToEndAsync();
                using var limit = CancellationTokenSource.CreateLinkedTokenSource(token); limit.CancelAfter(TimeSpan.FromSeconds(10));
                try { await process.WaitForExitAsync(limit.Token); }
                catch { try { if (!process.HasExited) process.Kill(true); } catch { } throw; }
                await Task.WhenAll(stdout, stderr);
                Console.WriteLine($"XRAY_CONFIG_CHECK flowVision={flow.Length > 0} binding={bound} exit={process.ExitCode}");
                if (process.ExitCode != 0) return process.ExitCode;
            }
            return 0;
        }
        finally
        {
            string absolute = Path.GetFullPath(directory);
            string root = Path.GetFullPath(Path.GetTempPath()).TrimEnd(Path.DirectorySeparatorChar) + Path.DirectorySeparatorChar;
            if (!absolute.StartsWith(root, StringComparison.OrdinalIgnoreCase) || !Path.GetFileName(absolute).StartsWith("QVPN.XrayConfigTests-", StringComparison.Ordinal))
                throw new InvalidOperationException("Unsafe Xray test cleanup target.");
            Directory.Delete(absolute, true);
        }
    }

    private static VpnNode Fixture()
    {
        string uuid = new Guid(Enumerable.Range(1, 16).Select(i => (byte)i).ToArray()).ToString();
        string key = Convert.ToBase64String(Enumerable.Range(1, 32).Select(i => (byte)i).ToArray()).TrimEnd('=').Replace('+', '-').Replace('/', '_');
        return new("synthetic", "Synthetic location", "8.8.8.8", 443, uuid, "example.com", key, "abcd", "chrome", "xtls-rprx-vision");
    }

    private static void Check(bool condition)
    {
        if (!condition) throw new InvalidOperationException("Xray configuration regression.");
    }

    private static void Throws<T>(Action action) where T : Exception
    {
        try { action(); } catch (T) { return; }
        throw new InvalidOperationException("Xray configuration validation regression.");
    }
}