// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using Aspire.Cli.Backchannel;
using ModelContextProtocol.Protocol;
using ModelContextProtocol.Server;
 
namespace Aspire.Cli.Mcp;
 
/// <summary>
/// Service responsible for refreshing resource-based MCP tools and sending tool list change notifications.
/// </summary>
internal interface IMcpResourceToolRefreshService
{
    /// <summary>
    /// Attempts to get the current resource tool map if it is valid for the resolved AppHost connection.
    /// </summary>
    /// <param name="connection">The resolved AppHost connection whose resource tools are requested.</param>
    /// <param name="snapshot">When this method returns <c>true</c>, contains the current connection-bound tool map.</param>
    /// <returns><c>true</c> if the tool map is valid and no refresh is needed; otherwise, <c>false</c>.</returns>
    bool TryGetResourceToolMap(
        IAppHostAuxiliaryBackchannel? connection,
        out ResourceToolMapSnapshot snapshot);
 
    /// <summary>
    /// Marks the resource tool map as needing a refresh.
    /// </summary>
    void InvalidateToolMap();
 
    /// <summary>
    /// Refreshes the resource tool map by discovering MCP tools from connected resources.
    /// </summary>
    /// <param name="cancellationToken">The cancellation token.</param>
    /// <returns>A tuple containing the refreshed connection-bound tool map and a flag indicating whether the tool set changed.</returns>
    Task<(ResourceToolMapSnapshot Snapshot, bool Changed)> RefreshResourceToolMapAsync(CancellationToken cancellationToken);
 
    /// <summary>
    /// Sends a tools list changed notification to connected MCP clients.
    /// </summary>
    /// <param name="cancellationToken">The cancellation token.</param>
    Task SendToolsListChangedNotificationAsync(CancellationToken cancellationToken);
 
    /// <summary>
    /// Sets the MCP server instance used for sending notifications.
    /// </summary>
    /// <param name="server">The MCP server, or null to clear.</param>
    void SetMcpServer(McpServer? server);
}
 
/// <summary>
/// Represents an entry in the resource tool map.
/// </summary>
/// <param name="ResourceName">The name of the resource that exposes the tool.</param>
/// <param name="Tool">The MCP tool definition.</param>
internal sealed record ResourceToolEntry(string ResourceName, Tool Tool)
{
    /// <summary>
    /// Projects the resource tool into the exact contract returned by <c>tools/list</c>.
    /// </summary>
    public Tool ToProtocolTool(string exposedName)
    {
        return new Tool
        {
            Name = exposedName,
            Description = Tool.Description,
            InputSchema = Tool.InputSchema,
            OutputSchema = Tool.OutputSchema,
            Annotations = Tool.Annotations
        };
    }
}
 
/// <summary>
/// Represents a resource tool map bound to the exact AppHost connection that produced it.
/// </summary>
/// <param name="Connection">The AppHost connection that produced the tool map, or <c>null</c> when no AppHost was selected.</param>
/// <param name="ToolMap">The resource tools discovered from the connection.</param>
internal sealed record ResourceToolMapSnapshot(
    IAppHostAuxiliaryBackchannel? Connection,
    IReadOnlyDictionary<string, ResourceToolEntry> ToolMap);