gmantaos/Goirate

package torrents

import (
    "encoding/json"
    "fmt"
    "net/url"
    "strings"
    "time"
)

// Torrent holds all the information regarding a torrent.
type Torrent struct {
    Title            string       `json:"title"`
    Size             int64        `json:"size"` // In kilobytes
    Seeders          int          `json:"seeders"`
    Leeches          int          `json:"leeches"`
    VerifiedUploader bool         `json:"verified_uploader"`
    VideoQuality     VideoQuality `json:"video_quality"`
    VideoRelease     VideoRelease `json:"video_release"`
    MirrorURL        string       `json:"mirror_url"`
    TorrentURL       string       `json:"torrent_path"`
    Magnet           string       `json:"magnet"`
    UploadTime       time.Time    `json:"upload_time"`
    Uploader         string       `json:"uploader"`
}

// FullURL returns the absolute URL for this torrent, including the mirror it was scraped from.
func (t Torrent) FullURL() string {
    fullURL, _ := url.Parse(t.MirrorURL)
    fullURL.Path = t.TorrentURL

    fullURLFormatted := strings.ReplaceAll(fullURL.String(), "%3F", "?")
    fullURLFormatted = strings.ReplaceAll(fullURLFormatted, "%28", "(")
    fullURLFormatted = strings.ReplaceAll(fullURLFormatted, "%29", ")")

    return fullURLFormatted
}

// PeersString returns a string representation of the torrent's connected peers
// in the Seeds/Peers format.
func (t Torrent) PeersString() string {
    return fmt.Sprintf("%v / %v", t.Seeders, t.Seeders+t.Leeches)
}

// SizeString returns a formatted string representation of the torrent's file size.
func (t Torrent) SizeString() string {
    const unit = 1000
    sizeBytes := t.Size * 1000
    if sizeBytes < unit {
        return fmt.Sprintf("%d B", sizeBytes)
    }
    div, exp := int64(unit), 0
    for n := sizeBytes / unit; n >= unit; n /= unit {
        div *= unit
        exp++
    }
    return fmt.Sprintf("%.1f %cB", float64(sizeBytes)/float64(div), "KMGTPE"[exp])
}

// MarshalJSON will override the json marshalling process so as to include the torrent's full url and its size in human readable format.
func (t *Torrent) MarshalJSON() ([]byte, error) {
    type Alias Torrent

    return json.Marshal(&struct {
        SizeString string `json:"size_string"`
        URL        string `json:"url"`
        *Alias
    }{
        SizeString: t.SizeString(),
        URL:        t.FullURL(),
        Alias:      (*Alias)(t),
    })
}

type sortBySeeds []Torrent

func (s sortBySeeds) Len() int {
    return len(s)
}
func (s sortBySeeds) Swap(i, j int) {
    s[i], s[j] = s[j], s[i]
}
func (s sortBySeeds) Less(i, j int) bool {
    return s[i].Seeders > s[j].Seeders
}