CBDDC/tests/ZB.MOM.WW.CBDDC.Core.Tests/OplogEntryTests.cs

using System.Globalization;
using System.Text.Json;

namespace ZB.MOM.WW.CBDDC.Core.Tests;

public class OplogEntryTests
{
    /// <summary>
    ///     Verifies that hash computation is deterministic even when payload content differs.
    /// </summary>
    [Fact]
    public void ComputeHash_ShouldBeDeterministic_RegardlessOfPayload()
    {
        // Arrange
        var collection = "test-collection";
        var key = "test-key";
        var op = OperationType.Put;
        var timestamp = new HlcTimestamp(100, 0, "node-1");
        var prevHash = "prev-hash";

        var payload1 = JsonDocument.Parse("{\"prop\": 1}").RootElement;
        var payload2 = JsonDocument.Parse("{\"prop\": 2, \"extra\": \"whitespace\"}").RootElement;

        // Act
        var entry1 = new OplogEntry(collection, key, op, payload1, timestamp, prevHash);
        var entry2 = new OplogEntry(collection, key, op, payload2, timestamp, prevHash);

        // Assert
        entry2.Hash.ShouldBe(entry1.Hash);
    }

    /// <summary>
    ///     Verifies that hash computation uses invariant culture formatting for timestamp values.
    /// </summary>
    [Fact]
    public void ComputeHash_ShouldUseInvariantCulture_ForTimestamp()
    {
        // Arrange
        var originalCulture = CultureInfo.CurrentCulture;
        try
        {
            var culture = CultureInfo.GetCultureInfo("de-DE");
            CultureInfo.CurrentCulture = culture;

            var timestamp = new HlcTimestamp(123456789, 1, "node");
            var entry = new OplogEntry("col", "key", OperationType.Put, null, timestamp, "prev");

            // Act
            string hash = entry.ComputeHash();

            // Assert
            CultureInfo.CurrentCulture = CultureInfo.InvariantCulture;
            var expectedEntry = new OplogEntry("col", "key", OperationType.Put, null, timestamp, "prev");
            hash.ShouldBe(expectedEntry.Hash);
        }
        finally
        {
            CultureInfo.CurrentCulture = originalCulture;
        }
    }

    /// <summary>
    ///     Verifies that an entry is valid when its stored hash matches computed content.
    /// </summary>
    [Fact]
    public void IsValid_ShouldReturnTrue_WhenHashMatches()
    {
        var timestamp = new HlcTimestamp(100, 0, "node-1");
        var entry = new OplogEntry("col", "key", OperationType.Put, null, timestamp, "prev");

        entry.IsValid().ShouldBeTrue();
    }

    /// <summary>
    ///     Verifies that entries default to the primary dataset when dataset is omitted.
    /// </summary>
    [Fact]
    public void Constructor_ShouldDefaultDatasetId_ToPrimary()
    {
        var entry = new OplogEntry("col", "key", OperationType.Put, null, new HlcTimestamp(1, 0, "node"), "prev");

        entry.DatasetId.ShouldBe(DatasetId.Primary);
    }

    /// <summary>
    ///     Verifies that hash computation includes dataset identity to prevent cross-dataset collisions.
    /// </summary>
    [Fact]
    public void ComputeHash_ShouldDiffer_WhenDatasetDiffers()
    {
        var timestamp = new HlcTimestamp(100, 0, "node-1");
        var primary = new OplogEntry("col", "key", OperationType.Put, null, timestamp, "prev", datasetId: "primary");
        var logs = new OplogEntry("col", "key", OperationType.Put, null, timestamp, "prev", datasetId: "logs");

        logs.Hash.ShouldNotBe(primary.Hash);
    }
}