using System.Text;
using System.Text.Json;
using Omika.Core.Observability.External;
using Omika.Core.Observability.Outbox;

namespace Omika.Tests.Observability.External;

/// <summary>
/// §5C.1C — Le source fichier du RemoteDiagnosticForwarder applique la même
/// protection partial-line que le reader du Worker (via JsonlCompleteLineReader).
/// </summary>
public class RemoteDiagnosticFileForwarderSourceTests
{
    private static readonly UTF8Encoding Utf8NoBom = new(encoderShouldEmitUTF8Identifier: false);

    private static readonly JsonSerializerOptions JsonOptions = new(JsonSerializerDefaults.Web);

    [Fact]
    public void PartialFinalLine_IsNotReturned_AndDoesNotAdvance()
    {
        string dir = CreateTempDir();
        try
        {
            string line1 = Serialize(NewRecord(Guid.NewGuid()));
            string line2 = Serialize(NewRecord(Guid.NewGuid())); // fragment sans newline
            File.WriteAllText(
                Path.Combine(dir, "omika-mobile-diagnostic-20260101-001.jsonl"),
                line1 + "\n" + line2,
                Utf8NoBom);

            var source = new RemoteDiagnosticFileForwarderSource(
                new RemoteDiagnosticOptions { Directory = dir },
                "forwarder-checkpoint.json");

            RemoteDiagnosticForwardReadResult read = source.ReadNext(null, 10);

            Assert.Single(read.Records); // seul line1 (complète)
            Assert.Equal(0, read.NextPosition!.LineIndex); // fragment non checkpointé
        }
        finally { Directory.Delete(dir, recursive: true); }
    }

    [Fact]
    public void CompletePoisonLine_IsSkipped_AndCursorAdvances()
    {
        string dir = CreateTempDir();
        try
        {
            string line = Serialize(NewRecord(Guid.NewGuid()));
            File.WriteAllText(
                Path.Combine(dir, "omika-mobile-diagnostic-20260101-001.jsonl"),
                "{ json invalide\n" + line + "\n",
                Utf8NoBom);

            var source = new RemoteDiagnosticFileForwarderSource(
                new RemoteDiagnosticOptions { Directory = dir },
                "forwarder-checkpoint.json");

            RemoteDiagnosticForwardReadResult read = source.ReadNext(null, 10);

            Assert.Single(read.Records);
            Assert.Equal(1, read.NextPosition!.LineIndex); // poison (0) sautée, ligne (1)
        }
        finally { Directory.Delete(dir, recursive: true); }
    }

    private static RemoteDiagnosticRecord NewRecord(Guid eventId) => new()
    {
        ReceivedAtUtc = DateTimeOffset.UtcNow,
        BatchId = Guid.NewGuid(),
        IngestionTraceId = Guid.NewGuid().ToString("D"),
        Event = new DiagnosticEventDto
        {
            EventId = eventId,
            EventCode = "TEST",
            TimestampUtc = DateTimeOffset.UtcNow,
            Level = "Info",
            Priority = "P2"
        }
    };

    private static string Serialize(RemoteDiagnosticRecord record) =>
        JsonSerializer.Serialize(record, JsonOptions);

    private static string CreateTempDir()
    {
        string dir = Path.Combine(Path.GetTempPath(), "omika-fwd-test-" + Guid.NewGuid().ToString("N"));
        Directory.CreateDirectory(dir);
        return dir;
    }
}