1 package main
2 
3 import (
4 	"crypto/tls"
5 	"flag"
6 	"fmt"
7 	"io"
8 	"io/ioutil"
9 	"log"
10 	"net/http"
11 	"path"
12 	"path/filepath"
13 	"regexp"
14 
15 	irc "github.com/fluffle/goirc/client"
16 )
17 
18 var (
19 	baseurl = flag.String("baseurl", "gemini://m2i.omarpolo.com", "base url")
20 	matrixOutDir = flag.String("matrix-out", "", "matrix out directory")
21 
22 	msgRe = regexp.MustCompile(`https://.*/[^\s]+\.(txt|png|jpg|jpeg|gif)`)
23 	channel = "#gemini-it"
24 )
25 
26 func matrix2gemini(conn *irc.Conn, line *irc.Line) {
27 	matches := msgRe.FindAllString(line.Text(), -1)
28 
29 	// it's not a good idea to defer inside a loop, but we know
30 	// len(matches) is small (usually just 1).  Morover, I like
31 	// living in danger!
32 
33 	for _, link := range matches {
34 		resp, err := http.Get(link)
35 		if err != nil {
36 			conn.Privmsg(
37 				channel,
38 				fmt.Sprintf("failed to download %q: %s", link, err),
39 			)
40 			continue
41 		}
42 		defer resp.Body.Close()
43 
44 		ext := path.Ext(link)
45 		tmpfile, err := ioutil.TempFile(*matrixOutDir, "message-*" + ext)
46 		if err != nil {
47 			conn.Privmsg(channel, fmt.Sprintf("failed to tmpfile: %s", err))
48 			return
49 		}
50 		defer tmpfile.Close()
51 
52 		io.Copy(tmpfile, resp.Body)
53 
54 		conn.Privmsg(
55 			channel,
56 			fmt.Sprintf(
57 				"better: %s/%s",
58 				*baseurl,
59 				filepath.Base(tmpfile.Name()),
60 			),
61 		)
62 	}
63 }
64 
65 func dostuff(conn *irc.Conn, line *irc.Line) {
66 	matrix2gemini(conn, line)
67 	// ...
68 }
69 
70 func main() {
71 	flag.Parse()
72 
73 	cfg := irc.NewConfig("gemitbot")
74 	cfg.SSL = true
75 	cfg.SSLConfig = &tls.Config{ServerName: "irc.libera.chat"}
76 	cfg.Server = "irc.libera.chat:7000"
77 	cfg.NewNick = func(n string) string { return n + "^" }
78 
79 	c := irc.Client(cfg)
80 
81 	c.HandleFunc(irc.CONNECTED, func(conn *irc.Conn, line *irc.Line) {
82 		log.Println("connected, joining", channel)
83 		conn.Join(channel)
84 	})
85 
86 	c.HandleFunc(irc.PRIVMSG, dostuff)
87 	c.HandleFunc(irc.ACTION, dostuff)
88 
89 	quit := make(chan bool)
90 
91 	c.HandleFunc(irc.DISCONNECTED, func(conn *irc.Conn, line *irc.Line) {
92 		quit <- true
93 	})
94 
95 	if err := c.Connect(); err != nil {
96 		log.Fatalln("connection error:", err)
97 	}
98 
99 	<-quit
100 }