segment_tags.go

package m3u8

import (
	"strconv"
	"strings"
	"time"
)

// SegmentTags represents the tags of a segment.
type SegmentTags Tags

// Raw returns the raw tags.
func (tags SegmentTags) Raw() Tags {
	return Tags(tags)
}

// First returns the first tag of the name.
func (tags SegmentTags) First(name string) *Tag {
	return tags.Raw().First(name)
}

// Last returns the last tag of the name.
func (tags SegmentTags) Last(name string) *Tag {
	return tags.Raw().Last(name)
}

// Set sets the tag.
// If the tag already exists, it will be overwritten.
func (tags SegmentTags) Set(tag *Tag) {
	tags.Raw().Set(tag)
}

// Remove removes the tag.
// If the tag does not exist, it will do nothing.
// If the tag exists multiple times, all of them will be removed.
func (tags SegmentTags) Remove(name string) {
	tags.Raw().Remove(name)
}

// ProgramDateTime returns the value of the EXT-X-PROGRAM-DATE-TIME tag.
func (tags SegmentTags) ProgramDateTime() (time.Time, bool) {
	values, ok := tags[TagExtXProgramDateTime]
	if !ok || len(values) == 0 {
		return time.Time{}, false
	}
	value := values[0]
	t, err := time.Parse(time.RFC3339Nano, value)
	if err != nil {
		return time.Time{}, false
	}
	return t, true
}

// SetProgramDateTime sets the value of the EXT-X-PROGRAM-DATE-TIME tag.
func (tags SegmentTags) SetProgramDateTime(t time.Time) {
	tags[TagExtXProgramDateTime] = []string{t.Format("2006-01-02T15:04:05.999Z07:00")}
}

// ExtInfValue returns the value of the EXTINF tag.
func (tags SegmentTags) ExtInfValue() float64 {
	values, ok := tags[TagExtInf]
	if !ok || len(values) == 0 {
		return 0
	}
	value := values[0]
	idx := strings.Index(value, ",")
	if idx <= 0 {
		return 0
	}
	duration, err := strconv.ParseFloat(value[:idx], 64)
	if err != nil {
		return 0
	}
	return duration
}

// SetExtInfValue sets the value of the EXTINF tag.
func (tags SegmentTags) SetExtInfValue(duration float64, bitSize int) {
	tags[TagExtInf] = []string{strconv.FormatFloat(duration, 'f', -1, bitSize) + ","}
}

// DateRange returns the attributes list of the EXT-X-DATERANGE tags.
func (tags SegmentTags) DateRange() []DateRangeAttrs {
	values := tags[TagExtXDateRange]
	list := make([]DateRangeAttrs, 0, len(values))
	for _, value := range values {
		attrs, err := ParseTagAttributes(value)
		if err != nil {
			continue
		}
		list = append(list, DateRangeAttrs(attrs))
	}
	return list
}