using Xunit;
using ZB.MOM.WW.OtOpcUa.Runtime.Historian;

namespace ZB.MOM.WW.OtOpcUa.Runtime.Tests.Historian;

/// <summary>
///     Verifies <see cref="ContinuousHistorizationOptions.Validate"/> self-gates on <c>Enabled</c> and
///     warns (warn-only, never blocks startup) on the two gated misconfigurations: a blank
///     <c>OutboxPath</c> while enabled, and a non-positive <c>CommitIntervalMs</c> under
///     <c>Periodic</c> commit mode. No warning text carries a secret value.
/// </summary>
public sealed class ContinuousHistorizationOptionsTests
{
    /// <summary>A disabled recorder yields no warnings regardless of the other knobs.</summary>
    [Fact]
    public void Disabled_no_warnings()
        => Assert.Empty(new ContinuousHistorizationOptions { Enabled = false }.Validate());

    /// <summary>An enabled recorder with a blank outbox directory warns about <c>OutboxPath</c>.</summary>
    [Fact]
    public void Enabled_requires_outbox_path()
        => Assert.Contains(
            new ContinuousHistorizationOptions { Enabled = true, OutboxPath = "" }.Validate(),
            m => m.Contains("OutboxPath"));

    /// <summary>Periodic commit mode with a non-positive interval warns about <c>CommitIntervalMs</c>.</summary>
    [Fact]
    public void Periodic_requires_positive_interval()
        => Assert.Contains(
            new ContinuousHistorizationOptions
            {
                Enabled = true,
                OutboxPath = "x",
                CommitMode = "Periodic",
                CommitIntervalMs = 0,
            }.Validate(),
            m => m.Contains("CommitIntervalMs"));

    /// <summary>
    ///     Pins the shipped defaults, which are a tuned set rather than arbitrary numbers: the drain is
    ///     bounded-parallel over an in-memory peek (so a wide <c>DrainBatchSize</c> is cheap and a narrow
    ///     one lets the outbox fill during a gateway hiccup), <c>Capacity</c> is the #538 disk backstop,
    ///     and <c>MaxWriteAttempts</c> is the #538 poison-tag budget. The shipped
    ///     <c>appsettings.json</c> restates these values, so a silent drift between the two is exactly
    ///     what this test exists to catch.
    /// </summary>
    [Fact]
    public void Defaults_are_the_documented_batch_era_values()
    {
        var options = new ContinuousHistorizationOptions();

        Assert.Equal("PerEntry", options.CommitMode);
        Assert.Equal(1024, options.DrainBatchSize);
        Assert.Equal(8, options.DrainConcurrency);
        Assert.Equal(500_000, options.Capacity);
        Assert.Equal(5, options.MaxWriteAttempts);
    }

    /// <summary>A fully-configured enabled recorder produces no warnings.</summary>
    [Fact]
    public void Valid_config_is_clean()
        => Assert.Empty(
            new ContinuousHistorizationOptions
            {
                Enabled = true,
                OutboxPath = "/var/lib/otopcua/historization",
                CommitMode = "PerEntry",
            }.Validate());
}