import { Config, IResourceLoad, Logger } from '@browserless.io/browserless';

import { EventEmitter } from 'events';

import si from 'systeminformation';

export class Monitoring extends EventEmitter {

protected log = new Logger('hardware');

constructor(protected config: Config) {

super();

}

public async getMachineStats(): Promise<IResourceLoad> {

const [cpuLoad, memLoad] = await Promise.all([

si.currentLoad(),

si.mem(),

]).catch((err) => {

this.log.error(`Error checking machine stats`, err);

return [null, null];

});

const cpu = cpuLoad ? cpuLoad.currentLoadUser / 100 : null;

const memory = memLoad ? memLoad.active / memLoad.total : null;

return {

cpu,

memory,

};

}

public async overloaded(): Promise<{

cpuInt: number | null;

cpuOverloaded: boolean;

memoryInt: number | null;

memoryOverloaded: boolean;

}> {

const { cpu, memory } = await this.getMachineStats();

const cpuInt = cpu && Math.ceil(cpu * 100);

const memoryInt = memory && Math.ceil(memory * 100);

this.log.debug(

`Checking overload status: CPU ${cpuInt}% Memory ${memoryInt}%`,

);

const cpuOverloaded = !!(cpuInt && cpuInt >= this.config.getCPULimit());

const memoryOverloaded = !!(

memoryInt && memoryInt >= this.config.getMemoryLimit()

);

return {

cpuInt,

cpuOverloaded,

memoryInt,

memoryOverloaded,

};

}

/**

* Implement any browserless-core-specific shutdown logic here.

* Calls the empty-SDK stop method for downstream implementations.

*/

public async shutdown() {

return await this.stop();

}

/**

* Left blank for downstream SDK modules to optionally implement.

*/

public stop() {}

}