feat: 🎸 Implement message prefetching and link previews

Author: highesttt

README.md

@@ -13,7 +13,7 @@ Based on the [mautrix-twilio](https://github.com/mautrix/twilio) bridge
 > Messages sent to the LINE Bot using Beeper Desktop may appear as indefinitely sending.\
 > Use Beeper Mobile to send commands to the LINE Bot account after creating the chat with Beeper Desktop.
 
-## Roadmap
+## Features
 
 - [x] Basic messaging (encrypted text messages)
 - [x] Actual login via mail/password (instead of access token)
@@ -24,10 +24,11 @@ Based on the [mautrix-twilio](https://github.com/mautrix/twilio) bridge
 - [x] Read receipts
 - [x] Reaction support (Receive ONLY)
 - [x] Reply support
-- [ ] Prefetch chats
+- [x] Prefetch chats
 - [x] Group chats
 - [x] Media messages (images, videos, voice notes, files)
 - [x] Sticker support
+- [x] Link previews
 
 ## How to Use
 

pkg/connector/client.go

@@ -18,6 +18,7 @@ import (
 	"io"
 	"net/http"
 	"os"
+	"regexp"
 	"strconv"
 	"strings"
 	"sync"
@@ -473,9 +474,57 @@ func (lc *LineClient) Connect(ctx context.Context) {
 	}
 
 	go lc.syncChats(ctx)
+	go lc.prefetchMessages(ctx)
 	go lc.pollLoop(ctx)
 }
 
+func (lc *LineClient) prefetchMessages(ctx context.Context) {
+	client := line.NewClient(lc.AccessToken)
+	opts := line.MessageBoxesOptions{
+		ActiveOnly:                     true,
+		MessageBoxCountLimit:           100,
+		WithUnreadCount:                true,
+		LastMessagesPerMessageBoxCount: 0,
+	}
+
+	res, err := client.GetMessageBoxes(opts)
+	if err != nil && lc.isRefreshRequired(err) {
+		if errRefresh := lc.refreshAndSave(ctx); errRefresh == nil {
+			client = line.NewClient(lc.AccessToken)
+			res, err = client.GetMessageBoxes(opts)
+		}
+	}
+	if err != nil {
+		lc.UserLogin.Bridge.Log.Warn().Err(err).Msg("Failed to prefetch message boxes")
+		return
+	}
+
+	for _, box := range res.MessageBoxes {
+		// Fetch recent messages for all active chats to ensure history is populated
+		msgs, err := client.GetRecentMessagesV2(box.ID, 50)
+		if err != nil {
+			lc.UserLogin.Bridge.Log.Warn().Err(err).Str("chat_mid", box.ID).Msg("Failed to fetch recent messages")
+			continue
+		}
+
+		// Reverse messages to process oldest first
+		for i := len(msgs) - 1; i >= 0; i-- {
+			msg := msgs[i]
+
+			existing, err := lc.UserLogin.Bridge.DB.Message.GetPartByID(ctx, lc.UserLogin.ID, networkid.MessageID(msg.ID), "")
+			if err == nil && existing != nil {
+				continue
+			}
+
+			opType := 26
+			if msg.From == lc.Mid {
+				opType = 25
+			}
+			lc.queueIncomingMessage(msg, opType)
+		}
+	}
+}
+
 func (lc *LineClient) syncChats(ctx context.Context) {
 	client := line.NewClient(lc.AccessToken)
 	midsResp, err := client.GetAllChatMids(true, true)
@@ -948,14 +997,20 @@ func (lc *LineClient) queueIncomingMessage(msg *line.Message, opType int) {
 	}
 	decryptedBody := bodyText
 
+	tsInt, _ := msg.CreatedTime.Int64()
+	ts := time.UnixMilli(tsInt)
+	if ts.IsZero() {
+		ts = time.Now()
+	}
+
 	lc.UserLogin.Bridge.QueueRemoteEvent(lc.UserLogin, &simplevent.Message[line.Message]{
 		EventMeta: simplevent.EventMeta{
 			Type:         bridgev2.RemoteEventMessage,
 			LogContext:   func(c zerolog.Context) zerolog.Context { return c.Str("msg_id", msg.ID) },
 			PortalKey:    portalKey,
 			CreatePortal: true,
 			Sender:       bridgev2.EventSender{Sender: senderID, IsFromMe: opType == 25},
-			Timestamp:    time.Now(),
+			Timestamp:    ts,
 		},
 		Data: *msg,
 		ID:   networkid.MessageID(msg.ID),
@@ -1370,15 +1425,43 @@ func (lc *LineClient) queueIncomingMessage(msg *line.Message, opType int) {
 			}
 
 			// Default to Text
+			content := &event.MessageEventContent{
+				MsgType:   event.MsgText,
+				Body:      unwrappedText,
+				RelatesTo: replyRelatesTo,
+			}
+
+			if strings.Contains(unwrappedText, ".") {
+				urlRegex := regexp.MustCompile(`(https?://)?([a-zA-Z0-9.-]+\.[a-zA-Z]{2,})(/[^\s]*)?`)
+				if match := urlRegex.FindString(unwrappedText); match != "" {
+					match = strings.TrimRight(match, ".,;:!?")
+					requestURL := match
+					if !strings.HasPrefix(match, "http") {
+						requestURL = "https://" + match
+					}
+					client := line.NewClient(lc.AccessToken)
+					if info, err := client.GetPageInfo(requestURL); err == nil {
+						preview := &event.BeeperLinkPreview{
+							MatchedURL: match,
+							LinkPreview: event.LinkPreview{
+								Title:        info.Title,
+								Description:  info.Summary,
+								CanonicalURL: info.Domain,
+							},
+						}
+						if info.Image != "" && info.Obs.CDN != "" {
+							preview.ImageURL = id.ContentURIString(info.Obs.CDN + info.Image)
+						}
+						content.BeeperLinkPreviews = []*event.BeeperLinkPreview{preview}
+					}
+				}
+			}
+
 			return &bridgev2.ConvertedMessage{
 				Parts: []*bridgev2.ConvertedMessagePart{
 					{
-						Type: event.EventMessage,
-						Content: &event.MessageEventContent{
-							MsgType:   event.MsgText,
-							Body:      unwrappedText,
-							RelatesTo: replyRelatesTo,
-						},
+						Type:    event.EventMessage,
+						Content: content,
 					},
 				},
 			}, nil

pkg/line/client.go

@@ -538,3 +538,43 @@ func (c *Client) constructTalkMeta(messageID string) string {
 
 	return base64.StdEncoding.EncodeToString(metaBytes)
 }
+
+func (c *Client) GetPageInfo(url string) (*PageInfoResult, error) {
+	apiURL := "https://legy-jp.line-apps.com/sc/api/v2/pageinfo/get"
+	req, err := http.NewRequest("GET", apiURL, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	q := req.URL.Query()
+	q.Add("url", url)
+	q.Add("caller", "LINE_CHROME")
+	req.URL.RawQuery = q.Encode()
+
+	req.Header.Set("User-Agent", UserAgent)
+	if c.AccessToken != "" {
+		req.Header.Set("x-line-access", c.AccessToken)
+		req.Header.Set("Cookie", fmt.Sprintf("lct=%s", c.AccessToken))
+	}
+
+	resp, err := c.HTTPClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("pageinfo request failed: %d", resp.StatusCode)
+	}
+
+	var wrapper PageInfoResponse
+	if err := json.NewDecoder(resp.Body).Decode(&wrapper); err != nil {
+		return nil, err
+	}
+
+	if wrapper.Code != 0 {
+		return nil, fmt.Errorf("pageinfo API error: %s", wrapper.Message)
+	}
+
+	return &wrapper.Result, nil
+}

pkg/line/methods.go

@@ -430,3 +430,41 @@ func (c *Client) AcquireEncryptedAccessToken() (string, error) {
 
 	return parts[1], nil
 }
+
+func (c *Client) GetMessageBoxes(options MessageBoxesOptions) (*MessageBoxesResponse, error) {
+	resp, err := c.callRPC("TalkService", "getMessageBoxes", options, 2)
+	if err != nil {
+		return nil, err
+	}
+	var wrapper struct {
+		Code    int                  `json:"code"`
+		Message string               `json:"message"`
+		Data    MessageBoxesResponse `json:"data"`
+	}
+	if err := json.Unmarshal(resp, &wrapper); err != nil {
+		return nil, err
+	}
+	if wrapper.Code != 0 {
+		return nil, fmt.Errorf("getMessageBoxes failed: %s", wrapper.Message)
+	}
+	return &wrapper.Data, nil
+}
+
+func (c *Client) GetRecentMessagesV2(chatMid string, limit int) ([]*Message, error) {
+	resp, err := c.callRPC("TalkService", "getRecentMessagesV2", chatMid, limit)
+	if err != nil {
+		return nil, err
+	}
+	var wrapper struct {
+		Code    int        `json:"code"`
+		Message string     `json:"message"`
+		Data    []*Message `json:"data"`
+	}
+	if err := json.Unmarshal(resp, &wrapper); err != nil {
+		return nil, err
+	}
+	if wrapper.Code != 0 {
+		return nil, fmt.Errorf("getRecentMessagesV2 failed: %s", wrapper.Message)
+	}
+	return wrapper.Data, nil
+}

pkg/line/structs.go

@@ -247,3 +247,49 @@ type AcquireEncryptedAccessTokenResponse struct {
 	Message string `json:"message"`
 	Data    string `json:"data"` // Format: "expirySeconds\x1eToken"
 }
+
+type MessageBoxesOptions struct {
+	ActiveOnly                     bool `json:"activeOnly"`
+	UnreadOnly                     bool `json:"unreadOnly"`
+	MessageBoxCountLimit           int  `json:"messageBoxCountLimit"`
+	WithUnreadCount                bool `json:"withUnreadCount"`
+	LastMessagesPerMessageBoxCount int  `json:"lastMessagesPerMessageBoxCount"`
+}
+
+type MessageBoxesResponse struct {
+	MessageBoxes []MessageBox `json:"messageBoxes"`
+	HasNext      bool         `json:"hasNext"`
+}
+
+type MessageBox struct {
+	ID                     string            `json:"id"`
+	MidType                int               `json:"midType"`
+	LastDeliveredMessageID *MessageIDWrapper `json:"lastDeliveredMessageId"`
+	LastSeenMessageID      string            `json:"lastSeenMessageId"`
+	UnreadCount            json.Number       `json:"unreadCount"`
+	LastMessages           []Message         `json:"lastMessages"`
+}
+
+type MessageIDWrapper struct {
+	DeliveredTime json.Number `json:"deliveredTime"`
+	MessageID     string      `json:"messageId"`
+}
+
+type PageInfoResponse struct {
+	Result  PageInfoResult `json:"result"`
+	Code    int            `json:"code"`
+	Message string         `json:"message"`
+}
+
+type PageInfoResult struct {
+	URL     string  `json:"url"`
+	Domain  string  `json:"domain"`
+	Title   string  `json:"title"`
+	Summary string  `json:"summary"`
+	Image   string  `json:"image"`
+	Obs     ObsInfo `json:"obs"`
+}
+
+type ObsInfo struct {
+	CDN string `json:"cdn"`
+}