// Copyright 2012-2026 The NATS Authors
// Licensed under the Apache License, Version 2.0

using Shouldly;
using ZB.MOM.NatsNet.Server;

namespace ZB.MOM.NatsNet.Server.Tests.JetStream;

public sealed class JetStreamFileStoreTests
{
    [Fact]
    public void StoreMsg_LoadAndPurge_ShouldRoundTrip()
    {
        var root = Path.Combine(Path.GetTempPath(), $"fs-{Guid.NewGuid():N}");
        Directory.CreateDirectory(root);
        try
        {
            var fs = NewStore(root);

            var (seq1, _) = fs.StoreMsg("foo", [1], [2, 3], 0);
            var (seq2, _) = fs.StoreMsg("bar", null, [4, 5], 0);

            seq1.ShouldBe(1UL);
            seq2.ShouldBe(2UL);
            fs.State().Msgs.ShouldBe(2UL);

            var msg = fs.LoadMsg(1, null);
            msg.ShouldNotBeNull();
            msg!.Subject.ShouldBe("foo");

            fs.SubjectForSeq(2).Subject.ShouldBe("bar");
            fs.SubjectsTotals(string.Empty).Count.ShouldBe(2);

            var (removed, remErr) = fs.RemoveMsg(1);
            removed.ShouldBeTrue();
            remErr.ShouldBeNull();
            fs.State().Msgs.ShouldBe(1UL);

            var (purged, purgeErr) = fs.Purge();
            purgeErr.ShouldBeNull();
            purged.ShouldBe(1UL);
            fs.State().Msgs.ShouldBe(0UL);

            var (snapshot, snapErr) = fs.Snapshot(TimeSpan.FromSeconds(1), includeConsumers: false, checkMsgs: false);
            snapErr.ShouldBeNull();
            snapshot.ShouldNotBeNull();
            snapshot!.Reader.ShouldNotBeNull();

            var (total, reported, utilErr) = fs.Utilization();
            utilErr.ShouldBeNull();
            total.ShouldBe(reported);

            fs.Stop();
        }
        finally
        {
            Directory.Delete(root, recursive: true);
        }
    }

    private static JetStreamFileStore NewStore(string root)
    {
        return new JetStreamFileStore(
            new FileStoreConfig { StoreDir = root },
            new FileStreamInfo
            {
                Created = DateTime.UtcNow,
                Config = new StreamConfig
                {
                    Name = "S",
                    Storage = StorageType.FileStorage,
                    Subjects = ["foo", "bar"],
                },
            });
    }
}