Manage options with CLI flags

2 files changed, 91 insertions, 15 deletions

diff --git a/flatbot.go b/flatbot.go
index ef10854..0a0e751 100644
--- a/flatbot.go
+++ b/flatbot.go
@@ -1,46 +1,119 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"io"
 	"log"
 	"net/http"
 	"os"
+	"time"
 )
 
+var (
+	apiToken = flag.String("api-token",
+		os.Getenv("FLATBOT_TELEGRAM_BOT_API_TOKEN"),
+		"Telegram Bot API token")
+	chatID = flag.String("chat-id",
+		os.Getenv("FLATBOT_TELEGRAM_CHAT_ID"),
+		"Telegram chat id where to send notification messages")
+	state = flag.String("state", "/tmp/flatbot-sent.json",
+		"Filename to save and load already sent flats")
+	interval = flag.Duration("frequency", 5*time.Minute,
+		"Frequency interval to fetch new data")
+	once   = flag.Bool("once", false, "Run fetch and message loop only once")
+	dryRun = flag.Bool("dry-run", false,
+		"Run entire flow, but print new flats to stdout instead of "+
+			"sending them to Telegram")
+)
+
+func usage() {
+	fmt.Fprintf(os.Stderr,
+		"usage: flatbot [-api-token token] [-chat-id id] "+
+			"[-state file] [-interval duration] [-once] [-send] "+
+			"URL...\n")
+	flag.PrintDefaults()
+	os.Exit(2)
+}
+
 func main() {
-	url := "http://localhost:8000/2025-02-19-isle-of-dogs.html"
-	body, err := fetch(url)
+	flag.Usage = usage
+	flag.Parse()
+	if !*dryRun {
+		if len(*apiToken) == 0 {
+			fmt.Fprintf(os.Stderr,
+				"Going to send messages to Telegram, "+
+					"but no API token was provided\n")
+			os.Exit(1)
+		}
+		if len(*chatID) == 0 {
+			fmt.Fprintf(os.Stderr,
+				"Going to send messages to Telegram, "+
+					"but no chat id was provided\n")
+			os.Exit(1)
+		}
+	}
+	if flag.NArg() == 0 {
+		usage()
+		os.Exit(1)
+	}
+
+	for {
+		err := loopOnce()
+		if err != nil {
+			log.Fatal(err)
+		}
+		if *once {
+			break
+		}
+		log.Printf("Going to sleep for %v", *interval)
+		time.Sleep(*interval)
+	}
+}
+
+func loopOnce() error {
+	sent, err := readSent(*state)
 	if err != nil {
-		log.Fatal(err)
+		return err
 	}
-	fetched, err := parse(body)
+	for _, url := range flag.Args() {
+		sent, err = doOneURL(url, sent)
+		if err != nil {
+			log.Print(err)
+			continue
+		}
+	}
+	// TODO: trim sent file here?
+	return writeSent(sent, *state)
+}
+
+func doOneURL(url string, sent []flat) ([]flat, error) {
+	body, err := fetch(url)
 	if err != nil {
-		log.Fatal(err)
+		return sent, err
 	}
-	sent, err := readSent("sent/sent.json")
+	fetched, err := parse(body)
 	if err != nil {
-		log.Fatal(err)
+		return sent, err
 	}
 	newFlats := removeAlreadySent(fetched, sent)
 	m := messenger{
-		Token:  os.Getenv("FLATBOT_TELEGRAM_BOT_API_TOKEN"),
-		ChatID: os.Getenv("FLATBOT_TELEGRAM_CHANNEL_ID"),
+		Token:  *apiToken,
+		ChatID: *chatID,
 	}
 	for _, f := range newFlats {
-		if false {
+		if !*dryRun {
 			err = m.Send(f)
 			if err != nil {
-				// TODO: what to do with it?
 				log.Print(err)
+				continue
 			}
 		}
+		log.Printf("Should have been sent to chat: %v, %v",
+			f.Price, f.URL())
 		sent = append(sent, f)
 	}
-	// Remove flats from sent that are no longer in the search response to
-	// prevent indefinite grow of sent file.
-	sent = removeDelisted(sent, fetched)
-	writeSent(sent, "/tmp/sent.json")
+	return sent, nil
 }
 
 func fetch(url string) ([]byte, error) {
diff --git a/sent.go b/sent.go
index 0c72e6b..f21b791 100644
--- a/sent.go
+++ b/sent.go
@@ -54,6 +54,9 @@ func removeDelisted(sent []flat, allFlats []flat) []flat {
 }
 
 func writeSent(sent []flat, filename string) error {
+	if !slices.IsSortedFunc(sent, compareID) {
+		slices.SortFunc(sent, compareID)
+	}
 	jsonData, err := json.Marshal(sent)
 	if err != nil {
 		return err