using Microsoft.Extensions.Options;

namespace ZB.MOM.WW.ScadaBridge.SiteEventLogging.Tests;

/// <summary>
/// <see cref="SiteEventLogOptions"/> retention/purge values drive the daily purge
/// PeriodicTimer (zero/negative trips its constructor) and the paging bounds gate
/// query result sizes. These tests assert the
/// <see cref="SiteEventLogOptionsValidator"/> rejects a bad
/// <c>ScadaBridge:SiteEventLog</c> section with a clear, key-naming message.
/// </summary>
public class SiteEventLogOptionsValidatorTests
{
    private static ValidateOptionsResult Validate(SiteEventLogOptions options) =>
        new SiteEventLogOptionsValidator().Validate(Options.DefaultName, options);

    /// <summary>Verifies that the default options are valid.</summary>
    [Fact]
    public void DefaultOptions_AreValid()
    {
        var result = Validate(new SiteEventLogOptions());
        Assert.True(result.Succeeded, result.FailureMessage);
    }

    /// <summary>Verifies that zero retention days is rejected.</summary>
    [Fact]
    public void ZeroRetentionDays_IsRejected()
    {
        var result = Validate(new SiteEventLogOptions { RetentionDays = 0 });

        Assert.True(result.Failed);
        Assert.Contains("RetentionDays", result.FailureMessage);
    }

    /// <summary>Verifies that a zero purge interval is rejected.</summary>
    [Fact]
    public void ZeroPurgeInterval_IsRejected()
    {
        var result = Validate(new SiteEventLogOptions { PurgeInterval = TimeSpan.Zero });

        Assert.True(result.Failed);
        Assert.Contains("PurgeInterval", result.FailureMessage);
    }

    /// <summary>Verifies that a maximum query page size below the default page size is rejected.</summary>
    [Fact]
    public void MaxQueryPageSize_BelowQueryPageSize_IsRejected()
    {
        var result = Validate(new SiteEventLogOptions { QueryPageSize = 500, MaxQueryPageSize = 100 });

        Assert.True(result.Failed);
        Assert.Contains("MaxQueryPageSize", result.FailureMessage);
    }

    // ── Register row 34: the per-tick purge ceiling ──

    /// <summary>Verifies that a negative maximum of purged rows per tick is rejected.</summary>
    [Fact]
    public void NegativeMaxPurgedRowsPerTick_IsRejected()
    {
        // 0 already means "unlimited" explicitly, so a negative value is a typo, not a synonym.
        // Accepting it would silently remove the only bound on a purge tick's CDC oplog burst.
        var result = Validate(new SiteEventLogOptions { MaxPurgedRowsPerTick = -1 });

        Assert.True(result.Failed);
        Assert.Contains("MaxPurgedRowsPerTick", result.FailureMessage);
    }

    /// <summary>Verifies that a zero maximum of purged rows per tick (unlimited) is accepted.</summary>
    [Fact]
    public void ZeroMaxPurgedRowsPerTick_IsAccepted()
    {
        // The documented escape hatch back to unbounded purges.
        var result = Validate(new SiteEventLogOptions { MaxPurgedRowsPerTick = 0 });

        Assert.True(result.Succeeded, result.FailureMessage);
    }

    /// <summary>Verifies that a zero purge catch-up interval is rejected.</summary>
    [Fact]
    public void ZeroPurgeCatchUpInterval_IsRejected()
    {
        // It is a Task.Delay period on the purge loop; zero would spin a ceiling-limited node.
        var result = Validate(new SiteEventLogOptions { PurgeCatchUpInterval = TimeSpan.Zero });

        Assert.True(result.Failed);
        Assert.Contains("PurgeCatchUpInterval", result.FailureMessage);
    }

    /// <summary>Verifies that a purge catch-up interval longer than the purge interval is rejected.</summary>
    [Fact]
    public void PurgeCatchUpInterval_LongerThanPurgeInterval_IsRejected()
    {
        // The catch-up is an ACCELERATED retry; a longer value would make hitting the ceiling
        // delay convergence instead of hastening it — the exact inverse of its purpose.
        var result = Validate(new SiteEventLogOptions
        {
            PurgeInterval = TimeSpan.FromMinutes(10),
            PurgeCatchUpInterval = TimeSpan.FromHours(1),
        });

        Assert.True(result.Failed);
        Assert.Contains("PurgeCatchUpInterval", result.FailureMessage);
    }
}