using System.IO;
using System.IO.Compression;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using FluentAssertions;
using StellaOps.Signals.Parsing;
using Xunit;

namespace StellaOps.Signals.Reachability.Tests;

public sealed class RuntimeFactsNdjsonReaderTests
{
    [Fact]
    public async Task ReadAsync_ParsesLines()
    {
        var ndjson = """
{"symbolId":"sym::foo","hitCount":2,"processId":10,"processName":"api"}
{"symbolId":"sym::bar","codeId":"elf:abcd","loaderBase":"0x1000","metadata":{"thread":"bg"}}
""";

        await using var stream = new MemoryStream(Encoding.UTF8.GetBytes(ndjson));
        var events = await RuntimeFactsNdjsonReader.ReadAsync(stream, gzipEncoded: false, CancellationToken.None);

        events.Should().HaveCount(2);
        events[0].SymbolId.Should().Be("sym::foo");
        events[0].ProcessId.Should().Be(10);
        events[0].ProcessName.Should().Be("api");
        events[1].LoaderBase.Should().Be("0x1000");
    }

    [Fact]
    public async Task ReadAsync_HandlesGzip()
    {
        var ndjson = """
{"symbolId":"sym::foo"}
""";
        await using var compressed = new MemoryStream();
        await using (var gzip = new GZipStream(compressed, CompressionLevel.Optimal, leaveOpen: true))
        await using (var writer = new StreamWriter(gzip, Encoding.UTF8, leaveOpen: true))
        {
            await writer.WriteAsync(ndjson);
        }

        compressed.Position = 0;

        var events = await RuntimeFactsNdjsonReader.ReadAsync(compressed, gzipEncoded: true, CancellationToken.None);
        events.Should().HaveCount(1);
    }
}