mcp-vala/examples/simple-server.vala

/*
 * Copyright (C) 2025 Mcp-Vala Project
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Author: Mcp-Vala Project
 */

using Mcp;

/**
 * Simple MCP server example.
 * 
 * This example demonstrates basic usage of the MCP Vala library
 * with a simple echo tool and basic resource provider.
 */
public class SimpleServer : GLib.Object {
    private Mcp.Core.Server server;
    
    /**
     * Creates a new SimpleServer.
     */
    public SimpleServer () {
        // Create server info
        var server_info = new Mcp.Types.Protocol.ServerInfo (
            "simple-server",
            "1.0.0"
        );
        server_info.description = "A simple MCP server example";
        
        // Create server capabilities
        var capabilities = new Mcp.Types.Protocol.ServerCapabilities ();
        capabilities.logging = true;
        
        // Create server
        server = new Mcp.Core.Server (server_info, capabilities);
        
        // Register tools with tool manager
        var echo_tool = new EchoTool ();
        try {
            server.tool_manager.register_executor ("echo", echo_tool);
        } catch (Error e) {
            // Error handling
        }
        
        var calculator_tool = new CalculatorTool ();
        try {
            server.tool_manager.register_executor ("calculator", calculator_tool);
        } catch (Error e) {
            // Error handling
        }
        
        var file_tool = new FileOperationTool ();
        try {
            server.tool_manager.register_executor ("file_ops", file_tool);
        } catch (Error e) {
            // Error handling
        }
        
        // Register resource providers with the resource manager
        var file_provider = new FileResourceProvider ();
        server.resource_manager.register_provider ("file", file_provider);
        
        var memory_provider = new MemoryResourceProvider ();
        server.resource_manager.register_provider ("memory", memory_provider);
        
        // Add a resource template
        var template = new Mcp.Resources.Types.Resource.ResourceTemplate (
            "note",
            "Create a new note"
        );
        template.description = "Creates a new text note with specified content";
        server.resource_manager.register_template ("note", template);
        
        // Register prompt templates with the prompt manager
        var code_review_prompt = new CodeReviewPromptTemplate ();
        try {
            server.prompt_manager.register_template ("code_review", code_review_prompt);
        } catch (Error e) {
            // Error handling
        }
        
        var summary_prompt = new SummaryPromptTemplate ();
        try {
            server.prompt_manager.register_template ("summary", summary_prompt);
        } catch (Error e) {
            // Error handling
        }
        
        var explain_prompt = new ExplainPromptTemplate ();
        try {
            server.prompt_manager.register_template ("explain", explain_prompt);
        } catch (Error e) {
            // Error handling
        }
    }
    
    /**
     * Runs the server.
     *
     * @return Exit code
     */
    public async int run () {
        try {
            // Start the server
            bool started = yield server.start ();
            if (!started) {
                return 1;
            }
            
            // Server started. Waiting for connections...
            
            // Start a demo timer to show resource updates
            Timeout.add_seconds (5, () => {
                demo_resource_updates ();
                return true; // Continue timer
            });
            
            // Run the main loop
            var main_loop = new MainLoop ();
            
            // Connect shutdown signal
            server.shutdown.connect (() => {
                main_loop.quit ();
            });
            
            main_loop.run ();
            
            return 0;
        } catch (Error e) {
            return 1;
        }
    }
    
    /**
     * Demonstrates resource updates and notifications.
     */
    private void demo_resource_updates () {
        // Get the memory provider
        // Get the memory provider from the resource manager's providers
        var providers = server.resource_manager.get_providers ();
        MemoryResourceProvider? provider = null;
        foreach (var key in providers.get_keys ()) {
            if (key == "memory") {
                provider = providers.get (key) as MemoryResourceProvider;
                break;
            }
        }
        if (provider != null) {
            // Increment the counter
            int new_value = provider.increment_counter ();
            
            // Create a new note every 30 seconds (6 * 5 second intervals)
            uint note_counter = 0;
            note_counter++;
            if (note_counter % 6 == 0) {
                string uri = provider.create_note (
                    "Demo Note %u".printf (note_counter / 6),
                    "This is an auto-generated note created at %s".printf (new DateTime.now_utc ().to_string ())
                );
            }
        }
    }
}

/**
 * Simple echo tool implementation.
 */
public class EchoTool : Mcp.Tools.BaseExecutor {
    /**
     * Creates a new EchoTool.
     */
    public EchoTool () {
        // Create tool definition using Variant
        var builder = new VariantBuilder (new VariantType ("a{sv}"));
        
        // Add schema properties
        builder.add ("{sv}", "type", new Variant.string ("object"));
        builder.add ("{sv}", "description", new Variant.string ("Text to echo back"));
        
        var properties_builder = new VariantBuilder (new VariantType ("a{sv}"));
        
        var text_prop_builder = new VariantBuilder (new VariantType ("a{sv}"));
        text_prop_builder.add ("{sv}", "type", new Variant.string ("string"));
        text_prop_builder.add ("{sv}", "description", new Variant.string ("The text to echo back"));
        properties_builder.add ("{sv}", "text", text_prop_builder.end ());
        
        builder.add ("{sv}", "properties", properties_builder.end ());
        
        var required_array_builder = new VariantBuilder (new VariantType ("as"));
        required_array_builder.add ("s", "text");
        builder.add ("{sv}", "required", required_array_builder.end ());
        
        var input_schema = builder.end ();
        
        var definition = new Mcp.Tools.Types.ToolDefinition ("echo", input_schema);
        definition.title = "Echo Tool";
        definition.description = "Echoes back the provided text";
        
        base (definition);
    }
    
    /**
     * {@inheritDoc}
     */
    protected override async Mcp.Tools.Types.CallToolResult do_execute (GLib.Variant arguments) throws Error {
        string text = get_string_arg (arguments, "text");
        
        return create_text_result ("Echo: %s".printf (text));
    }
}

/**
 * Calculator tool implementation.
 */
public class CalculatorTool : Mcp.Tools.BaseExecutor {
    /**
     * Creates a new CalculatorTool.
     */
    public CalculatorTool () {
        // Create tool definition using Variant
        var builder = new VariantBuilder (new VariantType ("a{sv}"));
        
        // Add schema properties
        builder.add ("{sv}", "type", new Variant.string ("object"));
        builder.add ("{sv}", "description", new Variant.string ("Perform mathematical calculations"));
        
        var properties_builder = new VariantBuilder (new VariantType ("a{sv}"));
        
        // Expression property
        var expr_prop_builder = new VariantBuilder (new VariantType ("a{sv}"));
        expr_prop_builder.add ("{sv}", "type", new Variant.string ("string"));
        expr_prop_builder.add ("{sv}", "description", new Variant.string ("Mathematical expression to evaluate (e.g., '2 + 3 * 4')"));
        properties_builder.add ("{sv}", "expression", expr_prop_builder.end ());
        
        // Operation property
        var op_prop_builder = new VariantBuilder (new VariantType ("a{sv}"));
        op_prop_builder.add ("{sv}", "type", new Variant.string ("string"));
        op_prop_builder.add ("{sv}", "description", new Variant.string ("Operation: add, subtract, multiply, divide"));
        
        var enum_array_builder = new VariantBuilder (new VariantType ("as"));
        enum_array_builder.add ("s", "add");
        enum_array_builder.add ("s", "subtract");
        enum_array_builder.add ("s", "multiply");
        enum_array_builder.add ("s", "divide");
        op_prop_builder.add ("{sv}", "enum", enum_array_builder.end ());
        properties_builder.add ("{sv}", "operation", op_prop_builder.end ());
        
        // Operands property
        var operands_prop_builder = new VariantBuilder (new VariantType ("a{sv}"));
        operands_prop_builder.add ("{sv}", "type", new Variant.string ("array"));
        operands_prop_builder.add ("{sv}", "description", new Variant.string ("Array of numbers for the operation"));
        
        var items_schema_builder = new VariantBuilder (new VariantType ("a{sv}"));
        items_schema_builder.add ("{sv}", "type", new Variant.string ("number"));
        operands_prop_builder.add ("{sv}", "items", items_schema_builder.end ());
        properties_builder.add ("{sv}", "operands", operands_prop_builder.end ());
        
        builder.add ("{sv}", "properties", properties_builder.end ());
        
        var required_array_builder = new VariantBuilder (new VariantType ("as"));
        required_array_builder.add ("s", "expression");
        builder.add ("{sv}", "required", required_array_builder.end ());
        
        var input_schema = builder.end ();
        
        var definition = new Mcp.Tools.Types.ToolDefinition ("calculator", input_schema);
        definition.title = "Calculator";
        definition.description = "Perform mathematical calculations";
        
        base (definition);
    }
    
    /**
     * {@inheritDoc}
     */
    protected override async Mcp.Tools.Types.CallToolResult do_execute (GLib.Variant arguments) throws Error {
        string expression = get_string_arg (arguments, "expression");
        string operation = get_string_arg (arguments, "operation", "");
        
        // Parse operands if provided
        double[] operands = {};
        if (arguments.lookup_value ("operands", null) != null) {
            var operands_variant = arguments.lookup_value ("operands", new VariantType ("ad"));
            if (operands_variant != null) {
                // Get the array from variant using proper GLib.Variant API
                size_t n_elements;
                double* elements = (double*) operands_variant.get_data ();
                n_elements = operands_variant.n_children ();
                
                operands = new double[n_elements];
                for (size_t i = 0; i < n_elements; i++) {
                    operands[i] = operands_variant.get_child_value (i).get_double ();
                }
            }
        }
        
        double result = 0.0;
        
        if (expression != "") {
            // Simple expression evaluation (in real implementation, use proper parser)
            try {
                result = evaluate_simple_expression (expression);
            } catch (Error e) {
                throw new Mcp.Core.McpError.INVALID_PARAMS ("Invalid expression: %s".printf (e.message));
            }
        } else if (operands.length > 0) {
            // Use operation with operands
            if (operands.length < 2) {
                throw new Mcp.Core.McpError.INVALID_PARAMS ("Operation requires at least 2 operands");
            }
            
            switch (operation) {
                case "add":
                    result = operands[0] + operands[1];
                    break;
                case "subtract":
                    result = operands[0] - operands[1];
                    break;
                case "multiply":
                    result = operands[0] * operands[1];
                    break;
                case "divide":
                    if (operands[1] == 0) {
                        throw new Mcp.Core.McpError.INVALID_PARAMS ("Division by zero");
                    }
                    result = operands[0] / operands[1];
                    break;
                default:
                    throw new Mcp.Core.McpError.INVALID_PARAMS ("Unknown operation: %s".printf (operation));
            }
        } else {
            throw new Mcp.Core.McpError.INVALID_PARAMS ("Either expression or operands must be provided");
        }
        
        // Create structured result using Variant
        var structured_data_builder = new VariantBuilder (new VariantType ("a{sv}"));
        structured_data_builder.add ("{sv}", "result", new Variant.double (result));
        structured_data_builder.add ("{sv}", "expression", new Variant.string (expression != "" ? expression : operation));
        
        var structured_data = structured_data_builder.end ();
        
        return create_structured_result ("Calculation result: %g".printf (result), structured_data);
    }
    
    /**
     * Evaluates a simple mathematical expression.
     *
     * @param expression The expression to evaluate
     * @return The result
     * @throws Error If evaluation fails
     */
    private double evaluate_simple_expression (string expression) throws Error {
        // Very simple expression evaluator for demonstration
        // In production, use a proper math expression parser
        
        // Handle basic operations
        if (expression.contains ("+")) {
            var parts = expression.split ("+");
            if (parts.length == 2) {
                double a = double.parse (parts[0].strip ());
                double b = double.parse (parts[1].strip ());
                return a + b;
            }
        } else if (expression.contains ("-")) {
            var parts = expression.split ("-");
            if (parts.length == 2) {
                double a = double.parse (parts[0].strip ());
                double b = double.parse (parts[1].strip ());
                return a - b;
            }
        } else if (expression.contains ("*")) {
            var parts = expression.split ("*");
            if (parts.length == 2) {
                double a = double.parse (parts[0].strip ());
                double b = double.parse (parts[1].strip ());
                return a * b;
            }
        } else if (expression.contains ("/")) {
            var parts = expression.split ("/");
            if (parts.length == 2) {
                double a = double.parse (parts[0].strip ());
                double b = double.parse (parts[1].strip ());
                if (b == 0) {
                    throw new Mcp.Core.McpError.INVALID_PARAMS ("Division by zero");
                }
                return a / b;
            }
        }
        
        // Try to parse as single number
        return double.parse (expression);
    }
}

/**
 * File operations tool implementation.
 */
public class FileOperationTool : Mcp.Tools.BaseExecutor {
    /**
     * Creates a new FileOperationTool.
     */
    public FileOperationTool () {
        // Create tool definition using Variant
        var builder = new VariantBuilder (new VariantType ("a{sv}"));
        
        // Add schema properties
        builder.add ("{sv}", "type", new Variant.string ("object"));
        builder.add ("{sv}", "description", new Variant.string ("Perform file operations"));
        
        var properties_builder = new VariantBuilder (new VariantType ("a{sv}"));
        
        // Operation property
        var op_prop_builder = new VariantBuilder (new VariantType ("a{sv}"));
        op_prop_builder.add ("{sv}", "type", new Variant.string ("string"));
        op_prop_builder.add ("{sv}", "description", new Variant.string ("Operation: read, write, list, delete"));
        
        var enum_array_builder = new VariantBuilder (new VariantType ("as"));
        enum_array_builder.add ("s", "read");
        enum_array_builder.add ("s", "write");
        enum_array_builder.add ("s", "list");
        enum_array_builder.add ("s", "delete");
        op_prop_builder.add ("{sv}", "enum", enum_array_builder.end ());
        properties_builder.add ("{sv}", "operation", op_prop_builder.end ());
        
        // Path property
        var path_prop_builder = new VariantBuilder (new VariantType ("a{sv}"));
        path_prop_builder.add ("{sv}", "type", new Variant.string ("string"));
        path_prop_builder.add ("{sv}", "description", new Variant.string ("File path"));
        properties_builder.add ("{sv}", "path", path_prop_builder.end ());
        
        // Content property (for write operation)
        var content_prop_builder = new VariantBuilder (new VariantType ("a{sv}"));
        content_prop_builder.add ("{sv}", "type", new Variant.string ("string"));
        content_prop_builder.add ("{sv}", "description", new Variant.string ("Content to write (for write operation)"));
        properties_builder.add ("{sv}", "content", content_prop_builder.end ());
        
        builder.add ("{sv}", "properties", properties_builder.end ());
        
        var required_array_builder = new VariantBuilder (new VariantType ("as"));
        required_array_builder.add ("s", "operation");
        required_array_builder.add ("s", "path");
        builder.add ("{sv}", "required", required_array_builder.end ());
        
        var input_schema = builder.end ();
        
        var definition = new Mcp.Tools.Types.ToolDefinition ("file_ops", input_schema);
        definition.title = "File Operations";
        definition.description = "Perform basic file operations";
        
        base (definition);
    }
    
    /**
     * {@inheritDoc}
     */
    protected override async Mcp.Tools.Types.CallToolResult do_execute (GLib.Variant arguments) throws Error {
        string operation = get_string_arg (arguments, "operation");
        string path = get_string_arg (arguments, "path");
        string content = get_string_arg (arguments, "content", "");
        
        switch (operation) {
            case "read":
                return yield handle_read (path);
            case "write":
                return yield handle_write (path, content);
            case "list":
                return yield handle_list (path);
            case "delete":
                return yield handle_delete (path);
            default:
                throw new Mcp.Core.McpError.INVALID_PARAMS ("Unknown operation: %s".printf (operation));
        }
    }
    
    /**
     * Handles file read operation.
     *
     * @param path The file path
     * @return The operation result
     * @throws Error If reading fails
     */
    private async Mcp.Tools.Types.CallToolResult handle_read (string path) throws Error {
        var file = File.new_for_path (path);
        if (!file.query_exists ()) {
            throw new Mcp.Core.McpError.RESOURCE_NOT_FOUND ("File not found: %s".printf (path));
        }
        
        uint8[] contents;
        string etag;
        yield file.load_contents_async (null, out contents, out etag);
        string text = (string) contents;
        
        return create_text_result ("File content:\n%s".printf (text));
    }
    
    /**
     * Handles file write operation.
     *
     * @param path The file path
     * @param content The content to write
     * @return The operation result
     * @throws Error If writing fails
     */
    private async Mcp.Tools.Types.CallToolResult handle_write (string path, string content) throws Error {
        var file = File.new_for_path (path);
        
        // Create parent directories if needed
        var parent = file.get_parent ();
        if (parent != null && !parent.query_exists ()) {
            try {
                parent.make_directory_with_parents ();
            } catch (Error e) {
                throw new Mcp.Core.McpError.INTERNAL_ERROR ("Failed to create parent directory: %s".printf (e.message));
            }
        }
        
        uint8[] data = content.data;
        string etag_out;
        try {
            yield file.replace_contents_async (
                data,
                null,
                false,
                FileCreateFlags.REPLACE_DESTINATION,
                null,
                out etag_out
            );
        } catch (Error e) {
            throw new Mcp.Core.McpError.INTERNAL_ERROR ("Failed to write file: %s".printf (e.message));
        }
        
        return create_text_result ("Wrote %u bytes to %s".printf (data.length, path));
    }
    
    /**
     * Handles file list operation.
     *
     * @param path The directory path
     * @return The operation result
     * @throws Error If listing fails
     */
    private async Mcp.Tools.Types.CallToolResult handle_list (string path) throws Error {
        var dir = File.new_for_path (path);
        if (!dir.query_exists ()) {
            throw new Mcp.Core.McpError.RESOURCE_NOT_FOUND ("Directory not found: %s".printf (path));
        }
        
        var enumerator = yield dir.enumerate_children_async (
            "standard::name,standard::type,standard::size",
            FileQueryInfoFlags.NONE,
            Priority.DEFAULT,
            null
        );
        
        string[] entries = {};
        FileInfo? file_info = null;
        while ((file_info = enumerator.next_file ()) != null) {
            string entry = "%s (%s)".printf (
                file_info.get_name (),
                file_info.get_file_type () == FileType.DIRECTORY ? "dir" : "file"
            );
            entries += entry;
        }
        
        return create_text_result ("Directory listing:\n%s".printf (string.joinv ("\n", entries)));
    }
    
    /**
     * Handles file delete operation.
     *
     * @param path The file path
     * @return The operation result
     * @throws Error If deletion fails
     */
    private async Mcp.Tools.Types.CallToolResult handle_delete (string path) throws Error {
        var file = File.new_for_path (path);
        if (!file.query_exists ()) {
            throw new Mcp.Core.McpError.RESOURCE_NOT_FOUND ("File not found: %s".printf (path));
        }
        
        yield file.delete_async ();
        
        return create_text_result ("Deleted: %s".printf (path));
    }
}

/**
 * Simple file resource provider implementation.
 */
public class FileResourceProvider : Mcp.Resources.BaseProvider {
    /**
     * Creates a new FileResourceProvider.
     */
    public FileResourceProvider () {
        Object ();
    }
    
    /**
     * {@inheritDoc}
     */
    public override async Gee.ArrayList<Mcp.Resources.Types.Resource> list_resources (string? cursor) throws Error {
        var resources = new Gee.ArrayList<Mcp.Resources.Types.Resource> ();
        
        // List files in current directory
        var dir = File.new_for_path (".");
        var enumerator = yield dir.enumerate_children_async (
            "standard::name,standard::type,standard::size",
            FileQueryInfoFlags.NONE,
            Priority.DEFAULT,
            null
        );
        
        FileInfo? file_info = null;
        while ((file_info = enumerator.next_file ()) != null) {
            if (file_info.get_file_type () == FileType.REGULAR) {
                var file = File.new_for_path (file_info.get_name ());
                var resource = new Mcp.Resources.Types.Resource (
                    file.get_uri (),
                    file_info.get_name ()
                );
                resource.mime_type = guess_mime_type (file_info.get_name ());
                resource.size = file_info.get_size ();
                
                resources.add (resource);
            }
        }
        
        return resources;
    }
    
    /**
     * {@inheritDoc}
     */
    public override async Gee.ArrayList<Mcp.Types.Common.ResourceContents> read_resource (string uri) throws Error {
        var file = File.new_for_uri (uri);
        if (!file.query_exists ()) {
            throw new Mcp.Core.McpError.RESOURCE_NOT_FOUND ("File not found: %s".printf (uri));
        }
        
        uint8[] contents;
        string etag;
        yield file.load_contents_async (null, out contents, out etag);
        
        string text = (string) contents;
        
        var result = new Gee.ArrayList<Mcp.Types.Common.ResourceContents> ();
        result.add (new Mcp.Types.Common.TextResourceContents (uri, text));
        
        return result;
    }
    
    /**
     * Guesses MIME type from filename.
     *
     * @param filename The filename
     * @return The guessed MIME type
     */
    private new string guess_mime_type (string filename) {
        // Simple MIME type guessing based on extension
        string extension = filename.down ();
        
        if (extension == "txt") {
            return "text/plain";
        } else if (extension == "json") {
            return "application/json";
        } else if (extension == "xml") {
            return "application/xml";
        } else {
            return "application/octet-stream";
        }
    }
}

/**
 * In-memory resource provider with subscription support.
 */
public class MemoryResourceProvider : Mcp.Resources.BaseProvider {
    private HashTable<string, string> resources;
    private uint32 next_id;
    
    /**
     * Creates a new MemoryResourceProvider.
     */
    public MemoryResourceProvider () {
        Object ();
        resources = new HashTable<string, string> (str_hash, str_equal);
        next_id = 1;
        
        // Add some initial resources
        resources.insert ("memory://note/1", "This is a sample note in memory.");
        resources.insert ("memory://note/2", "Another note with some content.");
        resources.insert ("memory://counter", "0");
    }
    
    /**
     * {@inheritDoc}
     */
    public override async Gee.ArrayList<Mcp.Resources.Types.Resource> list_resources (string? cursor) throws Error {
        var result = new Gee.ArrayList<Mcp.Resources.Types.Resource> ();
        
        foreach (var uri in resources.get_keys ()) {
            var resource = new Mcp.Resources.Types.Resource (uri, get_name_from_uri (uri));
            resource.mime_type = "text/plain";
            resource.size = resources[uri].length;
            
            result.add (resource);
        }
        
        return result;
    }
    
    /**
     * {@inheritDoc}
     */
    public override async Gee.ArrayList<Mcp.Types.Common.ResourceContents> read_resource (string uri) throws Error {
        if (!resources.contains (uri)) {
            throw new Mcp.Core.McpError.RESOURCE_NOT_FOUND ("Resource not found: %s".printf (uri));
        }
        
        var result = new Gee.ArrayList<Mcp.Types.Common.ResourceContents> ();
        result.add (new Mcp.Types.Common.TextResourceContents (uri, resources[uri]));
        
        return result;
    }
    
    /**
     * {@inheritDoc}
     */
    public override async void subscribe (string uri) throws Error {
        if (!resources.contains (uri)) {
            throw new Mcp.Core.McpError.RESOURCE_NOT_FOUND ("Resource not found: %s".printf (uri));
        }
        
        // BaseProvider will handle subscription tracking
        yield base.subscribe (uri);
    }
    
    /**
     * Updates a resource and notifies subscribers.
     *
     * @param uri The URI of the resource to update
     * @param content The new content
     */
    public void update_resource (string uri, string content) {
        if (!resources.contains (uri)) {
            return;
        }
        
        resources[uri] = content;
        notify_resource_updated (uri);
    }
    
    /**
     * Creates a new note resource.
     *
     * @param title The title of the note
     * @param content The content of the note
     * @return The URI of the new resource
     */
    public string create_note (string title, string content) {
        string uri = "memory://note/%u".printf (next_id++);
        resources.insert (uri, "Title: %s\n\n%s".printf (title, content));
        
        // The ResourceManager will handle list_changed notifications
        // when resources are listed
        
        return uri;
    }
    
    /**
     * Increments the counter resource.
     *
     * @return The new counter value
     */
    public int increment_counter () {
        string uri = "memory://counter";
        if (!resources.contains (uri)) {
            resources.insert (uri, "0");
        }
        
        int value = int.parse (resources[uri]);
        value++;
        resources[uri] = value.to_string ();
        
        // Notify subscribers
        notify_resource_updated (uri);
        
        return value;
    }
    
    /**
     * Extracts name from URI.
     *
     * @param uri The URI
     * @return The name
     */
    private string get_name_from_uri (string uri) {
        var parts = uri.split ("/");
        return parts[parts.length - 1];
    }
    
}

/**
 * Code review prompt template implementation.
 */
public class CodeReviewPromptTemplate : Mcp.Prompts.BaseTemplate {
    /**
     * Creates a new CodeReviewPromptTemplate.
     */
    public CodeReviewPromptTemplate () {
        base ("code_review", "Code Review", "Generates a code review prompt for analyzing code quality and best practices");
        
        // Add arguments
        add_argument ("code", "Code", "The code to review", true);
        add_argument ("language", "Language", "Programming language of the code", false);
        add_argument ("focus", "Focus Area", "Specific areas to focus on (e.g., security, performance, readability)", false);
    }
    
    /**
     * {@inheritDoc}
     */
    protected override Gee.ArrayList<Mcp.Prompts.Types.PromptMessage> generate_messages (GLib.Variant arguments) {
        var messages = new Gee.ArrayList<Mcp.Prompts.Types.PromptMessage> ();
        
        string language = "";
        if (arguments.lookup_value ("language", null) != null) {
            language = arguments.lookup_value ("language", new VariantType ("s")).get_string ();
        }
        
        string focus = "";
        if (arguments.lookup_value ("focus", null) != null) {
            focus = arguments.lookup_value ("focus", new VariantType ("s")).get_string ();
        }
        
        string template = """Please review the following {{language}} code:

```{{language}}
{{code}}
```

{{#focus}}
Please focus your review on: {{focus}}
{{/focus}}

Please analyze:
1. Code quality and readability
2. Potential bugs or issues
3. Performance considerations
4. Security vulnerabilities
5. Adherence to best practices
6. Suggestions for improvement

Provide specific, actionable feedback.""";
        
        messages.add (create_user_message (template, arguments));
        return messages;
    }
}

/**
 * Summary prompt template implementation.
 */
public class SummaryPromptTemplate : Mcp.Prompts.BaseTemplate {
    /**
     * Creates a new SummaryPromptTemplate.
     */
    public SummaryPromptTemplate () {
        base ("summary", "Text Summary", "Generates a summary of the provided text");
        
        // Add arguments
        add_argument ("text", "Text", "The text to summarize", true);
        add_argument ("length", "Summary Length", "Desired length of the summary (short, medium, long)", false);
        add_argument ("style", "Summary Style", "Style of the summary (bullet_points, paragraph, executive)", false);
    }
    
    /**
     * {@inheritDoc}
     */
    protected override Gee.ArrayList<Mcp.Prompts.Types.PromptMessage> generate_messages (GLib.Variant arguments) {
        var messages = new Gee.ArrayList<Mcp.Prompts.Types.PromptMessage> ();
        
        string length = "medium";
        if (arguments.lookup_value ("length", null) != null) {
            length = arguments.lookup_value ("length", new VariantType ("s")).get_string ();
        }
        
        string style = "paragraph";
        if (arguments.lookup_value ("style", null) != null) {
            style = arguments.lookup_value ("style", new VariantType ("s")).get_string ();
        }
        
        string template = """Please provide a {{length}} summary of the following text:

{{text}}

Please format the summary as {{style}}.

{{#style}}
{{#bullet_points}}
Use bullet points for key points.
{{/bullet_points}}
{{#paragraph}}
Write in a clear, concise paragraph.
{{/paragraph}}
{{#executive}}
Provide an executive summary with key takeaways.
{{/executive}}
{{/style}}""";
        
        messages.add (create_user_message (template, arguments));
        return messages;
    }
}

/**
 * Explain prompt template implementation.
 */
public class ExplainPromptTemplate : Mcp.Prompts.BaseTemplate {
    /**
     * Creates a new ExplainPromptTemplate.
     */
    public ExplainPromptTemplate () {
        base ("explain", "Explain Concept", "Generates an explanation of a concept or topic");
        
        // Add arguments
        add_argument ("topic", "Topic", "The concept or topic to explain", true);
        add_argument ("audience", "Audience", "Target audience level (beginner, intermediate, advanced)", false);
        add_argument ("depth", "Depth", "Depth of explanation (brief, detailed, comprehensive)", false);
        add_argument ("examples", "Include Examples", "Whether to include examples", false);
    }
    
    /**
     * {@inheritDoc}
     */
    protected override Gee.ArrayList<Mcp.Prompts.Types.PromptMessage> generate_messages (GLib.Variant arguments) {
        var messages = new Gee.ArrayList<Mcp.Prompts.Types.PromptMessage> ();
        
        string audience = "intermediate";
        if (arguments.lookup_value ("audience", null) != null) {
            audience = arguments.lookup_value ("audience", new VariantType ("s")).get_string ();
        }
        
        string depth = "detailed";
        if (arguments.lookup_value ("depth", null) != null) {
            depth = arguments.lookup_value ("depth", new VariantType ("s")).get_string ();
        }
        
        bool include_examples = false;
        if (arguments.lookup_value ("examples", null) != null) {
            include_examples = arguments.lookup_value ("examples", new VariantType ("b")).get_boolean ();
        }
        
        string template = """Please explain the concept of "{{topic}}" for a {{audience}} audience.

Provide a {{depth}} explanation that covers:
1. Definition and core concepts
2. Key principles and mechanisms
3. Practical applications and use cases
4. Common challenges and considerations

{{#examples}}
Please include relevant examples to illustrate the concept.
{{/examples}}

Tailor your explanation to the specified audience level and ensure clarity and accuracy.""";
        
        // Create a modified arguments variant for examples
        var builder = new VariantBuilder (new VariantType ("a{sv}"));
        
        // Copy all existing arguments
        var iter = arguments.iterator ();
        string key;
        Variant value;
        while (iter.next ("{sv}", out key, out value)) {
            builder.add ("{sv}", key, value);
        }
        
        // Add/override the examples flag
        builder.add ("{sv}", "examples", new Variant.boolean (include_examples));
        
        var modified_args = builder.end ();
        
        messages.add (create_user_message (template, modified_args));
        return messages;
    }
}

/**
 * Main function.
 *
 * @param args Command line arguments
 * @return Exit code
 */
public static int main (string[] args) {
    var server = new SimpleServer ();
    
    // Create a main loop
    var loop = new MainLoop ();
    
    server.run.begin ((obj, res) => {
        loop.quit ();
    });
    
    loop.run ();
    return 0;
}



/**
Content-Length: 54

{"jsonrpc":"2.0","id":1,"method":"initialize"}
*/