118 baris
2,4 KiB
Go
118 baris
2,4 KiB
Go
package rss
|
|
|
|
import (
|
|
"context"
|
|
"net/http"
|
|
"sync"
|
|
"time"
|
|
|
|
log "github.com/go-pkgz/lgr"
|
|
"github.com/mmcdole/gofeed"
|
|
"github.com/pkg/errors"
|
|
)
|
|
|
|
// Notify on RSS change
|
|
type Notify struct {
|
|
Feed string
|
|
Duration time.Duration
|
|
Timeout time.Duration
|
|
|
|
once sync.Once
|
|
ctx context.Context
|
|
cancel context.CancelFunc
|
|
}
|
|
|
|
// Event from RSS
|
|
type Event struct {
|
|
ChanTitle string
|
|
Title string
|
|
Link string
|
|
Text string
|
|
GUID string
|
|
Item gofeed.Item
|
|
Feed gofeed.Feed
|
|
}
|
|
|
|
// Go starts notifier and returns events channel
|
|
func (n *Notify) Go(ctx context.Context) <-chan Event {
|
|
log.Printf("[INFO] start notifier for %s, every %s", n.Feed, n.Duration)
|
|
n.once.Do(func() { n.ctx, n.cancel = context.WithCancel(ctx) })
|
|
|
|
ch := make(chan Event)
|
|
|
|
// wait for duration, can be terminated by ctx
|
|
waitOrCancel := func(ctx context.Context) bool {
|
|
select {
|
|
case <-ctx.Done():
|
|
return false
|
|
case <-time.After(n.Duration):
|
|
return true
|
|
}
|
|
}
|
|
|
|
go func() {
|
|
|
|
defer func() {
|
|
close(ch)
|
|
n.cancel()
|
|
}()
|
|
|
|
fp := gofeed.NewParser()
|
|
fp.Client = &http.Client{Timeout: n.Timeout}
|
|
log.Printf("[DEBUG] notifier uses http timeout %v", n.Timeout)
|
|
lastGUID := ""
|
|
for {
|
|
feedData, err := fp.ParseURL(n.Feed)
|
|
if err != nil {
|
|
log.Printf("[WARN] failed to fetch/parse url from %s, %v", n.Feed, err)
|
|
if !waitOrCancel(n.ctx) {
|
|
return
|
|
}
|
|
continue
|
|
}
|
|
event, err := n.feedEvent(feedData)
|
|
if lastGUID != event.GUID && err == nil {
|
|
if lastGUID != "" { // don't notify on initial change
|
|
log.Printf("[INFO] new event %s - %s", event.GUID, event.Title)
|
|
ch <- event
|
|
} else {
|
|
log.Printf("[INFO] ignore first event %s - %s", event.GUID, event.Title)
|
|
}
|
|
lastGUID = event.GUID
|
|
}
|
|
if !waitOrCancel(n.ctx) {
|
|
log.Print("[WARN] notifier canceled")
|
|
return
|
|
}
|
|
}
|
|
}()
|
|
|
|
return ch
|
|
}
|
|
|
|
// Shutdown notifier
|
|
func (n *Notify) Shutdown() {
|
|
log.Print("[DEBUG] shutdown initiated")
|
|
n.cancel()
|
|
<-n.ctx.Done()
|
|
}
|
|
|
|
// feedEvent gets latest item from rss feed
|
|
func (n *Notify) feedEvent(feed *gofeed.Feed) (e Event, err error) {
|
|
if len(feed.Items) == 0 {
|
|
return e, errors.New("no items in rss feed")
|
|
}
|
|
if feed.Items[0].GUID == "" {
|
|
return e, errors.Errorf("no guid for rss entry %+v", feed.Items[0])
|
|
}
|
|
|
|
e.ChanTitle = feed.Title
|
|
e.Item = *feed.Items[0]
|
|
e.Feed = *feed
|
|
e.Title = feed.Items[0].Title
|
|
e.Link = feed.Items[0].Link
|
|
e.Text = feed.Items[0].Description
|
|
e.GUID = feed.Items[0].GUID
|
|
|
|
return e, nil
|
|
}
|