const simpleGit = require('simple-git');
const semver = require('semver');
const { CronJob } = require('cron');
const fs = require('node:fs');
const path = require('node:path');
const restartApp = require('./restartApp.js');
const logger = require('../logger.js');
const { SERVER_ID, AUTO_UPDATE_SCHEDULE, EXTENDED_LOGS } = require('../../config.js').MAIN;

const git = simpleGit();
const pkgPath = path.resolve(__dirname, '../../package.json');
const LOCK_FILE = path.resolve(__dirname, '../../.git/index.lock');
const STALE_LOCK_THRESHOLD = 60_000;

const getLocalVersion = () => {
	delete require.cache[require.resolve(pkgPath)];
	return require(pkgPath).version;
};

const cleanStaleLock = () => {
	try {
		const stat = fs.statSync(LOCK_FILE);
		if (Date.now() - stat.mtimeMs > STALE_LOCK_THRESHOLD) {
			fs.unlinkSync(LOCK_FILE);
			logger.warn('Removed stale .git/index.lock file', { discord: true });
		}
	} catch (err) {
		if (err.code !== 'ENOENT') logger.error(`Failed to check/remove index.lock: ${err.message}`);
	}
};

const pull = async () => {
	try {
		if (SERVER_ID !== 'development') {
			if (EXTENDED_LOGS) logger.info('Resetting local repository to HEAD (--hard)...');
			await git.reset(['--hard']);
		}

		logger.info('Pulling the repository and the required submodule...');

		// Get submodule status before update
		const submoduleBefore = await git.raw(['submodule', 'status']);

		// Pull main repo and update submodules
		const pullResult = await git.pull();
		await git.submoduleUpdate(['--init', '--recursive', '--remote', '--merge']);

		// Get submodule status after update
		const submoduleAfter = await git.raw(['submodule', 'status']);
		const submoduleChanged = submoduleBefore !== submoduleAfter;

		const { changes, insertions, deletions } = pullResult.summary;
		const mainRepoChanged = changes > 0 || insertions > 0 || deletions > 0;
		const hasChanges = mainRepoChanged || submoduleChanged;
		if (hasChanges) {
			const parts = [];
			if (mainRepoChanged) parts.push(`Main repo - Changes: ${changes}; Insertions: ${insertions}; Deletions: ${deletions};`);
			if (submoduleChanged) parts.push('Submodule updated.');
			logger.success(`Updates pulled successfully! ${parts.join(' ')}`, { discord: true });
		} else {
			logger.info('No new updates detected');
		}

		return hasChanges;
	} catch (err) {
		logger.error(err.stack);
		return null;
	}
};

const pullAndRestart = async () => {
	try {
		cleanStaleLock();

		const oldVersion = getLocalVersion();
		const hasChanges = await pull();
		if (!hasChanges) return;

		const newVersion = getLocalVersion();
		if (semver.neq(newVersion, oldVersion)) {
			logger.success(`Version changed: ${oldVersion} → ${newVersion}`, { discord: true });
		}

		await restartApp();
	} catch (err) {
		logger.error(err.stack);
	}
};

new CronJob(AUTO_UPDATE_SCHEDULE, pullAndRestart, null, true);
module.exports = pullAndRestart;