ai.js

import OpenAI from 'openai';
import chalk from 'chalk';

// Lazy initialization of OpenAI client
let openai = null;

function getOpenAIClient() {
  if (!openai) {
    openai = new OpenAI({
      apiKey: process.env.OPENAI_API_KEY,
    });
  }
  return openai;
}

/**
 * Generate a commit message using OpenAI
 * @param {string} diff - The git diff output
 * @returns {Promise<string>} The generated commit message
 */
export async function generateCommitMessage(diff) {
  try {
    if (!diff || diff.trim() === '') {
      throw new Error('No diff provided for commit message generation');
    }

    const model = process.env.OPENAI_MODEL || 'gpt-4o-mini';
    
    const prompt = createCommitPrompt(diff);
    
    const completion = await getOpenAIClient().chat.completions.create({
      model: model,
      messages: [
        {
          role: 'system',
          content: 'You are a helpful assistant that writes clear and concise git commit messages following best practices.'
        },
        {
          role: 'user',
          content: prompt
        }
      ],
      max_tokens: 100,
      temperature: 0.7,
    });

    const message = completion.choices[0]?.message?.content?.trim();
    
    if (!message) {
      throw new Error('No commit message generated by AI');
    }

    return cleanCommitMessage(message);
  } catch (error) {
    if (error.status === 401) {
      throw new Error('Invalid OpenAI API key. Please check your .env file.');
    } else if (error.status === 429) {
      throw new Error('OpenAI API rate limit exceeded. Please try again later.');
    } else if (error.status === 500) {
      throw new Error('OpenAI API server error. Please try again later.');
    }
    
    throw new Error(`Failed to generate commit message: ${error.message}`);
  }
}

/**
 * Analyze diff to determine the type of changes and suggest appropriate emoji
 * @param {string} diff - The git diff output
 * @returns {string} The appropriate emoji for the changes
 */
export function analyzeDiffForEmoji(diff) {
  const lowerDiff = diff.toLowerCase();
  
  // Bug fixes (check first to avoid conflicts with "add")
  if (lowerDiff.includes('fix') || lowerDiff.includes('bug') || lowerDiff.includes('error') || 
      lowerDiff.includes('issue') || lowerDiff.includes('problem') || lowerDiff.includes('exception')) {
    return '🐛';
  }
  
  // Performance improvements (check before feature additions)
  if (lowerDiff.includes('performance') || lowerDiff.includes('optimize') || lowerDiff.includes('speed') ||
      lowerDiff.includes('fast') || lowerDiff.includes('efficient') || lowerDiff.includes('cache')) {
    return '⚡';
  }
  
  // Feature additions
  if (lowerDiff.includes('add') || lowerDiff.includes('new') || lowerDiff.includes('create') || 
      lowerDiff.includes('implement') || lowerDiff.includes('introduce')) {
    return '✨';
  }
  
  // Performance improvements
  if (lowerDiff.includes('performance') || lowerDiff.includes('optimize') || lowerDiff.includes('speed') ||
      lowerDiff.includes('fast') || lowerDiff.includes('efficient') || lowerDiff.includes('cache')) {
    return '⚡';
  }
  
  // Documentation
  if (lowerDiff.includes('readme') || lowerDiff.includes('docs') || lowerDiff.includes('documentation') ||
      lowerDiff.includes('comment') || lowerDiff.includes('doc')) {
    return '📚';
  }
  

  
  // Refactoring
  if (lowerDiff.includes('refactor') || lowerDiff.includes('restructure') || lowerDiff.includes('clean') ||
      lowerDiff.includes('improve') || lowerDiff.includes('update')) {
    return '♻️';
  }
  
  // Testing
  if (lowerDiff.includes('test') || lowerDiff.includes('spec') || lowerDiff.includes('unit') ||
      lowerDiff.includes('integration') || lowerDiff.includes('coverage')) {
    return '🧪';
  }
  
  // Configuration changes
  if (lowerDiff.includes('config') || lowerDiff.includes('setting') || lowerDiff.includes('env') ||
      lowerDiff.includes('package.json') || lowerDiff.includes('dependencies')) {
    return '⚙️';
  }
  
  // Security
  if (lowerDiff.includes('security') || lowerDiff.includes('vulnerability') || lowerDiff.includes('auth') ||
      lowerDiff.includes('password') || lowerDiff.includes('token')) {
    return '🔒';
  }
  
  // UI/UX changes
  if (lowerDiff.includes('ui') || lowerDiff.includes('ux') || lowerDiff.includes('style') ||
      lowerDiff.includes('css') || lowerDiff.includes('design') || lowerDiff.includes('layout')) {
    return '🎨';
  }
  
  // Database changes
  if (lowerDiff.includes('database') || lowerDiff.includes('db') || lowerDiff.includes('sql') ||
      lowerDiff.includes('migration') || lowerDiff.includes('schema')) {
    return '🗄️';
  }
  
  // API changes
  if (lowerDiff.includes('api') || lowerDiff.includes('endpoint') || lowerDiff.includes('route') ||
      lowerDiff.includes('controller') || lowerDiff.includes('service')) {
    return '🔌';
  }
  
  // Deployment/CI/CD
  if (lowerDiff.includes('deploy') || lowerDiff.includes('ci') || lowerDiff.includes('cd') ||
      lowerDiff.includes('pipeline') || lowerDiff.includes('docker') || lowerDiff.includes('build')) {
    return '🚀';
  }
  
  // Dependencies
  if (lowerDiff.includes('package.json') || lowerDiff.includes('dependencies') || lowerDiff.includes('npm') ||
      lowerDiff.includes('yarn') || lowerDiff.includes('install')) {
    return '📦';
  }
  
  // Default for general changes
  return '📝';
}

/**
 * Create the prompt for the AI model
 * @param {string} diff - The git diff output
 * @returns {string} The formatted prompt
 */
function createCommitPrompt(diff) {
  // Truncate very long diffs to avoid token limits
  const maxDiffLength = 8000;
  const truncatedDiff = diff.length > maxDiffLength 
    ? diff.substring(0, maxDiffLength) + '\n\n... (diff truncated for brevity)'
    : diff;

  // Analyze diff to determine appropriate emoji
  const emoji = analyzeDiffForEmoji(diff);

  return `Generate a clear and concise git commit message for the following staged changes. 

The commit message should:
- Start with the emoji: ${emoji}
- Be written in the imperative mood (e.g., "Add feature" not "Added feature")
- Be concise but descriptive (ideally under 72 characters)
- Focus on what the change does, not how it does it
- Not include unnecessary punctuation or quotes
- Follow conventional commit format if appropriate (feat:, fix:, docs:, etc.)

Here are the staged changes:

${truncatedDiff}

Respond with just the commit message starting with the emoji, nothing else.`;
}

/**
 * Clean and validate the AI-generated commit message
 * @param {string} message - The raw message from AI
 * @returns {string} The cleaned message
 */
function cleanCommitMessage(message) {
  // Remove quotes if present
  let cleaned = message.replace(/^["']|["']$/g, '');
  
  // Remove any extra whitespace
  cleaned = cleaned.trim();
  
  // Remove trailing periods unless it's part of an abbreviation
  cleaned = cleaned.replace(/\.$/, '');
  
  // Ensure the message starts with an emoji
  const emojiRegex = /^[^\w\s]*[\u{1F600}-\u{1F64F}\u{1F300}-\u{1F5FF}\u{1F680}-\u{1F6FF}\u{1F1E0}-\u{1F1FF}\u{2600}-\u{26FF}\u{2700}-\u{27BF}][^\w\s]*/u;
  
  if (!emojiRegex.test(cleaned)) {
    // If no emoji at the start, add a default one
    cleaned = '📝 ' + cleaned;
  }
  
  // Ensure first letter after emoji is capitalized if not using conventional commit format
  const afterEmoji = cleaned.replace(/^[^\w\s]*[\u{1F600}-\u{1F64F}\u{1F300}-\u{1F5FF}\u{1F680}-\u{1F6FF}\u{1F1E0}-\u{1F1FF}\u{2600}-\u{26FF}\u{2700}-\u{27BF}][^\w\s]*/u, '').trim();
  
  if (!afterEmoji.match(/^(feat|fix|docs|style|refactor|perf|test|chore|build|ci):/i)) {
    // Capitalize the first letter after emoji
    const capitalizedAfterEmoji = afterEmoji.charAt(0).toUpperCase() + afterEmoji.slice(1);
    cleaned = cleaned.replace(afterEmoji, capitalizedAfterEmoji);
  }
  
  return cleaned;
}

/**
 * Test the OpenAI connection
 * @returns {Promise<boolean>} True if connection is successful
 */
export async function testOpenAIConnection() {
  try {
    await getOpenAIClient().models.list();
    return true;
  } catch (error) {
    console.log(chalk.red(`❌ OpenAI connection failed: ${error.message}`));
    return false;
  }
}

/**
 * Get available OpenAI models
 * @returns {Promise<Array>} List of available models
 */
export async function getAvailableModels() {
  try {
    const models = await getOpenAIClient().models.list();
    return models.data
      .filter(model => model.id.includes('gpt'))
      .map(model => model.id)
      .sort();
  } catch (error) {
    throw new Error(`Failed to fetch available models: ${error.message}`);
  }
}