random-by-weight.js

const _ = require("lodash");
const fs = require("fs");

const teams = [
  { name: "Phap", weight: 5, rank: 5 },
  { name: "Duc", weight: 3, rank: 5 },
  { name: "Bo dao nha", weight: 2, rank: 5 },
];

const list = _.chain(teams)
  .flatMap((team) => Array(team.weight).fill(team.name))
  .shuffle()
  .value();

function getRandomTeam() {
  return _.sample(list);
}

const reports = [];

_.forEach(_.range(1, 1000000 + 1, 1), (idx) => {
  const name = getRandomTeam();
  reports.push({
    turn: idx,
    name,
  });
});
console.log(reports.length);

_.forEach(teams, (team) => {
  const filteredReports = _.filter(
    reports,
    (report) => report.name === team.name
  );
  const percent = _.round((filteredReports.length / reports.length) * 100, 2);
  console.log(team.name, filteredReports.length, `${percent}%`);
});

fs.writeFileSync("./report.json", JSON.stringify(reports));