// Copyright (c) Microsoft. All rights reserved.

// %%% SAVE - RE-ANALYZE
//using System.Collections.Generic;
//using System.Threading;
//using System.Threading.Tasks;
//using Microsoft.Agents.AI.Compaction;
//using Microsoft.Extensions.AI;
//using Moq;

//namespace Microsoft.Agents.AI.UnitTests.Compaction;

///// <summary>
///// Contains tests for the compaction integration with <see cref="InMemoryChatHistoryProvider"/>.
///// </summary>
//public class InMemoryChatHistoryProviderCompactionTests
//{
//    private static readonly AIAgent s_mockAgent = new Mock<AIAgent>().Object;

//    private static AgentSession CreateMockSession() => new Mock<AgentSession>().Object;

//    [Fact]
//    public void Constructor_SetsCompactionStrategy_FromOptions()
//    {
//        // Arrange
//        Mock<ICompactionStrategy> strategy = new();

//        // Act
//        InMemoryChatHistoryProvider provider = new(new InMemoryChatHistoryProviderOptions
//        {
//            CompactionStrategy = strategy.Object,
//        });

//        // Assert
//        Assert.Same(strategy.Object, provider.CompactionStrategy);
//    }

//    [Fact]
//    public void Constructor_CompactionStrategyIsNull_ByDefault()
//    {
//        // Arrange & Act
//        InMemoryChatHistoryProvider provider = new();

//        // Assert
//        Assert.Null(provider.CompactionStrategy);
//    }

//    [Fact]
//    public async Task StoreChatHistoryAsync_AppliesCompaction_WhenStrategyConfiguredAsync()
//    {
//        // Arrange — mock strategy that excludes the first included non-system group
//        Mock<ICompactionStrategy> mockStrategy = new();
//        mockStrategy.Setup(s => s.CompactAsync(It.IsAny<MessageIndex>(), It.IsAny<CancellationToken>()))
//            .Callback<MessageIndex, CancellationToken>((groups, _) =>
//            {
//                foreach (MessageGroup group in groups.Groups)
//                {
//                    if (!group.IsExcluded && group.Kind != MessageGroupKind.System)
//                    {
//                        group.IsExcluded = true;
//                        group.ExcludeReason = "Mock compaction";
//                        break;
//                    }
//                }
//            })
//            .ReturnsAsync(true);

//        InMemoryChatHistoryProvider provider = new(new InMemoryChatHistoryProviderOptions
//        {
//            CompactionStrategy = mockStrategy.Object,
//        });

//        AgentSession session = CreateMockSession();

//        // Pre-populate with some messages
//        List<ChatMessage> existingMessages =
//        [
//            new ChatMessage(ChatRole.User, "First"),
//            new ChatMessage(ChatRole.Assistant, "Response 1"),
//        ];
//        provider.SetMessages(session, existingMessages);

//        // Invoke the store flow with additional messages
//        List<ChatMessage> requestMessages =
//        [
//            new ChatMessage(ChatRole.User, "Second"),
//        ];
//        List<ChatMessage> responseMessages =
//        [
//            new ChatMessage(ChatRole.Assistant, "Response 2"),
//        ];

//        ChatHistoryProvider.InvokedContext context = new(s_mockAgent, session, requestMessages, responseMessages);

//        // Act
//        await provider.InvokedAsync(context);

//        // Assert - compaction should have removed one group
//        List<ChatMessage> storedMessages = provider.GetMessages(session);
//        Assert.Equal(3, storedMessages.Count);
//        mockStrategy.Verify(s => s.CompactAsync(It.IsAny<MessageIndex>(), It.IsAny<CancellationToken>()), Times.Once);
//    }

//    [Fact]
//    public async Task StoreChatHistoryAsync_DoesNotCompact_WhenNoStrategyAsync()
//    {
//        // Arrange
//        InMemoryChatHistoryProvider provider = new();
//        AgentSession session = CreateMockSession();

//        List<ChatMessage> requestMessages =
//        [
//            new ChatMessage(ChatRole.User, "Hello"),
//        ];
//        List<ChatMessage> responseMessages =
//        [
//            new ChatMessage(ChatRole.Assistant, "Hi!"),
//        ];

//        ChatHistoryProvider.InvokedContext context = new(s_mockAgent, session, requestMessages, responseMessages);

//        // Act
//        await provider.InvokedAsync(context);

//        // Assert - all messages should be stored
//        List<ChatMessage> storedMessages = provider.GetMessages(session);
//        Assert.Equal(2, storedMessages.Count);
//    }

//    [Fact]
//    public async Task CompactStorageAsync_CompactsStoredMessagesAsync()
//    {
//        // Arrange — mock strategy that excludes the two oldest non-system groups
//        Mock<ICompactionStrategy> mockStrategy = new();
//        mockStrategy.Setup(s => s.CompactAsync(It.IsAny<MessageIndex>(), It.IsAny<CancellationToken>()))
//            .Callback<MessageIndex, CancellationToken>((groups, _) =>
//            {
//                int excluded = 0;
//                foreach (MessageGroup group in groups.Groups)
//                {
//                    if (!group.IsExcluded && group.Kind != MessageGroupKind.System && excluded < 2)
//                    {
//                        group.IsExcluded = true;
//                        excluded++;
//                    }
//                }
//            })
//            .ReturnsAsync(true);

//        InMemoryChatHistoryProvider provider = new(new InMemoryChatHistoryProviderOptions
//        {
//            CompactionStrategy = mockStrategy.Object,
//        });

//        AgentSession session = CreateMockSession();
//        provider.SetMessages(session,
//        [
//            new ChatMessage(ChatRole.User, "First"),
//            new ChatMessage(ChatRole.Assistant, "Response 1"),
//            new ChatMessage(ChatRole.User, "Second"),
//            new ChatMessage(ChatRole.Assistant, "Response 2"),
//        ]);

//        // Act
//        bool result = await provider.CompactStorageAsync(session);

//        // Assert
//        Assert.True(result);
//        List<ChatMessage> messages = provider.GetMessages(session);
//        Assert.Equal(2, messages.Count);
//        mockStrategy.Verify(s => s.CompactAsync(It.IsAny<MessageIndex>(), It.IsAny<CancellationToken>()), Times.Once);
//    }

//    [Fact]
//    public async Task CompactStorageAsync_UsesProvidedStrategy_OverDefaultAsync()
//    {
//        // Arrange
//        Mock<ICompactionStrategy> defaultStrategy = new();
//        Mock<ICompactionStrategy> overrideStrategy = new();

//        overrideStrategy.Setup(s => s.CompactAsync(It.IsAny<MessageIndex>(), It.IsAny<CancellationToken>()))
//            .Callback<MessageIndex, CancellationToken>((groups, _) =>
//            {
//                // Exclude all but the last group
//                for (int i = 0; i < groups.Groups.Count - 1; i++)
//                {
//                    groups.Groups[i].IsExcluded = true;
//                }
//            })
//            .ReturnsAsync(true);

//        InMemoryChatHistoryProvider provider = new(new InMemoryChatHistoryProviderOptions
//        {
//            CompactionStrategy = defaultStrategy.Object,
//        });

//        AgentSession session = CreateMockSession();
//        provider.SetMessages(session,
//        [
//            new ChatMessage(ChatRole.User, "First"),
//            new ChatMessage(ChatRole.User, "Second"),
//            new ChatMessage(ChatRole.User, "Third"),
//        ]);

//        // Act
//        bool result = await provider.CompactStorageAsync(session, overrideStrategy.Object);

//        // Assert
//        Assert.True(result);
//        List<ChatMessage> messages = provider.GetMessages(session);
//        Assert.Single(messages);
//        Assert.Equal("Third", messages[0].Text);

//        // Verify the override was used, not the default
//        overrideStrategy.Verify(s => s.CompactAsync(It.IsAny<MessageIndex>(), It.IsAny<CancellationToken>()), Times.Once);
//        defaultStrategy.Verify(s => s.CompactAsync(It.IsAny<MessageIndex>(), It.IsAny<CancellationToken>()), Times.Never);
//    }

//    [Fact]
//    public async Task CompactStorageAsync_Throws_WhenNoStrategyAvailableAsync()
//    {
//        // Arrange
//        InMemoryChatHistoryProvider provider = new();
//        AgentSession session = CreateMockSession();

//        // Act & Assert
//        await Assert.ThrowsAsync<System.InvalidOperationException>(
//            () => provider.CompactStorageAsync(session));
//    }

//    [Fact]
//    public async Task CompactStorageAsync_WithCustomStrategy_AppliesCustomLogicAsync()
//    {
//        // Arrange
//        Mock<ICompactionStrategy> mockStrategy = new();
//        mockStrategy.Setup(s => s.CompactAsync(It.IsAny<MessageIndex>(), It.IsAny<CancellationToken>()))
//            .Callback<MessageIndex, CancellationToken>((groups, _) =>
//            {
//                // Exclude all user groups
//                foreach (MessageGroup group in groups.Groups)
//                {
//                    if (group.Kind == MessageGroupKind.User)
//                    {
//                        group.IsExcluded = true;
//                    }
//                }
//            })
//            .ReturnsAsync(true);

//        InMemoryChatHistoryProvider provider = new();
//        AgentSession session = CreateMockSession();
//        provider.SetMessages(session,
//        [
//            new ChatMessage(ChatRole.System, "System"),
//            new ChatMessage(ChatRole.User, "User message"),
//            new ChatMessage(ChatRole.Assistant, "Response"),
//        ]);

//        // Act
//        bool result = await provider.CompactStorageAsync(session, mockStrategy.Object);

//        // Assert
//        Assert.True(result);
//        List<ChatMessage> messages = provider.GetMessages(session);
//        Assert.Equal(2, messages.Count);
//        Assert.Equal(ChatRole.System, messages[0].Role);
//        Assert.Equal(ChatRole.Assistant, messages[1].Role);
//    }
//}