using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Host.Configuration;
using ZB.MOM.WW.OtOpcUa.OpcUaServer;

namespace ZB.MOM.WW.OtOpcUa.Host.IntegrationTests;

/// <summary>
/// Task 4 — verifies the net-new <see cref="OpcUaApplicationHostOptionsValidator"/> (built on the
/// shared <c>ZB.MOM.WW.Configuration</c> <c>OptionsValidatorBase</c>/<c>ValidationBuilder</c>) that
/// gates the OPC UA host options at startup. The C# defaults are all valid so a host with no
/// explicit <c>"OpcUa"</c> section still passes; the validator exists to reject explicit
/// prod/env overrides. Failure messages carry the real <c>"OpcUa:"</c> section prefix and the
/// exact shared-primitive wording so they read correctly when surfaced via <c>ValidateOnStart</c>.
/// </summary>
public sealed class OpcUaApplicationHostOptionsValidatorTests
{
    private static readonly OpcUaApplicationHostOptionsValidator Sut = new();

    /// <summary>The C# defaults (the as-bound shape when the section is absent) pass validation.</summary>
    [Fact]
    public void Default_options_succeed()
    {
        Sut.Validate(null, new OpcUaApplicationHostOptions()).Succeeded.ShouldBeTrue();
    }

    /// <summary>A port of 0 reports the shared port-range failure with the OpcUa prefix.</summary>
    [Fact]
    public void Zero_port_fails()
    {
        var result = Sut.Validate(null, new OpcUaApplicationHostOptions { OpcUaPort = 0 });

        result.Failed.ShouldBeTrue();
        result.Failures.ShouldContain("OpcUa:OpcUaPort must be between 1 and 65535 (was 0)");
    }

    /// <summary>A blank public hostname reports the shared required failure with the OpcUa prefix.</summary>
    [Fact]
    public void Blank_public_hostname_fails()
    {
        var result = Sut.Validate(null, new OpcUaApplicationHostOptions { PublicHostname = "" });

        result.Failed.ShouldBeTrue();
        result.Failures.ShouldContain("OpcUa:PublicHostname is required");
    }

    /// <summary>An empty security-profile list reports the shared min-count failure with the OpcUa prefix.</summary>
    [Fact]
    public void Empty_security_profiles_fails()
    {
        var result = Sut.Validate(null, new OpcUaApplicationHostOptions
        {
            EnabledSecurityProfiles = new List<OpcUaSecurityProfile>(),
        });

        result.Failed.ShouldBeTrue();
        result.Failures.ShouldContain("OpcUa:EnabledSecurityProfiles must contain at least 1 item(s) (had 0)");
    }

    /// <summary>#833 review: an enabled lockout with a non-positive duration fails; a disabled one is not checked.</summary>
    [Theory]
    [InlineData(5, 0, 60, false)]
    [InlineData(5, 300, 0, false)]
    [InlineData(5, -1, -1, false)]
    [InlineData(5, 30, 600, true)]
    [InlineData(0, 0, 0, true)]
    [InlineData(-1, 0, 0, true)]
    public void Credential_lockout_durations_must_be_positive_while_enabled(
        int maxFailedAttempts, int lockoutSeconds, int windowSeconds, bool valid)
    {
        var result = Sut.Validate(null, new OpcUaApplicationHostOptions
        {
            CredentialLockout = new ZB.MOM.WW.OtOpcUa.OpcUaServer.Security.OpcUaCredentialLockoutOptions
            {
                MaxFailedAttempts = maxFailedAttempts, LockoutSeconds = lockoutSeconds, FailureWindowSeconds = windowSeconds,
            },
        });

        result.Succeeded.ShouldBe(valid);
        if (!valid) result.Failures!.ShouldContain(f => f.Contains("OpcUa:CredentialLockout:LockoutSeconds"));
    }

    /// <summary>#833 review: the slot wait must be positive while the lockout is enabled.</summary>
    [Fact]
    public void Credential_lockout_slot_wait_must_be_positive_while_enabled()
    {
        var result = Sut.Validate(null, new OpcUaApplicationHostOptions
        {
            CredentialLockout = new ZB.MOM.WW.OtOpcUa.OpcUaServer.Security.OpcUaCredentialLockoutOptions { SlotWaitSeconds = 0 },
        });

        result.Failed.ShouldBeTrue();
        result.Failures!.ShouldContain(f => f.Contains("OpcUa:CredentialLockout:SlotWaitSeconds"));
    }

    /// <summary>#844: the per-client cap may be unset (0) or at least the per-credential threshold.</summary>
    [Theory]
    [InlineData(0, true)]
    [InlineData(5, true)]
    [InlineData(20, true)]
    [InlineData(4, false)]
    public void Credential_lockout_per_client_cap_is_unset_or_at_least_the_per_credential_threshold(int perClient, bool valid)
    {
        var result = Sut.Validate(null, new OpcUaApplicationHostOptions
        {
            CredentialLockout = new ZB.MOM.WW.OtOpcUa.OpcUaServer.Security.OpcUaCredentialLockoutOptions
            {
                MaxFailedAttempts = 5, MaxFailedAttemptsPerClient = perClient,
            },
        });

        result.Succeeded.ShouldBe(valid);
        if (!valid) result.Failures!.ShouldContain(f => f.Contains("OpcUa:CredentialLockout:MaxFailedAttemptsPerClient"));
    }

    /// <summary>#876: discovery registration is opt-in; a configured URL must be opc.tcp and the interval positive.</summary>
    [Theory]
    [InlineData(null, 30_000, true)]
    [InlineData("", 0, true)]
    [InlineData("opc.tcp://lds-host:4840", 30_000, true)]
    [InlineData("http://lds-host:4840", 30_000, false)]
    [InlineData("lds-host:4840", 30_000, false)]
    [InlineData("opc.tcp://lds-host:4840", 0, false)]
    public void Discovery_server_url_must_be_opc_tcp_with_a_positive_interval(string? url, int intervalMs, bool valid)
    {
        var result = Sut.Validate(null, new OpcUaApplicationHostOptions
        {
            DiscoveryServerUrl = url, DiscoveryRegistrationIntervalMs = intervalMs,
        });

        result.Succeeded.ShouldBe(valid);
        if (!valid) result.Failures!.ShouldContain(f => f.Contains("OpcUa:Discovery"));
    }
}