package player

import "time"

// Engine is the interface used by the TUI model to control audio playback.
// It is satisfied by *Player and can be replaced with a mock for testing.
type Engine interface {
	// Playback control
	Play(path string, knownDuration time.Duration) error
	PlayYTDL(pageURL string, knownDuration time.Duration) error
	Preload(path string, knownDuration time.Duration) error
	PreloadYTDL(pageURL string, knownDuration time.Duration) error
	ClearPreload()
	Stop()
	Close()
	TogglePause()

	// Seeking
	Seek(d time.Duration) error
	SeekYTDL(d time.Duration) error
	CancelSeekYTDL()

	// State queries
	IsPlaying() bool
	IsPaused() bool
	Drained() bool
	HasPreload() bool
	Seekable() bool
	IsStreamSeek() bool
	IsYTDLSeek() bool
	GaplessAdvanced() bool

	// Position and duration
	Position() time.Duration
	Duration() time.Duration
	PositionAndDuration() (time.Duration, time.Duration)

	// Volume
	SetVolumeMin(db float64)
	VolumeMin() float64
	SetVolume(db float64)
	Volume() float64

	// Speed
	SetSpeed(ratio float64)
	Speed() float64

	// Mono
	ToggleMono()
	Mono() bool

	// EQ
	SetEQBand(band int, dB float64)
	EQBands() [10]float64

	// Stream info
	StreamErr() error
	StreamTitle() string
	StreamBytes() (downloaded, total int64)

	// Audio samples for visualizer
	SamplesInto(dst []float64) int
	SampleRate() int
}

// Compile-time check that *Player satisfies Engine.
var _ Engine = (*Player)(nil)