package main

import (

"bufio"

"context"

"errors"

"regexp"

"strings"

gemini "git.sr.ht/~adnano/go-gemini"

)

var (

ErrNoTitle = errors.New(`no title found`)

title1 = regexp.MustCompile(`^#[^#]`)

title2 = regexp.MustCompile(`^##[^#]`)

title3 = regexp.MustCompile(`^###`)

)

func geminiTitle(url string) (string, error) {

client := gemini.Client{}

ctx := context.Background()

resp, err := client.Get(ctx, url)

if err != nil {

return "", err

}

defer resp.Body.Close()

if resp.Status != 20 || !strings.HasPrefix(resp.Meta, "text/gemini") {

return "", ErrNoTitle

}

var t2, t3 string

scanner := bufio.NewScanner(resp.Body)

for scanner.Scan() {

line := scanner.Text()

switch {

case title1.MatchString(line):

return line, nil

case title2.MatchString(line) && t2 == "":

t2 = line

case title3.MatchString(line) && t3 == "":

t3 = line

}

}

if t2 != "" {

return t2, nil

}

if t3 != "" {

return t3, nil

}

return "", ErrNoTitle

}