package nyaafeeds

// rss support
// validation done according to spec here:
//    http://cyber.law.harvard.edu/rss/rss.html

import (
	"encoding/xml"
	"fmt"
	"strconv"
	"time"

	"github.com/gorilla/feeds"
)

// rssFeedXML private wrapper around the RssFeed which gives us the <rss>..</rss> xml
type rssFeedXML struct {
	XMLName  xml.Name `xml:"rss"`
	Xmlns    string   `xml:"xmlns:torznab,attr,omitempty"`
	Version  string   `xml:"version,attr"`
	Encoding string   `xml:"encoding,attr"`
	Channel  *RssFeed `xml:"channel,omitempty"`
	Caps     *RssCaps `xml:"caps,omitempty"`
}

// RssImage RSS image struct
type RssImage struct {
	XMLName xml.Name `xml:"image"`
	URL     string   `xml:"url"`
	Title   string   `xml:"title"`
	Link    string   `xml:"link"`
	Width   int      `xml:"width,omitempty"`
	Height  int      `xml:"height,omitempty"`
}

// RssTextInput RSS text struct
type RssTextInput struct {
	XMLName     xml.Name `xml:"textInput"`
	Title       string   `xml:"title"`
	Description string   `xml:"description"`
	Name        string   `xml:"name"`
	Link        string   `xml:"link"`
}

// RssMagnetLink RSS struct for magnet links
type RssMagnetLink struct {
	XMLName xml.Name `xml:"link"`
	Text    string   `xml:",cdata"`
}

// RssFeed  RSS feed struct
type RssFeed struct {
	XMLName        xml.Name `xml:"channel"`
	Xmlns          string   `xml:"-"`
	Title          string   `xml:"title"`       // required
	Link           string   `xml:"link"`        // required
	Description    string   `xml:"description"` // required
	Language       string   `xml:"language,omitempty"`
	Copyright      string   `xml:"copyright,omitempty"`
	ManagingEditor string   `xml:"managingEditor,omitempty"` // Author used
	WebMaster      string   `xml:"webMaster,omitempty"`
	PubDate        string   `xml:"pubDate,omitempty"`       // created or updated
	LastBuildDate  string   `xml:"lastBuildDate,omitempty"` // updated used
	Category       string   `xml:"category,omitempty"`
	Generator      string   `xml:"generator,omitempty"`
	Docs           string   `xml:"docs,omitempty"`
	Cloud          string   `xml:"cloud,omitempty"`
	TTL            int      `xml:"ttl,omitempty"`
	Rating         string   `xml:"rating,omitempty"`
	SkipHours      string   `xml:"skipHours,omitempty"`
	SkipDays       string   `xml:"skipDays,omitempty"`
	Image          *RssImage
	TextInput      *RssTextInput
	Items          []*RssItem
}

// RssItem struct for rss feed items
type RssItem struct {
	XMLName     xml.Name     `xml:"item"`
	Title       string       `xml:"title"` // required
	Link        interface{}  `xml:"link,omitempty"`
	Description string       `xml:"description"` // required
	Author      string       `xml:"author,omitempty"`
	Category    *RssCategory `xml:"category,omitempty"`
	Comments    string       `xml:"comments,omitempty"`
	Enclosure   *RssEnclosure
	GUID        string      `xml:"guid,omitempty"`    // Id used
	PubDate     string      `xml:"pubDate,omitempty"` // created or updated
	Source      string      `xml:"source,omitempty"`
	Torrent     *RssTorrent `xml:"torrent,omitempty"`
	Torznab     []*RssTorznab
}

// RssCaps xml struct for torznab caps
type RssCaps struct {
	XMLName      xml.Name         `xml:"caps"`
	Server       *RssServer       `xml:"server,omitempty"`
	Limits       *RssLimits       `xml:"limits,omitempty"`
	Registration *RssRegistration `xml:"registration,omitempty"`
	Searching    *RssSearching    `xml:"searching,omitempty"`
	Categories   *RssCategories   `xml:"categories,omitempty"`
}

// RssServer basic server information
type RssServer struct {
	XMLName   xml.Name `xml:"server"`
	Xmlns     string   `xml:"xmlns,attr"`
	Version   string   `xml:"version,attr"`
	Title     string   `xml:"title,attr"`
	Strapline string   `xml:"strapline,attr"`
	Email     string   `xml:"email,attr"`
	URL       string   `xml:"url,attr"`
	Image     string   `xml:"image,attr"`
}

// RssLimits struct for max results
type RssLimits struct {
	XMLName xml.Name `xml:"limits"`
	Max     string   `xml:"max,attr"`
	Default string   `xml:"default,attr"`
}

// RssRegistration torznab registration information
type RssRegistration struct {
	XMLName   xml.Name `xml:"registration"`
	Available string   `xml:"available,attr"`
	Open      string   `xml:"open,attr"`
}

// RssSearching struct for supported search types
type RssSearching struct {
	XMLName     xml.Name   `xml:"searching"`
	Search      *RssSearch `xml:"search,omitempty"`
	TvSearch    *RssSearch `xml:"tv-search,omitempty"`
	MovieSearch *RssSearch `xml:"movie-search,omitempty"`
}

// RssSearch struct for supported searching params
type RssSearch struct {
	Available       string `xml:"available,attr"`
	SupportedParams string `xml:"supportedParams,attr,omitempty"`
}

// RssCategories categories for rss
type RssCategories struct {
	XMLName  xml.Name `xml:"categories"`
	Category []*RssCategoryTorznab
}

// RssCategoryTorznab categories for torznab
type RssCategoryTorznab struct {
	XMLName     xml.Name `xml:"category"`
	ID          string   `xml:"id,attr"`
	Name        string   `xml:"name,attr"`
	Subcat      []*RssSubCat
	Description string `xml:"description,attr,omitempty"`
}

// RssSubCat sub category
type RssSubCat struct {
	XMLName     xml.Name `xml:"subcat"`
	ID          string   `xml:"id,attr"`
	Name        string   `xml:"name,attr"`
	Description string   `xml:"description,attr,omitempty"`
}

// RssTorrent item for torrents
type RssTorrent struct {
	XMLName       xml.Name `xml:"torrent"`
	Xmlns         string   `xml:"xmlns,attr"`
	FileName      string   `xml:"fileName,omitempty"`
	ContentLength string   `xml:"contentLength,omitempty"`
	InfoHash      string   `xml:"infoHash,omitempty"`
	MagnetURI     string   `xml:"magnetUri,omitempty"`
}

// RssTorznab feed for torznab
type RssTorznab struct {
	XMLName xml.Name `xml:"torznab:attr,omitempty"`
	Name    string   `xml:"name,attr,omitempty"`
	Value   string   `xml:"value,attr,omitempty"`
}

// RssCategory is a category for rss item
type RssCategory struct {
	XMLName xml.Name `xml:"category"`
	Domain  string   `xml:"domain"`
}

// RssEnclosure enclosure for downloads
type RssEnclosure struct {
	//RSS 2.0 <enclosure url="http://example.com/file.mp3" length="123456789" type="audio/mpeg" />
	XMLName xml.Name `xml:"enclosure"`
	URL     string   `xml:"url,attr"`
	Length  string   `xml:"length,attr"`
	Type    string   `xml:"type,attr"`
}

// Rss struct
type Rss struct {
	*feeds.Feed
}

// create a new RssItem with a generic Item struct's data
func newRssItem(i *feeds.Item) *RssItem {
	item := &RssItem{
		Title:       i.Title,
		Link:        i.Link.Href,
		Description: i.Description,
		GUID:        i.Id,
		PubDate:     anyTimeFormat(time.RFC1123Z, i.Created, i.Updated),
	}

	intLength, err := strconv.ParseInt(i.Link.Length, 10, 64)

	if err == nil && (intLength > 0 || i.Link.Type != "") {
		item.Enclosure = &RssEnclosure{URL: i.Link.Href, Type: i.Link.Type, Length: i.Link.Length}
	}
	if i.Author != nil {
		item.Author = i.Author.Name
	}
	return item
}

// returns the first non-zero time formatted as a string or ""
func anyTimeFormat(format string, times ...time.Time) string {
	for _, t := range times {
		if !t.IsZero() {
			return t.Format(format)
		}
	}
	return ""
}

// RssFeed : create a new RssFeed with a generic Feed struct's data
func (r *Rss) RssFeed() *RssFeed {
	pub := anyTimeFormat(time.RFC1123Z, r.Created, r.Updated)
	build := anyTimeFormat(time.RFC1123Z, r.Updated)
	author := ""
	if r.Author != nil {
		author = r.Author.Email
		if len(r.Author.Name) > 0 {
			author = fmt.Sprintf("%s (%s)", r.Author.Email, r.Author.Name)
		}
	}

	channel := &RssFeed{
		Title:          r.Title,
		Link:           r.Link.Href,
		Description:    r.Description,
		ManagingEditor: author,
		PubDate:        pub,
		LastBuildDate:  build,
		Copyright:      r.Copyright,
	}
	for _, i := range r.Items {
		channel.Items = append(channel.Items, newRssItem(i))
	}
	return channel
}

// FeedXML : return an XML-Ready object for an Rss object
func (r *Rss) FeedXml() interface{} {
	// only generate version 2.0 feeds for now
	return r.RssFeed().FeedXml()

}

// FeedXML : return an XML-ready object for an RssFeed object
func (r *RssFeed) FeedXml() interface{} {
	if r.Xmlns != "" {
		return &rssFeedXML{Version: "2.0", Encoding: "UTF-8", Channel: r, Xmlns: r.Xmlns}
	}
	return &rssFeedXML{Version: "2.0", Encoding: "UTF-8", Channel: r}
}

// FeedXML : return an XML-ready object for an RssFeed object
func (r *RssCaps) FeedXml() interface{} {
	return r
}