Rssmon2/rss/feed.go

110 lines
2.2 KiB
Go

package rss
import (
"bytes"
"encoding/gob"
"errors"
"io/ioutil"
"net/http"
"regexp"
"time"
"github.com/mmcdole/gofeed"
)
type Feed struct {
Updated time.Time
Items []string
ItemFilter string
ContentFilter string
Source string
}
func NewFeed(source, itemFilter, contentFilter string) (*Feed, error) {
if _, err := regexp.Compile(itemFilter); err != nil {
return nil, err
}
if _, err := regexp.Compile(contentFilter); err != nil {
return nil, err
}
f := &Feed{
Items: []string{},
ItemFilter: itemFilter,
ContentFilter: contentFilter,
Source: source,
}
if _, err := f.Update(); err != nil {
return nil, err
}
return f, errors.New("not implemented")
}
func Deserialize(src []byte) (*Feed, error) {
buffer := bytes.NewBuffer(src)
dec := gob.NewDecoder(buffer)
var dst Feed
err := dec.Decode(&dst)
return &dst, err
}
func (f *Feed) Serialize() ([]byte, error) {
var buffer bytes.Buffer
enc := gob.NewEncoder(&buffer)
err := enc.Encode(f)
return buffer.Bytes(), err
}
func (f *Feed) Update() ([]*Item, error) {
resp, err := http.Get(f.Source)
if err != nil {
return nil, err
}
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, err
}
parser := gofeed.NewParser()
feed, err := parser.Parse(bytes.NewBuffer(body))
if err != nil {
return nil, err
}
return f.fromGofeed(feed)
}
func (f *Feed) fromGofeed(feed *gofeed.Feed) ([]*Item, error) {
updated := feed.PublishedParsed
if updated == nil {
updated = feed.UpdatedParsed
}
if updated == nil && len(feed.Items) > 0 {
updated = gofeedItemTS(feed.Items[0])
}
if updated == nil {
t := time.Now()
updated = &t
}
newitems, err := f.appendNewItems(feed.Items)
if err != nil {
return nil, err
}
f.Updated = *updated
return newitems, nil
}
func (f *Feed) appendNewItems(items []*gofeed.Item) ([]*Item, error) {
newitems := []*Item{}
for i := range items {
t := gofeedItemTS(items[i])
if t.Before(f.Updated) {
continue
}
if ok, _ := regexp.MatchString(f.ItemFilter, items[i].Title); !ok {
continue
}
item := fromGofeedItem(items[i], f.ContentFilter)
newitems = append(newitems, item)
f.Items = append(f.Items, item.Name)
}
return newitems, nil
}