main.go

package main

import (
    "fmt"
    "html/template"
    "net/http"
    "os"
    "sort"
    "sync"
    "time"

    "github.com/mmcdole/gofeed"
)

func getIndexHandle(items []Item) http.HandlerFunc {
    return func(w http.ResponseWriter, r *http.Request) {
        fmt.Println("serving")
        w.Header().Set("Content-Type", "text/html")
        t := template.Must(template.New("main").Parse(mainTemplate))
        if err := t.Execute(w, items); err != nil {
            panic(err)
        }
    }
}

func parseItem(item *gofeed.Item) Item {
    newItem := Item{
        Title: item.Title,
        Link:  item.Link,
    }
    if item.PublishedParsed != nil {
        newItem.Date = *item.PublishedParsed
    } else {
        newItem.Date = *item.UpdatedParsed
    }
    if item.Author != nil {
        newItem.Author = item.Author.Name
    }
    if yt, isYt := item.Extensions["yt"]; isYt {
        id := yt["videoId"][0].Value
        newItem.Content = template.HTML(`<iframe width="560" height="315" src="https://www.youtube-nocookie.com/embed/` + id + `?rel=0" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe><a href="https://youtube.com/embed/` + id + `">Fullscreen</a>`)
    } else {
        newItem.Content = template.HTML(item.Description)
    }
    return newItem
}

// FetchFeed fetches single feed and reports parsed RSS Items to channel
func FetchFeed(ch chan<- Item, url string) {
    fp := gofeed.NewParser()
    feed, err := fp.ParseURL(url)
    if err != nil {
        panic(err)
    }
    fmt.Println("fetching feed:", feed.Title)
    for _, item := range feed.Items {
        newItem := parseItem(item)
        if newItem.Date.After(time.Now().Add(-lastDays * 24 * time.Hour)) {
            ch <- newItem
        }
    }
}

// FetchFeeds concurrently fetches list of feeds by URL
func FetchFeeds(urls []string) []Item {
    ch := make(chan Item)
    go func() {
        var wg sync.WaitGroup
        for _, url := range urls {
            wg.Add(1)
            go func(url string) {
                FetchFeed(ch, url)
                wg.Done()
            }(url)
        }
        wg.Wait()
        close(ch)
    }()
    items := []Item{}
    for i := range ch {
        items = append(items, i)
    }
    sort.Sort(ItemSlice(items))
    return items
}

func main() {
    port := defaultPort
    if len(os.Args) > 1 {
        port = os.Args[1]
    }
    items := FetchFeeds(Urls)
    fmt.Println("items:", len(items))
    fmt.Printf("newest item: [%v] %s\n", items[0].Date, items[0].Title)
    fmt.Print("listening on :", port, "\n")
    http.HandleFunc("/", getIndexHandle(items))
    if err := http.ListenAndServe("0.0.0.0:"+port, nil); err != nil {
        panic(err)
    }
}