package rss

import (
	"io/ioutil"
	"net/http"
	"net/http/httptest"
	"os"
	"path"
	"testing"
)

func Test_RSSFeed(t *testing.T) {
	s := RSSServer()
	defer s.Close()
	cases := []struct {
		itemFilter    string
		contentFilter string
		itemsOut      int
	}{
		{
			itemFilter:    "Blue",
			contentFilter: "<img.*?/(img)?>",
			itemsOut:      1,
		},
		{
			itemFilter: "Blue",
			itemsOut:   1,
		},
		{
			itemsOut: 4,
		},
	}
	for _, c := range cases {
		feed, err := New(s.URL, c.itemFilter, c.contentFilter)
		if err != nil {
			t.Errorf("couldn't create new feed %v: %v", feed, err)
		}
		items, err := feed.Update()
		if err != nil {
			t.Errorf("cannot update feed %q: %v", s.URL, err)
		}
		if len(items) != c.itemsOut {
			t.Errorf("couldn't get all items from feed: got %v, wanted %v", len(items), c.itemsOut)
		}
		for i := range items {
			if len(items[i].Content) == 0 {
				t.Errorf("Empty content for %v with filter %q %q", items[i].Name, c.itemFilter, c.contentFilter)
			}
		}
		serialized, err := feed.Serialize()
		if err != nil {
			t.Fatalf("Cannot serialize feed: %v", err)
		}
		deserialized, err := Deserialize(serialized)
		if err != nil {
			t.Fatalf("Cannot deserialize feed: %v", err)
		}
		if feed.String() != deserialized.String() {
			t.Fatalf("deserialized != feed: %s, expected %s", deserialized.String(), feed.String())
		}
	}
}

func RSSServer() *httptest.Server {
	var content []byte
	feedPath := "./testdata/feed.xml"
	if _, err := os.Stat(feedPath); os.IsNotExist(err) {
		resp, err := http.Get("https://xkcd.com/rss.xml")
		if err != nil {
			panic(err)
		}
		defer resp.Body.Close()
		b, err := ioutil.ReadAll(resp.Body)
		if err != nil {
			panic(err)
		}
		if err := os.MkdirAll(path.Dir(feedPath), os.ModePerm); err != nil {
			panic(err)
		}
		if err := ioutil.WriteFile(feedPath, b, os.ModePerm); err != nil {
			panic(err)
		}
		content = b
	} else {
		b, err := ioutil.ReadFile(feedPath)
		if err != nil {
			panic(err)
		}
		content = b
	}

	return httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Write(content)
	}))
}