// Fenrir console screen reader.
// Copyright (c) 2026 Storm Dragon
// SPDX-License-Identifier: GPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
// more details.
//
// You should have received a copy of the GNU General Public License along with
// this program. If not, see <https://www.gnu.org/licenses/gpl-3.0.html>.

package sound

import (
	"context"
	"crypto/sha256"
	"encoding/binary"
	"fmt"
	"math"
	"slices"
	"sync"
	"testing"

	"git.stormux.org/storm/fenrir/internal/presentation"
)

func TestProgressTonePitchDurationStereoAndVolume(t *testing.T) {
	for _, percentage := range []float64{0, 25, 50, 75, 100} {
		item := progress_tone(percentage)
		frames := len(item.samples) / 2
		if frames < sampleRate*40/1000 || frames > sampleRate*50/1000 {
			t.Fatal("duration", frames)
		}
		crossings := 0
		for frame := range frames {
			left, right := item.samples[frame*2], item.samples[frame*2+1]
			if left != right || math.Abs(float64(left)) > 7000.0/32768+0.00001 {
				t.Fatal("stereo/amplitude", left, right)
			}
			if frame > 0 && item.samples[(frame-1)*2] <= 0 && left > 0 {
				crossings++
			}
		}
		gotHz := float64(crossings) * sampleRate / float64(frames)
		wantHz := 110 * math.Pow(2, percentage/25)
		if math.Abs(gotHz-wantHz) > 26 {
			t.Fatal("pitch", percentage, gotHz, wantHz)
		}
	}
	s := &Service{tones: progress_clips()}
	s.Set_volume(.25)
	s.Play_progress(50)
	buffer := make([]float32, len(s.tones[50].samples))
	s.read_samples(buffer)
	for index, value := range buffer {
		if value != s.tones[50].samples[index]*(float32(.25)*float32(1.0506)) {
			t.Fatal("unscaled progress")
		}
	}
}

func TestProgressPriorityCoalescingAndCancellation(t *testing.T) {
	s := &Service{clips: map[presentation.Cue]*clip{
		presentation.Ready: {samples: []float32{1, 1, 2, 2}},
		presentation.Top:   {samples: []float32{3, 3, 4, 4}},
	}, tones: [101]*clip{0: {samples: []float32{5, 5, 6, 6}}, 50: {samples: []float32{7, 7, 8, 8}}, 100: {samples: []float32{9, 9}}}}
	s.Set_volume(1)
	buffer := make([]float32, 2)
	read := func(want float32) {
		t.Helper()
		s.read_samples(buffer)
		if math.Abs(float64(buffer[0]-want)) > 0.00001 {
			t.Fatal("wrong audio", buffer, want)
		}
	}
	s.Play(presentation.Ready)
	s.Play_progress(0)
	read(1)
	s.Play(presentation.Top)
	s.Play_progress(50)
	read(2)
	read(3)
	read(4)
	read(7 * 1.0506)
	s.Play_progress(0)
	s.Play_progress(100)
	read(8 * 1.0506)
	read(9 * 1.0506)
	read(0)
	// Ordinary cues can interrupt a tone, and a pending tone survives that cue.
	s.Play_progress(50)
	read(7 * 1.0506)
	s.Play_progress(100)
	s.Play(presentation.Top)
	read(3)
	read(4)
	read(9 * 1.0506)
	s.Play_progress(50)
	read(7 * 1.0506)
	s.Play_progress(100)
	s.Clear_progress()
	read(0)
	s.Play(presentation.Top)
	read(3)
	s.Clear_progress()
	read(4)
	// Shutdown stops progress admission and discards pending tones.
	s.Play_progress(100)
	s.Finish(context.Background())
	read(0)
	if s.Play_progress(50) {
		t.Fatal("accepted during shutdown")
	}
	s.Close()
	if s.Play_progress(50) {
		t.Fatal("accepted after close")
	}
}

func TestProgressAdmissionIsBoundedAndConcurrent(t *testing.T) {
	s := &Service{tones: progress_clips()}
	s.Set_volume(1)
	for _, value := range []float64{-1, 101, math.NaN(), math.Inf(1)} {
		if s.Play_progress(value) {
			t.Fatal("invalid progress", value)
		}
	}
	s.Play_progress(49.6)
	if s.progress.Load() != s.tones[50] {
		t.Fatal("fraction rounding")
	}
	cached := slices.Clone(s.tones[50].samples)
	var workers sync.WaitGroup
	workers.Go(func() {
		for range 10000 {
			s.Play_progress(50)
			s.Discard_progress()
			s.Clear_progress()
			s.Play_progress(100)
		}
	})
	buffer := make([]float32, 128)
	for range 10000 {
		s.read_samples(buffer)
	}
	workers.Wait()
	if !slices.Equal(cached, s.tones[50].samples) {
		t.Fatal("mutated cache")
	}
	if allocations := testing.AllocsPerRun(100, func() { s.Play_progress(50) }); allocations != 0 {
		t.Fatal("admission allocates", allocations)
	}
	if allocations := testing.AllocsPerRun(100, func() { s.read_samples(buffer) }); allocations != 0 {
		t.Fatal("callback allocates", allocations)
	}
}

func TestDiscardProgressPreservesEntirePlayingTone(t *testing.T) {
	s := &Service{tones: progress_clips()}
	s.Set_volume(1)
	s.Play_progress(50)
	tone := s.tones[50].samples
	split := len(tone) / 4 * 2 // Keep stereo frames paired.
	first := make([]float32, split)
	s.read_samples(first)
	s.Play_progress(100)
	s.Discard_progress()
	tail := make([]float32, len(tone)-split)
	s.read_samples(tail)
	for index, value := range append(first, tail...) {
		if value != tone[index]*float32(progressGain) {
			t.Fatalf("tone cut short or altered at sample %d: got %v, want %v", index, value, tone[index]*float32(progressGain))
		}
	}
	s.read_samples(tail)
	for _, value := range tail {
		if value != 0 {
			t.Fatal("discarded waiting tone still played")
		}
	}
	// A reset must not prevent the next job from making progress sounds.
	s.Play_progress(100)
	s.read_samples(tail)
	if !slices.ContainsFunc(tail, func(value float32) bool { return value != 0 }) {
		t.Fatal("new progress tone was lost after discard")
	}
}

func TestProgressSamplesMatchCthulhuReference(t *testing.T) {
	// Digest of Cthulhu's unmodified progress_tone_wav for integer 0..100,
	// independently resampled from 44100 Hz PCM16 to our 48000 Hz stereo float.
	hash := sha256.New()
	for _, item := range progress_clips() {
		for _, sample := range item.samples {
			if err := binary.Write(hash, binary.LittleEndian, sample); err != nil {
				t.Fatal(err)
			}
		}
	}
	if got := fmt.Sprintf("%x", hash.Sum(nil)); got != "b6e0adff86b6659465ff6942c4651b84e76d855ba6a8b7e3a982a88f8dde4e9b" {
		t.Fatal("Cthulhu tone samples differ", got)
	}
}