using System.Text.Json.Nodes;
using backend.Conversations;
using backend.Realtime;
using backend.Tools;
using FluentAssertions;
using Microsoft.Extensions.DependencyInjection;
using Xunit;

namespace backend.tests;

public class RealtimeSessionAudioTests(ApiFactory factory) : IClassFixture<ApiFactory>
{
    private readonly ApiFactory _factory = factory;

    [Fact]
    public async Task Uplink_bytes_become_input_audio_buffer_append()
    {
        using var scope = _factory.Services.CreateScope();
        var log = scope.ServiceProvider.GetRequiredService<ConversationLog>();
        var reg = new ToolRegistry(Array.Empty<ITool>());
        var upstream = new ScriptedRealtimeUpstream();
        var sink = new RecordingSink();
        var cfg = new RealtimeSettings("m", "v", "p", 30, new HashSet<string>());
        var session = new RealtimeSession(Guid.NewGuid(), upstream, sink, log, reg, cfg,
            new FakeDeviceChannel(), NullLogger.Instance);

        upstream.Push(new JsonObject { ["type"] = "session.updated" });
        var cts = new CancellationTokenSource();
        var run = session.RunAsync(cts.Token);
        await sink.WaitForAsync("session_started", TimeSpan.FromSeconds(2));

        var frame = new byte[3840];
        for (int i = 0; i < frame.Length; i++) frame[i] = (byte)(i % 256);
        await session.WriteUplinkAsync(frame, default);

        await Task.Delay(100);

        var appended = upstream.Sent
            .FirstOrDefault(e => (string?)e["type"] == "input_audio_buffer.append");
        appended.Should().NotBeNull();
        var b64 = (string?)appended!["audio"];
        Convert.FromBase64String(b64!).Length.Should().Be(3840);

        cts.Cancel();
        await run;
    }

    [Fact]
    public async Task Audio_delta_from_upstream_becomes_binary_to_device()
    {
        using var scope = _factory.Services.CreateScope();
        var log = scope.ServiceProvider.GetRequiredService<ConversationLog>();
        var reg = new ToolRegistry(Array.Empty<ITool>());
        var upstream = new ScriptedRealtimeUpstream();
        var sink = new RecordingSink();
        var cfg = new RealtimeSettings("m", "v", "p", 30, new HashSet<string>());
        var session = new RealtimeSession(Guid.NewGuid(), upstream, sink, log, reg, cfg,
            new FakeDeviceChannel(), NullLogger.Instance);

        upstream.Push(new JsonObject { ["type"] = "session.updated" });
        var cts = new CancellationTokenSource();
        var run = session.RunAsync(cts.Token);
        await sink.WaitForAsync("session_started", TimeSpan.FromSeconds(2));

        var payload = new byte[3840];
        for (int i = 0; i < payload.Length; i++) payload[i] = (byte)((i + 1) % 256);
        upstream.Push(new JsonObject
        {
            ["type"] = "response.audio.delta",
            ["delta"] = Convert.ToBase64String(payload),
        });

        await Task.Delay(100);
        sink.Binary.Should().NotBeEmpty();
        sink.Binary[0].Length.Should().Be(3840);
        sink.Binary[0][0].Should().Be(1);

        cts.Cancel();
        await run;
    }
}