using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.Browser;

namespace ZB.MOM.WW.OtOpcUa.Driver.OpcUaClient.Browser.Tests;

/// <summary>
///     Unit-only coverage of <see cref="OpcUaClientDriverBrowser"/>'s pre-connect
///     validation. These tests do not require a live OPC UA endpoint and are safe to
///     run without the opc-plc Docker fixture.
/// </summary>
[Trait("Category", "Unit")]
public sealed class OpcUaClientDriverBrowserTests
{
    private readonly OpcUaClientDriverBrowser _sut = new();

    /// <summary>The DriverType key must match the AdminUI's persisted value.</summary>
    [Fact]
    public void DriverType_is_OpcUaClient() => _sut.DriverType.ShouldBe("OpcUaClient");

    /// <summary>An empty endpoint must fail fast with a clear EndpointUrl-mentioning message.</summary>
    [Fact]
    public async Task OpenAsync_with_empty_endpoint_throws()
    {
        var json = """{"EndpointUrl":"","EndpointUrls":[]}""";
        var ex = await Should.ThrowAsync<InvalidOperationException>(
            () => _sut.OpenAsync(json, TestContext.Current.CancellationToken));
        ex.Message.ShouldContain("EndpointUrl");
    }

    /// <summary>A JSON literal that deserializes to null must fail fast.</summary>
    [Fact]
    public async Task OpenAsync_with_null_json_throws()
    {
        var ex = await Should.ThrowAsync<InvalidOperationException>(
            () => _sut.OpenAsync("null", TestContext.Current.CancellationToken));
        ex.Message.ShouldContain("null");
    }

    /// <summary>Certificate auth is not supported by the browser; the failure message
    /// must say so explicitly rather than surfacing a downstream COM/SDK error.
    /// <c>OpcUaAuthType.Certificate</c> serializes as the numeric value 2 under the
    /// browser's default System.Text.Json options (no string-enum converter).</summary>
    [Fact]
    public async Task OpenAsync_with_certificate_auth_throws_clear_message()
    {
        var json = """{"EndpointUrl":"opc.tcp://127.0.0.1:1","AuthType":2}""";
        var ex = await Should.ThrowAsync<InvalidOperationException>(
            () => _sut.OpenAsync(json, TestContext.Current.CancellationToken));
        ex.Message.ShouldContain("Certificate");
    }
}
