package audio

import (
	"testing"
	"time"
)

// A silent second source must not silence the recording.
//
// From a real session: a Flex with "From Radio" on DAX RX and "Recording mic"
// on DAX Mic. In CW the mic path does not run, so DAX Mic delivered nothing —
// and because the mixer took min(len(A), len(B)) samples, nothing at all was
// recorded. The whole QSO ended in "recording was empty".
func TestMixerSurvivesASilentSource(t *testing.T) {
	r := &Recorder{twoSrc: true, gainA: 1, gainB: 1, running: true, active: true, prerollSamples: sampleRate}

	// The radio has been talking; the mic has not spoken for well over the
	// grace period.
	r.bufA = make([]int16, 800)
	for i := range r.bufA {
		r.bufA[i] = 1000
	}
	r.lastA = time.Now()
	r.lastB = time.Now().Add(-5 * time.Second)

	r.mixTick()

	if len(r.acc) == 0 {
		t.Fatal("nothing was recorded — a silent mic must not stop the radio being captured")
	}
	if r.acc[0] != 1000 {
		t.Errorf("sample = %d, want 1000 — the live source must pass through unchanged", r.acc[0])
	}
}

// While BOTH sources are alive the two are mixed, as before.
func TestMixerStillMixesBothSources(t *testing.T) {
	r := &Recorder{twoSrc: true, gainA: 1, gainB: 1, running: true, active: true, prerollSamples: sampleRate}
	r.bufA = []int16{100, 100, 100}
	r.bufB = []int16{50, 50, 50}
	now := time.Now()
	r.lastA, r.lastB = now, now

	r.mixTick()

	if len(r.acc) != 3 {
		t.Fatalf("recorded %d samples, want 3", len(r.acc))
	}
	if r.acc[0] != 150 {
		t.Errorf("sample = %d, want 150 — both sources should be summed", r.acc[0])
	}
}

// Before either source has EVER delivered, neither may be written off: at
// startup both timestamps are zero, and declaring one dead then would drop the
// first moments of every recording.
func TestMixerWaitsForBothAtStartup(t *testing.T) {
	r := &Recorder{twoSrc: true, gainA: 1, gainB: 1, running: true, active: true, prerollSamples: sampleRate}
	r.bufA = []int16{100, 100}
	// lastA/lastB both zero — nothing has been heard from either yet.

	r.mixTick()

	if len(r.acc) != 0 {
		t.Errorf("recorded %d samples before the second source was known to be silent", len(r.acc))
	}
}