bashpush.go

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"html"
	"io/ioutil"
	"net/http"
	"os"
	"regexp"
	"strings"

	"github.com/SlyMarbo/rss"
	"github.com/gregdel/pushover"
)

func main() {
	quote, link, id := getLastQuote()
	if isNew(id) {
		err := ioutil.WriteFile("lastquote.txt", []byte(id), 0644)
		if err == nil {
			// Panicking on the error but sending the notifications nonetheless
			// would spam pushover and slack every minute until I fix it due
			// to cron. Let's not do that.
			sendPushoverNotifications(quote, link)
			sendSlackNotification(id, link)
		}
	}
}

func getLastQuote() (string, string, string) {

	bashFeedURL := os.Getenv("BASH_FEED_URL")
	if bashFeedURL == "" {
		panic("BASH_FEED_URL not set")
	}

	feed, err := rss.Fetch(bashFeedURL)
	if err != nil {
		panic(err)
	}

	r, _ := regexp.Compile(`\d+`)
	lastQuote := feed.Items[0]
	content := lastQuote.Content
	content = html.UnescapeString(content)

	return content, lastQuote.Link, r.FindString(lastQuote.Link)
}

func isNew(id string) bool {
	if _, err := os.Stat("lastquote.txt"); os.IsNotExist(err) {
		// lastquote.txt does not yet exist
		err := ioutil.WriteFile("lastquote.txt", []byte{}, 0644)
		if err != nil {
			panic(err)
		}
	}
	last, err := ioutil.ReadFile("lastquote.txt")
	if err != nil {
		panic(err)
	}
	return id != strings.TrimSpace(string(last))
}

func sendPushoverNotifications(quote, link string) {
	pushoverAPIToken := os.Getenv("PUSHOVER_API_TOKEN")
	pushoverRecipient := os.Getenv("PUSHOVER_RECIPIENT")
	if pushoverAPIToken == "" || pushoverRecipient == "" {
		panic("PUSHOVER_API_TOKEN or PUSHOVER_RECIPIENT not set")
	}

	app := pushover.New(pushoverAPIToken)
	recipient := pushover.NewRecipient(pushoverRecipient)

	message := &pushover.Message{
		Title:   "fsr.bash",
		Message: quote,
		URL:     link,
	}
	_, err := app.SendMessage(message, recipient)
	if err != nil {
		panic(err)
	}
}

func sendSlackNotification(id, link string) {
	hc := http.Client{}

	slackHookURL := os.Getenv("SLACK_HOOK_URL")
	if slackHookURL == "" {
		panic("SLACK_HOOK_URL not set")
	}

	quoteString := fmt.Sprintf("Neues Bash Zitat -> <%s|%s> 🤐", link, id)
	payload := map[string]string{"text": quoteString}
	jsonPayload, _ := json.Marshal(payload)

	req, _ := http.NewRequest("POST", slackHookURL, bytes.NewBufferString(string(jsonPayload)))
	resp, _ := hc.Do(req)
	if resp.StatusCode != 200 {
		panic("Post to Slack failed /o\\")
	}
}