NL Analytics MCP Server for Apache Druid

/* * Copyright (C) 2025 Christian Schmitt, Tim Frey * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package com.iunera.druidmcpserver.config; import org.springframework.beans.factory.annotation.Value; import org.springframework.core.env.Environment; import org.springframework.stereotype.Service; import java.util.HashMap; import java.util.Map; /** * Service for loading and processing prompt templates from properties files. * Supports variable substitution and property overrides via Java system properties. */ @Service public class PromptTemplateService { private final Environment environment; @Value("${mcp.prompts.watermark:Generated by Druid MCP Server}") private String watermark; @Value("${mcp.prompts.custom.organization-name:Your Organization}") private String organizationName; @Value("${mcp.prompts.custom.environment:production}") private String environmentName; @Value("${mcp.prompts.custom.contact-info:your-team@company.com}") private String contactInfo; public PromptTemplateService(Environment environment) { this.environment = environment; } /** * Load a prompt template and substitute variables * * @param templateKey The property key for the template (e.g., "prompts.druid-data-exploration.template") * @param variables Map of variables to substitute in the template * @return The processed template with variables substituted */ public String loadTemplate(String templateKey, Map<String, String> variables) { String template = environment.getProperty(templateKey, ""); if (template.isEmpty()) { throw new IllegalArgumentException("Template not found for key: " + templateKey); } // Create a combined map with default variables and provided variables Map<String, String> allVariables = new HashMap<>(); allVariables.put("watermark", watermark); allVariables.put("organizationName", organizationName); allVariables.put("environment", environmentName); allVariables.put("contactInfo", contactInfo); // Override with provided variables if (variables != null) { allVariables.putAll(variables); } // Substitute variables in the template String result = template; for (Map.Entry<String, String> entry : allVariables.entrySet()) { String placeholder = "{" + entry.getKey() + "}"; String value = entry.getValue() != null ? entry.getValue() : ""; result = result.replace(placeholder, value); } // Convert \n to actual newlines result = result.replace("\\n", "\n"); return result; } /** * Load a template section (like conditional sections) * * @param sectionKey The property key for the section * @param variables Map of variables to substitute * @return The processed section */ public String loadSection(String sectionKey, Map<String, String> variables) { String section = environment.getProperty(sectionKey, ""); if (section.isEmpty()) { return ""; } // Substitute variables String result = section; if (variables != null) { for (Map.Entry<String, String> entry : variables.entrySet()) { String placeholder = "{" + entry.getKey() + "}"; String value = entry.getValue() != null ? entry.getValue() : ""; result = result.replace(placeholder, value); } } // Convert \n to actual newlines result = result.replace("\\n", "\n"); return result; } /** * Convenience method to create a variables map */ public Map<String, String> createVariables() { return new HashMap<>(); } /** * Convenience method to add a variable to the map */ public Map<String, String> addVariable(Map<String, String> variables, String key, String value) { if (value != null && !value.isEmpty()) { variables.put(key, value); } return variables; } }