// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Logging.Abstractions;
using Microsoft.Extensions.Logging.Testing;
using Xunit;
 
namespace Microsoft.Extensions.AI;
 
public class LoggingChatClientTests
{
    [Fact]
    public void LoggingChatClient_InvalidArgs_Throws()
    {
        Assert.Throws<ArgumentNullException>("innerClient", () => new LoggingChatClient(null!, NullLogger.Instance));
        Assert.Throws<ArgumentNullException>("logger", () => new LoggingChatClient(new TestChatClient(), null!));
    }
 
    [Fact]
    public void UseLogging_AvoidsInjectingNopClient()
    {
        using var innerClient = new TestChatClient();
 
        Assert.Null(innerClient.AsBuilder().UseLogging(NullLoggerFactory.Instance).Build().GetService(typeof(LoggingChatClient)));
        Assert.Same(innerClient, innerClient.AsBuilder().UseLogging(NullLoggerFactory.Instance).Build().GetService(typeof(IChatClient)));
 
        using var factory = LoggerFactory.Create(b => b.AddFakeLogging());
        Assert.NotNull(innerClient.AsBuilder().UseLogging(factory).Build().GetService(typeof(LoggingChatClient)));
 
        ServiceCollection c = new();
        c.AddFakeLogging();
        var services = c.BuildServiceProvider();
        Assert.NotNull(innerClient.AsBuilder().UseLogging().Build(services).GetService(typeof(LoggingChatClient)));
        Assert.NotNull(innerClient.AsBuilder().UseLogging(null).Build(services).GetService(typeof(LoggingChatClient)));
        Assert.Null(innerClient.AsBuilder().UseLogging(NullLoggerFactory.Instance).Build(services).GetService(typeof(LoggingChatClient)));
    }
 
    [Theory]
    [InlineData(LogLevel.Trace)]
    [InlineData(LogLevel.Debug)]
    [InlineData(LogLevel.Information)]
    public async Task GetResponseAsync_LogsResponseInvocationAndCompletion(LogLevel level)
    {
        var collector = new FakeLogCollector();
 
        ServiceCollection c = new();
        c.AddLogging(b => b.AddProvider(new FakeLoggerProvider(collector)).SetMinimumLevel(level));
        var services = c.BuildServiceProvider();
 
        using IChatClient innerClient = new TestChatClient
        {
            GetResponseAsyncCallback = (messages, options, cancellationToken) =>
            {
                return Task.FromResult(new ChatResponse(new ChatMessage(ChatRole.Assistant, "blue whale")));
            },
        };
 
        using IChatClient client = innerClient
            .AsBuilder()
            .UseLogging()
            .Build(services);
 
        await client.GetResponseAsync(
            [new(ChatRole.User, "What's the biggest animal?")],
            new ChatOptions { FrequencyPenalty = 3.0f });
 
        var logs = collector.GetSnapshot();
        if (level is LogLevel.Trace)
        {
            Assert.Collection(logs,
                entry => Assert.True(entry.Message.Contains("GetResponseAsync invoked:") && entry.Message.Contains("biggest animal")),
                entry => Assert.True(entry.Message.Contains("GetResponseAsync completed:") && entry.Message.Contains("blue whale")));
        }
        else if (level is LogLevel.Debug)
        {
            Assert.Collection(logs,
                entry => Assert.True(entry.Message.Contains("GetResponseAsync invoked.") && !entry.Message.Contains("biggest animal")),
                entry => Assert.True(entry.Message.Contains("GetResponseAsync completed.") && !entry.Message.Contains("blue whale")));
        }
        else
        {
            Assert.Empty(logs);
        }
    }
 
    [Theory]
    [InlineData(LogLevel.Trace)]
    [InlineData(LogLevel.Debug)]
    [InlineData(LogLevel.Information)]
    public async Task GetResponseStreamingStreamAsync_LogsUpdateReceived(LogLevel level)
    {
        var collector = new FakeLogCollector();
        using ILoggerFactory loggerFactory = LoggerFactory.Create(b => b.AddProvider(new FakeLoggerProvider(collector)).SetMinimumLevel(level));
 
        using IChatClient innerClient = new TestChatClient
        {
            GetStreamingResponseAsyncCallback = (messages, options, cancellationToken) => GetUpdatesAsync()
        };
 
        static async IAsyncEnumerable<ChatResponseUpdate> GetUpdatesAsync()
        {
            await Task.Yield();
            yield return new(ChatRole.Assistant, "blue ");
            yield return new(ChatRole.Assistant, "whale");
        }
 
        using IChatClient client = innerClient
            .AsBuilder()
            .UseLogging(loggerFactory)
            .Build();
 
        await foreach (var update in client.GetStreamingResponseAsync(
            [new(ChatRole.User, "What's the biggest animal?")],
            new ChatOptions { FrequencyPenalty = 3.0f }))
        {
            // nop
        }
 
        var logs = collector.GetSnapshot();
        if (level is LogLevel.Trace)
        {
            Assert.Collection(logs,
                entry => Assert.True(entry.Message.Contains("GetStreamingResponseAsync invoked:") && entry.Message.Contains("biggest animal")),
                entry => Assert.True(entry.Message.Contains("GetStreamingResponseAsync received update:") && entry.Message.Contains("blue")),
                entry => Assert.True(entry.Message.Contains("GetStreamingResponseAsync received update:") && entry.Message.Contains("whale")),
                entry => Assert.Contains("GetStreamingResponseAsync completed.", entry.Message));
        }
        else if (level is LogLevel.Debug)
        {
            Assert.Collection(logs,
                entry => Assert.True(entry.Message.Contains("GetStreamingResponseAsync invoked.") && !entry.Message.Contains("biggest animal")),
                entry => Assert.Contains("GetStreamingResponseAsync completed.", entry.Message));
        }
        else
        {
            Assert.Empty(logs);
        }
    }
}