AI Code Toolkit

/** * GetFileDesignPattern Hook for Gemini CLI * * DESIGN PATTERNS: * - Class-based hook pattern: Encapsulates lifecycle hooks in a single class * - Fail-open pattern: Errors allow operation to proceed with warning * - Single responsibility: Each hook handles specific lifecycle stage * * CODING STANDARDS: * - Export a class with preToolUse, postToolUse methods * - Handle all errors gracefully with fail-open behavior * - Format messages clearly for LLM consumption * * AVOID: * - Blocking operations on errors * - Complex business logic (delegate to tools/services) * - Mutating context object */ import type { GeminiCliHookInput, HookResponse } from '@agiflowai/hooks-adapter'; import { ExecutionLogService, DECISION_SKIP, DECISION_DENY } from '@agiflowai/hooks-adapter'; import { isValidLlmTool } from '@agiflowai/coding-agent-bridge'; import { GetFileDesignPatternTool } from '../../tools/GetFileDesignPatternTool'; import { TemplateFinder } from '../../services/TemplateFinder'; import { ArchitectParser } from '../../services/ArchitectParser'; import { PatternMatcher } from '../../services/PatternMatcher'; /** * GetFileDesignPattern Hook class for Gemini CLI * * Provides lifecycle hooks for tool execution: * - preToolUse: Provides design patterns before file edit/write operations * - postToolUse: Not applicable for this hook (returns skip) */ export class GetFileDesignPatternHook { /** * PreToolUse hook for Gemini CLI * Provides design patterns before file edit/write operations * * @param context - Gemini CLI hook input * @returns Hook response with design patterns or skip decision */ async preToolUse(context: GeminiCliHookInput): Promise<HookResponse> { // Extract file path from tool input const filePath = context.tool_input?.file_path; // Only process file operations if (!filePath) { return { decision: DECISION_SKIP, message: 'Not a file operation', }; } try { // Create execution log service for this session const executionLog = new ExecutionLogService(context.session_id); // Get matched file patterns early for logging const templateFinder = new TemplateFinder(); const architectParser = new ArchitectParser(); const patternMatcher = new PatternMatcher(); const templateMapping = await templateFinder.findTemplateForFile(filePath); const templateConfig = templateMapping ? await architectParser.parseArchitectFile(templateMapping.templatePath) : null; const globalConfig = await architectParser.parseGlobalArchitectFile(); const filePatterns = patternMatcher.getMatchedFilePatterns( filePath, templateConfig, globalConfig, templateMapping?.projectPath, ); // If no patterns match, skip early if (!filePatterns) { return { decision: DECISION_SKIP, message: 'No design patterns configured for this file', }; } // Derive operation from tool name const operation = extractOperation(context.tool_name); const projectPath = templateMapping?.projectPath; // Check if we already showed patterns for this file in this session const alreadyShown = await executionLog.hasExecuted({ filePath, decision: DECISION_DENY, // 'deny' means we showed patterns filePattern: filePatterns, projectPath, }); if (alreadyShown) { // Already showed patterns - skip hook and let Gemini continue normally await executionLog.logExecution({ filePath: filePath, operation: operation, decision: DECISION_SKIP, filePattern: filePatterns, projectPath, }); return { decision: DECISION_SKIP, message: 'Design patterns already provided for this file', }; } // First edit - get design patterns and deny to show them to Gemini // Validate llm_tool before passing to tool constructor const llmTool = context.llm_tool && isValidLlmTool(context.llm_tool) ? context.llm_tool : undefined; const tool = new GetFileDesignPatternTool({ llmTool }); const result = await tool.execute({ file_path: filePath }); // Parse result const firstContent = result.content[0]; if (firstContent.type !== 'text') { return { decision: DECISION_SKIP, message: '⚠️ Unexpected response type from design pattern tool', }; } const data = JSON.parse(firstContent.text); if (result.isError) { // Error getting patterns - skip and let Gemini continue await executionLog.logExecution({ filePath: filePath, operation: operation, decision: DECISION_SKIP, filePattern: filePatterns, projectPath, }); return { decision: DECISION_SKIP, message: `⚠️ Could not load design patterns: ${data.error}`, }; } // If no patterns matched, skip and let Gemini continue normally if (!data.matched_patterns || data.matched_patterns.length === 0) { return { decision: DECISION_SKIP, message: 'No specific patterns matched for this file', }; } // Format patterns for LLM let message = 'You must follow these design patterns when editing/writing this file:\n\n'; message += `**Matched file patterns:** ${filePatterns}\n\n`; for (const pattern of data.matched_patterns) { message += `**${pattern.design_pattern}**\n${pattern.description}\n\n`; } // Log that we showed patterns (decision: deny) await executionLog.logExecution({ filePath: filePath, operation: operation, decision: DECISION_DENY, filePattern: filePatterns, projectPath, }); // Return DENY so Gemini sees the patterns // In Gemini CLI, this will block the tool and show the message to the LLM return { decision: DECISION_DENY, message, }; } catch (error) { // Fail open: skip hook and let Gemini continue return { decision: DECISION_SKIP, message: `⚠️ Hook error: ${error instanceof Error ? error.message : String(error)}`, }; } } /** * PostToolUse hook - not applicable for getFileDesignPattern * This tool is only called before file operations * * @param _context - Gemini CLI hook input (unused) * @returns Hook response with skip decision */ async postToolUse(_context: GeminiCliHookInput): Promise<HookResponse> { return { decision: DECISION_SKIP, message: 'PostToolUse not applicable for getFileDesignPattern', }; } } /** * Extract operation type from tool name */ function extractOperation(toolName: string): string { const lowerToolName = toolName.toLowerCase(); if (lowerToolName === 'edit' || lowerToolName === 'update') return 'edit'; if (lowerToolName === 'write') return 'write'; if (lowerToolName === 'read') return 'read'; return 'unknown'; }