using System.Runtime.CompilerServices;
using System.Text.Json;
using WxAgent.Service;
using Xunit;

namespace WxAgent.Service.Tests;

public sealed class EventPumpTests
{
    private sealed class SourceBackend : IAgentBackend, IAgentEventSource
    {
        public IReadOnlyList<AgentCapability> Capabilities => [new("listener-events", true, true, true, true, false, "read", false, 30, null, [])];
        public Task<object> StatusAsync(CancellationToken ct) => Task.FromResult<object>(new { ok = true });
        public async IAsyncEnumerable<AgentEvent> ListenAsync([EnumeratorCancellation] CancellationToken ct)
        { yield return new AgentEvent("evt", "ui-current", "session", "message", "summary", DateTimeOffset.UtcNow); await Task.Delay(Timeout.Infinite, ct); }
    }

    private sealed class DisabledSourceBackend : IAgentBackend, IAgentEventSource
    {
        public bool ListenCalled { get; private set; }
        public IReadOnlyList<AgentCapability> Capabilities => [new("listener-events", true, true, false, true, false, "read", false, 30, "disabled", [])];
        public Task<object> StatusAsync(CancellationToken ct) => Task.FromResult<object>(new { ok = true });
        public async IAsyncEnumerable<AgentEvent> ListenAsync([EnumeratorCancellation] CancellationToken ct)
        {
            ListenCalled = true;
            await Task.CompletedTask;
            yield break;
        }
    }

    [Fact]
    public async Task DisabledListenerDoesNotStartUiSource()
    {
        var source = new DisabledSourceBackend();
        using var pump = new EventPump(source, new EventHub(), new ServiceOptions
        {
            DataDirectory = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString("N")),
            CredentialFile = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString("N"), "credentials.json")
        });
        await pump.StartAsync(default);
        await Task.Delay(100);
        await pump.StopAsync(default);
        Assert.False(source.ListenCalled);
    }

    [Fact]
    public async Task PumpForwardsToTheConfiguredPrincipal()
    {
        var dir = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString("N")); Directory.CreateDirectory(dir);
        var options = new ServiceOptions { DataDirectory = dir, CredentialFile = Path.Combine(dir, "credentials.json") };
        File.WriteAllText(options.CredentialFile, JsonSerializer.Serialize(new[]
        {
            new ServiceCredential("alice", new string('A', 64), ["read"], [])
        }));
        try
        {
            var hub = new EventHub(); var subscription = hub.Subscribe("alice", null);
            using var pump = new EventPump(new SourceBackend(), hub, options);
            await pump.StartAsync(default);
            var ct = new CancellationTokenSource(TimeSpan.FromSeconds(5));
            while (!hub.TryGet(subscription.SubscriptionId, "alice", out var current) || !current.Channel.Reader.TryRead(out _))
                await Task.Delay(10, ct.Token);
            await pump.StopAsync(default);
        }
        finally { Microsoft.Data.Sqlite.SqliteConnection.ClearAllPools(); Directory.Delete(dir, true); }
    }
}