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import "@hatch:assert" for Expect

// `Future`, `Browser`, `WebSocket`, `Dom`, `LocalStorage` are
// loaded by the runtime — no boilerplate needed. Async bridges
// resume through the scheduler in both modes; print *inside*
// the fiber so results land in the output pane.

var fiber = Fiber.new {
  System.print("before: %(Dom.text("#title").await)")
  Browser.setTimeout(0).await
  Dom.setText("#title", "rewritten by wren").await
  Dom.setText("#msg", "scheduler resumed me after 0ms").await
  Dom.addClass("#title", "dim").await
  System.print("done")
}
fiber.try()

// Recursive compute through the wasm tier-up JIT. fib(20) lands
// at ~3 ms post-warmup on both worker and main mode.
// Bump to fib(28) if you want to feel the runtime in earnest.
var start = System.clock
var fib
fib = Fn.new {|n| n < 2 ? n : fib.call(n - 1) + fib.call(n - 2) }
var result = fib.call(20)
var elapsed = (System.clock - start) * 1000

// `@hatch:assert` is fetched on demand from the dev server
Expect.that(result).toBe(6765)
Expect.that(elapsed).not.toBeNull()
// Wren's Num→String drops trailing zeros, so dividing by 100
// would render `8.0` as `"8"`. Build the two-digit fraction by
// hand: round to hundredths, split into whole + frac, pad.
var hundredths = (elapsed * 100).round
var whole = (hundredths / 100).floor
var frac = hundredths - whole * 100
var fracStr = frac < 10 ? "0%(frac)" : "%(frac)"
System.print("fib(20) = %(result)  (%(whole).%(fracStr) ms)")

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