X-Git-Url: https://git.giacomolli.uk/onechat/blobdiff_plain/790279faf0fda789d93a75f6f5996e65d5de4a18..effd32b0f2e4d146b219b1727601b0b7f6593638:/whatsapp.go

diff --git a/whatsapp.go b/whatsapp.go
index 95e1d54..851cfd1 100644
--- a/whatsapp.go
+++ b/whatsapp.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"database/sql"
 	"errors"
 	"fmt"
 	"log/slog"
@@ -163,7 +164,9 @@ func openWhatsApp(ctx context.Context, dir string, clock func() time.Time, logge
 // of the client that asked. A logout from the phone comes as an event of the
 // library, and Run deletes the session. The mutex protects the session, the
 // client, and the state of the connection, which the event handler of the
-// library changes from its own goroutines.
+// library changes from its own goroutines. The sessionMutex serializes session
+// creation, close, removal, and snapshots. It is held before mutex, and stays
+// held when removal releases mutex for client callbacks.
 //
 // The inbox puts the text messages into batches and logs them, and groups
 // holds the names of the groups. Both get a WhatsAppLink from link for each
@@ -187,7 +190,9 @@ type WhatsApp struct {
 	state       *WhatsAppState
 	groups      *WhatsAppGroups
 	inbox       *WhatsAppInbox
+	routes      *Routes
 
+	sessionMutex   sync.Mutex
 	mutex          sync.Mutex
 	container      *sqlstore.Container
 	device         *store.Device
@@ -354,28 +359,90 @@ func (w *WhatsApp) Command(args string, answer func(text string)) {
 }
 
 // Status returns the state of the link: not linked, linked and connected, or
-// linked and disconnected, with the times of the connection. It never holds the
-// phone number.
+// linked and disconnected, with the times of the connection and the routes.
+// Route source IDs can hold the phone numbers of other chats.
 func (w *WhatsApp) Status() string {
 	w.mutex.Lock()
 	defer w.mutex.Unlock()
 
+	routes := ""
+	if w.routes != nil {
+		listed := w.routes.List()
+		if listed != "No routes." {
+			routes = "\nWhatsApp routes:\n" + listed
+		}
+	}
+
 	switch {
 	case !w.linked:
-		return "WhatsApp is not linked. Run /whatsapp pair PHONE to link it."
+		return "WhatsApp is not linked. Run /whatsapp pair PHONE to link it." + routes
 	case w.connected:
-		return "WhatsApp is linked and connected since " + w.connectedAt.Format(whatsappTimeLayout) + "."
+		return "WhatsApp is linked and connected since " + w.connectedAt.Format(whatsappTimeLayout) + "." + routes
 	case w.disconnectedAt.IsZero():
-		return "WhatsApp is linked and not connected yet."
+		return "WhatsApp is linked and not connected yet." + routes
 	case w.connectedAt.IsZero():
-		return "WhatsApp is linked and disconnected since " + w.disconnectedAt.Format(whatsappTimeLayout) + "."
+		return "WhatsApp is linked and disconnected since " + w.disconnectedAt.Format(whatsappTimeLayout) + "." + routes
 	default:
-		return "WhatsApp is linked and disconnected since " + w.disconnectedAt.Format(whatsappTimeLayout) + ". The last connection started at " + w.connectedAt.Format(whatsappTimeLayout) + "."
+		return "WhatsApp is linked and disconnected since " + w.disconnectedAt.Format(whatsappTimeLayout) + ". The last connection started at " + w.connectedAt.Format(whatsappTimeLayout) + "." + routes
 	}
 }
 
+// BackupSession writes a consistent SQLite snapshot to path while the session
+// cannot be created, closed, or removed. The source opens without creation
+// permission. No session file means no linked state to copy.
+func (w *WhatsApp) BackupSession(ctx context.Context, path string) (err error) {
+	w.sessionMutex.Lock()
+	defer w.sessionMutex.Unlock()
+
+	w.mutex.Lock()
+	defer w.mutex.Unlock()
+
+	_, err = os.Stat(w.sessionPath())
+	if errors.Is(err, os.ErrNotExist) {
+		return nil
+	}
+
+	if err != nil {
+		return fmt.Errorf("read session file: %w", err)
+	}
+
+	err = os.MkdirAll(filepath.Dir(path), 0o700)
+	if err != nil {
+		return fmt.Errorf("create session snapshot directory: %w", err)
+	}
+
+	address, err := whatsappSessionAddress(w.sessionPath())
+	if err != nil {
+		return fmt.Errorf("find session database: %w", err)
+	}
+
+	database, err := sql.Open("sqlite", address+"&mode=rw")
+	if err != nil {
+		return fmt.Errorf("open session snapshot source: %w", err)
+	}
+
+	defer func() {
+		err = errors.Join(err, database.Close())
+	}()
+
+	_, err = database.ExecContext(ctx, "VACUUM INTO ?", path)
+	if err != nil {
+		return fmt.Errorf("snapshot session database: %w", err)
+	}
+
+	err = os.Chmod(path, 0o600)
+	if err != nil {
+		return fmt.Errorf("set session snapshot mode: %w", err)
+	}
+
+	return nil
+}
+
 // Close closes the session database.
 func (w *WhatsApp) Close() error {
+	w.sessionMutex.Lock()
+	defer w.sessionMutex.Unlock()
+
 	w.mutex.Lock()
 	defer w.mutex.Unlock()
 
@@ -618,8 +685,12 @@ func (w *WhatsApp) unlink(ctx context.Context, l *TurnLoop, answer func(text str
 }
 
 // removeSession ends the connection, closes the session database, and deletes
-// its files.
+// its files. The session lock covers the cleanup after mutex is released, so a
+// snapshot or a new session cannot open files that cleanup removes.
 func (w *WhatsApp) removeSession() error {
+	w.sessionMutex.Lock()
+	defer w.sessionMutex.Unlock()
+
 	w.mutex.Lock()
 
 	client := w.client
@@ -773,6 +844,9 @@ func (w *WhatsApp) pair(ctx, runCtx context.Context, l *TurnLoop, phone string,
 // directory and the file of the session first, with their modes, when they do
 // not exist.
 func (w *WhatsApp) newDevice(ctx context.Context) (*store.Device, error) {
+	w.sessionMutex.Lock()
+	defer w.sessionMutex.Unlock()
+
 	w.mutex.Lock()
 	defer w.mutex.Unlock()