package mixer

import (
	"testing"
	"time"

	"rhemawavetech.com/rhemawave/internal/db"
)

// Regression tests for critical audio bugs (v0.5)

// Regression: Stop() used to return early when AudioEnabled was false,
// leaving music playing after the user toggled audio off mid-playback.
func TestStopCleansUpWhenAudioDisabled(t *testing.T) {
	mu.Lock()
	wasInited := inited
	inited = true
	deviceOpen = false
	currentPath = "/some/track.wav"
	currentLoops = -1
	mu.Unlock()

	defer func() {
		mu.Lock()
		inited = wasInited
		currentPath = ""
		currentLoops = 0
		mu.Unlock()
	}()

	cfg := &db.AppConfig{AudioEnabled: false}
	Stop(0, cfg)

	mu.Lock()
	defer mu.Unlock()
	if currentPath != "" {
		t.Errorf("currentPath = %q, want empty after Stop with AudioEnabled=false", currentPath)
	}
	if currentLoops != 0 {
		t.Errorf("currentLoops = %d, want 0 after Stop with AudioEnabled=false", currentLoops)
	}
}

// Regression: SwitchDevice used to convert oldDevice="" to "system default"
// and pass that string to openDeviceLocked, which SDL does not recognize.
func TestSwitchDeviceReturnsErrorWhenUninitialized(t *testing.T) {
	mu.Lock()
	wasInited := inited
	inited = false
	deviceOpen = false
	mu.Unlock()

	defer func() {
		mu.Lock()
		inited = wasInited
		mu.Unlock()
	}()

	cfg := &db.AppConfig{AudioEnabled: true, SavedVolume: 0.5}
	err := SwitchDevice("Some Device", cfg)
	if err == nil {
		t.Fatal("SwitchDevice on uninitialized mixer should return error")
	}
}

// Regression: SwitchDevice with nil config must not panic when attempting
// to restore volume after reopening the device.
func TestSwitchDeviceNilConfigDoesNotPanic(t *testing.T) {
	mu.Lock()
	wasInited := inited
	inited = false
	deviceOpen = false
	mu.Unlock()

	defer func() {
		mu.Lock()
		inited = wasInited
		mu.Unlock()
	}()

	err := SwitchDevice("Some Device", nil)
	if err == nil {
		t.Fatal("SwitchDevice on uninitialized mixer should return error")
	}
}

// Regression: SwitchDevice with empty device name (system default) should
// not be converted to "system default" before passing to openDeviceLocked.
func TestSwitchDeviceAcceptsEmptyDeviceName(t *testing.T) {
	mu.Lock()
	wasInited := inited
	inited = false
	deviceOpen = false
	mu.Unlock()

	defer func() {
		mu.Lock()
		inited = wasInited
		mu.Unlock()
	}()

	cfg := &db.AppConfig{SavedVolume: 0.75}
	err := SwitchDevice("", cfg)
	// Returns error because mixer is not initialized, but should not panic
	// and should handle the empty name gracefully.
	if err == nil {
		t.Fatal("SwitchDevice on uninitialized mixer should return error")
	}
}

// TestPlayDoesNotDeadlockWhenUninitialized verifies that Play() returns an error
// (not a deadlock) when the mixer has not been initialized.
// The old code would deadlock because Play() held mu then called SwitchDevice()
// which also tried to acquire mu.
func TestPlayDoesNotDeadlockWhenUninitialized(t *testing.T) {
	// Ensure mixer is in uninitialized state
	mu.Lock()
	wasInited := inited
	inited = false
	deviceOpen = false
	mu.Unlock()

	defer func() {
		mu.Lock()
		inited = wasInited
		mu.Unlock()
	}()

	cfg := &db.AppConfig{AudioEnabled: true}
	done := make(chan error, 1)
	go func() {
		done <- Play("nonexistent.wav", false, cfg)
	}()

	select {
	case err := <-done:
		if err == nil {
			t.Fatal("Play() returned nil error on uninitialized mixer, want error")
		}
	case <-time.After(5 * time.Second):
		t.Fatal("Play() deadlocked on uninitialized mixer (did not return within 5s)")
	}
}