From a714c2eabb3c624f8bd5820d384e91405a35fb8b Mon Sep 17 00:00:00 2001
From: Gergely Radics <gergely.radics@bitpanda.com>
Date: Thu, 21 Aug 2025 12:33:53 +0200
Subject: [PATCH 1/4] feat: added telegram client with image handling

---
 cmd/client-telegram/main.go | 131 ++++++++++++++++++++++++++++++++++++
 go.mod                      |   3 +-
 go.sum                      |   2 +
 internal/ai/gemini/logic.go |   5 +-
 pkg/httpBotter/logic.go     |  92 +++++++++++++++++++++++++
 5 files changed, 231 insertions(+), 2 deletions(-)
 create mode 100644 cmd/client-telegram/main.go
 create mode 100644 pkg/httpBotter/logic.go

diff --git a/cmd/client-telegram/main.go b/cmd/client-telegram/main.go
new file mode 100644
index 0000000..2131d56
--- /dev/null
+++ b/cmd/client-telegram/main.go
@@ -0,0 +1,131 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"hairy-botter/pkg/httpBotter"
+	"io"
+	"net/http"
+	"os"
+	"os/signal"
+
+	"github.com/go-telegram/bot"
+	"github.com/go-telegram/bot/models"
+)
+
+// Send any text message to the bot after the bot has been started
+
+func main() {
+	token := os.Getenv("BOT_TOKEN")
+	if token == "" {
+		fmt.Println("BOT_TOKEN must be set")
+
+		os.Exit(1)
+		return
+	}
+
+	aiSrv := os.Getenv("AI_SERVICE")
+	if aiSrv == "" {
+		aiSrv = "http://127.0.0.1:8080"
+	}
+
+	l := New(aiSrv)
+	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt)
+	defer cancel()
+
+	opts := []bot.Option{
+		bot.WithDefaultHandler(l.Handler),
+	}
+
+	b, err := bot.New(token, opts...)
+	if err != nil {
+		fmt.Println(err)
+
+		os.Exit(1)
+		return
+	}
+
+	b.Start(ctx)
+}
+
+type Logic struct {
+	httpB *httpBotter.Logic
+}
+
+func New(baseURL string) *Logic {
+	return &Logic{
+		httpB: httpBotter.New(baseURL),
+	}
+}
+
+// Handler .
+func (l *Logic) Handler(ctx context.Context, b *bot.Bot, update *models.Update) {
+	var payload []byte
+	msg := update.Message.Text
+
+	if len(update.Message.Photo) > 0 {
+		highResImg := biggestImage(update.Message.Photo)
+		fmt.Println("photo file ID:", highResImg.FileID)
+		fmt.Printf("photo info: W: %d, H: %d, Size: %d\n", highResImg.Width, highResImg.Height, highResImg.FileSize)
+		fmt.Println("caption:", update.Message.Caption)
+		f, err := b.GetFile(ctx, &bot.GetFileParams{
+			FileID: highResImg.FileID,
+		})
+		if err != nil {
+			fmt.Println("error getting file:", err)
+			return
+		}
+
+		// Download the file
+		dlURL := b.FileDownloadLink(f)
+		resp, err := http.Get(dlURL)
+		if err != nil {
+			fmt.Println("error downloading file:", err)
+			return
+		}
+		defer func() { _ = resp.Body.Close() }()
+
+		payload, err = io.ReadAll(resp.Body)
+		if err != nil {
+			fmt.Println("error reading file:", err)
+			return
+		}
+
+		if update.Message.Caption != "" {
+			msg = update.Message.Caption
+		}
+	}
+
+	fmt.Println("Sending message to AI service:", msg)
+	res, err := l.httpB.Send(fmt.Sprintf("tg-%d", update.Message.Chat.ID), msg, payload)
+	if err != nil {
+		fmt.Println("error sending message to AI service:", err)
+		return
+	}
+
+	fmt.Println("AI service response:", res)
+	_, err = b.SendMessage(ctx, &bot.SendMessageParams{
+		ChatID: update.Message.Chat.ID,
+		Text:   res,
+	})
+	if err != nil {
+		fmt.Println("error sending response back to Telegram:", err)
+		return
+	}
+
+}
+
+func biggestImage(photos []models.PhotoSize) models.PhotoSize {
+	if len(photos) == 0 {
+		return models.PhotoSize{}
+	}
+
+	biggest := photos[0]
+	for _, photo := range photos {
+		if photo.FileSize > biggest.FileSize {
+			biggest = photo
+		}
+	}
+
+	return biggest
+}
diff --git a/go.mod b/go.mod
index a48c06f..dfb6ed4 100644
--- a/go.mod
+++ b/go.mod
@@ -5,7 +5,9 @@ go 1.24.3
 require (
 	github.com/briandowns/spinner v1.23.2
 	github.com/go-chi/chi/v5 v5.2.1
+	github.com/go-telegram/bot v1.17.0
 	github.com/mark3labs/mcp-go v0.29.1-0.20250521213157-f99e5472f312
+	github.com/philippgille/chromem-go v0.7.0
 	google.golang.org/genai v1.5.0
 )
 
@@ -22,7 +24,6 @@ require (
 	github.com/gorilla/websocket v1.5.3 // indirect
 	github.com/mattn/go-colorable v0.1.2 // indirect
 	github.com/mattn/go-isatty v0.0.8 // indirect
-	github.com/philippgille/chromem-go v0.7.0 // indirect
 	github.com/spf13/cast v1.7.1 // indirect
 	github.com/yosida95/uritemplate/v3 v3.0.2 // indirect
 	go.opencensus.io v0.24.0 // indirect
diff --git a/go.sum b/go.sum
index e913f21..51c6905 100644
--- a/go.sum
+++ b/go.sum
@@ -24,6 +24,8 @@ github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHk
 github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
 github.com/go-chi/chi/v5 v5.2.1 h1:KOIHODQj58PmL80G2Eak4WdvUzjSJSm0vG72crDCqb8=
 github.com/go-chi/chi/v5 v5.2.1/go.mod h1:L2yAIGWB3H+phAw1NxKwWM+7eUH/lU8pOMm5hHcoops=
+github.com/go-telegram/bot v1.17.0 h1:Hs0kGxSj97QFqOQP0zxduY/4tSx8QDzvNI9uVRS+zmY=
+github.com/go-telegram/bot v1.17.0/go.mod h1:i2TRs7fXWIeaceF3z7KzsMt/he0TwkVC680mvdTFYeM=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=
 github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da h1:oI5xCqsCo564l8iNU+DwB5epxmsaqB+rhGL0m5jtYqE=
diff --git a/internal/ai/gemini/logic.go b/internal/ai/gemini/logic.go
index 5077b6c..bab11e7 100644
--- a/internal/ai/gemini/logic.go
+++ b/internal/ai/gemini/logic.go
@@ -204,7 +204,10 @@ func (l *Logic) HandleMessage(ctx context.Context, sessionID string, req domain.
 	}
 
 	logger.Info("sending message")
-	promptParts = append(promptParts, genai.Part{Text: fmt.Sprintf("%s%s", userMessagePrefix, req.Message)})
+	text := fmt.Sprintf("%s%s", userMessagePrefix, req.Message)
+	if text != "" {
+		promptParts = append(promptParts, genai.Part{Text: text})
+	}
 	if req.InlineData != nil {
 		promptParts = append(promptParts, *genai.NewPartFromBytes(req.InlineData.Data, req.InlineData.MimeType))
 	}
diff --git a/pkg/httpBotter/logic.go b/pkg/httpBotter/logic.go
new file mode 100644
index 0000000..f5ee56b
--- /dev/null
+++ b/pkg/httpBotter/logic.go
@@ -0,0 +1,92 @@
+package httpBotter
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"mime/multipart"
+	"net/http"
+	"net/textproto"
+)
+
+// Logic .
+type Logic struct {
+	baseURL    string
+	httpClient *http.Client
+}
+
+// New .
+func New(baseURL string) *Logic {
+	return &Logic{
+		baseURL:    baseURL,
+		httpClient: http.DefaultClient,
+	}
+}
+
+func (l *Logic) Send(userID string, msg string, payload []byte) (string, error) {
+	var buff bytes.Buffer
+
+	// Build multipart form data
+	mpw := multipart.NewWriter(&buff)
+	// Add message
+	err := mpw.WriteField("message", msg)
+	if err != nil {
+		return "", fmt.Errorf("failed to write message filed: %w", err)
+	}
+	// Add file if exists
+	if len(payload) > 0 {
+		h := make(textproto.MIMEHeader)
+		h.Set("Content-Disposition", multipart.FileContentDisposition("payload", "payload.data"))
+		h.Set("Content-Type", http.DetectContentType(payload))
+		part, err := mpw.CreatePart(h)
+		if err != nil {
+			return "", fmt.Errorf("failed to create payload file: %w", err)
+		}
+		_, err = io.Copy(part, bytes.NewReader(payload))
+		if err != nil {
+			return "", fmt.Errorf("failed to write payload file: %w", err)
+		}
+	}
+
+	// Close the writer to finalize the multipart form
+	err = mpw.Close()
+	if err != nil {
+		return "", fmt.Errorf("failed to close multipart writer: %w", err)
+	}
+
+	req, err := http.NewRequest(http.MethodPost, fmt.Sprintf("%s/message", l.baseURL), &buff)
+	if err != nil {
+		return "", fmt.Errorf("failed to create request: %w", err)
+	}
+	req.Header.Set("Content-Type", mpw.FormDataContentType())
+	req.Header.Set("X-User-ID", userID)
+
+	resp, err := l.httpClient.Do(req)
+	if err != nil {
+		return "", fmt.Errorf("failed to send request: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	var response struct {
+		Response string `json:"response"`
+	}
+
+	b, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", fmt.Errorf("failed to read response body: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		// Debug the response body
+		fmt.Println(string(bytes.TrimSpace(b)))
+	}
+
+	//err = json.NewDecoder(resp.Body).Decode(&response)
+	err = json.NewDecoder(bytes.NewReader(b)).Decode(&response)
+	if err != nil {
+		return "", fmt.Errorf("failed to decode response body: %w", err)
+	}
+
+	return response.Response, nil
+}

From eaa9dfea0ff096bc9b69e247c75aaa1fdb435fc5 Mon Sep 17 00:00:00 2001
From: Gergely Radics <gergely.radics@bitpanda.com>
Date: Thu, 21 Aug 2025 12:49:19 +0200
Subject: [PATCH 2/4] fix: added markdown formatter

---
 cmd/client-telegram/main.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/cmd/client-telegram/main.go b/cmd/client-telegram/main.go
index 2131d56..5994643 100644
--- a/cmd/client-telegram/main.go
+++ b/cmd/client-telegram/main.go
@@ -105,8 +105,9 @@ func (l *Logic) Handler(ctx context.Context, b *bot.Bot, update *models.Update)
 
 	fmt.Println("AI service response:", res)
 	_, err = b.SendMessage(ctx, &bot.SendMessageParams{
-		ChatID: update.Message.Chat.ID,
-		Text:   res,
+		ParseMode: models.ParseModeMarkdown,
+		ChatID:    update.Message.Chat.ID,
+		Text:      bot.EscapeMarkdownUnescaped(res),
 	})
 	if err != nil {
 		fmt.Println("error sending response back to Telegram:", err)

From 8ee0fc186617956401e1415f65aa9fdfffd8d859 Mon Sep 17 00:00:00 2001
From: Gergely Radics <gergely.radics@bitpanda.com>
Date: Thu, 21 Aug 2025 12:55:16 +0200
Subject: [PATCH 3/4] chore: added telegram client doc

---
 README.md | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/README.md b/README.md
index 7683cc3..50402da 100644
--- a/README.md
+++ b/README.md
@@ -101,6 +101,23 @@ Feel free to use the generated binary in the release as well.
 
 ![cli-client](examples/client-cli-demo.svg)
 
+#### Telegram client
+
+To use this you only need to create a new Bot in Telegram and get the token.
+
+Then you can run the server with the following way:
+```
+BOT_TOKEN=<generated_token> go run cmd/client-telegram/main.go
+```
+
+You can set the AI service base url with the `AI_SERVICE` env variable.
+
+If you add a caption to an image it will be used as the question.
+
+Env variables:
+- `BOT_TOKEN` - The token of the bot you created in Telegram
+- `AI_SERVICE` - AI service (the server-bot's) address (Default: `http://127.0.0.1:8080`)
+
 
 #### Facebook messenger client
 

From a24bcea258b02e3789b71bfae87034f051114b00 Mon Sep 17 00:00:00 2001
From: Gergely Radics <gergely.radics@bitpanda.com>
Date: Thu, 21 Aug 2025 12:57:44 +0200
Subject: [PATCH 4/4] chore: updated go version

---
 .github/workflows/go.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
index 09a5b81..bf8a1d1 100644
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -19,7 +19,7 @@ jobs:
     - name: Set up Go
       uses: actions/setup-go@v4
       with:
-        go-version: '1.24'
+        go-version: '1.25'
 
     - name: Build
       run: go build -v ./...