let's fetch some feeds

go.mod

@@ -1,3 +1,5 @@
 module git.tilde.town/magical/feedget
 
 go 1.14
+
+require github.com/mmcdole/gofeed v1.1.3

main.go

@@ -1,3 +1,101 @@
 // Feedget scrapes RSS feeds (and other sources)
 // and spits the latest headline from each onto a static web page.
 package main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"sort"
+	"sync"
+	"time"
+
+	"github.com/mmcdole/gofeed"
+)
+
+var feedurls = []string{
+	"https://tilde.team/~dozens/dreams/rss.xml",
+	//"https://xkcd.com/atom.xml",
+	"https://tilde.town/~magical/xkcd.xml",
+}
+
+func main() {
+	var sources = make([]*FeedSource, len(feedurls)) // TODO: interface Source
+	for i, u := range feedurls {
+		sources[i] = NewFeed(u)
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(len(sources))
+	for i := range sources {
+		src := sources[i]
+		go func() {
+			src.update()
+			wg.Done()
+		}()
+	}
+	wg.Wait()
+
+	for _, src := range sources {
+		fmt.Println(src.Title, src.Error)
+	}
+	//var feeds []*gofeed.Feed
+	//var errors []error
+
+	//for _, url := range feedUrls {
+	//}
+}
+
+type Source interface {
+	Title() string
+	Link() string
+	Error() error
+	Update(context.Context)
+}
+
+// want to keep track of:
+// - whether the most recent update suceeded
+// - when the last successful update was
+// - how many of the last N updates succeeded
+// - status codes for the last N updates
+// - response time for the last N updates
+// - how frequently items are posted
+
+type Cache struct {
+}
+
+type FeedSource struct {
+	Items     []*gofeed.Item
+	Title     string
+	URL       string
+	LastFetch time.Time
+	Error     error
+
+	mu sync.Mutex
+}
+
+func NewFeed(url string) *FeedSource {
+	return &FeedSource{
+		URL: url,
+	}
+}
+
+func (src *FeedSource) update() {
+	src.mu.Lock()
+	defer src.mu.Unlock()
+	fp := gofeed.NewParser()
+	feed, err := fp.ParseURL(src.URL)
+	if err != nil {
+		err := fmt.Errorf("error parsing %q: %v", src.URL, err)
+		log.Println(err)
+		src.Error = err
+		return // return err?
+	}
+	items := feed.Items
+	sort.Slice(items, func(i, j int) bool {
+		return items[i].Updated >= items[j].Updated
+	})
+	src.Title = feed.Title
+	src.Items = items
+	src.LastFetch = time.Now()
+}