Initial rss with partially tested items

rss/feed.go

@@ -0,0 +1,109 @@
+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
+}