git.giacomolli.uk - onechat/blob - whatsapp_image.go

   1 package main
   2
   3 import (
   4         "context"
   5         "errors"
   6         "fmt"
   7         "time"
   8
   9         "go.mau.fi/whatsmeow"
  10         "go.mau.fi/whatsmeow/proto/waE2E"
  11 )
  12
  13 // whatsappImageTime is the longest time of an image download.
  14 const whatsappImageTime = 2 * time.Minute
  15
  16 // whatsappImage downloads only supported images and stores them before the
  17 // event can be acknowledged. Both the declared size and the downloaded bytes
  18 // must fit the image store. Decoded bytes determine the stored format.
  19 func whatsappImage(ctx context.Context, client WhatsAppClient, store *ImageStore, message *waE2E.ImageMessage) (string, error) {
  20         if message.GetFileLength() > imageMaxBytes {
  21                 return "", errImageSize
  22         }
  23
  24         switch message.GetMimetype() {
  25         case "image/jpeg", "image/png", "image/webp":
  26         default:
  27                 return "", errImageFormat
  28         }
  29
  30         if client == nil {
  31                 return "", errors.New("WhatsApp client is not available")
  32         }
  33
  34         data, err := client.Download(ctx, message)
  35         if err != nil {
  36                 return "", fmt.Errorf("download image: %w", whatsappImageDownloadError(err))
  37         }
  38
  39         name, err := store.Save(data)
  40         if err != nil {
  41                 return "", fmt.Errorf("store image: %w", err)
  42         }
  43
  44         return name, nil
  45 }
  46
  47 // whatsappImageDownloadError keeps only known safe causes. Library errors can
  48 // contain signed URLs or direct paths even when request preparation fails, so
  49 // arbitrary error text cannot go to the daemon log.
  50 func whatsappImageDownloadError(err error) error {
  51         switch {
  52         case errors.Is(err, context.Canceled):
  53                 return context.Canceled
  54         case errors.Is(err, context.DeadlineExceeded):
  55                 return context.DeadlineExceeded
  56         }
  57
  58         var response whatsmeow.DownloadHTTPError
  59
  60         if errors.As(err, &response) && response.Response != nil {
  61                 return fmt.Errorf("media server returned HTTP %d", response.StatusCode)
  62         }
  63
  64         return errors.New("media download failed")
  65 }