/**
* Consolidated code generation utilities for Google Apps Script
* Replaces duplicate functions from gasClient.ts and execution.ts
*
* This utility consolidates:
* - GASClient.generateMcpGasRunClass() (87 lines) -> System with built-in execution
* - ExecTool.getProxyFunctionCode() (140 lines) -> Web app proxy
*
* Architecture: Self-contained system with dynamic execution
* - __mcp_exec: System shim ONLY - never modified after creation
* - User code: Separate .gs files (e.g., Code.gs, UserFunctions.gs)
* - Dynamic code execution via Function constructor
*/
import { GASFile } from '../api/gasClient.js';
import * as fs from 'fs';
import * as path from 'path';
export interface ProxyCodeOptions {
type: 'head_deployment' | 'execution_api';
userCode?: string;
timezone?: string;
includeTestFunctions?: boolean;
mcpVersion?: string;
responseFormat?: 'structured' | 'legacy';
}
export interface CodeGenerationResult {
files: GASFile[];
totalLines: number;
description: string;
}
/**
* Simple template reader that reads template content from src directory
* @param templateName - The template filename (e.g., '__mcp_exec.js', 'require.js')
* @returns Template content as string
*/
function getTemplate(templateName: string): string {
try {
// Get the directory of this file - when compiled, this will be in dist/src/utils/
const currentDir = path.dirname(new URL(import.meta.url).pathname);
// Determine if we're running from compiled code (dist/) or source code (src/)
let srcDir: string;
if (currentDir.includes('/dist/')) {
// Running from compiled code: dist/src/utils -> go up to project root, then to src
const projectRoot = currentDir.replace(/\/dist\/.*$/, '');
srcDir = path.join(projectRoot, 'src');
} else {
// Running from source code: src/utils -> go up to src
srcDir = path.join(currentDir, '..');
}
const templatePath = path.join(srcDir, templateName);
return fs.readFileSync(templatePath, 'utf8');
} catch (error) {
throw new Error(`Template ${templateName} not found: ${error instanceof Error ? error.message : String(error)}`);
}
}
/**
* Comprehensive code generation for Google Apps Script projects
* Supports multiple deployment types and user code integration
*/
export class CodeGenerator {
/**
* Generate complete GAS project files based on options
* @param options - Configuration for code generation
* @returns Generated files with metadata
*/
static generateProjectFiles(options: ProxyCodeOptions): CodeGenerationResult {
const {
type,
userCode = '',
timezone = 'America/New_York',
includeTestFunctions = false,
mcpVersion = '1.3.3',
responseFormat = 'structured'
} = options;
const files: GASFile[] = [];
let totalLines = 0;
// Always include the MCP system file
const mcpSystemContent = this.generateMcpClassFile(timezone, mcpVersion);
files.push({
name: 'common-js/__mcp_exec',
type: 'SERVER_JS',
source: mcpSystemContent
});
totalLines += mcpSystemContent.split('\n').length;
// Always include the CommonJS module system
const shimContent = this.generateShimFile();
files.push({
name: 'common-js/require',
type: 'SERVER_JS',
source: shimContent
});
totalLines += shimContent.split('\n').length;
// Add user code if provided
if (userCode.trim()) {
files.push({
name: 'Code',
type: 'SERVER_JS',
source: userCode
});
totalLines += userCode.split('\n').length;
}
// Add test functions if requested
if (includeTestFunctions) {
const testContent = this.generateTestFunctions();
files.push({
name: 'TestFunctions',
type: 'SERVER_JS',
source: testContent
});
totalLines += testContent.split('\n').length;
}
return {
files,
totalLines,
description: `Generated ${files.length} files for ${type} deployment (${totalLines} total lines)`
};
}
/**
* Generate the main MCP system file
* Contains:
* - doGet/doPost handlers for web app endpoints
* - Built-in __gas_run function for dynamic code execution
* - System exception handler (__mcp_handleMcpException)
* - Uses Function constructor for runtime code execution
* - ALL USER CODE MUST BE IN SEPARATE .GS FILES
*/
private static generateMcpClassFile(timezone: string, mcpVersion: string): string {
return getTemplate('__mcp_exec.js');
}
/**
* Generate the CommonJS module system file
* Contains the module loading and require() system
*/
private static generateShimFile(): string {
return getTemplate('require.js');
}
/**
* Generate test functions for debugging and validation
*/
private static generateTestFunctions(): string {
return `
/**
* Test functions for MCP Gas integration
* These functions help validate the system is working correctly
*/
function testBasicExecution() {
return "Basic execution test passed";
}
function testMathOperations() {
return {
addition: 2 + 3,
multiplication: 4 * 5,
timestamp: new Date().toISOString()
};
}
function testLoggerCapture() {
Logger.log("Test log message 1");
Logger.log("Test log message 2");
return "Logger test completed";
}
`.trim();
}
/**
* Utility method to get available generation types
* Helpful for documentation and validation
*/
static getAvailableTypes(): string[] {
return ['head_deployment', 'execution_api'];
}
/**
* Get template content by name (for external use)
*/
static getTemplateContent(templateName: string): string {
return getTemplate(templateName);
}
}
