#!/usr/bin/env node

/**
 * Git Commit Automation Script
 *
 * Automatically generates commit messages using OpenRouter AI (inception/mercury-coder)
 * based on staged changes. Supports message editing and optional pushing.
 *
 * Usage:
 *   1. Stage your changes: git add <files>
 *   2. Run: pnpm commit
 *   3. Review/edit the generated message
 *   4. Approve and optionally push
 */

import { execSync, spawnSync } from 'child_process';
import { createInterface } from 'readline';
import { readFileSync, writeFileSync, unlinkSync } from 'fs';
import { join, dirname } from 'path';
import { fileURLToPath } from 'url';
import { tmpdir } from 'os';

// Get current directory for ES modules
const __filename = fileURLToPath(import.meta.url);
const __dirname = dirname(__filename);

// Load environment variables from .env file
function loadEnv() {
  try {
    const envPath = join(__dirname, '.env');
    const envContent = readFileSync(envPath, 'utf-8');
    const lines = envContent.split('\n');

    for (const line of lines) {
      const trimmed = line.trim();
      if (!trimmed || trimmed.startsWith('#')) continue;

      const [key, ...valueParts] = trimmed.split('=');
      const value = valueParts.join('=').trim();

      if (key && value) {
        process.env[key.trim()] = value.replace(/^["']|["']$/g, '');
      }
    }
  } catch (error) {
    console.error(`${colors.red}❌ Failed to load .env file${colors.reset}`);
    console.error(`${colors.yellow}💡 Create a .env file in src/utils/ with:${colors.reset}`);
    console.error(`   ${colors.dim}OPENROUTER_API_KEY=your_api_key_here${colors.reset}\n`);
    process.exit(1);
  }
}

// Configuration
const OPENROUTER_API_URL = 'https://openrouter.ai/api/v1';
const MODEL_NAME = 'inception/mercury-coder';

// Color codes for terminal output
const colors = {
  reset: '\x1b[0m',
  bright: '\x1b[1m',
  dim: '\x1b[2m',
  red: '\x1b[31m',
  green: '\x1b[32m',
  yellow: '\x1b[33m',
  blue: '\x1b[34m',
  cyan: '\x1b[36m',
};

/**
 * Execute a git command and return the output
 */
function git(command, silent = false) {
  try {
    return execSync(`git ${command}`, {
      encoding: 'utf-8',
      stdio: silent ? 'pipe' : ['pipe', 'pipe', 'pipe']
    }).trim();
  } catch (error) {
    if (!silent) {
      console.error(`${colors.red}❌ Git command failed: ${command}${colors.reset}`);
      console.error(error.message);
    }
    return null;
  }
}

/**
 * Check if there are staged changes
 */
function checkStagedChanges() {
  const stagedFiles = git('diff --staged --name-only', true);
  return stagedFiles && stagedFiles.length > 0;
}

/**
 * Get git context for AI commit message generation
 */
function getGitContext() {
  console.log(`${colors.cyan}🔍 Gathering git context...${colors.reset}`);

  const status = git('status --short');
  const diff = git('diff --staged');
  const stagedFiles = git('diff --staged --name-only');

  return {
    status,
    diff,
    stagedFiles
  };
}

/**
 * Call OpenRouter API to generate commit message
 */
async function generateCommitMessage(context) {
  console.log(`${colors.cyan}🤖 Generating commit message with OpenRouter...${colors.reset}`);

  const systemPrompt = `You are a helpful assistant that generates concise, clear git commit messages.

Generate commit messages following these guidelines:
- Use imperative mood (e.g., "Add", "Fix", "Update", "Refactor")
- Keep it concise but descriptive
- First line should be a short summary (50-72 characters)
- If needed, add a blank line and then bullet points for details
- Focus on WHAT changed and WHY, not HOW

Generate ONLY the commit message, nothing else. Do not include any explanations or meta-commentary.`;

  const userPrompt = `Based on the following git changes, generate a commit message:

Staged files:
${context.stagedFiles}

Git status:
${context.status}

Git diff:
${context.diff.slice(0, 8000)}${context.diff.length > 8000 ? '\n... (diff truncated)' : ''}`;

  try {
    const apiKey = process.env.OPENROUTER_API_KEY;

    if (!apiKey) {
      throw new Error('OPENROUTER_API_KEY not found in environment variables');
    }

    const response = await fetch(`${OPENROUTER_API_URL}/chat/completions`, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json',
        'Authorization': `Bearer ${apiKey}`,
        'HTTP-Referer': 'https://github.com/yourusername/git-commit-automation',
        'X-Title': 'Git Commit Automation',
      },
      body: JSON.stringify({
        model: MODEL_NAME,
        messages: [
          { role: 'system', content: systemPrompt },
          { role: 'user', content: userPrompt }
        ],
      }),
    });

    if (!response.ok) {
      const errorData = await response.json().catch(() => ({}));
      throw new Error(`OpenRouter API error: ${response.status} ${response.statusText}\n${JSON.stringify(errorData, null, 2)}`);
    }

    const data = await response.json();

    if (!data.choices || !data.choices[0] || !data.choices[0].message) {
      throw new Error('Unexpected API response format');
    }

    return data.choices[0].message.content.trim();
  } catch (error) {
    console.error(`${colors.red}❌ Failed to generate commit message${colors.reset}`);
    console.error(error.message);

    // Check for common errors
    if (error.message.includes('OPENROUTER_API_KEY not found')) {
      console.log(`\n${colors.yellow}💡 Make sure you have a .env file in src/utils/ with:${colors.reset}`);
      console.log(`   ${colors.dim}OPENROUTER_API_KEY=your_api_key_here${colors.reset}`);
      console.log(`\n${colors.yellow}💡 Get your API key from:${colors.reset}`);
      console.log(`   ${colors.dim}https://openrouter.ai/keys${colors.reset}`);
    } else if (error.message.includes('ECONNREFUSED') || error.message.includes('fetch failed')) {
      console.log(`\n${colors.yellow}💡 Check your internet connection${colors.reset}`);
    } else if (error.message.includes('401')) {
      console.log(`\n${colors.yellow}💡 Invalid API key. Check your OPENROUTER_API_KEY in .env${colors.reset}`);
    }

    process.exit(1);
  }
}

/**
 * Create readline interface for user input
 */
function createReadlineInterface() {
  return createInterface({
    input: process.stdin,
    output: process.stdout,
  });
}

/**
 * Ask user a question and get input
 */
function question(rl, query) {
  return new Promise((resolve) => {
    rl.question(query, resolve);
  });
}

/**
 * Open neovim to edit the commit message
 */
function editInNeovim(message) {
  // Create a temporary file for editing
  const tempFile = join(tmpdir(), `git-commit-${Date.now()}.txt`);

  try {
    // Write the current message to the temp file
    writeFileSync(tempFile, message, 'utf-8');

    console.log(`\n${colors.cyan}✏️  Opening neovim to edit commit message...${colors.reset}`);

    // Open neovim with the temp file
    const result = spawnSync('nvim', [tempFile], {
      stdio: 'inherit',
      shell: false
    });

    if (result.error) {
      throw new Error(`Failed to open neovim: ${result.error.message}`);
    }

    // Read the edited content
    const editedMessage = readFileSync(tempFile, 'utf-8').trim();

    // Clean up temp file
    unlinkSync(tempFile);

    return editedMessage;
  } catch (error) {
    // Clean up temp file if it exists
    try {
      unlinkSync(tempFile);
    } catch {}

    console.error(`${colors.red}❌ Failed to edit in neovim${colors.reset}`);
    console.error(error.message);

    if (error.message.includes('Failed to open neovim')) {
      console.log(`\n${colors.yellow}💡 Make sure neovim is installed:${colors.reset}`);
      console.log(`   ${colors.dim}# Arch Linux${colors.reset}`);
      console.log(`   ${colors.dim}sudo pacman -S neovim${colors.reset}`);
    }

    // Return the original message if editing fails
    return message;
  }
}

/**
 * Display the commit message and get user approval
 */
async function getUserApproval(message, rl) {
  console.log(`\n${colors.bright}${colors.green}📝 Generated commit message:${colors.reset}`);
  console.log(`${colors.dim}${'─'.repeat(60)}${colors.reset}`);
  console.log(message);
  console.log(`${colors.dim}${'─'.repeat(60)}${colors.reset}\n`);

  while (true) {
    const answer = await question(
      rl,
      `${colors.yellow}[A]ccept / [E]dit / [C]ancel?${colors.reset} `
    );

    const choice = answer.trim().toLowerCase();

    if (choice === 'a' || choice === 'accept') {
      return { approved: true, message };
    } else if (choice === 'e' || choice === 'edit') {
      // Close readline to give full control to neovim
      rl.pause();

      // Open neovim for editing
      const editedMessage = editInNeovim(message);

      // Resume readline
      rl.resume();

      // Show the edited message and ask for approval again
      return getUserApproval(editedMessage, rl);
    } else if (choice === 'c' || choice === 'cancel') {
      return { approved: false, message: null };
    } else {
      console.log(`${colors.red}Invalid option. Please enter A, E, or C.${colors.reset}`);
    }
  }
}

/**
 * Create the commit with the approved message
 */
function createCommit(message) {
  console.log(`\n${colors.cyan}📦 Creating commit...${colors.reset}`);

  try {
    // Use a temporary file for the commit message to handle multi-line messages
    execSync(`git commit -F -`, {
      input: message,
      encoding: 'utf-8',
      stdio: ['pipe', 'inherit', 'inherit']
    });

    console.log(`${colors.green}✅ Commit created successfully!${colors.reset}`);
    return true;
  } catch (error) {
    console.error(`${colors.red}❌ Failed to create commit${colors.reset}`);
    console.error(error.message);
    return false;
  }
}

/**
 * Ask if user wants to push to remote
 */
async function askToPush(rl) {
  const answer = await question(
    rl,
    `\n${colors.yellow}Push to remote? [y/N]${colors.reset} `
  );

  return answer.trim().toLowerCase() === 'y' || answer.trim().toLowerCase() === 'yes';
}

/**
 * Push to remote repository
 */
function pushToRemote() {
  console.log(`${colors.cyan}🚀 Pushing to remote...${colors.reset}`);

  try {
    // Get current branch
    const branch = git('rev-parse --abbrev-ref HEAD');

    execSync(`git push origin ${branch}`, {
      encoding: 'utf-8',
      stdio: 'inherit'
    });

    console.log(`${colors.green}✅ Pushed successfully!${colors.reset}`);
    return true;
  } catch (error) {
    console.error(`${colors.red}❌ Failed to push${colors.reset}`);
    console.error(error.message);
    return false;
  }
}

/**
 * Show help message
 */
function showHelp() {
  console.log(`
${colors.bright}Git Commit Automation Script${colors.reset}
${colors.dim}Generates commit messages using OpenRouter AI${colors.reset}

${colors.bright}Usage:${colors.reset}
  1. Stage your changes:
     ${colors.cyan}git add <files>${colors.reset}

  2. Run this script:
     ${colors.cyan}pnpm commit${colors.reset}

  3. Review the AI-generated commit message

  4. Choose to accept, edit, or cancel

  5. Optionally push to remote

${colors.bright}Requirements:${colors.reset}
  - OpenRouter API key in .env file
  - Create ${colors.dim}src/utils/.env${colors.reset} with:
    ${colors.dim}OPENROUTER_API_KEY=your_api_key_here${colors.reset}
  - Get your key from: ${colors.dim}https://openrouter.ai/keys${colors.reset}

${colors.bright}Options:${colors.reset}
  --help, -h    Show this help message
`);
}

/**
 * Main function
 */
async function main() {
  // Check for help flag
  const args = process.argv.slice(2);
  if (args.includes('--help') || args.includes('-h')) {
    showHelp();
    process.exit(0);
  }

  // Load environment variables
  loadEnv();

  console.log(`${colors.bright}${colors.blue}🚀 Git Commit Automation${colors.reset}\n`);

  // Check if we're in a git repository
  if (!git('rev-parse --git-dir', true)) {
    console.error(`${colors.red}❌ Not a git repository${colors.reset}`);
    process.exit(1);
  }

  // Check for staged changes
  if (!checkStagedChanges()) {
    console.error(`${colors.red}❌ No staged changes found${colors.reset}`);
    console.log(`\n${colors.yellow}💡 Stage your changes first:${colors.reset}`);
    console.log(`   ${colors.dim}git add <files>${colors.reset}\n`);
    process.exit(1);
  }

  // Get git context
  const context = getGitContext();

  // Generate commit message using OpenRouter
  const generatedMessage = await generateCommitMessage(context);

  // Get user approval
  const rl = createReadlineInterface();
  const { approved, message } = await getUserApproval(generatedMessage, rl);

  if (!approved) {
    console.log(`\n${colors.yellow}⏭️  Commit cancelled${colors.reset}`);
    rl.close();
    process.exit(0);
  }

  // Create the commit
  const commitSuccess = createCommit(message);

  if (!commitSuccess) {
    rl.close();
    process.exit(1);
  }

  // Ask to push
  const shouldPush = await askToPush(rl);
  rl.close();

  if (shouldPush) {
    pushToRemote();
  }

  console.log(`\n${colors.green}✨ Done!${colors.reset}\n`);
}

// Run the script
main().catch((error) => {
  console.error(`${colors.red}❌ Unexpected error:${colors.reset}`, error);
  process.exit(1);
});