content_filtering.go

package main

import (
	"context"
	"fmt"
	"regexp"
	"slices"
	"strings"

	"github.com/nbd-wtf/go-nostr"
	"github.com/nbd-wtf/go-nostr/sdk"
)

func isMaliciousBridged(pm sdk.ProfileMetadata) bool {
	return strings.Contains(pm.NIP05, "rape.pet") || strings.Contains(pm.NIP05, "rape-pet")
}

func hasProhibitedWordOrTag(event *nostr.Event) bool {
	for _, tag := range event.Tags {
		if len(tag) >= 2 && tag[0] == "t" && slices.Contains(pornTags, strings.ToLower(tag[1])) {
			return true
		}
	}

	return pornWordsRe.MatchString(event.Content)
}

// hasExplicitMedia checks if the event contains explicit media content
// by examining image/video URLs in the content and checking them against the media alert API
func hasExplicitMedia(ctx context.Context, event *nostr.Event) bool {
	// extract image and video URLs from content
	var mediaURLs []string

	// find image URLs
	imgMatches := imageExtensionMatcher.FindAllStringSubmatch(event.Content, -1)
	for _, match := range imgMatches {
		if len(match) > 0 {
			mediaURLs = append(mediaURLs, match[0])
		}
	}

	// find video URLs
	vidMatches := videoExtensionMatcher.FindAllStringSubmatch(event.Content, -1)
	for _, match := range vidMatches {
		if len(match) > 0 {
			mediaURLs = append(mediaURLs, match[0])
		}
	}

	// check each URL for explicit content
	for _, mediaURL := range mediaURLs {
		isExplicit, err := isExplicitContent(ctx, mediaURL)
		if err != nil {
			log.Warn().Err(err).Str("url", mediaURL).Msg("failed to check media content")
			continue
		}

		if isExplicit {
			return true
		}
	}

	return false
}

// list copied from https://jsr.io/@gleasonator/policy/0.2.0/data/porntags.json
var pornTags = []string{
	"adult",
	"ass",
	"assworship",
	"boobs",
	"boobies",
	"butt",
	"cock",
	"dick",
	"dickpic",
	"explosionloli",
	"femboi",
	"femboy",
	"fetish",
	"fuck",
	"freeporn",
	"girls",
	"lewd",
	"loli",
	"milf",
	"naked",
	"nude",
	"nudes",
	"nudeart",
	"nudity",
	"nsfw",
	"pantsu",
	"pussy",
	"porn",
	"porngif",
	"porno",
	"pornstar",
	"porntube",
	"pornvideo",
	"sex",
	"sexpervertsyndicate",
	"sexporn",
	"sexworker",
	"sexy",
	"slut",
	"teen",
	"tits",
	"teenporn",
	"teens",
	"transnsfw",
	"xxx",
}

var pornWordsRe = func() *regexp.Regexp {
	// list copied from https://jsr.io/@gleasonator/policy/0.2.0/data/pornwords.json
	pornWords := []string{
		"loli",
		"nsfw",
		"teen porn",
	}
	concat := strings.Join(pornWords, "|")
	regex := fmt.Sprintf(`\b(%s)\b`, concat)
	return regexp.MustCompile(regex)
}()