package main

import (
	"math"
	"testing"
)

// sine builds `ms` milliseconds of a 16 kHz tone at the given amplitude, so we
// can exercise the energy gate without real audio or whisper.
func sine(ms int, amp float64) []float32 {
	n := whisperSampleRate * ms / 1000
	out := make([]float32, n)
	for i := range out {
		out[i] = float32(amp * math.Sin(2*math.Pi*440*float64(i)/whisperSampleRate))
	}
	return out
}

func TestGateReason(t *testing.T) {
	const (
		minMs  = 300
		minRMS = 0.01
	)
	tests := []struct {
		name    string
		samples []float32
		gated   bool // true ⇒ expect a non-empty reason (dropped)
	}{
		{"empty", nil, true},
		{"too short", sine(100, 0.5), true},                           // 100ms < 300ms
		{"long but silent", make([]float32, whisperSampleRate), true}, // 1s of zeros
		{"long but near-silent", sine(500, 0.005), true},              // rms ~0.0035 < floor
		{"real speech-ish", sine(500, 0.3), false},                    // loud enough, long enough
	}
	for _, tc := range tests {
		t.Run(tc.name, func(t *testing.T) {
			reason := gateReason(tc.samples, whisperSampleRate, minMs, minRMS)
			if (reason != "") != tc.gated {
				t.Fatalf("gateReason=%q, want gated=%v", reason, tc.gated)
			}
		})
	}
}