From 6644f90e6a7e29a862cee4c0138bfe322deff24a Mon Sep 17 00:00:00 2001
From: Eggbertx <eggbertx@users.noreply.github.com>
Date: Thu, 15 Jun 2023 11:43:05 -0700
Subject: [PATCH] Replace link TLD checking Go plugin with Lua plugin

---
 sample-plugins/check-link-tlds/main.go | 67 --------------------------
 sample-plugins/check_links.lua         | 55 +++++++++++++++++++++
 2 files changed, 55 insertions(+), 67 deletions(-)
 delete mode 100644 sample-plugins/check-link-tlds/main.go
 create mode 100644 sample-plugins/check_links.lua

diff --git a/sample-plugins/check-link-tlds/main.go b/sample-plugins/check-link-tlds/main.go
deleted file mode 100644
index 0d05055e..00000000
--- a/sample-plugins/check-link-tlds/main.go
+++ /dev/null
@@ -1,67 +0,0 @@
-package main
-
-import (
-	"errors"
-	"fmt"
-	"regexp"
-
-	"github.com/gochan-org/gochan/pkg/events"
-	"github.com/gochan-org/gochan/pkg/gcsql"
-)
-
-var (
-	basicUrlRE       = regexp.MustCompile(`https?://\S+\.(\S+)`)
-	recognizedTLDs   = []string{"com", "net", "org", "edu", "gov", "us", "uk"}
-	errUntrustedURLs = errors.New("post contains one or more untrusted links")
-)
-
-func hasUntrustedTLD(msg string) bool {
-	urls := basicUrlRE.FindAllStringSubmatch(msg, -1)
-	for _, match := range urls {
-		tld := match[1]
-		trusted := false
-		for _, recognized := range recognizedTLDs {
-			if tld == recognized {
-				trusted = true
-				break
-			}
-		}
-		if !trusted {
-			return true
-		}
-	}
-	return false
-}
-
-func isNewPoster(post *gcsql.Post) (bool, error) {
-	var ipCount int
-	err := gcsql.QueryRowSQL(`SELECT COUNT(*) FROM DBPREFIXposts WHERE ip = ?`, []any{post.IP}, []any{&ipCount})
-	return ipCount == 0, err
-}
-
-func InitPlugin() error {
-	events.RegisterEvent([]string{"message-pre-format"}, func(trigger string, args ...interface{}) error {
-		if len(args) == 0 {
-			return nil
-		}
-
-		post, ok := args[0].(*gcsql.Post)
-		if !ok {
-			// argument isn't actually a post
-			return fmt.Errorf(events.InvalidArgumentErrorStr, trigger)
-		}
-
-		newPoster, err := isNewPoster(post)
-		if err != nil {
-			return err
-		}
-
-		if newPoster && hasUntrustedTLD(post.MessageRaw) {
-			return errUntrustedURLs
-		}
-
-		return nil
-	})
-
-	return nil
-}
diff --git a/sample-plugins/check_links.lua b/sample-plugins/check_links.lua
new file mode 100644
index 00000000..623d80c0
--- /dev/null
+++ b/sample-plugins/check_links.lua
@@ -0,0 +1,55 @@
+local string = require("string")
+
+local recognized_tlds = {"com", "net", "org", "edu", "gov", "us", "uk"}
+
+local function is_new_poster(ip)
+	rows, err = db_query("SELECT COUNT(*) FROM DBPREFIXposts WHERE ip = ?", {ip})
+	if(err ~= nil) then
+		return true, err
+	end
+
+	is_new = true
+	while rows:Next() do
+		rows_table = {}
+		err = db_scan_rows(rows, rows_table)
+		if(err ~= nil) then
+			rows:Close()
+			return true, err
+		end
+		if(rows_table["COUNT(*)"] > 0) then
+			is_new = false
+			break 
+		end
+	end
+	rows:Close()
+	return is_new
+end
+
+
+event_register({"message-pre-format"}, function(tr, post)
+	is_new, err = is_new_poster(post.IP)
+	if(err ~= nil) then
+		error_log(err:Error())
+			:Str("lua", "check_links.lua")
+			:Str("event", tr)
+			:Send()
+		return err:Error()
+	end
+	if(is_new == false) then
+		-- Not a new poster, skip TLD check
+		return
+	end
+
+	for tld in string.gmatch(post.MessageRaw, "%a+://%w+.(%w+)") do
+		found = false
+		for _, recognized in pairs(recognized_tlds) do
+			if(tld == recognized) then
+				found = true
+				break
+			end
+		end
+		if(found == false) then
+			return "post contains one or more untrusted links"
+		end
+	end
+end)