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

using System.Collections.Generic;
using A2A;

namespace Microsoft.Extensions.AI.Agents.A2A.UnitTests;

/// <summary>
/// Unit tests for the <see cref="ChatMessageExtensions"/> class.
/// </summary>
public sealed class ChatMessageExtensionsTests
{
    [Fact]
    public void ToA2AMessage_WithMessageContainingMultipleContents_AddsAllContentsAsParts()
    {
        // Arrange
        var contents = new List<AIContent>
        {
            new HostedFileContent("https://example.com/report.pdf"),
            new TextContent("please summarize the file content"),
            new TextContent("and send it to me over email")
        };
        var chatMessage = new ChatMessage(ChatRole.User, contents);
        var messages = new List<ChatMessage> { chatMessage };

        // Act
        var a2aMessage = messages.ToA2AMessage();

        // Assert
        Assert.NotNull(a2aMessage);
        Assert.NotNull(a2aMessage.MessageId);
        Assert.NotEmpty(a2aMessage.MessageId);

        Assert.Equal(MessageRole.User, a2aMessage.Role);

        Assert.NotNull(a2aMessage.Parts);
        Assert.Equal(3, a2aMessage.Parts.Count);

        var filePart = Assert.IsType<FilePart>(a2aMessage.Parts[0]);
        Assert.NotNull(filePart.File);
        var fileWithUri = Assert.IsType<FileWithUri>(filePart.File);
        Assert.Equal("https://example.com/report.pdf", fileWithUri.Uri);

        var secondTextPart = Assert.IsType<TextPart>(a2aMessage.Parts[1]);
        Assert.Equal("please summarize the file content", secondTextPart.Text);

        var thirdTextPart = Assert.IsType<TextPart>(a2aMessage.Parts[2]);
        Assert.Equal("and send it to me over email", thirdTextPart.Text);
    }

    [Fact]
    public void ToA2AMessage_WithMixedMessages_AddsAllContentsAsParts()
    {
        // Arrange
        var firstMessage = new ChatMessage(ChatRole.User, [
            new HostedFileContent("https://example.com/report.pdf")
        ]);
        var secondMessage = new ChatMessage(ChatRole.User, [
            new TextContent("please summarize the file content")
        ]);
        var thirdMessage = new ChatMessage(ChatRole.User, [
            new TextContent("and send it to me over email")
        ]);
        var messages = new List<ChatMessage> { firstMessage, secondMessage, thirdMessage };

        // Act
        var a2aMessage = messages.ToA2AMessage();

        // Assert
        Assert.NotNull(a2aMessage);
        Assert.NotNull(a2aMessage.MessageId);
        Assert.NotEmpty(a2aMessage.MessageId);

        Assert.Equal(MessageRole.User, a2aMessage.Role);

        Assert.NotNull(a2aMessage.Parts);
        Assert.Equal(3, a2aMessage.Parts.Count);

        var filePart = Assert.IsType<FilePart>(a2aMessage.Parts[0]);
        Assert.NotNull(filePart.File);
        var fileWithUri = Assert.IsType<FileWithUri>(filePart.File);
        Assert.Equal("https://example.com/report.pdf", fileWithUri.Uri);

        var secondTextPart = Assert.IsType<TextPart>(a2aMessage.Parts[1]);
        Assert.Equal("please summarize the file content", secondTextPart.Text);

        var thirdTextPart = Assert.IsType<TextPart>(a2aMessage.Parts[2]);
        Assert.Equal("and send it to me over email", thirdTextPart.Text);
    }
}