import { readdir, readFile } from 'node:fs/promises';
import { platform } from 'node:os';
import { join, resolve } from 'node:path';
import { kill } from 'node:process';

import log from '~/utils/log';

import { createIntegration } from './integration';

interface Context {
	pid: number | undefined;
}

export default createIntegration<Context>({
	name: 'Native Linux (/proc)',
	context: {
		pid: undefined,
	},
	isAvailable: async (context) => {
		if (platform() !== 'linux') {
			log.error('INTG', '/proc is only available on Linux');
			return false;
		}

		log.debug('INTG', 'Checking /proc for Headscale process');
		const dir = resolve('/proc');
		try {
			const subdirs = await readdir(dir);
			const promises = subdirs.map(async (dir) => {
				const pid = Number.parseInt(dir, 10);

				if (Number.isNaN(pid)) {
					return;
				}

				const path = join('/proc', dir, 'cmdline');
				try {
					log.debug('INTG', 'Reading %s', path);
					const data = await readFile(path, 'utf8');
					if (data.includes('headscale')) {
						return pid;
					}
				} catch (error) {
					log.error('INTG', 'Failed to read %s: %s', path, error);
				}
			});

			const results = await Promise.allSettled(promises);
			const pids = [];

			for (const result of results) {
				if (result.status === 'fulfilled' && result.value) {
					pids.push(result.value);
				}
			}

			log.debug('INTG', 'Found Headscale processes: %o', pids);
			if (pids.length > 1) {
				log.error(
					'INTG',
					'Found %d Headscale processes: %s',
					pids.length,
					pids.join(', '),
				);
				return false;
			}

			if (pids.length === 0) {
				log.error('INTG', 'Could not find Headscale process');
				return false;
			}

			context.pid = pids[0];
			log.info('INTG', 'Found Headscale process with PID: %d', context.pid);
			return true;
		} catch {
			log.error('INTG', 'Failed to read /proc');
			return false;
		}
	},
});