package radio

import (
	"encoding/json"
	"time"
)

type Song struct {
	Artist        string
	Title         string
	StartAt       time.Time
	Duration      time.Duration
	Listeners     int64
	PeakListeners int64
}

// DurationString returns song's duration as a string formatted as [H:]M:SS.
func (s *Song) DurationString() string {
	if s.Duration.Hours() >= 1 {
		return time.UnixMilli(s.Duration.Milliseconds()).Format("3:4:05")
	}
	return time.UnixMilli(s.Duration.Milliseconds()).Format("4:05")
}

func (s *Song) MarshalJSON() ([]byte, error) {
	return json.Marshal(&struct {
		Artist        string `json:"artist"`
		Title         string `json:"title"`
		DurationMill  int64  `json:"duration_msec,omitempty"`
		Listeners     int64  `json:"listeners,omitempty"`
		PeakListeners int64  `json:"peak_listeners,omitempty"`
		StartAt       string `json:"start_at"`
	}{
		Artist:        s.Artist,
		Title:         s.Title,
		DurationMill:  s.Duration.Milliseconds(),
		Listeners:     s.Listeners,
		PeakListeners: s.PeakListeners,
		StartAt:       s.StartAt.UTC().Format(time.RFC3339)})
}