Working captcha, need to template all the messages

go.mod

@@ -2,16 +2,21 @@ module nefrace.ru/kickbot.ng
 
 go 1.22.5
 
+require github.com/fogleman/gg v1.3.0
+
 require (
+	github.com/anthonynsimon/bild v0.14.0 // indirect
 	github.com/dustin/go-humanize v1.0.1 // indirect
-	github.com/fogleman/gg v1.3.0 
 	github.com/glebarez/go-sqlite v1.22.0 // indirect
 	github.com/go-telegram/bot v1.5.0 // indirect
 	github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 // indirect
 	github.com/google/uuid v1.5.0 // indirect
+	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/jmoiron/sqlx v1.4.0 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec // indirect
+	github.com/spf13/cobra v0.0.5 // indirect
+	github.com/spf13/pflag v1.0.3 // indirect
 	go.etcd.io/bbolt v1.3.10 // indirect
 	golang.org/x/image v0.18.0 // indirect
 	golang.org/x/sys v0.15.0 // indirect

go.sum

@@ -1,8 +1,18 @@
 filippo.io/edwards25519 v1.1.0/go.mod h1:BxyFTGdWcka3PhytdK4V28tE5sGfRvvvRV7EaN4VDT4=
+github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+github.com/anthonynsimon/bild v0.14.0 h1:IFRkmKdNdqmexXHfEU7rPlAmdUZ8BDZEGtGHDnGWync=
+github.com/anthonynsimon/bild v0.14.0/go.mod h1:hcvEAyBjTW69qkKJTfpcDQ83sSZHxwOunsseDfeQhUs=
+github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5doyWs3UAsr3K4I6qtAmlQcZDesFNEHPZAzj8=
+github.com/coreos/etcd v3.3.10+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
+github.com/coreos/go-etcd v2.0.0+incompatible/go.mod h1:Jez6KQU2B/sWsbdaef3ED8NzMklzPG4d5KIOhIy30Tk=
+github.com/coreos/go-semver v0.2.0/go.mod h1:nnelYz7RCh+5ahJtPPxZlU+153eP4D4r3EedlOD2RNk=
+github.com/cpuguy83/go-md2man v1.0.10/go.mod h1:SmD6nW6nTyfqj6ABTjUi3V3JVMnlJmwcJI5acqYI6dE=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/dustin/go-humanize v1.0.1 h1:GzkhY7T5VNhEkwH0PVJgjz+fX1rhBrR7pRT3mDkpeCY=
 github.com/dustin/go-humanize v1.0.1/go.mod h1:Mu1zIs6XwVuF/gI1OepvI0qD18qycQx+mFykh5fBlto=
 github.com/fogleman/gg v1.3.0 h1:/7zJX8F6AaYQc57WQCyN9cAIz+4bCJGO9B+dyW29am8=
 github.com/fogleman/gg v1.3.0/go.mod h1:R/bRT+9gY/C5z7JzPU0zXsXHKM4/ayA+zqcVNZzPa1k=
+github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMoQvtojpjFo=
 github.com/glebarez/go-sqlite v1.22.0 h1:uAcMJhaA6r3LHMTFgP0SifzgXg46yJkgxqyuyec+ruQ=
 github.com/glebarez/go-sqlite v1.22.0/go.mod h1:PlBIdHe0+aUEFn+r2/uthrWq4FxbzugL0L8Li6yQJbc=
 github.com/go-sql-driver/mysql v1.8.1/go.mod h1:wEBSXgmK//2ZFJyE+qWnIsVGmvmEKlqwuVSjsCm7DZg=
@@ -12,23 +22,48 @@ github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0 h1:DACJavvAHhabrF0
 github.com/golang/freetype v0.0.0-20170609003504-e2365dfdc4a0/go.mod h1:E/TSTwGwJL78qG/PmXZO1EjYhfJinVAhrmmHX6Z8B9k=
 github.com/google/uuid v1.5.0 h1:1p67kYwdtXjb0gL0BPiP1Av9wiZPo5A8z2cWkTZ+eyU=
 github.com/google/uuid v1.5.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
+github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NHg9XEKhtSvM=
+github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
 github.com/jmoiron/sqlx v1.4.0 h1:1PLqN7S1UYp5t4SrVVnt4nUVNemrDAtxlulVe+Qgm3o=
 github.com/jmoiron/sqlx v1.4.0/go.mod h1:ZrZ7UsYB/weZdl2Bxg6jCRO9c3YHl8r3ahlKmRT4JLY=
 github.com/lib/pq v1.10.9/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
+github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
 github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
 github.com/mattn/go-sqlite3 v1.14.22/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
+github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
+github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
+github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec h1:W09IVJc94icq4NjY3clb7Lk8O1qJ8BdBEF8z0ibU0rE=
 github.com/remyoudompheng/bigfft v0.0.0-20230129092748-24d4a6f8daec/go.mod h1:qqbHyh8v60DhA7CoWK5oRCqLrMHRGoxYCSS9EjAz6Eo=
+github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
+github.com/spf13/afero v1.1.2/go.mod h1:j4pytiNVoe2o6bmDsKpLACNPDBIoEAkihy7loJ1B0CQ=
+github.com/spf13/cast v1.3.0/go.mod h1:Qx5cxh0v+4UWYiBimWS+eyWzqEqokIECu5etghLkUJE=
+github.com/spf13/cobra v0.0.5 h1:f0B+LkLX6DtmRH1isoNA9VTtNUK9K8xYd28JNNfOv/s=
+github.com/spf13/cobra v0.0.5/go.mod h1:3K3wKZymM7VvHMDS9+Akkh4K60UwM26emMESw8tLCHU=
+github.com/spf13/jwalterweatherman v1.0.0/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb68N+wFjFa4jdeBTo=
+github.com/spf13/pflag v1.0.3 h1:zPAT6CGy6wXeQ7NtTnaTerfKOsV6V6F8agHXFiazDkg=
+github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
+github.com/spf13/viper v1.3.2/go.mod h1:ZiWeW+zYFKm7srdB9IoDzzZXaJaI5eL9QjNiN/DMA2s=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+github.com/ugorji/go/codec v0.0.0-20181204163529-d75b2dcb6bc8/go.mod h1:VFNgLljTbGfSG7qAOspJ7OScBnGdDN/yBr0sguwnwf0=
+github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:aYKd//L2LvnjZzWKhF00oedf4jCCReLcmhLdhm1A27Q=
 go.etcd.io/bbolt v1.3.10 h1:+BqfJTcCzTItrop8mq/lbzL8wSGtj94UO/3U31shqG0=
 go.etcd.io/bbolt v1.3.10/go.mod h1:bK3UQLPJZly7IlNmV7uVHJDxfe5aK9Ll93e/74Y9oEQ=
+golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/image v0.18.0 h1:jGzIakQa/ZXI1I0Fxvaa9W7yP25TqT6cHIHn+6CqvSQ=
 golang.org/x/image v0.18.0/go.mod h1:4yyo5vMFQjVjUcVk4jEQcU9MGy/rulF5WvUILseCM2E=
+golang.org/x/sys v0.0.0-20181205085412-a5c9d58dba9a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.4.0 h1:Zr2JFtRQNX3BCZ8YtxRE9hNJYC8J6I1MVbMg6owUp18=
 golang.org/x/sys v0.4.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.15.0 h1:h48lPFYpsTvQJZF4EKyI4aLHaev3CxivZmv7yZig9pc=
 golang.org/x/sys v0.15.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 modernc.org/libc v1.37.6 h1:orZH3c5wmhIQFTXF+Nt+eeauyd+ZIt2BX6ARe+kD+aw=
 modernc.org/libc v1.37.6/go.mod h1:YAXkAZ8ktnkCKaN9sw/UDeUVkGYJ/YquGO4FTi5nmHE=
 modernc.org/mathutil v1.6.0 h1:fRe9+AmYlaej+64JsEEhoWuAYBkOtQiMEU7n/XgfYi4=

src/botutils.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"fmt"
+	"math/rand"
 	"time"
 
 	"github.com/go-telegram/bot"
@@ -43,3 +44,18 @@ func IsAdmin(member models.ChatMember) bool {
 func DeleteAfterSeconds(chatID int64, msgID int, seconds int) error {
 	return AddMessageToDelete(MessageToDelete{MessageId: msgID, ChatId: chatID, DeleteDate: time.Now().Add(time.Duration(seconds) * time.Second).Unix(), Tries: 0})
 }
+
+func generateRandomDigits(length int) string {
+	digits := make([]byte, length)
+
+	for i := 0; i < length; i++ {
+		digits[i] = byte(rand.Intn(10) + '0') // Generate a random digit
+	}
+
+	return string(digits)
+}
+
+func Mention(name string, id int64) string {
+	text := fmt.Sprintf("[%s](tg://user?id=%d)", bot.EscapeMarkdown(name), id)
+	return text
+}

src/captcha.go

@@ -1,29 +1,128 @@
 package main
 
 import (
+	"bytes"
 	"embed"
+	"image"
 	"image/color"
+	"image/png"
+	"log"
+	"math/rand"
+	"path/filepath"
+	"strings"
 
 	"github.com/fogleman/gg"
+	"github.com/golang/freetype/truetype"
+	"golang.org/x/image/font"
 )
 
 var (
-	res embed.FS
+	//go:embed resources/*
+	res          embed.FS
+	fnt          font.Face
+	Images       []image.Image
+	CorrectImage int
 )
 
-func GenCaptcha() {
-	dc := gg.NewContext(400, 300)
-	gd := gg.NewLinearGradient(0, 0, 400, 300)
-	gd.AddColorStop(0, color.RGBA{189, 24, 229, 255})
-	gd.AddColorStop(1, color.RGBA{27, 21, 123, 255})
-	dc.SetFillStyle(gd)
-	dc.DrawRectangle(0, 0, 400, 300)
-	dc.Fill()
-	dc.SetRGBA(0, 0, 0, 0.05)
-	dc.SetLineWidth(27)
-	for i := 0.0; i < 20; i += 1 {
-		dc.DrawLine(i * 70, -100, i * 70 - 500, 400)
-		dc.Stroke()
-	}
-	dc.SavePNG("grad.png")
+type Item struct {
+	img     image.Image
+	code    string
+	correct bool
+}
+
+func InitResources() {
+	dir := "resources"
+	files, err := res.ReadDir(dir)
+
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	for i, file := range files {
+		name := file.Name()
+		p := filepath.Join(dir, name)
+		ext := filepath.Ext(name)
+
+		switch ext {
+		case ".ttf":
+			b, _ := res.ReadFile(p)
+			f, _ := truetype.Parse(b)
+			fnt = truetype.NewFace(f, &truetype.Options{
+				Size: 25,
+			})
+		case ".png":
+			b, _ := res.ReadFile(p)
+			img, _, err := image.Decode(bytes.NewReader(b))
+			if err != nil {
+				log.Fatal("Can't load image: ", err)
+			}
+			Images = append(Images, img)
+
+			if strings.HasPrefix(name, "correct") {
+				CorrectImage = i
+				log.Println("Correct one found: ", CorrectImage)
+			}
+			log.Println(name, "loaded successfully")
+		}
+	}
+
+}
+
+func GenCaptcha() ([]byte, string) {
+	width, height := 500.0, 500.0
+	ctx := gg.NewContext(int(width), int(height))
+	// Make gradient
+	gradient := gg.NewLinearGradient(0, 0, width, height)
+	gradient.AddColorStop(0, color.RGBA{189, 24, 229, 255})
+	gradient.AddColorStop(1, color.RGBA{27, 21, 123, 255})
+
+	// Fill background
+	ctx.SetFillStyle(gradient)
+	ctx.DrawRectangle(0, 0, width, height)
+	ctx.Fill()
+
+	// Stripes for background
+	ctx.SetRGBA(0, 0, 0, 0.05)
+	ctx.SetLineWidth(27)
+	for i := 0.0; i < 20; i += 1 {
+		ctx.DrawLine(i*70, -100, i*70-500, width)
+		ctx.Stroke()
+	}
+
+	items := []Item{}
+	for i, image := range Images {
+		items = append(items, Item{
+			img:     image,
+			code:    generateRandomDigits(4),
+			correct: i == CorrectImage,
+		})
+	}
+	rand.Shuffle(len(items), func(i, j int) { items[i], items[j] = items[j], items[i] })
+
+	correctAnswer := ""
+	minX, maxX := 60, int(width-60)
+	xrange := maxX - minX
+	step := xrange / (len(items) - 1)
+	ctx.SetFontFace(fnt)
+	ctx.SetRGBA(1, 1, 1, 0.5)
+	for i, img := range items {
+		x := minX + i*step
+		y := 100 + rand.Intn(int(height)-200)
+		if img.correct {
+			correctAnswer = img.code
+		}
+		ctx.DrawImageAnchored(img.img, x, y, 0.5, 0.5)
+		offset := 70
+		if rand.Float32() < 0.5 {
+			offset = -70
+		}
+		ctx.DrawStringAnchored(img.code, float64(x), float64(y+offset), 0.5, 0.5)
+	}
+
+	buff := new(bytes.Buffer)
+	err := png.Encode(buff, ctx.Image())
+	if err != nil {
+		log.Fatal("can't encode png: ", err)
+	}
+	return buff.Bytes(), correctAnswer
 }

src/db.go

@@ -55,7 +55,7 @@ id INTEGER PRIMARY KEY AUTOINCREMENT,
 user_id INTEGER,
 chat_id INTEGER,
 message_id INTEGER,
-correct_answer INTEGER DEFAULT 0,
+correct_answer TEXT DEFAULT '',
 blocked_until INTEGER DEFAULT 0,
 FOREIGN KEY (user_id) REFERENCES users (id) ON DELETE CASCADE,
 FOREIGN KEY (chat_id) REFERENCES chats (id) ON DELETE CASCADE
@@ -66,7 +66,7 @@ type ChatSchema struct {
 	Id       int64  `json:"id" db:"id"`
 	Name     string `json:"name" db:"name"`
 	Username string `json:"username" db:"username"`
-	Topic    int64  `json:"topic" db:"topic"`
+	Topic    int    `json:"topic" db:"topic"`
 	Active   bool   `json:"active" db:"active"`
 }
 
@@ -85,12 +85,12 @@ type User struct {
 }
 
 type Captcha struct {
-	Id            int64 `db:"id"`
-	UserID        int64 `db:"user_id"`
-	ChatID        int64 `db:"chat_id"`
-	MessageID     int   `db:"message_id"`
-	CorrectAnswer int   `db:"correct_answer"`
-	BlockedUntil  int64	`db:"blocked_until"`
+	Id            int64  `db:"id"`
+	UserID        int64  `db:"user_id"`
+	ChatID        int64  `db:"chat_id"`
+	MessageID     int    `db:"message_id"`
+	CorrectAnswer string `db:"correct_answer"`
+	BlockedUntil  int64  `db:"blocked_until"`
 }
 
 var db *sqlx.DB
@@ -149,8 +149,8 @@ func UseActivation(code string) bool {
 	return err == nil
 }
 
-func ActivateChat(id int64) error {
-	_, err := db.Exec(`update chats set active = 1 where id = $1`, id)
+func ActivateChat(id int64, thread int) error {
+	_, err := db.Exec(`update chats set active = 1, topic = $2 where id = $1`, id, thread)
 	return err
 }
 

src/handlers.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"bytes"
 	"context"
 	"database/sql"
 	"errors"
@@ -43,7 +44,7 @@ func registerChat(ctx context.Context, b *bot.Bot, update *models.Update) {
 			log.Println("register: wrong code: ", args[1])
 			return
 		}
-		if err := ActivateChat(msg.Chat.ID); err != nil {
+		if err := ActivateChat(msg.Chat.ID, msg.MessageThreadID); err != nil {
 			log.Println("Error activating chat: ", err)
 			return
 		}
@@ -66,12 +67,56 @@ func registerChat(ctx context.Context, b *bot.Bot, update *models.Update) {
 		log.Println("register: error", err)
 	}
 }
+func unregisterChat(ctx context.Context, b *bot.Bot, update *models.Update) {
+	msg := update.Message
+	log.Println("unregistering", msg.Chat.ID)
+	m, err := FetchMemberFromChat(ctx, b, msg.Chat.ID, msg.From.ID)
+	if err == nil {
+		if !IsAdmin(*m) {
+			log.Println("register: user is not admin")
+			return
+		}
+		b.DeleteMessage(ctx, &bot.DeleteMessageParams{
+			ChatID:    msg.Chat.ID,
+			MessageID: msg.ID,
+		})
+		db.Exec("update chats set active = 0 where id = $1", msg.Chat.ID)
+		sent, err := b.SendMessage(ctx, &bot.SendMessageParams{
+			ChatID:          msg.Chat.ID,
+			Text:            "Чат удалён",
+			MessageThreadID: msg.MessageThreadID,
+		})
+		if err == nil {
+			err := DeleteAfterSeconds(msg.Chat.ID, sent.ID, 60)
+			if err != nil {
+				log.Println("register: failed to add to delete", err)
+			}
+		}
+	} else {
+		log.Println("register: error", err)
+	}
+}
+
+var NewUserTemplate = `
+Приветствую тебя, *%s*\!
+Ты не можешь писать ничего в данном чате, пока не пройдешь капчу, которую я тебе пришлю в личку\.
+
+Нужно только нажать на кнопку ниже\.
+`
 
 func handleNewJoined(ctx context.Context, b *bot.Bot, u *models.Update) {
+	var chat ChatSchema
+	err := db.Get(&chat, "select * from chats where id = $1 and active = 1", u.Message.Chat.ID)
+	if err != nil {
+		log.Println("can't get chat for new joined: ", err)
+	}
 	for _, user := range u.Message.NewChatMembers {
-		msg, _ := b.SendMessage(ctx, &bot.SendMessageParams{
-			ChatID: u.Message.Chat.ID,
-			Text:   "Check the capthca!",
+		text := fmt.Sprintf(NewUserTemplate, Mention(user.FirstName, user.ID))
+		msg, err := b.SendMessage(ctx, &bot.SendMessageParams{
+			ChatID:          chat.Id,
+			MessageThreadID: int(chat.Topic),
+			Text:            text,
+			ParseMode:       models.ParseModeMarkdown,
 			ReplyMarkup: models.InlineKeyboardMarkup{
 				InlineKeyboard: [][]models.InlineKeyboardButton{
 					{
@@ -80,7 +125,10 @@ func handleNewJoined(ctx context.Context, b *bot.Bot, u *models.Update) {
 				},
 			},
 		})
-		_, err := db.Exec(`INSERT INTO captchas (user_id, chat_id, message_id) values ($1, $2, $3)`, user.ID, u.Message.Chat.ID, msg.ID)
+		if err != nil {
+			log.Println("Can't send message: ", err, "\n", text)
+		}
+		_, err = db.Exec(`INSERT INTO captchas (user_id, chat_id, message_id) values ($1, $2, $3)`, user.ID, u.Message.Chat.ID, msg.ID)
 		if err != nil {
 			log.Println("newusers: can't add to db: ", err)
 			return
@@ -115,6 +163,13 @@ func banUser(ctx context.Context, b *bot.Bot, u *models.Update) {
 
 }
 
+var NewCaptchaTemplate = `
+*%s*, тебе необходимо пройти капчу для чата *%s*\.
+
+Для этого посмотри на картинку, найди логотип движка, который относится к вышеуказанному чату, а потом введи сюда код, который расположен над или под ним\.
+Время у тебя неограничено, я буду ждать\!
+`
+
 func handlePrivateStartCaptcha(ctx context.Context, b *bot.Bot, u *models.Update) {
 	args := strings.Split(u.Message.Text, " ")
 	userID := u.Message.From.ID
@@ -133,37 +188,59 @@ func handlePrivateStartCaptcha(ctx context.Context, b *bot.Bot, u *models.Update
 		err = db.Get(&captcha, `select * from captchas where user_id = $1 and chat_id = $2`, userID, chatID)
 		if errors.Is(err, sql.ErrNoRows) {
 			b.SendMessage(ctx, &bot.SendMessageParams{
-				Text:   " There's no captchas for that chat you came from.",
+				Text:   "В чате, откуда ты пришёл, у тебя нет активных капч. Приходи в другой раз.",
 				ChatID: u.Message.Chat.ID,
 			})
 			return
 		}
 	} else {
-		err = db.Get(&captcha, `select * from captchas where user_id = $1 and correct_answer != 0`, userID)
+		err = db.Get(&captcha, `select * from captchas where user_id = $1 and correct_answer != ''`, userID)
 		if err != nil {
 			b.SendMessage(ctx, &bot.SendMessageParams{
-				Text:   " There's no captchas for that chat you came from.",
+				Text:   "У тебя нет активных капч ни в одном чате. Приходи в другой раз.",
 				ChatID: u.Message.Chat.ID,
 			})
 			return
 		}
 	}
-	if captcha.CorrectAnswer == 0 {
-		captcha.CorrectAnswer = 42
-		msg, err := b.SendMessage(ctx, &bot.SendMessageParams{
-			Text:   "Get me the answer!",
-			ChatID: u.Message.Chat.ID,
-		})
-		if err == nil {
-			captcha.MessageID = msg.ID
+
+	type UserChatCaptcha struct {
+		Id       int64  `db:"id"`
+		UserID   int64  `db:"user_id"`
+		UserName string `db:"user_name"`
+		ChatID   int64  `db:"chat_id"`
+		ChatName string `db:"chat_name"`
+	}
+
+	var userchat UserChatCaptcha
+	err = db.Get(&userchat, `
+SELECT U.id AS user_id, C.id as chat_id, U.name as user_name, C.name as chat_name
+FROM captchas
+JOIN users AS U ON U.id = captchas.user_id
+JOIN chats AS C ON C.id = captchas.chat_id
+WHERE captchas.id = $1`, captcha.Id)
+	if err != nil {
+		log.Println("Can't get user and chat names: ", err)
+	}
+
+	if captcha.CorrectAnswer == "" {
+		img, answer := GenCaptcha()
+		captcha.CorrectAnswer = answer
+		if _, err := b.SendPhoto(ctx, &bot.SendPhotoParams{
+			Caption:   fmt.Sprintf(NewCaptchaTemplate, userchat.UserName, userchat.ChatName),
+			Photo:     &models.InputFileUpload{Filename: "captcha.png", Data: bytes.NewReader(img)},
+			ChatID:    u.Message.Chat.ID,
+			ParseMode: models.ParseModeMarkdown,
+		}); err != nil {
+			log.Println("can't send private captcha: ", err)
 		}
-		_, err = db.NamedExec("update captchas set correct_answer = :correct_answer, message_id = :message_id where id = :id", captcha)
+		_, err = db.NamedExec("update captchas set correct_answer = :correct_answer where id = :id", captcha)
 		if err != nil {
 			log.Println("Can't update captcha:", err)
 		}
 	} else {
 		b.SendMessage(ctx, &bot.SendMessageParams{
-			Text:   fmt.Sprintf("You already have captcha for chat %d", captcha.ChatID),
+			Text:   fmt.Sprintf("Я тебе уже выдавал капчу для %d", captcha.ChatID),
 			ChatID: u.Message.Chat.ID,
 		})
 	}
@@ -186,13 +263,10 @@ func handlePrivateCaptcha(ctx context.Context, b *bot.Bot, u *models.Update) {
 	}
 
 	ban_minutes := 0
-	num, err := strconv.Atoi(msg.Text)
-	text := "That's not a number. Try again in 30 minutes."
-	if err != nil {
-		ban_minutes = 30
-	} else if num != captcha.CorrectAnswer {
-		text = "That's the wrong answer. Try again in 5 hours."
-		ban_minutes = 300
+	text := ""
+	if msg.Text != captcha.CorrectAnswer {
+		text = "That's the wrong answer. Try again in 1 hour."
+		ban_minutes = 60
 	}
 
 	if ban_minutes > 0 {
@@ -223,7 +297,16 @@ func handlePrivateCaptcha(ctx context.Context, b *bot.Bot, u *models.Update) {
 	if err != nil {
 		log.Println("Can't unrestrict user: ", err)
 	}
+	log.Println("Deleting message: ", captcha.ChatID, captcha.MessageID)
+	result, err := b.DeleteMessage(ctx, &bot.DeleteMessageParams{
+		ChatID:    captcha.ChatID,
+		MessageID: captcha.MessageID,
+	})
+	log.Println("Deleting message:", result, err)
+	db.Exec("delete from captchas where id = $1", captcha.Id)
 
-	b.SendMessage(ctx, &bot.SendMessageParams{Text: "Captcha solved! Congrats!", ChatID: msg.From.ID})
-
+	b.SendMessage(ctx, &bot.SendMessageParams{
+		Text:   "Капча решена! Поздравляю! Теперь можешь вернуться в чат, я вернул тебе возможность отправлять там сообщения.\n\nСоветую ознакомиться с местными правилами, прежде чем что-либо писать!",
+		ChatID: msg.From.ID,
+	})
 }

src/main.go

@@ -14,7 +14,8 @@ import (
 )
 
 func main() {
-	GenCaptcha()
+	log.SetFlags(log.Lshortfile + log.Ltime + log.Ldate)
+	InitResources()
 	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt)
 	defer cancel()
 
@@ -36,6 +37,7 @@ func main() {
 	}
 
 	b.RegisterHandler(bot.HandlerTypeMessageText, "/register", bot.MatchTypePrefix, registerChat)
+	b.RegisterHandler(bot.HandlerTypeMessageText, "/unregister", bot.MatchTypePrefix, unregisterChat)
 	b.RegisterHandler(bot.HandlerTypeMessageText, "/ban", bot.MatchTypePrefix, banUser)
 	b.RegisterHandlerMatchFunc(func(update *models.Update) bool {
 		return update.Message != nil && len(update.Message.NewChatMembers) > 0