AX-Copilot-Codex/src/AxCopilot.Tests/Services/AgentLoopLlmRequestPreparationServiceTests.cs

using AxCopilot.Models;
using AxCopilot.Services.Agent;
using FluentAssertions;
using Xunit;

namespace AxCopilot.Tests.Services;

public class AgentLoopLlmRequestPreparationServiceTests
{
    [Fact]
    public void Prepare_ShouldInjectToolReminderOnFirstForcedCall()
    {
        var queryMessages = new List<ChatMessage>
        {
            new()
            {
                Role = "user",
                Content = "inspect the repository"
            }
        };

        var result = AgentLoopLlmRequestPreparationService.Prepare(
            queryMessages,
            totalToolCalls: 0,
            forceInitialToolCallEnabled: true,
            injectPreCallToolReminder: true,
            noToolCallLoopRetry: 0);

        result.ForceInitialToolCall.Should().BeTrue();
        result.InjectedToolReminder.Should().BeTrue();
        result.SendMessages.Should().HaveCount(2);
        result.SendMessages.Last().Content.Should().Contain("[TOOL_REQUIRED]");
    }

    [Fact]
    public void Prepare_ShouldSkipReminderWhenRetryLoopIsAlreadyActive()
    {
        var queryMessages = new List<ChatMessage>
        {
            new()
            {
                Role = "user",
                Content = "inspect the repository"
            }
        };

        var result = AgentLoopLlmRequestPreparationService.Prepare(
            queryMessages,
            totalToolCalls: 0,
            forceInitialToolCallEnabled: true,
            injectPreCallToolReminder: true,
            noToolCallLoopRetry: 1);

        result.ForceInitialToolCall.Should().BeTrue();
        result.InjectedToolReminder.Should().BeFalse();
        result.SendMessages.Should().HaveCount(1);
    }

    [Fact]
    public void Prepare_ShouldAppendSupplementalMessagesBeforeReminder()
    {
        var queryMessages = new List<ChatMessage>
        {
            new()
            {
                Role = "user",
                Content = "fix the latest build failure"
            }
        };
        var supplemental = new ChatMessage
        {
            Role = "system",
            MetaKind = "code_working_set",
            Content = "[code-working-set]\n- Active diagnostic: MC4005 - Themes/ControlStyles.xaml"
        };

        var result = AgentLoopLlmRequestPreparationService.Prepare(
            queryMessages,
            totalToolCalls: 0,
            forceInitialToolCallEnabled: true,
            injectPreCallToolReminder: true,
            noToolCallLoopRetry: 0,
            supplementalMessages: [supplemental]);

        result.SupplementalMessageCount.Should().Be(1);
        result.SendMessages[1].MetaKind.Should().Be("code_working_set");
        result.SendMessages.Last().Content.Should().Contain("[TOOL_REQUIRED]");
    }

    [Fact]
    public void Prepare_ShouldNormalizeBrokenHistoricalToolTraceBeforeSend()
    {
        var queryMessages = new List<ChatMessage>
        {
            new()
            {
                Role = "assistant",
                Content = """{"_tool_use_blocks":[{"type":"text","text":"Inspecting source"},{"type":"tool_use","id":"call-missing","name":"file_read","input":{"path":"App.xaml"}}]}"""
            },
            new()
            {
                Role = "user",
                Content = "fix the latest build failure"
            }
        };

        var result = AgentLoopLlmRequestPreparationService.Prepare(
            queryMessages,
            totalToolCalls: 1,
            forceInitialToolCallEnabled: true,
            injectPreCallToolReminder: true,
            noToolCallLoopRetry: 0);

        result.FlattenedStructuredAssistantCount.Should().Be(1);
        result.ConvertedOrphanToolResultCount.Should().Be(0);
        result.SendMessages[0].Content.Should().Be("Inspecting source\n[previous tool call] file_read");
        queryMessages[0].Content.Should().StartWith("{\"_tool_use_blocks\"");
    }
}