X-Git-Url: https://git.giacomolli.uk/onechat/blobdiff_plain/add3cf6416e33c24331fd1e90e99284f44d2aae2..b1be0ee8530df5db8973bfe355f2f6d3149383a0:/telegram_api.go?ds=inline

diff --git a/telegram_api.go b/telegram_api.go
index 8f78387..508010e 100644
--- a/telegram_api.go
+++ b/telegram_api.go
@@ -7,9 +7,11 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"mime/multipart"
 	"net/http"
 	"net/url"
 	"path"
+	"strconv"
 	"strings"
 	"time"
 )
@@ -196,6 +198,64 @@ func (b *TelegramAPI) SendRichMessage(ctx context.Context, chat int64, markdown
 	}, nil)
 }
 
+// SendImage uploads an image to the owner as a photo, or as a document when the
+// Bot API refuses the photo. Network failures do not trigger a second send.
+func (b *TelegramAPI) SendImage(ctx context.Context, chat int64, name string, data []byte, caption string) error {
+	err := b.sendImage(ctx, "sendPhoto", "photo", chat, name, data, caption)
+	if telegramRejected(err) {
+		err = b.sendImage(ctx, "sendDocument", "document", chat, name, data, caption)
+	}
+
+	return err
+}
+
+func (b *TelegramAPI) sendImage(ctx context.Context, method, field string, chat int64, name string, data []byte, caption string) error {
+	ctx, cancel := context.WithTimeout(ctx, telegramSendTimeout)
+	defer cancel()
+
+	var body bytes.Buffer
+
+	writer := multipart.NewWriter(&body)
+	err := writer.WriteField("chat_id", strconv.FormatInt(chat, 10))
+	if err != nil {
+		return fmt.Errorf("write image chat: %w", err)
+	}
+
+	err = writer.WriteField("caption", caption)
+	if err != nil {
+		return fmt.Errorf("write image caption: %w", err)
+	}
+
+	part, err := writer.CreateFormFile(field, name)
+	if err != nil {
+		return fmt.Errorf("make image part: %w", err)
+	}
+
+	_, err = part.Write(data)
+	if err != nil {
+		return fmt.Errorf("write image part: %w", err)
+	}
+
+	err = writer.Close()
+	if err != nil {
+		return fmt.Errorf("close image form: %w", err)
+	}
+
+	request, err := http.NewRequestWithContext(ctx, http.MethodPost, b.base+"/bot"+b.token+"/"+method, &body)
+	if err != nil {
+		return fmt.Errorf("make image upload: %s", b.redact(err))
+	}
+
+	request.Header.Set("Content-Type", writer.FormDataContentType())
+
+	err = b.answer(request, telegramSendTimeout, nil)
+	if err != nil {
+		return fmt.Errorf("upload image: %w", err)
+	}
+
+	return nil
+}
+
 // SendTyping shows the typing action in chat for about five seconds. A call
 // that takes longer than telegramTypingTimeout fails with a
 // TelegramNetworkError.
@@ -226,6 +286,11 @@ func (b *TelegramAPI) call(ctx context.Context, timeout time.Duration, method st
 
 	request.Header.Set("Content-Type", "application/json")
 
+	return b.answer(request, timeout, result)
+}
+
+// answer reads the bounded Bot API response without keeping its request URL.
+func (b *TelegramAPI) answer(request *http.Request, timeout time.Duration, result any) error {
 	response, err := b.http.Do(request)
 	if err != nil {
 		return b.networkError("no answer", err, timeout)