From 9c39e3cd415b68dbd7be399a20ec53d23d8a9426 Mon Sep 17 00:00:00 2001
From: skkiesel <skiesel@cs.unh.edu>
Date: Wed, 10 May 2017 15:15:24 -0400
Subject: [PATCH] barebones rss headline skimmer

---
 main.go                 |  2 +
 plugins/rss/rss.go      | 92 +++++++++++++++++++++++++++++++++++++++++
 plugins/rss/rss_test.go | 44 ++++++++++++++++++++
 3 files changed, 138 insertions(+)
 create mode 100644 plugins/rss/rss.go
 create mode 100644 plugins/rss/rss_test.go

diff --git a/main.go b/main.go
index 6d8f86d..f542e30 100644
--- a/main.go
+++ b/main.go
@@ -18,6 +18,7 @@ import (
 	"github.com/velour/catbase/plugins/fact"
 	"github.com/velour/catbase/plugins/leftpad"
 	"github.com/velour/catbase/plugins/reminder"
+	"github.com/velour/catbase/plugins/rss"
 	"github.com/velour/catbase/plugins/talker"
 	"github.com/velour/catbase/plugins/your"
 	"github.com/velour/catbase/plugins/zork"
@@ -57,6 +58,7 @@ func main() {
 	b.AddHandler("reminder", reminder.New(b))
 	b.AddHandler("babbler", babbler.New(b))
 	b.AddHandler("zork", zork.New(b))
+	b.AddHandler("rss", rss.New(b))
 	// catches anything left, will always return true
 	b.AddHandler("factoid", fact.New(b))
 
diff --git a/plugins/rss/rss.go b/plugins/rss/rss.go
new file mode 100644
index 0000000..c12a935
--- /dev/null
+++ b/plugins/rss/rss.go
@@ -0,0 +1,92 @@
+package rss
+
+import (
+	"fmt"
+	"log"
+	"strings"
+	"time"
+
+	"github.com/velour/catbase/bot"
+	"github.com/velour/catbase/bot/msg"
+
+	"github.com/mmcdole/gofeed"
+)
+
+type RSSPlugin struct {
+	Bot       bot.Bot
+	cache     map[string]*cacheItem
+	shelfLife time.Duration
+}
+
+type cacheItem struct {
+	key        string
+	data       string
+	expiration time.Time
+}
+
+func New(bot bot.Bot) *RSSPlugin {
+	return &RSSPlugin{
+		Bot:       bot,
+		cache:     map[string]*cacheItem{},
+		shelfLife: time.Minute * 20,
+	}
+}
+
+func (p *RSSPlugin) Message(message msg.Message) bool {
+	tokens := strings.Fields(message.Body)
+	numTokens := len(tokens)
+
+	if numTokens == 2 && strings.ToLower(tokens[0]) == "rss" {
+		if data, ok := p.cache[strings.ToLower(tokens[1])]; ok && time.Now().Before(data.expiration) {
+			log.Printf("rss cache hit")
+			p.Bot.SendMessage(message.Channel, data.data)
+			return true
+		} else {
+			fp := gofeed.NewParser()
+			feed, err := fp.ParseURL(tokens[1])
+			if err != nil {
+				p.Bot.SendMessage(message.Channel, fmt.Sprintf("RSS error: %s", err.Error()))
+				return true
+			}
+			response := feed.Title
+			for _, item := range feed.Items {
+				response += fmt.Sprintf("\n%s", item.Title)
+			}
+
+			p.cache[strings.ToLower(tokens[1])] = &cacheItem{
+				key:        strings.ToLower(tokens[1]),
+				data:       response,
+				expiration: time.Now().Add(p.shelfLife),
+			}
+
+			p.Bot.SendMessage(message.Channel, response)
+			return true
+		}
+	}
+
+	return false
+}
+
+func (p *RSSPlugin) LoadData() {
+	// This bot has no data to load
+}
+
+// Help responds to help requests. Every plugin must implement a help function.
+func (p *RSSPlugin) Help(channel string, parts []string) {
+	p.Bot.SendMessage(channel, "try '!rss http://rss.cnn.com/rss/edition.rss'")
+}
+
+// Empty event handler because this plugin does not do anything on event recv
+func (p *RSSPlugin) Event(kind string, message msg.Message) bool {
+	return false
+}
+
+// Handler for bot's own messages
+func (p *RSSPlugin) BotMessage(message msg.Message) bool {
+	return false
+}
+
+// Register any web URLs desired
+func (p *RSSPlugin) RegisterWeb() *string {
+	return nil
+}
diff --git a/plugins/rss/rss_test.go b/plugins/rss/rss_test.go
new file mode 100644
index 0000000..3a00bec
--- /dev/null
+++ b/plugins/rss/rss_test.go
@@ -0,0 +1,44 @@
+package rss
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/velour/catbase/bot"
+	"github.com/velour/catbase/bot/msg"
+	"github.com/velour/catbase/bot/user"
+)
+
+func makeMessage(payload string) msg.Message {
+	isCmd := strings.HasPrefix(payload, "!")
+	if isCmd {
+		payload = payload[1:]
+	}
+	return msg.Message{
+		User:    &user.User{Name: "tester"},
+		Channel: "test",
+		Body:    payload,
+		Command: isCmd,
+	}
+}
+
+func TestRSS(t *testing.T) {
+	mb := bot.NewMockBot()
+	c := New(mb)
+	assert.NotNil(t, c)
+	res := c.Message(makeMessage("!rss http://rss.cnn.com/rss/edition.rss"))
+	assert.Len(t, mb.Messages, 1)
+	assert.True(t, res)
+}
+
+func TestRSSCache(t *testing.T) {
+	mb := bot.NewMockBot()
+	c := New(mb)
+	assert.NotNil(t, c)
+	res := c.Message(makeMessage("!rss http://rss.cnn.com/rss/edition.rss"))
+	assert.True(t, res)
+	res = c.Message(makeMessage("!rss http://rss.cnn.com/rss/edition.rss"))
+	assert.Len(t, mb.Messages, 2)
+	assert.True(t, res)
+}