'use strict';

const fs = require('node:fs/promises');

const { Console } = require('node:console');

class Logger {

#files = new Map();

async use(filename) {

let instance = this.#files.get(filename);

if (!instance) {

instance = await Logger.#open(filename);

this.#files.set(filename, instance);

}

instance.count++;

console.log(`👉 Use: ${filename}`);

const disposable = Object.create(instance.console);

disposable[Symbol.asyncDispose] = async () => {

instance.count--;

console.log(`👉 Dispose: ${filename}`);

if (instance.count > 0) return;

console.log(`👉 Close: ${filename}`);

await instance.fd.close();

this.#files.delete(filename);

};

return disposable;

}

static async #open(filename) {

console.log(`👉 Open: ${filename}`);

const fd = await fs.open(filename, 'a');

const stream = fd.createWriteStream(filename, { flush: true });

const con = new Console({ stdout: stream });

return { count: 0, fd, console: con };

}

}

// Usage

const logger = new Logger();

const main = async () => {

// Block 0

await using console = await logger.use('output.log');

console.log('Log 0');

{

// Block 1

await using console = await logger.use('output.log');

console.log('Log 1');

}

{

// Block 2

await using console = await logger.use('output.log');

console.log('Log 2');

{

// Block 3

await using console = await logger.use('output3.log');

console.log('Log 3');

{

// Block 4

await using console = await logger.use('output.log');

console.log('Log 4');

}

}

}

return console;

};

main().then((ref) => {

// Block 5

console.log('After main');

ref.log('Log 5');

});