package wshub

import (
	"math"
	"testing"
)

// A short window at a high sample rate fits in a ring's initial capacity, so the
// retune sweep used to leave it there — and a ring holding exactly the window has
// already rolled past the front of a capture by the time that capture is read,
// which happens a post-window plus captureMarginSec after the trigger fires.
//
// 1 MSps over a 200 ms window: 200 k points fit in the 250 k initial ring, and
// every shot came back missing its first 123 ms.
func TestCaptureWholeAtHighRateShortWindow(t *testing.T) {
	const (
		key      = "s1:Ch1"
		rate     = 1e6
		window   = 0.2
		prePct   = 20.0
		batchSec = 1.0 / 30.0
		simSec   = 6.0
	)

	h := NewHub()
	h.SetRingBudget(defaultRingPts)
	h.rings[key] = newSigRing(ringCapInitial)
	h.trigger.SetConfig(trigConfig{signalKey: key, edge: "rising", threshold: 0,
		windowSec: window, prePercent: prePct, mode: "normal", holdoffSec: 0.2})

	rateHz := float64(rate)
	nBatch := int(rateHz * batchSec)
	ts := make([]float64, nBatch)
	vs := make([]float64, nBatch)

	armed, shots := false, 0
	for now := 0.0; now < simSec; now += batchSec {
		for i := range ts {
			ts[i] = now + float64(i)/rateHz
			vs[i] = math.Sin(2 * math.Pi * 5 * ts[i]) // a rising crossing every 200 ms
		}
		h.ingest(key, 1, ts, vs)
		h.retuneRings(now)
		h.refreshTriggerFill()

		if !armed && now > 2 {
			h.trigger.Arm()
			armed = true
		}
		trigTime, pre, post, ok := h.trigger.dueCapture(now + batchSec)
		if !ok {
			if h.trigger.dueRearm(now + batchSec) {
				h.trigger.Arm()
			}
			continue
		}
		t0 := trigTime - pre
		buf := h.buildTriggerCapture(trigTime, pre, post)
		if buf == nil {
			t.Fatalf("shot at t=%.4f produced no frame at all", trigTime)
		}
		first, last, n := decodeCaptureSpan(t, buf, key)
		shots++
		if lost := first - t0; lost > shortCaptureTol*window {
			_, span := h.rings[key].stats()
			t.Errorf("shot at t=%.4f is missing %.0f ms at the front of its %.0f ms window "+
				"(got [%.4f,%.4f], %d pts; ring holds %.4f s in %d points)",
				trigTime, 1e3*lost, 1e3*window, first, last, n, span, h.rings[key].capacity())
		}
		h.trigger.markTriggered(now + batchSec)
	}
	if shots < 3 {
		t.Fatalf("only %d shots in %.0f s", shots, simSec)
	}
}