using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.Recorder;
using ZB.MOM.WW.OtOpcUa.Runtime.Historian;

namespace ZB.MOM.WW.OtOpcUa.Driver.Historian.Gateway.Tests;

/// <summary>
///     Continuous historization on the Gateway backend silently loses what the SQL backends keep — every sample's
///     quality (the gateway stores Good), comms-loss outage markers and non-numeric values — so building the live writer
///     (which only happens when continuous historization is enabled) logs one startup Warning naming the gaps.
/// </summary>
public sealed class GatewayContinuousHistorizationWarningTests
{
    private sealed class CapturingProvider : ILoggerProvider
    {
        public readonly List<(LogLevel Level, string Message)> Entries = new();
        public ILogger CreateLogger(string categoryName) => new L(this);
        public void Dispose() { }

        private sealed class L(CapturingProvider owner) : ILogger
        {
            public IDisposable? BeginScope<TState>(TState state) where TState : notnull => null;
            public bool IsEnabled(LogLevel logLevel) => true;
            public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception? exception, Func<TState, Exception?, string> formatter)
            {
                lock (owner.Entries) owner.Entries.Add((logLevel, formatter(state, exception)));
            }
        }
    }

    [Fact]
    public async Task Building_the_gateway_live_writer_warns_once_about_what_the_backend_drops()
    {
        var capture = new CapturingProvider();
        using var sp = new ServiceCollection().AddLogging(b => b.AddProvider(capture)).BuildServiceProvider();
        var provider = new GatewayHistorianProvider(
            new ServerHistorianOptions { Endpoint = "http://localhost:5222", UseTls = false, ApiKey = "histgw_test_secret" });

        var writer = Assert.IsType<GatewayHistorianValueWriter>(provider.CreateValueWriter(sp));

        var warning = capture.Entries.Where(e => e.Level == LogLevel.Warning).ShouldHaveSingleItem().Message;
        warning.ShouldContain("quality");
        warning.ShouldContain("Good");
        warning.ShouldContain("outage");
        warning.ShouldContain("non-numeric");
        warning.ShouldContain("SqlServer");
        await writer.DisposeAsync();

        // Positive control in the other direction: the read path alone (no continuous historization) does not warn.
        capture.Entries.Clear();
        await using var ds = (GatewayHistorianDataSource)provider.CreateDataSource(sp);
        capture.Entries.ShouldNotContain(e => e.Level == LogLevel.Warning);
    }
}