FsMcp/FsMcp/Tools/ConversationsTools.cs

using System.ComponentModel;
using System.Net.Http.Json;
using System.Text.Json.Serialization;
using FsMcp;
using ModelContextProtocol.Server;

namespace FsMcp.Tools;

internal sealed class ConversationsTools
{
    private readonly FoodsharingApiClient _apiClient;

    public ConversationsTools(FoodsharingApiClient apiClient)
    {
        _apiClient = apiClient;
    }

    [McpServerTool]
    [Description(@"Get the list of conversations for the current user from GET /api/conversations. 
    Conversations with titles beginning with 'Team' are very likely store-chats. Conversations titled
    with a first name are very likely private conversations with other users. The conversation title is
    not necessarily the same as the store name or user name, though.")]
    public async Task<ConversationsResponse> GetConversationsAsync(
        [Description("Maximum number of results to return.")] int? limit = null,
        [Description("The 0-based index of the first entry that is included.")] int? offset = null)
    {
        await _apiClient.EnsureLoginAsync();
        
        var response = await _apiClient.HttpClient.GetAsync(Endpoints.Conversations(limit, offset));
        if (!response.IsSuccessStatusCode)
        {
            var content = await response.Content.ReadAsStringAsync();
            throw new InvalidOperationException($"API request failed with status {response.StatusCode}: {content}");
        }

        var result = await response.Content.ReadFromJsonAsync<ConversationsResponse>();
        return result ?? new ConversationsResponse();
    }

    [McpServerTool]
    [Description("Get a conversation including some messages from GET /api/conversations/{conversationId}.")]
    public async Task<ConversationResponse> GetConversationAsync(
        [Description("Conversation ID as positive integer (OpenAPI path pattern: [1-9][0-9]*).")] int conversationId,
        [Description("Maximum number of results to return.")] int? limit = null,
        [Description("Set to true to mark the conversation as read.")] bool? markAsRead = null)
    {
        if (conversationId <= 0) throw new ArgumentOutOfRangeException(nameof(conversationId), "conversationId must be positive.");

        await _apiClient.EnsureLoginAsync();

        var response = await _apiClient.HttpClient.GetAsync(Endpoints.Conversation(conversationId, limit, markAsRead));
        if (!response.IsSuccessStatusCode)
        {
            var content = await response.Content.ReadAsStringAsync();
            throw new InvalidOperationException($"API request failed with status {response.StatusCode}: {content}");
        }

        var result = await response.Content.ReadFromJsonAsync<ConversationResponse>();
        return result ?? new ConversationResponse();
    }

    [McpServerTool]
    [Description("Get messages from a conversation from GET /api/conversations/{conversationId}/messages.")]
    public async Task<MessageCollection> GetConversationMessagesAsync(
        [Description("Conversation ID as positive integer (OpenAPI path pattern: [1-9][0-9]*).")] int conversationId,
        [Description("ID of a message to get older messages than this one.")] int? olderThanId = null,
        [Description("Maximum number of results to return.")] int? limit = null)
    {
        if (conversationId <= 0) throw new ArgumentOutOfRangeException(nameof(conversationId), "conversationId must be positive.");

        await _apiClient.EnsureLoginAsync();

        var response = await _apiClient.HttpClient.GetAsync(Endpoints.ConversationMessages(conversationId, olderThanId, limit));
        if (!response.IsSuccessStatusCode)
        {
            var content = await response.Content.ReadAsStringAsync();
            throw new InvalidOperationException($"API request failed with status {response.StatusCode}: {content}");
        }

        var result = await response.Content.ReadFromJsonAsync<MessageCollection>();
        return result ?? new MessageCollection();
    }
}

public sealed record ConversationsResponse
{
    [Description("List of conversations.")]
    [JsonPropertyName("conversations")]
    public IReadOnlyList<Conversation> Conversations { get; init; } = Array.Empty<Conversation>();

    [Description("List of user profiles referenced in the conversations.")]
    [JsonPropertyName("profiles")]
    public IReadOnlyList<ConversationProfile> Profiles { get; init; } = Array.Empty<ConversationProfile>();
}

public sealed record ConversationResponse
{
    [Description("The conversation object.")]
    [JsonPropertyName("conversation")]
    public Conversation? Conversation { get; init; }

    [Description("List of user profiles referenced in this conversation.")]
    [JsonPropertyName("profiles")]
    public IReadOnlyList<ConversationProfile> Profiles { get; init; } = Array.Empty<ConversationProfile>();
}

public sealed record MessageCollection
{
    [Description("List of messages.")]
    [JsonPropertyName("messages")]
    public IReadOnlyList<Message> Messages { get; init; } = Array.Empty<Message>();

    [Description("List of user profiles referenced in the messages.")]
    [JsonPropertyName("profiles")]
    public IReadOnlyList<ConversationProfile> Profiles { get; init; } = Array.Empty<ConversationProfile>();
}

public sealed record Conversation
{
    [Description("Unique identifier of the conversation.")]
    [JsonPropertyName("id")]
    public int Id { get; init; }

    [Description("Title of the conversation.")]
    [JsonPropertyName("title")]
    public string? Title { get; init; }

    [Description("Store ID associated with the conversation, if any.")]
    [JsonPropertyName("storeId")]
    public int? StoreId { get; init; }

    [Description("Number of unread messages.")]
    [JsonPropertyName("unreadMessages")]
    public int? UnreadMessages { get; init; }

    [Description("The latest message in the conversation.")]
    [JsonPropertyName("lastMessage")]
    public Message? LastMessage { get; init; }

    [Description("Messages in the conversation.")]
    [JsonPropertyName("messages")]
    public IReadOnlyList<Message> Messages { get; init; } = Array.Empty<Message>();
}

public sealed record Message
{
    [Description("Unique identifier of the message.")]
    [JsonPropertyName("id")]
    public int Id { get; init; }

    [Description("Body of the message.")]
    [JsonPropertyName("body")]
    public string? Body { get; init; }

    [Description("Timestamp when the message was sent.")]
    [JsonPropertyName("sentAt")]
    public DateTimeOffset? SentAt { get; init; }

    [Description("ID of the author of the message.")]
    [JsonPropertyName("authorId")]
    public int? AuthorId { get; init; }
}

public sealed record ConversationProfile
{
    [Description("ID of the user.")]
    [JsonPropertyName("id")]
    public int Id { get; init; }

    [Description("Name of the user.")]
    [JsonPropertyName("name")]
    public string? Name { get; init; }

    [Description("Avatar path of the user.")]
    [JsonPropertyName("avatar")]
    public string? Avatar { get; init; }

    [Description("Whether the user is currently using the sleeping hat function.")]
    [JsonPropertyName("isSleeping")]
    public bool? IsSleeping { get; init; }
}