tabler/shared/lib/pseudo-random.ts

// Deterministic pseudo-random values seeded by a loop index, used to generate
// stable-looking demo data (numbers, dates, "time ago" labels) without a real RNG.

export function randomNumber(x: number, min = 0, max = 100, round = 0): number {
  let value = ((x * x * Math.PI * Math.E * (max + 1) * (Math.sin(x) / Math.cos(x * x))) % (max + 1 - min)) + min

  value = value > max ? max : value
  value = value < min ? min : value

  if (round !== 0) {
    value = parseFloat(value.toFixed(round))
  } else {
    value = Math.floor(value)
  }

  return value
}

export function randomDate(x: number): Date {
  const start = new Date('2024-01-01').getTime() / 1000
  const end = new Date('2024-12-30').getTime() / 1000

  return new Date(randomNumber(x, start, end) * 1000)
}

export function randomItem<T>(x: number, items: T[]): T {
  return items[randomNumber(x, 0, items.length - 1)]
}

/** A date up to `maxDays` days ago, formatted as "now" / "N day(s) ago". */
export function timeagoLabel(index: number, maxDays: number): string {
  const days = randomNumber(index, 0, maxDays)
  if (days === 0) return 'now'
  return `${days} day${days > 1 ? 's' : ''} ago`
}