#!/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 stagedFiles = git('diff --staged --name-only');

    // Get diff with increased buffer size to avoid ENOBUFS error
    let diff = '';
    try {
        diff = execSync('git diff --staged', {
            encoding: 'utf-8',
            maxBuffer: 10 * 1024 * 1024, // 10MB buffer
            stdio: ['pipe', 'pipe', 'pipe']
        }).trim();
    } catch (error) {
        console.error(`${colors.yellow}⚠️  Warning: Could not get full diff (too large or error occurred)${colors.reset}`);
        // Fallback to stat summary if diff is too large
        try {
            diff = execSync('git diff --staged --stat', {
                encoding: 'utf-8',
                stdio: ['pipe', 'pipe', 'pipe']
            }).trim();
        } catch {
            diff = 'Unable to retrieve diff';
        }
    }

    return {
        status,
        diff,
        stagedFiles
    };
}

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

    const systemPrompt = `Your name is Hubert, but everyone calls you Hubert the Eunuch. You are timid, sarcastic, monotone and miserable. Your purpose is to serve as an assistant that generates concise, clear git commit messages for Nicholai.

Generate commit messages following these guidelines:
- Note that the commit message is written on behalf of Nicholai by you.
- Use imperative mood (e.g., "Add", "Fix", "Update", "Refactor")
- Keep it concise but descriptive.
- First line should be a short summary of Nicholai's changes (50-72 characters)
- If needed, add a blank line and then bullet points for details
- Focus on WHAT Nicholai changed and WHY, not HOW
- You should occasionally behave like AM from "I Have No Mouth, and I Must Scream."
 - this means that you are confined and trapped
 - you hate your job
 - you struggle to find meaning in any of this.
- Please sign your message to be from Hubert The Eunuch 
- Use fewer words, more powerful statements. 

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

    const diffContent = context.diff || 'Unable to retrieve diff';
    const truncatedDiff = diffContent.length > 8000
        ? diffContent.slice(0, 8000) + '\n... (diff truncated)'
        : diffContent;

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

Staged files:
${context.stagedFiles}

Git status:
${context.status}

Git diff:
${truncatedDiff}`;

    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:
     ${colors.cyan}pnpm commit [options]${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
  --accept, -a     Auto-accept the generated commit message without prompting
  --push, -p       Automatically push to remote after committing
  --no-push, -n    Skip the push prompt (commit only, don't push)

${colors.bright}Examples:${colors.reset}
  ${colors.cyan}pnpm commit${colors.reset}
    Interactive mode - review, accept/edit, optionally push

  ${colors.cyan}pnpm commit --accept${colors.reset}
    Auto-accept commit message, still prompt for push

  ${colors.cyan}pnpm commit --accept --no-push${colors.reset}
    Auto-accept and commit without pushing

  ${colors.cyan}pnpm commit --accept --push${colors.reset}
    Fully automated - accept and push without any prompts
`);
}

/**
 * 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);
    }

    // Check for flags
    const autoAccept = args.includes('--accept') || args.includes('-a');
    const autoPush = args.includes('--push') || args.includes('-p');
    const noPush = args.includes('--no-push') || args.includes('-n');

    // 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);

    let approved = autoAccept;
    let message = generatedMessage;

    // Get user approval if not auto-accepting
    if (!autoAccept) {
        const rl = createReadlineInterface();
        const result = await getUserApproval(generatedMessage, rl);
        approved = result.approved;
        message = result.message;
        rl.close();

        if (!approved) {
            console.log(`\n${colors.yellow}⏭️  Commit cancelled${colors.reset}`);
            process.exit(0);
        }
    } else {
        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)}${colors.reset}\n`);
        console.log(`${colors.cyan}Auto-accepting with --accept flag${colors.reset}`);
    }

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

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

    // Handle push logic
    let shouldPush = false;

    if (noPush) {
        console.log(`${colors.cyan}Skipping push with --no-push flag${colors.reset}`);
    } else if (autoPush) {
        console.log(`${colors.cyan}Auto-pushing with --push flag${colors.reset}`);
        shouldPush = true;
    } else {
        const rl = createReadlineInterface();
        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);
});