using Microsoft.Extensions.Options;

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

/// <summary>
/// <see cref="SiteRuntimeOptions"/> values size the staggered Instance-Actor
/// startup batches, the dedicated script-execution thread scheduler, and the
/// site-wide stream buffer. A zero/negative count crashes actor construction with
/// an opaque <see cref="ArgumentOutOfRangeException"/>; these tests assert the
/// <see cref="SiteRuntimeOptionsValidator"/> rejects a bad
/// <c>ScadaBridge:SiteRuntime</c> section with a clear, key-naming message.
/// </summary>
public class SiteRuntimeOptionsValidatorTests
{
    private static ValidateOptionsResult Validate(SiteRuntimeOptions options) =>
        new SiteRuntimeOptionsValidator().Validate(Options.DefaultName, options);

    [Fact]
    public void DefaultOptions_AreValid()
    {
        var result = Validate(new SiteRuntimeOptions());
        Assert.True(result.Succeeded, result.FailureMessage);
    }

    [Fact]
    public void ZeroStartupBatchSize_IsRejected()
    {
        var result = Validate(new SiteRuntimeOptions { StartupBatchSize = 0 });

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

    [Fact]
    public void ZeroScriptExecutionThreadCount_IsRejected()
    {
        var result = Validate(new SiteRuntimeOptions { ScriptExecutionThreadCount = 0 });

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

    [Fact]
    public void ZeroTagSubscribeRetryIntervalMs_IsRejected()
    {
        var result = Validate(new SiteRuntimeOptions { TagSubscribeRetryIntervalMs = 0 });

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

    [Fact]
    public void NegativeStuckScriptGraceMs_IsRejected()
    {
        var result = Validate(new SiteRuntimeOptions { StuckScriptGraceMs = -1 });

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

    [Fact]
    public void ZeroStreamBufferSize_IsRejected()
    {
        var result = Validate(new SiteRuntimeOptions { StreamBufferSize = 0 });

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

    [Fact]
    public void NegativeStartupBatchDelayMs_IsRejected()
    {
        var result = Validate(new SiteRuntimeOptions { StartupBatchDelayMs = -1 });

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

    [Fact]
    public void ZeroAlarmPublishQueueCapacity_IsRejected()
    {
        var result = Validate(new SiteRuntimeOptions { AlarmPublishQueueCapacity = 0 });

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

    // ── WP3.1 options ──────────────────────────────────────────────────────────────

    /// <summary>
    /// The ceiling is the upper bound of the instance-scaled pool; below the floor it would
    /// silently shrink the configured pool instead of growing it.
    /// </summary>
    [Fact]
    public void ScriptExecutionMaxThreadCountBelowThreadCount_IsRejected()
    {
        var result = Validate(new SiteRuntimeOptions
        {
            ScriptExecutionThreadCount = 8,
            ScriptExecutionMaxThreadCount = 4
        });

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

    [Fact]
    public void EqualScriptExecutionThreadCountAndMax_IsAccepted()
    {
        var result = Validate(new SiteRuntimeOptions
        {
            ScriptExecutionThreadCount = 8,
            ScriptExecutionMaxThreadCount = 8
        });

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

    /// <summary>A zero gate would park every Expression trigger on the node forever.</summary>
    [Fact]
    public void ZeroTriggerEvalMaxConcurrency_IsRejected()
    {
        var result = Validate(new SiteRuntimeOptions { TriggerEvalMaxConcurrency = 0 });

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

    [Fact]
    public void ZeroTriggerEvalTimeoutSeconds_IsRejected()
    {
        var result = Validate(new SiteRuntimeOptions { TriggerEvalTimeoutSeconds = 0 });

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

    /// <summary>A zero cap would shed every trigger, silently disabling all scripts.</summary>
    [Fact]
    public void ZeroTraceArmWindowSeconds_IsRejected()
    {
        // Flow Debugger design 2026-09-05 §5.3: the arm window must be positive.
        var result = Validate(new SiteRuntimeOptions { TraceArmWindowSeconds = 0 });

        Assert.True(result.Failed);
        Assert.Contains("TraceArmWindowSeconds", result.FailureMessage);
        Assert.Equal(30, new SiteRuntimeOptions().TraceArmWindowSeconds);
    }

    /// <summary>A zero cap would drop every log line AND the closing row that reports the drops.</summary>
    [Fact]
    public void ZeroMaxLogLinesPerRun_IsRejected()
    {
        // Flow Debugger step logs (design 2026-09-09 D7): the per-run cap must be positive.
        var result = Validate(new SiteRuntimeOptions { MaxLogLinesPerRun = 0 });

        Assert.True(result.Failed);
        Assert.Contains("MaxLogLinesPerRun", result.FailureMessage);
        Assert.Equal(200, new SiteRuntimeOptions().MaxLogLinesPerRun);
    }

    [Fact]
    public void ZeroMaxConcurrentRunsPerScript_IsRejected()
    {
        var result = Validate(new SiteRuntimeOptions { MaxConcurrentRunsPerScript = 0 });

        Assert.True(result.Failed);
        Assert.Contains("MaxConcurrentRunsPerScript", result.FailureMessage);
    }
    // --- Lever 1 (2026-08-28): tag-subscribe backoff + in-flight ceiling ---

    [Fact]
    public void TagSubscribeRetryMaxIntervalMs_BelowFloor_IsRejected()
    {
        var result = Validate(new SiteRuntimeOptions
        {
            TagSubscribeRetryIntervalMs = 5000,
            TagSubscribeRetryMaxIntervalMs = 4999,
        });

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

    [Fact]
    public void TagSubscribeRetryMaxIntervalMs_EqualToFloor_IsValid()
    {
        var result = Validate(new SiteRuntimeOptions
        {
            TagSubscribeRetryIntervalMs = 5000,
            TagSubscribeRetryMaxIntervalMs = 5000,
        });
        Assert.True(result.Succeeded, result.FailureMessage);
    }

    [Fact]
    public void ZeroTagSubscribeInFlightCeilingMs_IsRejected()
    {
        var result = Validate(new SiteRuntimeOptions { TagSubscribeInFlightCeilingMs = 0 });

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