humanus.cpp/tool/base.h

#ifndef HUMANUS_TOOL_BASE_H
#define HUMANUS_TOOL_BASE_H

#include "toml.hpp"
#include "schema.h"
#include "agent/base.h"
#include "mcp/include/mcp_client.h"
#include "mcp/include/mcp_stdio_client.h"
#include "mcp/include/mcp_sse_client.h"
#include <string>

namespace humanus {

// Read tool configuration from config_mcp.toml
struct MCPToolConfig {
    std::string type;
    std::string host;
    int port;
    std::string url;
    std::string command;
    std::vector<std::string> args;
    json env_vars = json::object();
    
    static MCPToolConfig load_from_toml(const std::string& tool_name) {
        MCPToolConfig config;
        
        try {
            // Get config file path
            auto config_path = PROJECT_ROOT / "config" / "config_mcp.toml";
            if (!std::filesystem::exists(config_path)) {
                throw std::runtime_error("MCP config file not found: " + config_path.string());
            }
            
            // Parse TOML file
            const auto& data = toml::parse_file(config_path.string());
            
            // Check if tool config exists
            if (!data.contains(tool_name) || !data[tool_name].is_table()) {
                throw std::runtime_error("Tool configuration not found in MCP config file: " + tool_name);
            }
            
            const auto& tool_table = *data[tool_name].as_table();

            // Read type
            if (!tool_table.contains("type") || !tool_table["type"].is_string()) {
                throw std::runtime_error("Tool configuration missing type field: " + tool_name);
            }
            config.type = tool_table["type"].as_string()->get();

            if (config.type == "stdio") {
                // Read command
                if (!tool_table.contains("command") || !tool_table["command"].is_string()) {
                    throw std::runtime_error("stdio type tool configuration missing command field: " + tool_name);
                }
                config.command = tool_table["command"].as_string()->get();
                
                // Read arguments (if any)
                if (tool_table.contains("args") && tool_table["args"].is_array()) {
                    const auto& args_array = *tool_table["args"].as_array();
                    for (const auto& arg : args_array) {
                        if (arg.is_string()) {
                            config.args.push_back(arg.as_string()->get());
                        }
                    }
                }
                
                // Read environment variables
                if (tool_table.contains("env") && tool_table["env"].is_table()) {
                    const auto& env_table = *tool_table["env"].as_table();
                    for (const auto& [key, value] : env_table) {
                        if (value.is_string()) {
                            config.env_vars[key] = value.as_string()->get();
                        } else if (value.is_integer()) {
                            config.env_vars[key] = value.as_integer()->get();
                        } else if (value.is_floating_point()) {
                            config.env_vars[key] = value.as_floating_point()->get();
                        } else if (value.is_boolean()) {
                            config.env_vars[key] = value.as_boolean()->get();
                        }
                    }
                }
            } else if (config.type == "sse") {
                // Read host and port or url
                if (tool_table.contains("url") && tool_table["url"].is_string()) {
                    config.url = tool_table["url"].as_string()->get();
                } else {
                    if (!tool_table.contains("host") || !tool_table["host"].is_string()) {
                        throw std::runtime_error("sse type tool configuration missing host field: " + tool_name);
                    }
                    config.host = tool_table["host"].as_string()->get();

                    if (!tool_table.contains("port") || !tool_table["port"].is_integer()) {
                        throw std::runtime_error("sse type tool configuration missing port field: " + tool_name);
                    }
                    config.port = tool_table["port"].as_integer()->get();
                }
            } else {
                throw std::runtime_error("Unsupported tool type: " + config.type);
            }
        } catch (const std::exception& e) {
            std::cerr << "Failed to load MCP tool configuration: " << e.what() << std::endl;
            throw;
        }
        
        return config;
    }
};

// Represents the result of a tool execution.
struct ToolResult {
    json output;
    json error;
    json system;

    ToolResult(const json& output, const json& error = {}, const json& system = {}) 
        : output(output), error(error), system(system) {}

    bool empty() const {
        return output.empty() && error.empty() && system.empty();
    }

    ToolResult operator+(const ToolResult& other) const {
        auto combined_field = [](const json& field, const json& other_field) {
            if (field.empty()) {
                return other_field;
            }
            if (other_field.empty()) {
                return field;
            }
            json result = json::array();
            if (field.is_array()) {
                result.insert(result.end(), field.begin(), field.end());
            } else  {
                result.push_back(field);
            }
            if (other_field.is_array()) {
                result.insert(result.end(), other_field.begin(), other_field.end());
            } else  {
                result.push_back(other_field);
            }
            return result;
        };

        return {
            combined_field(output, other.output),
            combined_field(error, other.error),
            combined_field(system, other.system)
        };
    }

    static std::string parse_json_content(const json& content) {
        if (content.is_string()) {
            return content.get<std::string>();
        } else {
            return content.dump(2);
        }
    }

    std::string to_string() const {
        return !error.empty() ? "Error: " + parse_json_content(error) : parse_json_content(output);
    }
};

// A ToolResult that represents a failure.
struct ToolError : ToolResult {
    ToolError(const json& error) : ToolResult({}, error) {}
};

// Execute the tool with given parameters.
struct BaseTool {
    inline static std::set<std::string> special_tool_name = {"terminate", "planning"};

    std::string name;
    std::string description;
    json parameters;

    std::unique_ptr<mcp::client> _client;

    BaseTool(const std::string& name, const std::string& description, const json& parameters) :
        name(name), description(description), parameters(parameters) {
        if (special_tool_name.find(name) != special_tool_name.end()) {
            return;
        }
        // Load tool configuration from config file
        auto _config = MCPToolConfig::load_from_toml(name);

        if (_config.type == "stdio") {
            std::string command = _config.command;
            if (!_config.args.empty()) {
                for (const auto& arg : _config.args) {
                    command += " " + arg;
                }
            }
            _client = std::make_unique<mcp::stdio_client>(command, _config.env_vars);
        } else if (_config.type == "sse") {
            if (!_config.host.empty() && _config.port > 0) {
                _client = std::make_unique<mcp::sse_client>(_config.host, _config.port);
            } else if (!_config.url.empty()) {
                _client = std::make_unique<mcp::sse_client>(_config.url, "/sse");
            } else {
                throw std::runtime_error("MCP SSE configuration missing host or port or url");
            }
        }

        _client->initialize(name + "_client", "0.0.1");
    }

    // Execute the tool with given parameters.
    ToolResult operator()(const json& arguments) {
        return execute(arguments);
    }
    
    // Execute the tool with given parameters.
    virtual ToolResult execute(const json& arguments) {
        try {
            if (!_client) {
                throw std::runtime_error("MCP client not initialized");
            }
            json result = _client->call_tool(name, arguments);
            bool is_error = result.value("isError", false);
            // Return different ToolResult based on whether there is an error
            if (is_error) {
                return ToolError(result.value("content", json::array()));
            } else {
                return ToolResult(result.value("content", json::array()));
            }
        } catch (const std::exception& e) {
            return ToolError(e.what());
        }
    }

    json to_param() const {
        return {
            {"type", "function"},
            {"function", {
                {"name", name},
                {"description", description},
                {"parameters", parameters}
            }}
        };
    }
};

struct AgentAware : ToolResult {
    std::shared_ptr<BaseAgent> agent = nullptr;
};

}

#endif // HUMANUS_TOOL_BASE_H