mautrix-whatsapp/urlpreview.go

185 lines
6.2 KiB
Go

// mautrix-whatsapp - A Matrix-WhatsApp puppeting bridge.
// Copyright (C) 2022 Tulir Asokan
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
package main
import (
"bytes"
"context"
"encoding/json"
"image"
"net/http"
"strings"
"time"
"github.com/tidwall/gjson"
"google.golang.org/protobuf/proto"
"maunium.net/go/mautrix/appservice"
"maunium.net/go/mautrix/crypto/attachment"
"maunium.net/go/mautrix/event"
"maunium.net/go/mautrix/id"
"go.mau.fi/whatsmeow"
waProto "go.mau.fi/whatsmeow/binary/proto"
)
type BeeperLinkPreview struct {
MatchedURL string `json:"matched_url"`
CanonicalURL string `json:"og:url,omitempty"`
Title string `json:"og:title,omitempty"`
Type string `json:"og:type,omitempty"`
Description string `json:"og:description,omitempty"`
ImageURL id.ContentURIString `json:"og:image,omitempty"`
ImageEncryption *event.EncryptedFileInfo `json:"beeper:image:encryption,omitempty"`
ImageSize int `json:"matrix:image:size,omitempty"`
ImageWidth int `json:"og:image:width,omitempty"`
ImageHeight int `json:"og:image:height,omitempty"`
ImageType string `json:"og:image:type,omitempty"`
}
func (portal *Portal) convertURLPreviewToBeeper(intent *appservice.IntentAPI, source *User, msg *waProto.ExtendedTextMessage) []*BeeperLinkPreview {
if msg.GetMatchedText() == "" {
return []*BeeperLinkPreview{}
}
output := &BeeperLinkPreview{
MatchedURL: msg.GetMatchedText(),
CanonicalURL: msg.GetCanonicalUrl(),
Title: msg.GetTitle(),
Description: msg.GetDescription(),
}
if len(output.CanonicalURL) == 0 {
output.CanonicalURL = output.MatchedURL
}
var thumbnailData []byte
if msg.ThumbnailDirectPath != nil {
var err error
thumbnailData, err = source.Client.DownloadThumbnail(msg)
if err != nil {
portal.log.Warnfln("Failed to download thumbnail for link preview: %v", err)
}
} else if msg.JpegThumbnail != nil {
thumbnailData = msg.JpegThumbnail
}
if thumbnailData != nil {
output.ImageHeight = int(msg.GetThumbnailHeight())
output.ImageWidth = int(msg.GetThumbnailWidth())
if output.ImageHeight == 0 || output.ImageWidth == 0 {
src, _, err := image.Decode(bytes.NewReader(thumbnailData))
if err == nil {
imageBounds := src.Bounds()
output.ImageWidth, output.ImageHeight = imageBounds.Max.X, imageBounds.Max.Y
}
}
output.ImageSize = len(thumbnailData)
output.ImageType = http.DetectContentType(thumbnailData)
uploadData, uploadMime := thumbnailData, output.ImageType
if portal.Encrypted {
crypto := attachment.NewEncryptedFile()
uploadData = crypto.Encrypt(uploadData)
uploadMime = "application/octet-stream"
output.ImageEncryption = &event.EncryptedFileInfo{EncryptedFile: *crypto}
}
resp, err := intent.UploadBytes(uploadData, uploadMime)
if err != nil {
portal.log.Warnfln("Failed to reupload thumbnail for link preview: %v", err)
} else {
if output.ImageEncryption != nil {
output.ImageEncryption.URL = resp.ContentURI.CUString()
} else {
output.ImageURL = resp.ContentURI.CUString()
}
}
}
if msg.GetPreviewType() == waProto.ExtendedTextMessage_VIDEO {
output.Type = "video.other"
}
return []*BeeperLinkPreview{output}
}
func (portal *Portal) convertURLPreviewToWhatsApp(sender *User, evt *event.Event, dest *waProto.ExtendedTextMessage) {
rawPreview := gjson.GetBytes(evt.Content.VeryRaw, `com\.beeper\.linkpreviews`)
if !rawPreview.Exists() || !rawPreview.IsArray() {
return
}
var previews []BeeperLinkPreview
if err := json.Unmarshal([]byte(rawPreview.Raw), &previews); err != nil || len(previews) == 0 {
return
}
// WhatsApp only supports a single preview.
preview := previews[0]
if len(preview.MatchedURL) == 0 {
return
}
dest.MatchedText = &preview.MatchedURL
if len(preview.CanonicalURL) > 0 {
dest.CanonicalUrl = &preview.CanonicalURL
}
if len(preview.Description) > 0 {
dest.Description = &preview.Description
}
if len(preview.Title) > 0 {
dest.Title = &preview.Title
}
if strings.HasPrefix(preview.Type, "video.") {
dest.PreviewType = waProto.ExtendedTextMessage_VIDEO.Enum()
}
imageMXC := preview.ImageURL.ParseOrIgnore()
if preview.ImageEncryption != nil {
imageMXC = preview.ImageEncryption.URL.ParseOrIgnore()
}
if !imageMXC.IsEmpty() {
data, err := portal.MainIntent().DownloadBytes(imageMXC)
if err != nil {
portal.log.Errorfln("Failed to download URL preview image %s in %s: %v", preview.ImageURL, evt.ID, err)
return
}
if preview.ImageEncryption != nil {
data, err = preview.ImageEncryption.Decrypt(data)
if err != nil {
portal.log.Errorfln("Failed to decrypt URL preview image in %s: %v", evt.ID, err)
return
}
}
dest.MediaKeyTimestamp = proto.Int64(time.Now().Unix())
uploadResp, err := sender.Client.Upload(context.Background(), data, whatsmeow.MediaLinkThumbnail)
if err != nil {
portal.log.Errorfln("Failed to upload URL preview thumbnail in %s: %v", evt.ID, err)
return
}
dest.ThumbnailSha256 = uploadResp.FileSHA256
dest.ThumbnailEncSha256 = uploadResp.FileEncSHA256
dest.ThumbnailDirectPath = &uploadResp.DirectPath
dest.MediaKey = uploadResp.MediaKey
var width, height int
dest.JpegThumbnail, width, height, err = createJPEGThumbnailAndGetSize(data)
if err != nil {
portal.log.Warnfln("Failed to create JPEG thumbnail for URL preview in %s: %v", evt.ID, err)
}
if preview.ImageHeight > 0 && preview.ImageWidth > 0 {
dest.ThumbnailWidth = proto.Uint32(uint32(preview.ImageWidth))
dest.ThumbnailHeight = proto.Uint32(uint32(preview.ImageHeight))
} else if width > 0 && height > 0 {
dest.ThumbnailWidth = proto.Uint32(uint32(width))
dest.ThumbnailHeight = proto.Uint32(uint32(height))
}
}
}