using VoiceCat.Transport;
using System.Net;
using System.Net.Sockets;
using System.Text.Json;
using VoiceCat.Crypto;
using VoiceCat.Server;
using VoiceCat.Server.Data;
using VoiceCat.Server.Transport;
using static VoiceCat.Tests.ServerTests;

namespace VoiceCat.Tests;

public class ProductionServerTests
{
    [Fact]
    public async Task HealthCheckPerformsTlsHandshakeAndCanPinCertificate()
    {
        await using var fixture = new ServerFixture();
        using var credentials = ServerCredentials.LoadOrCreate(fixture.Directory, "VoiceCat Server");
        var output = new StringWriter(); var error = new StringWriter();
        string endpoint = "127.0.0.1:" + fixture.Server.EndPoint.Port;
        Assert.Equal(0, await ServerCommand.RunAsync(["--health-check", endpoint], output, error));
        Assert.Contains("\"status\":\"healthy\"", output.ToString());
        output.GetStringBuilder().Clear();
        Assert.Equal(0, await ServerCommand.RunAsync(["--health-check", endpoint, "--expect-fingerprint", credentials.CertificateFingerprint], output, error));
        Assert.Equal(1, await ServerCommand.RunAsync(["--health-check", endpoint, "--expect-fingerprint", new string('0', 64)], output, error));
        Assert.Equal(1, await ServerCommand.RunAsync(["--health-check", "127.0.0.1:1"], output, error));
    }
    [PublishedServerFact]
    public async Task PublishedExecutableProvisionsAdminAndReportsFingerprintsWithoutPasswordOutput()
    {
        string directory = Path.Combine(Path.GetTempPath(), "voicecat-published-" + Guid.NewGuid().ToString("N"));
        async Task<string> Run(params string[] arguments)
        {
            var start = new System.Diagnostics.ProcessStartInfo(Environment.GetEnvironmentVariable("VOICECAT_PUBLISHED_SERVER")!)
            { UseShellExecute = false, CreateNoWindow = true, RedirectStandardOutput = true, RedirectStandardError = true };
            start.Environment["VOICECAT_ADMIN_PASSWORD"] = "published test password";
            foreach (string argument in arguments.Concat(new[] { "--data-dir", directory })) start.ArgumentList.Add(argument);
            using var process = System.Diagnostics.Process.Start(start)!;
            Task<string> stdout = process.StandardOutput.ReadToEndAsync(), stderr = process.StandardError.ReadToEndAsync();
            using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(20));
            try
            {
                await process.WaitForExitAsync(timeout.Token);
                string log = await stdout + await stderr;
                Assert.True(process.ExitCode == 0, log); Assert.DoesNotContain("published test password", log);
                return log;
            }
            finally { if (!process.HasExited) { process.Kill(true); await process.WaitForExitAsync(); } }
        }
        try
        {
            await Run("account", "add", "Operator", "--admin");
            Assert.Contains("Operator", await Run("account", "list"));
            using (var store = new AccountStore(Path.Combine(directory, "voicecat.db")))
                Assert.True((await store.AuthenticateAsync("Operator", "published test password"))!.IsAdmin);
            string fingerprint = (await Run("--print-fingerprint")).Trim();
            Assert.Equal(64, fingerprint.Length);
            Assert.Equal(fingerprint, (await Run("--print-fingerprint")).Trim());
            await Run("account", "reset", "Operator"); await Run("account", "delete", "Operator");
            Assert.DoesNotContain("Operator", await Run("account", "list"));
        }
        finally { if (Directory.Exists(directory)) Directory.Delete(directory, true); }
    }

    private sealed class PublishedServerFactAttribute : FactAttribute
    {
        public PublishedServerFactAttribute()
        {
            if (string.IsNullOrEmpty(Environment.GetEnvironmentVariable("VOICECAT_PUBLISHED_SERVER"))) Skip = "Set VOICECAT_PUBLISHED_SERVER to the self-contained executable.";
        }
    }

    [Fact]
    public void ConfigurationHonorsEnvironmentAndCommandPrecedenceWithoutCreatingFiles()
    {
        var env = new Dictionary<string, string> { ["VOICECAT_BIND_PORT"] = "9000", ["VOICECAT_ALLOW_GUESTS"] = "false", ["VOICECAT_SERVER_NAME"] = "Environment" };
        var config = ServerCommand.Parse(["--port", "0", "--name", "Command", "--bind", "::1", "--idle-seconds", "0"], key => env.GetValueOrDefault(key));
        Assert.Equal(0, config.Port); Assert.Equal("Command", config.Options.Name);
        Assert.False(config.Options.AllowGuests); Assert.Equal("::1", config.BindAddress);
        Assert.Equal(TimeSpan.Zero, config.Options.IdleTimeout);
        Assert.Equal(8384, ServerCommand.Parse([], _ => null).Port);
        Assert.Equal("0.0.0.0", ServerCommand.Parse([], _ => null).BindAddress);
        Assert.Throws<ArgumentException>(() => ServerCommand.Parse(["--port", "65536"], _ => null));
        Assert.Throws<ArgumentException>(() => ServerCommand.Parse(["--bind", "example.com"], _ => null));
        Assert.Throws<ArgumentException>(() => ServerCommand.Parse(["--port"], _ => null));
        Assert.Throws<ArgumentException>(() => ServerCommand.Parse(["--unencrypted", "true"], _ => null));
        Assert.Throws<ArgumentOutOfRangeException>(() => ServerCommand.Parse(["--auth-burst", "0"], _ => null));
        Assert.EndsWith("admin-data", ServerCommand.Parse(["account", "list", "--data-dir", "admin-data"], _ => null).Directory);
    }

    [Fact]
    public void AuthenticationLimitsAreSharedAcrossConnectionsAndAddressesWithBackoff()
    {
        var clock = new TestClock();
        var limiter = new AuthenticationLimiter(new() { AuthenticationBurst = 5 }, clock);
        for (int i = 0; i < 3; i++) { Assert.True(limiter.TryAcquire("a", "user")); limiter.Record("a", "user", false); }
        Assert.False(limiter.TryAcquire("a", "other"));
        Assert.False(limiter.TryAcquire("b", "user"));
        clock.Advance(1);
        Assert.True(limiter.TryAcquire("b", "user")); limiter.Record("b", "user", false);
        clock.Advance(1); Assert.False(limiter.TryAcquire("c", "user"));
        clock.Advance(1); Assert.True(limiter.TryAcquire("c", "user")); limiter.Record("c", "user", true);
        Assert.False(limiter.TryAcquire("d", "user")); // Success does not restore spent tokens.
        clock.Advance(10); Assert.True(limiter.TryAcquire("d", "user"));
    }

    [Fact]
    public async Task PasswordThrottleSurvivesReconnectAndRefillsBeforeSuccessfulLogin()
    {
        var clock = new TestClock();
        await using var fixture = new ServerFixture(options: new() { AuthenticationBurst = 1 }, timeProvider: clock);
        using (var store = new AccountStore(Path.Combine(fixture.Directory, "voicecat.db"))) await store.CreateAccountAsync("Member", "secret");
        async Task<bool> Login(string password)
        {
            await using var client = await fixture.ConnectAsync();
            client.Send(new() { ClientHello = new() { ProtoVersion = 2 } }); await client.ReadUntilAsync(e => e.ServerHello is not null);
            client.Send(new() { AuthRequest = new() { Password = new() { Username = "Member", Password = password } } });
            return (await client.ReadUntilAsync(e => e.AuthResult is not null)).AuthResult.Ok;
        }
        Assert.False(await Login("wrong")); Assert.False(await Login("secret"));
        clock.Advance(10); Assert.True(await Login("secret"));
    }

    [Fact]
    public async Task HostPublishesReadinessPreventsDuplicateInstancesAndShutsDownActiveTls()
    {
        string directory = Path.Combine(Path.GetTempPath(), "voicecat-host-" + Guid.NewGuid().ToString("N"));
        using var stop = new CancellationTokenSource(TimeSpan.FromSeconds(20));
        var output = new ReadyWriter(); var error = new StringWriter();
        Task<int> running = ServerCommand.RunAsync(["--data-dir", directory, "--bind", "127.0.0.1", "--port", "0"], output, error, stop.Token);
        try
        {
            using JsonDocument ready = JsonDocument.Parse(await output.Ready.Task.WaitAsync(stop.Token));
            int port = ready.RootElement.GetProperty("port").GetInt32();
            Assert.Equal(port, ready.RootElement.GetProperty("udp_port").GetInt32());
            Assert.Equal(64, ready.RootElement.GetProperty("certificate_fingerprint").GetString()!.Length);
            Assert.Equal(1, await ServerCommand.RunAsync(["--data-dir", directory, "--port", "0"], new StringWriter(), new StringWriter()));
            var socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            await socket.ConnectAsync(new IPEndPoint(IPAddress.Loopback, port), stop.Token);
            string fingerprint = ready.RootElement.GetProperty("certificate_fingerprint").GetString()!;
            await using var client = new Client(new TlsControlConnection(socket, TlsSession.CreateClient(value => value == fingerprint), CancellationToken.None));
            await client.LoginAsync("Host test");
            stop.Cancel(); Assert.Equal(0, await running.WaitAsync(TimeSpan.FromSeconds(10)));
            Assert.Equal("", error.ToString());
        }
        finally { stop.Cancel(); await running; Directory.Delete(directory, true); }
    }

    private sealed class ReadyWriter : StringWriter
    {
        internal TaskCompletionSource<string> Ready = new(TaskCreationOptions.RunContinuationsAsynchronously);
        public override Task WriteLineAsync(string? value) { if (value?.Contains("\"ready\"", StringComparison.Ordinal) == true) Ready.TrySetResult(value); return base.WriteLineAsync(value); }
    }
    private sealed class TestClock : TimeProvider
    {
        private long timestamp;
        public override long TimestampFrequency => 1000;
        public override long GetTimestamp() => timestamp;
        internal void Advance(int seconds) => timestamp += seconds * 1000;
    }
}