import { VERSION } from "./types";

export const HELP = `rand — Generate random numbers

Usage:
  rand [options] [args]

Options:
  -c, --count <n>     Number of random numbers to output (default: 1)
  -f[N]               Decimal places: -f = -f2, -f3 = 3 places
  --float [N]         Long form of -f
  -d, --dist <name>   Distribution (default: uniform)
  -h, --help          Show this help
  -V, --version       Show version

Distributions and their positional args:
  uniform             rand [min] [max]                (default: 0 100)
  normal              rand -d normal [mean] [stddev]  (default: 0 1)
  binomial            rand -d binomial [n] [p]         (default: 10 0.5)
  poisson             rand -d poisson [lambda]         (default: 1)
  exponential         rand -d exponential [lambda]     (default: 1)
  hypergeometric      rand -d hypergeometric [N] [K] [n]
                                                   (default: 100 50 10)

Examples:
  rand                               # uniform 0–100
  rand -d normal                     # normal μ=0, σ=1
  rand -d normal 100 15 -f1          # normal μ=100, σ=15, 1 decimal
  rand -d binomial 20 0.3 -c 5     # 5 binomial(n=20, p=0.3)
  rand -d poisson 3                  # poisson λ=3
  rand -d exponential 0.5            # exponential λ=0.5
  echo "5 2" | rand -d normal       # stdin overrides positional args
  rand | xargs echo                 # pipe output`;

export function showHelp(): never {
  console.log(HELP);
  process.exit(0);
}

export function showVersion(): never {
  console.log(`rand v${VERSION}`);
  process.exit(0);
}