using Microsoft.Extensions.Logging.Abstractions;
using NSubstitute;
using ZB.MOM.WW.ScadaBridge.Commons.Entities.InboundApi;
using ZB.MOM.WW.ScadaBridge.Commons.Messages.Communication;

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

/// <summary>
/// ScadaBridge#103: a peer central node's <see cref="InboundApiMethodInvalidated"/> drops this
/// node's compiled handler, known-bad record and cached row for that method only.
/// </summary>
public class InboundApiCacheInvalidationHandlerTests
{
    private readonly InboundScriptExecutor _executor =
        new(NullLogger<InboundScriptExecutor>.Instance, Substitute.For<IServiceProvider>());
    private readonly ApiMethodCache _cache = new(TimeSpan.FromHours(1));

    private async Task<bool> Refetches(string name)
    {
        var fetched = false;
        await _cache.GetOrFetchAsync(name, _ => { fetched = true; return Task.FromResult<ApiMethod?>(null); }, CancellationToken.None);
        return fetched;
    }

    /// <summary>The named method's known-bad record, handler and row are dropped; others are kept.</summary>
    /// <returns>A task that represents the asynchronous operation.</returns>
    [Fact]
    public async Task Apply_DropsOnlyTheNamedMethod()
    {
        var bad = new ApiMethod("Bad", "return doesNotExist;");
        var good = new ApiMethod("Good", "return 1;");
        Assert.False(_executor.CompileAndRegister(bad));
        Assert.True(_executor.CompileAndRegister(good));
        await _cache.GetOrFetchAsync("Bad", _ => Task.FromResult<ApiMethod?>(bad), CancellationToken.None);
        await _cache.GetOrFetchAsync("Good", _ => Task.FromResult<ApiMethod?>(good), CancellationToken.None);

        var handler = new InboundApiCacheInvalidationHandler(_executor, _cache);
        handler.Apply(new InboundApiMethodInvalidated("Bad"));
        handler.Apply(new RoleMappingsInvalidated()); // not ours: ignored

        Assert.False(_executor.GetCompileState("Bad", bad.Script).IsKnownBad);
        Assert.True(await Refetches("Bad"));
        Assert.True(_executor.GetCompileState("Good", good.Script).IsCompiled);
        Assert.False(await Refetches("Good"));
    }
}