package playback

import (
	"context"
	"fmt"
	"time"
)

type Unit uint8

const (
	UnitVideo Unit = iota
	UnitAudio
	UnitSync
)

type State uint8

const (
	StateIdle State = iota
	StateConnecting
	StatePlaying
	StateReconnecting
	StateFailed
	StateStopping
)

type Status struct {
	Unit           Unit
	State          State
	Generation     uint64
	Attempt        int
	FailedAttempts int
	RetryIn        time.Duration
	Err            error
}

type StatusObserver func(Status)

type generationContextKey struct{}

func withGeneration(ctx context.Context, generation uint64) context.Context {
	return context.WithValue(ctx, generationContextKey{}, generation)
}

func generationFromContext(ctx context.Context) uint64 {
	generation, _ := ctx.Value(generationContextKey{}).(uint64)
	return generation
}

func (u Unit) String() string {
	switch u {
	case UnitVideo:
		return "video"
	case UnitAudio:
		return "audio"
	case UnitSync:
		return "sync"
	default:
		return fmt.Sprintf("Unit(%d)", uint8(u))
	}
}

func (s State) String() string {
	switch s {
	case StateIdle:
		return "idle"
	case StateConnecting:
		return "connecting"
	case StatePlaying:
		return "playing"
	case StateReconnecting:
		return "reconnecting"
	case StateFailed:
		return "failed"
	case StateStopping:
		return "stopping"
	default:
		return fmt.Sprintf("State(%d)", uint8(s))
	}
}