X-Git-Url: https://git.giacomolli.uk/onechat/blobdiff_plain/a85d214071706753f358f0af23cfd525c28dbfe0..add3cf6416e33c24331fd1e90e99284f44d2aae2:/whatsapp.go

diff --git a/whatsapp.go b/whatsapp.go
index 42b95a8..97b1e85 100644
--- a/whatsapp.go
+++ b/whatsapp.go
@@ -1,14 +1,11 @@
 package main
 
 import (
-	"cmp"
 	"context"
-	"crypto/sha256"
-	"encoding/hex"
+	"database/sql"
 	"errors"
 	"fmt"
-	"log"
-	"maps"
+	"log/slog"
 	"net/url"
 	"os"
 	"path/filepath"
@@ -16,19 +13,15 @@ import (
 	"strings"
 	"sync"
 	"time"
-	"unicode"
 
 	"go.mau.fi/whatsmeow"
+	"go.mau.fi/whatsmeow/proto/waCompanionReg"
 	"go.mau.fi/whatsmeow/proto/waE2E"
 	"go.mau.fi/whatsmeow/store"
 	"go.mau.fi/whatsmeow/store/sqlstore"
 	"go.mau.fi/whatsmeow/types"
 	"go.mau.fi/whatsmeow/types/events"
 	waLog "go.mau.fi/whatsmeow/util/log"
-	"golang.org/x/text/runes"
-	"golang.org/x/text/transform"
-	"golang.org/x/text/unicode/norm"
-
 	// The session store of the library opens SQLite with this pure Go
 	// driver.
 	_ "modernc.org/sqlite"
@@ -61,67 +54,31 @@ const (
 	// whatsappTimeLayout is the layout of the times in the answers.
 	whatsappTimeLayout = "2006-01-02 15:04"
 
-	// whatsappPairTime is the longest time of a pairing. The library closes
-	// the pairing connection after about 160 seconds.
-	whatsappPairTime = 3 * time.Minute
+	// whatsappPairTimeout is the longest time of a pairing. The library
+	// closes the pairing connection after about 160 seconds.
+	whatsappPairTimeout = 3 * time.Minute
 
-	// whatsappLogoutTime is the longest time of the logout call of an
+	// whatsappLogoutTimeout is the longest time of the logout call of an
 	// unlink.
-	whatsappLogoutTime = 30 * time.Second
+	whatsappLogoutTimeout = 30 * time.Second
+
+	// whatsappOutageNoticeDelay is the delay from a disconnection to its
+	// notice to the user.
+	whatsappOutageNoticeDelay = 10 * time.Minute
 
-	// whatsappNoticeDelay is how long a disconnection lasts before the user
-	// gets a notice.
-	whatsappNoticeDelay = 10 * time.Minute
+	// whatsappRetryDelay is the first wait after a failed starting
+	// connection.
+	whatsappRetryDelay = 2 * time.Second
+
+	// whatsappRetryLimit is the longest wait between starting connections.
+	whatsappRetryLimit = 5 * time.Minute
 
 	// whatsappRequests is the number of pair and unlink commands that can
 	// wait for Run.
 	whatsappRequests = 8
 
-	// whatsappSource is the source of the work events of the batches.
-	whatsappSource = "whatsapp"
-
-	// whatsappLookupTime is the longest time of a read of the names in the
-	// session database or of the groups from WhatsApp.
-	whatsappLookupTime = 10 * time.Second
-
-	// whatsappGroupsRefresh is the shortest time between two reads of the
-	// groups from WhatsApp for a group with no name.
-	whatsappGroupsRefresh = time.Minute
-
-	// whatsappUnknownGroup is the name of a group whose name is not known.
-	whatsappUnknownGroup = "A group with no known name"
-
-	// whatsappCatchupLimit is the longest wait for the end of the catch-up
-	// after a connection.
-	whatsappCatchupLimit = time.Minute
-
-	// whatsappGroupsAge is how long whatsapp_find uses the groups that it
-	// read from WhatsApp.
-	whatsappGroupsAge = time.Hour
-
-	// whatsappFindMatches is the most matches of whatsapp_find.
-	whatsappFindMatches = 20
-
 	// whatsappNotLinked is the answer of a WhatsApp tool without a link.
 	whatsappNotLinked = "WhatsApp is not linked. Tell the user to run /whatsapp pair PHONE in the terminal or in Telegram."
-
-	// whatsappSendTime is the longest time of a send.
-	whatsappSendTime = 30 * time.Second
-
-	// whatsappSendBytes is the most bytes of the text of a send.
-	whatsappSendBytes = 65536
-
-	// whatsappSendIDBytes is the most bytes of the ID of a send.
-	whatsappSendIDBytes = 100
-
-	// The states of a send record.
-	whatsappSending = "sending"
-	whatsappSent    = "sent"
-	whatsappFailed  = "failed"
-
-	// whatsappNamesNotReady is the answer of whatsapp_find before the names
-	// arrive from the phone.
-	whatsappNamesNotReady = "The names of the contacts and groups have not arrived from the phone yet. They come some minutes after the link. Try again later."
 )
 
 // WhatsAppClient is the part of the WhatsApp client that the daemon uses. The
@@ -134,6 +91,7 @@ type WhatsAppClient interface {
 	PairPhone(ctx context.Context, phone string, showPushNotification bool, clientType whatsmeow.PairClientType, clientDisplayName string) (string, error)
 	Logout(ctx context.Context) error
 	GetJoinedGroups(ctx context.Context) ([]*types.GroupInfo, error)
+	Download(ctx context.Context, message whatsmeow.DownloadableMessage) ([]byte, error)
 	GenerateMessageID() types.MessageID
 	SendMessage(ctx context.Context, to types.JID, message *waE2E.Message, extra ...whatsmeow.SendRequestExtra) (whatsmeow.SendResponse, error)
 }
@@ -143,27 +101,27 @@ type WhatsAppClient interface {
 // the account, so a file that another user can read is an error. The clock
 // gives the times of the status, logger gets the failures, and newClient makes
 // the client of a device with its event handler.
-func openWhatsApp(ctx context.Context, dir string, clock func() time.Time, logger *log.Logger, newClient func(device *store.Device, handle func(event any) bool) WhatsAppClient) (*WhatsApp, error) {
+func openWhatsApp(ctx context.Context, dir string, clock func() time.Time, logger *slog.Logger, newClient func(device *store.Device, handle func(event any) bool) WhatsAppClient) (*WhatsApp, error) {
 	w := &WhatsApp{
-		dir:          filepath.Join(dir, whatsappDirName),
-		clock:        clock,
-		logger:       logger,
-		newClient:    newClient,
-		noticeDelay:  whatsappNoticeDelay,
-		catchupLimit: whatsappCatchupLimit,
-		requests:     make(chan WhatsAppRequest, whatsappRequests),
-		logouts:      make(chan struct{}, 1),
-		wake:         make(chan struct{}, 1),
-		failures:     make(chan error, 1),
-		groupNames:   make(map[string]string),
+		ctx:       ctx,
+		dir:       filepath.Join(dir, whatsappDirName),
+		clock:     clock,
+		logger:    logger,
+		newClient: newClient,
+		requests:  make(chan WhatsAppRequest, whatsappRequests),
+		logouts:   make(chan struct{}, 1),
+		groups:    newWhatsAppGroups(logger),
 	}
 
 	var err error
-	w.state, err = openWhatsAppState(filepath.Join(w.dir, whatsappStateFileName), whatsappBatchQuiet, whatsappBatchWindow)
+
+	w.state, err = openWhatsAppState(filepath.Join(w.dir, whatsappStateFileName))
 	if err != nil {
 		return nil, err
 	}
 
+	w.inbox = newWhatsAppInbox(w.state, clock, w.groups, &ImageStore{dir: filepath.Join(dir, imageDirName)}, logger)
+
 	info, err := os.Stat(w.sessionPath())
 	if errors.Is(err, os.ErrNotExist) {
 		return w, nil
@@ -184,7 +142,8 @@ func openWhatsApp(ctx context.Context, dir string, clock func() time.Time, logge
 
 	if w.device.ID != nil {
 		w.linked = true
-		w.catchingUp = true
+		w.inbox.waitForCatchup()
+
 		w.own = whatsappOwnIDs(w.device.ID.User, w.device.LID.User)
 	}
 
@@ -202,22 +161,16 @@ 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 text messages go into batches, one chat at a time, as WhatsAppState says.
-// Run logs each closed batch as a work message that starts with [WhatsApp], and
-// a batch that needs the user wakes the turn loop.
+// ctx is the caller context until Run sets its context for library callbacks.
+// The mutex protects it, so callbacks follow daemon cancellation.
 //
-// After each connection, the servers send the messages that came while the
-// daemon was away, and then OfflineSyncCompleted. Until then, or until
-// catchupLimit passes, the closed batches wait in the state file. At the end of
-// the catch-up, Run closes all batches, logs them, and wakes the turn loop
-// once, so the whole catch-up gives one turn and not one turn for each chat.
-// The batches of the state file at the start wait for the first catch-up in the
-// same way. The event handler acknowledges a message only after the state file
-// holds it, so the servers send again a message that a crash lost. A batch
-// leaves the state file only after its work message is durable in the log. A
-// crash between the two makes the batch repeat once.
+// The inbox puts messages into batches and logs them, and groups holds the
+// names of the groups. Both get a WhatsAppLink from link for each call, so they
+// use the current device and client.
 //
 // The library logs nothing, because its log lines hold the ID of the own
 // account, which is the phone number of the user. The own number and the own
@@ -227,18 +180,19 @@ func openWhatsApp(ctx context.Context, dir string, clock func() time.Time, logge
 // log, and those of private chats hold phone numbers, because the agent needs
 // them to send.
 type WhatsApp struct {
-	dir          string
-	clock        func() time.Time
-	logger       *log.Logger
-	newClient    func(device *store.Device, handle func(event any) bool) WhatsAppClient
-	noticeDelay  time.Duration
-	catchupLimit time.Duration
-	requests     chan WhatsAppRequest
-	logouts      chan struct{}
-	wake         chan struct{}
-	failures     chan error
-	state        *WhatsAppState
-
+	ctx       context.Context
+	dir       string
+	clock     func() time.Time
+	logger    *slog.Logger
+	newClient func(device *store.Device, handle func(event any) bool) WhatsAppClient
+	requests  chan WhatsAppRequest
+	logouts   chan struct{}
+	state     *WhatsAppState
+	groups    *WhatsAppGroups
+	inbox     *WhatsAppInbox
+	routes    *Routes
+
+	sessionMutex   sync.Mutex
 	mutex          sync.Mutex
 	container      *sqlstore.Container
 	device         *store.Device
@@ -247,39 +201,64 @@ type WhatsApp struct {
 	own            []string
 	notify         func(Event)
 	connected      bool
+	retrying       bool
 	connectedAt    time.Time
 	disconnectedAt time.Time
 	disconnections int
 	noticed        bool
 	timer          *time.Timer
 	closed         bool
-	groupNames     map[string]string
-	groupsAt       time.Time
-	groupsRead     time.Time
-	catchingUp     bool
-	caughtUp       bool
-	catchups       int
-	catchupTimer   *time.Timer
 }
 
 // Run connects a linked device, logs the closed batches in l, runs the pair and
 // unlink commands, and handles a logout from the phone, until ctx ends. Its
 // notes go to the log of l, and notify gets the notices for all clients. A
-// failed first connection is logged, and the library tries again when the
-// failure is one of the network. Run returns the error of a write of the log or
-// of the state file, which stops the daemon, because then messages would be
-// lost.
+// failed first connection starts the same outage notice as a lost connection. A
+// timer in the select retries it with a doubled wait from 2 seconds to 5
+// minutes, without a retry goroutine or a wait that blocks commands or the
+// inbox. A connection, unlink, logout, or ctx end stops retries. The library
+// owns retries after a connection opens. Run returns the error of a write of
+// the log or of the state file, which stops the daemon, because then messages
+// would be lost.
 func (w *WhatsApp) Run(ctx context.Context, l *TurnLoop, notify func(Event)) error {
 	w.mutex.Lock()
+
+	w.ctx = ctx
 	w.notify = notify
 	linked := w.linked
+	w.retrying = linked
 	w.mutex.Unlock()
 
-	if linked {
-		w.connect(ctx)
+	timer := time.NewTimer(whatsappRetryDelay)
+	timer.Stop()
+	defer timer.Stop()
+
+	var retry <-chan time.Time
+
+	delay := whatsappRetryDelay
+	connect := func() {
+		retry = nil
+		if w.connect(ctx) {
+			timer.Reset(delay)
+
+			retry = timer.C
+			delay = min(2*delay, whatsappRetryLimit)
+		}
+	}
+
+	stopRetry := func() {
+		timer.Stop()
+
+		retry = nil
+
+		w.mutex.Lock()
+
+		w.retrying = false
+		w.mutex.Unlock()
 	}
 
 	var pairing sync.WaitGroup
+
 	cancel := func() {}
 	defer func() {
 		cancel()
@@ -287,26 +266,28 @@ func (w *WhatsApp) Run(ctx context.Context, l *TurnLoop, notify func(Event)) err
 		w.close()
 	}()
 
+	if linked {
+		connect()
+	}
+
 	for {
-		err := w.deliver(ctx, l, false)
+		err := w.inbox.deliver(ctx, l, w.link(), false)
 		if err != nil {
 			return err
 		}
 
-		var due <-chan time.Time
-		wait, open := w.state.Wait(time.Now())
-		if open {
-			due = time.After(wait)
-		}
-
 		select {
 		case <-ctx.Done():
 			return nil
-		case err = <-w.failures:
+		case err = <-w.inbox.failures:
 			return err
-		case <-w.wake:
-		case <-due:
+		case <-w.inbox.wake:
+		case <-w.inbox.due():
+		case <-retry:
+			connect()
 		case <-w.logouts:
+			stopRetry()
+
 			err = w.loggedOut(ctx, l)
 			if err != nil {
 				return err
@@ -314,10 +295,13 @@ func (w *WhatsApp) Run(ctx context.Context, l *TurnLoop, notify func(Event)) err
 		case request := <-w.requests:
 			cancel()
 			pairing.Wait()
+
 			cancel = func() {}
 
 			switch {
 			case request.unlink:
+				stopRetry()
+
 				err = w.unlink(ctx, l, request.answer)
 				if err != nil {
 					return err
@@ -325,7 +309,7 @@ func (w *WhatsApp) Run(ctx context.Context, l *TurnLoop, notify func(Event)) err
 			case w.isLinked():
 				request.answer("WhatsApp is linked already. Run /whatsapp unlink first.")
 			default:
-				pairCtx, cancelPair := context.WithTimeout(ctx, whatsappPairTime)
+				pairCtx, cancelPair := context.WithTimeout(ctx, whatsappPairTimeout)
 				cancel = cancelPair
 				pairing.Go(func() {
 					defer cancelPair()
@@ -349,6 +333,7 @@ func (w *WhatsApp) Command(args string, answer func(text string)) {
 	switch {
 	case len(fields) == 1 && fields[0] == "status":
 		answer(w.Status())
+
 		return
 	case len(fields) == 1 && fields[0] == "unlink":
 		request.unlink = true
@@ -356,12 +341,14 @@ func (w *WhatsApp) Command(args string, answer func(text string)) {
 		phone, valid := whatsappPhone(strings.Join(fields[1:], ""))
 		if !valid {
 			answer("PHONE must be the number of your WhatsApp account with its country code: 7 to 15 digits, such as +15550001111.")
+
 			return
 		}
 
 		request.phone = phone
 	default:
 		answer(whatsappUsage)
+
 		return
 	}
 
@@ -373,28 +360,90 @@ 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()
 
@@ -408,6 +457,17 @@ func (w *WhatsApp) Close() error {
 	return err
 }
 
+// Find returns the answer of whatsapp_find for name, as whatsappFind says.
+func (w *WhatsApp) Find(ctx context.Context, name string) (string, error) {
+	return whatsappFind(ctx, w.link(), w.groups, name)
+}
+
+// Send returns the answer of whatsapp_send for the send id of text to chat, as
+// whatsappSend says.
+func (w *WhatsApp) Send(ctx context.Context, id, chat, text string) (string, error) {
+	return whatsappSend(ctx, w.link(), w.groups, w.state, w.clock, id, chat, text)
+}
+
 func (w *WhatsApp) sessionPath() string {
 	return filepath.Join(w.dir, whatsappSessionFileName)
 }
@@ -443,35 +503,97 @@ func (w *WhatsApp) isLinked() bool {
 	return w.linked
 }
 
-// connect makes the client of the linked device and connects it.
-func (w *WhatsApp) connect(ctx context.Context) {
+// link returns a copy of the link of the device: whether it is linked, the
+// device, the client, whether it is connected, and the own IDs.
+func (w *WhatsApp) link() WhatsAppLink {
+	w.mutex.Lock()
+	defer w.mutex.Unlock()
+
+	return WhatsAppLink{
+		linked:    w.linked,
+		device:    w.device,
+		client:    w.client,
+		connected: w.connected,
+		own:       slices.Clone(w.own),
+	}
+}
+
+// connect tries the starting connection of the linked device with one client.
+// It returns whether Run must retry. A failed call starts the shared outage
+// state and logs its redacted cause once, because a returned ConnectContext
+// error does not emit Disconnected. Connected logs recovery after
+// authentication.
+func (w *WhatsApp) connect(ctx context.Context) bool {
 	w.mutex.Lock()
-	w.client = w.newClient(w.device, w.handle)
+
+	if ctx.Err() != nil || !w.linked || !w.retrying || w.closed {
+		w.mutex.Unlock()
+
+		return false
+	}
+
+	if w.client == nil {
+		w.client = w.newClient(w.device, w.handle)
+	}
+
 	client := w.client
 	w.mutex.Unlock()
 
 	err := client.ConnectContext(ctx)
-	if err != nil {
-		w.logger.Printf("connect: %s", w.redact(err.Error()))
+
+	w.mutex.Lock()
+
+	if err == nil || ctx.Err() != nil || !w.retrying || !w.linked {
+		w.retrying = false
+		w.mutex.Unlock()
+
+		return false
 	}
+
+	first := w.startOutage()
+	cause := whatsappRedact(w.own, err.Error())
+	w.mutex.Unlock()
+
+	if first {
+		w.logger.Warn("first connect failed, retrying", "err", cause)
+	}
+
+	return true
+}
+
+// startOutage starts the shared outage time and notice timer once. The caller
+// holds the mutex. Its result tells whether this is the first failure.
+func (w *WhatsApp) startOutage() bool {
+	first := w.linked && (w.connected || w.disconnectedAt.IsZero())
+	if first {
+		w.disconnectedAt = w.clock()
+		w.disconnections++
+		disconnections := w.disconnections
+		w.timer = time.AfterFunc(whatsappOutageNoticeDelay, func() {
+			w.disconnectedLong(disconnections)
+		})
+	}
+
+	w.connected = false
+
+	return first
 }
 
 // close ends the connection and the timer of the notice, and stops all notices.
 func (w *WhatsApp) close() {
 	w.mutex.Lock()
+
 	w.closed = true
 	if w.timer != nil {
 		w.timer.Stop()
 	}
 
-	if w.catchupTimer != nil {
-		w.catchupTimer.Stop()
-	}
-
 	client := w.client
 	w.client = nil
 	w.mutex.Unlock()
 
+	w.inbox.close()
+
 	if client != nil {
 		client.Disconnect()
 	}
@@ -484,19 +606,21 @@ func (w *WhatsApp) loggedOut(ctx context.Context, l *TurnLoop) error {
 		return nil
 	}
 
-	err := w.deliver(ctx, l, true)
+	w.logger.Error("logged out by the phone, run /whatsapp pair PHONE")
+
+	err := w.inbox.deliver(ctx, l, w.link(), true)
 	if err != nil {
 		return err
 	}
 
 	err = w.removeSession()
 	if err != nil {
-		w.logger.Printf("delete the session after the logout: %v", err)
+		w.logger.Error("session delete failed", "err", err)
 	}
 
 	err = l.note("WhatsApp was unlinked from the phone.")
 	if err != nil {
-		w.logger.Printf("note the logout: %v", err)
+		w.logger.Error("chat note failed", "err", err)
 	}
 
 	w.broadcast("WhatsApp was unlinked from the phone. Run /whatsapp pair PHONE to link it again.")
@@ -511,23 +635,26 @@ func (w *WhatsApp) loggedOut(ctx context.Context, l *TurnLoop) error {
 // file.
 func (w *WhatsApp) unlink(ctx context.Context, l *TurnLoop, answer func(text string)) error {
 	w.mutex.Lock()
+
 	linked := w.linked
 	client := w.client
 	w.mutex.Unlock()
 
 	if !linked {
 		answer("WhatsApp is not linked.")
+
 		return nil
 	}
 
-	err := w.deliver(ctx, l, true)
+	err := w.inbox.deliver(ctx, l, w.link(), true)
 	if err != nil {
 		return err
 	}
 
 	var logoutErr error
+
 	if client != nil {
-		ctx, cancel := context.WithTimeout(ctx, whatsappLogoutTime)
+		ctx, cancel := context.WithTimeout(ctx, whatsappLogoutTimeout)
 		defer cancel()
 
 		logoutErr = client.Logout(ctx)
@@ -536,233 +663,44 @@ func (w *WhatsApp) unlink(ctx context.Context, l *TurnLoop, answer func(text str
 	err = w.removeSession()
 	if err != nil {
 		answer("The unlink failed: " + w.redact(err.Error()))
+
 		return nil
 	}
 
+	w.logger.Info("unlinked")
+
 	err = l.note("WhatsApp is unlinked.")
 	if err != nil {
-		w.logger.Printf("note the unlink: %v", err)
+		w.logger.Error("chat note failed", "err", err)
 	}
 
 	if client == nil || logoutErr != nil {
 		answer("WhatsApp is unlinked here, but the phone did not get the logout. In WhatsApp on your phone, open Linked devices and remove the device.")
-		return nil
-	}
 
-	answer("WhatsApp is unlinked.")
-
-	return nil
-}
-
-// deliver logs the closed batches in l in order, each as a work message of
-// whatsappSource, and wakes the loop once with the batches that start a turn. A
-// batch leaves the state file after its message is durable in the log. A group
-// with no name gets its name from WhatsApp first. During a catch-up it logs
-// nothing, and at its end it closes all batches first. With all, it closes and
-// logs all batches also during a catch-up.
-func (w *WhatsApp) deliver(ctx context.Context, l *TurnLoop, all bool) error {
-	w.mutex.Lock()
-	catchingUp := w.catchingUp
-	caughtUp := w.caughtUp
-	w.caughtUp = false
-	w.mutex.Unlock()
-
-	var err error
-	switch {
-	case all || caughtUp:
-		err = w.state.CloseAll()
-	case catchingUp:
 		return nil
-	default:
-		_, err = w.state.CloseDue(time.Now())
-	}
-
-	if err != nil {
-		return err
 	}
 
-	var turns []Message
-	for _, batch := range w.state.Closed() {
-		if batch.Chat.Group && batch.Chat.Name == "" {
-			batch.Chat.Name = w.groupName(ctx, batch.Chat.ID)
-		}
-
-		message, err := l.Work(whatsappSource, batch.Text(w.clock().Location()), "")
-		if err != nil {
-			return fmt.Errorf("log a WhatsApp batch: %w", err)
-		}
-
-		// A stop of the daemon during the flush is no failure: the
-		// batch stays in the state file and repeats once at the next
-		// start.
-		err = l.Flush(ctx)
-		if ctx.Err() != nil {
-			return nil
-		}
-
-		if err != nil {
-			return fmt.Errorf("log a WhatsApp batch: %w", err)
-		}
-
-		err = w.state.Remove(batch.Number)
-		if err != nil {
-			return err
-		}
-
-		if batch.Turn() {
-			turns = append(turns, message)
-		}
-	}
-
-	l.Wake(turns...)
+	answer("WhatsApp is unlinked.")
 
 	return nil
 }
 
-// groupName returns the name of the group id, or whatsappUnknownGroup. A group
-// that is not in the names of the groups reads the groups from WhatsApp again,
-// at most once in whatsappGroupsRefresh.
-func (w *WhatsApp) groupName(ctx context.Context, id string) string {
-	w.mutex.Lock()
-	name, found := w.groupNames[id]
-	fresh := time.Since(w.groupsAt) < whatsappGroupsRefresh
-	w.mutex.Unlock()
-
-	if !found && !fresh {
-		w.readGroups(ctx)
-
-		w.mutex.Lock()
-		name, found = w.groupNames[id]
-		w.mutex.Unlock()
-	}
-
-	if !found || name == "" {
-		return whatsappUnknownGroup
-	}
-
-	return name
-}
-
-// readGroups reads the names of the groups of the account from WhatsApp, and
-// tells if it could. They stay in memory only.
-func (w *WhatsApp) readGroups(ctx context.Context) bool {
-	w.mutex.Lock()
-	client := w.client
-	w.mutex.Unlock()
-
-	if client == nil {
-		return false
-	}
-
-	ctx, cancel := context.WithTimeout(ctx, whatsappLookupTime)
-	defer cancel()
-
-	groups, err := client.GetJoinedGroups(ctx)
-	if err != nil {
-		w.logger.Printf("read the groups: %s", w.redact(err.Error()))
-	}
-
-	w.mutex.Lock()
-	defer w.mutex.Unlock()
-
-	w.groupsAt = time.Now()
-	if err != nil {
-		return false
-	}
-
-	w.groupsRead = w.groupsAt
-	for _, group := range groups {
-		w.groupNames[group.JID.String()] = group.Name
-	}
-
-	return true
-}
-
-// Find returns the contacts and the groups whose name contains name, with no
-// regard to case and accents, as lines "ID | name | contact" or "ID | name |
-// group", sorted by name. It gives at most whatsappFindMatches lines and the
-// number of the others. The contacts come from the session database, and the
-// groups from WhatsApp, read again after whatsappGroupsAge. When the groups
-// cannot be read and none are known, the answer says so. Before the names
-// arrive from the phone, it says that they are not ready.
-func (w *WhatsApp) Find(ctx context.Context, name string) (string, error) {
-	w.mutex.Lock()
-	linked := w.linked
-	device := w.device
-	own := slices.Clone(w.own)
-	stale := time.Since(w.groupsRead) >= whatsappGroupsAge
-	w.mutex.Unlock()
-
-	if !linked {
-		return whatsappNotLinked, nil
-	}
-
-	query := whatsappFold(name)
-	if query == "" {
-		return "", errors.New("name is empty: give a part of the name of the contact or the group")
-	}
-
-	contacts, err := device.Contacts.GetAllContacts(ctx)
-	if err != nil {
-		return "", fmt.Errorf("read the contacts: %s", w.redact(err.Error()))
-	}
-
-	read := !stale || w.readGroups(ctx)
-	w.mutex.Lock()
-	groups := maps.Clone(w.groupNames)
-	w.mutex.Unlock()
-
-	if len(contacts) == 0 && len(groups) == 0 {
-		if !read {
-			return "The names are not known yet, and WhatsApp is disconnected, so the groups cannot be read. Try again later.", nil
-		}
-
-		return whatsappNamesNotReady, nil
-	}
-
-	var matches []WhatsAppMatch
-	for jid, contact := range contacts {
-		names := []string{contact.FullName, contact.FirstName, contact.BusinessName, contact.PushName}
-		shown := slices.IndexFunc(names, func(name string) bool {
-			return name != ""
-		})
-
-		if slices.Contains(own, jid.User) || shown < 0 || !slices.ContainsFunc(names, func(name string) bool {
-			return strings.Contains(whatsappFold(name), query)
-		}) {
-			continue
-		}
-
-		matches = append(matches, WhatsAppMatch{
-			id:   jid.ToNonAD().String(),
-			name: names[shown],
-			kind: "contact",
-		})
-	}
-
-	for id, group := range groups {
-		if strings.Contains(whatsappFold(group), query) {
-			matches = append(matches, WhatsAppMatch{
-				id:   id,
-				name: group,
-				kind: "group",
-			})
-		}
-	}
-
-	return whatsappFindAnswer(name, matches, read || len(groups) > 0), nil
-}
-
 // 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
 	w.client = nil
 	w.linked = false
+	w.retrying = false
 	w.own = nil
 	w.connected = false
-	w.catchingUp = false
+	w.disconnectedAt = time.Time{}
 	if w.timer != nil {
 		w.timer.Stop()
 	}
@@ -773,11 +711,14 @@ func (w *WhatsApp) removeSession() error {
 	w.device = nil
 	w.mutex.Unlock()
 
+	w.inbox.stopCatchup()
+
 	if client != nil {
 		client.Disconnect()
 	}
 
 	var err error
+
 	if container != nil {
 		err = container.Close()
 	}
@@ -807,6 +748,7 @@ func (w *WhatsApp) pair(ctx, runCtx context.Context, l *TurnLoop, phone string,
 	device, err := w.newDevice(ctx)
 	if err != nil {
 		answer("The pairing failed: " + err.Error())
+
 		return
 	}
 
@@ -825,6 +767,7 @@ func (w *WhatsApp) pair(ctx, runCtx context.Context, l *TurnLoop, phone string,
 
 	if err != nil {
 		answer("The connection to WhatsApp failed: " + err.Error())
+
 		return
 	}
 
@@ -832,6 +775,7 @@ func (w *WhatsApp) pair(ctx, runCtx context.Context, l *TurnLoop, phone string,
 	case item, open := <-qr:
 		if !open || item.Event != whatsmeow.QRChannelEventCode {
 			answer("WhatsApp did not start the pairing. Try again later.")
+
 			return
 		}
 	case <-ctx.Done():
@@ -842,9 +786,12 @@ func (w *WhatsApp) pair(ctx, runCtx context.Context, l *TurnLoop, phone string,
 		return
 	}
 
+	// The server accepts only a display name of the form "Browser (OS)"
+	// with a common browser and OS, and refuses the pairing otherwise.
 	code, err := client.PairPhone(ctx, phone, true, whatsmeow.PairClientChrome, "Chrome (Linux)")
 	if err != nil {
 		answer("WhatsApp refused the pairing: " + err.Error() + ". Check the phone number and run /whatsapp pair PHONE again.")
+
 		return
 	}
 
@@ -853,6 +800,7 @@ func (w *WhatsApp) pair(ctx, runCtx context.Context, l *TurnLoop, phone string,
 
 	for {
 		var item whatsmeow.QRChannelItem
+
 		open := true
 		select {
 		case item, open = <-qr:
@@ -867,16 +815,19 @@ func (w *WhatsApp) pair(ctx, runCtx context.Context, l *TurnLoop, phone string,
 		switch {
 		case !open || item.Event == whatsmeow.QRChannelTimeout.Event:
 			answer(whatsappPairExpired)
+
 			return
 		case item.Event == whatsmeow.QRChannelEventCode:
 			continue
 		case item.Event == whatsmeow.QRChannelSuccess.Event:
 			linked = true
+
 			w.linkedBy(client)
+			w.logger.Info("linked")
 
 			err = l.note("WhatsApp is linked.")
 			if err != nil {
-				w.logger.Printf("note the link: %v", err)
+				w.logger.Error("chat note failed", "err", err)
 			}
 
 			answer("WhatsApp is linked to +" + phone + ".")
@@ -884,6 +835,7 @@ func (w *WhatsApp) pair(ctx, runCtx context.Context, l *TurnLoop, phone string,
 			return
 		default:
 			answer("The pairing failed: " + whatsappItemError(item) + ". Run /whatsapp pair PHONE again.")
+
 			return
 		}
 	}
@@ -893,6 +845,9 @@ 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()
 
@@ -933,42 +888,69 @@ func (w *WhatsApp) linkedBy(client WhatsAppClient) {
 }
 
 // handle takes one event of the library and tells if it was handled. A message
-// goes to receive. The names of the groups follow the events of the groups. A
-// connection starts a catch-up, which ends at OfflineSyncCompleted or after
-// catchupLimit. A disconnection keeps the time of its start while the library
-// tries again. After noticeDelay of a disconnection, all clients get one
-// notice, and they get one more when the connection comes back. A disconnection
-// that the library does not try again gives a notice at once.
+// goes to the inbox. The names of the groups follow the events of the groups. A
+// connection starts a catch-up of the inbox, which ends at OfflineSyncCompleted
+// or after whatsappCatchupTimeout. A disconnection keeps the time of its start
+// while Run or the library tries again. After whatsappOutageNoticeDelay of a
+// disconnection, all clients get one notice, and they get one more when the
+// connection comes back. A disconnection that the library does not try again
+// gives a notice at once.
+//
+// The log of the daemon gets one line for each change of the connection of the
+// linked device: connected, a failed first connection, a lost connection, and
+// connected again with the length of the outage. The retries of the library and
+// Run between them log nothing.
 func (w *WhatsApp) handle(event any) bool {
-	message, isMessage := event.(*events.Message)
-	if isMessage {
-		return w.receive(message)
-	}
-
-	var notice string
 	w.mutex.Lock()
+
+	ctx := w.ctx
+	w.mutex.Unlock()
+
 	switch event := event.(type) {
+	case *events.Message:
+		return w.inbox.receive(ctx, w.link(), event)
 	case *events.GroupInfo:
 		if event.Name != nil {
-			w.groupNames[event.JID.String()] = event.Name.Name
+			w.groups.set(event.JID.String(), event.Name.Name)
 		}
+
+		return true
 	case *events.JoinedGroup:
-		w.groupNames[event.JID.String()] = event.Name
+		w.groups.set(event.JID.String(), event.Name)
+
+		return true
+	case *events.OfflineSyncCompleted:
+		w.inbox.endCatchup()
+
+		return true
+	case *events.Connected:
+		w.inbox.startCatchup()
+	}
+
+	var notice, line string
+
+	level := slog.LevelInfo
+
+	var attrs []any
+
+	w.mutex.Lock()
+
+	switch event := event.(type) {
 	case *events.PairSuccess:
 		w.own = whatsappOwnIDs(event.ID.User, event.LID.User)
 	case *events.Connected:
-		w.connected = true
-		w.connectedAt = w.clock()
-		w.catchingUp = true
-		w.catchups++
-		catchups := w.catchups
-		if w.catchupTimer != nil {
-			w.catchupTimer.Stop()
+		switch {
+		case !w.linked || w.connected:
+		case w.disconnectedAt.IsZero():
+			line = "connected"
+		default:
+			line = "connected again"
+			attrs = append(attrs, "after", w.clock().Sub(w.disconnectedAt))
 		}
 
-		w.catchupTimer = time.AfterFunc(w.catchupLimit, func() {
-			w.caughtUpBy(catchups)
-		})
+		w.connected = true
+		w.retrying = false
+		w.connectedAt = w.clock()
 		if w.timer != nil {
 			w.timer.Stop()
 		}
@@ -978,196 +960,54 @@ func (w *WhatsApp) handle(event any) bool {
 			notice = "WhatsApp is connected again."
 		}
 	case *events.Disconnected:
-		if w.linked && (w.connected || w.disconnectedAt.IsZero()) {
-			w.disconnectedAt = w.clock()
-			w.disconnections++
-			disconnections := w.disconnections
-			w.timer = time.AfterFunc(w.noticeDelay, func() {
-				w.disconnectedLong(disconnections)
-			})
+		connected := w.connected
+		if w.startOutage() {
+			level = slog.LevelWarn
+			line = "disconnected, retrying"
+			if !connected {
+				line = "first connect failed, retrying"
+			}
 		}
-
-		w.connected = false
-	case *events.OfflineSyncCompleted:
-		w.endCatchup()
 	case *events.LoggedOut:
+		w.retrying = false
 		select {
 		case w.logouts <- struct{}{}:
 		default:
 		}
 	case events.PermanentDisconnect:
+		w.retrying = false
 		if w.linked {
 			w.connected = false
 			w.noticed = true
 			notice = "WhatsApp is disconnected and does not connect again by itself: " + event.PermanentDisconnectDescription() + ". Restart the daemon to try again."
+			level = slog.LevelError
+			line = "disconnected for good, restart to retry"
+			attrs = append(attrs, "err", whatsappRedact(w.own, event.PermanentDisconnectDescription()))
 		}
 	}
-	w.mutex.Unlock()
-
-	if notice != "" {
-		w.broadcast(notice)
-	}
-
-	return true
-}
-
-// receive puts the text of event into its batch and wakes Run. It returns false
-// when the state file cannot hold the message, so that the library does not
-// acknowledge it, and Run stops the daemon. A message that is not text, or that
-// the batches do not take, is handled with nothing to do.
-func (w *WhatsApp) receive(event *events.Message) bool {
-	ctx, cancel := context.WithTimeout(context.Background(), whatsappLookupTime)
-	defer cancel()
-
-	chat, message, found := w.message(ctx, event)
-	if !found {
-		return true
-	}
-
-	_, err := w.state.Add(chat, message, time.Now())
-	if err != nil {
-		select {
-		case w.failures <- err:
-		default:
-		}
-
-		return false
-	}
 
-	select {
-	case w.wake <- struct{}{}:
-	default:
+	if w.closed {
+		line = ""
 	}
 
-	return true
-}
-
-// message returns the chat and the batch message of event, or false when the
-// batches do not take it. They take the text of a private chat or a group, from
-// another person or from the user. They do not take media, reactions, edits,
-// deletions, view-once and disappearing messages, old history, status
-// broadcasts, channels, and the chat of the user with itself.
-//
-// A mention of the user becomes @you, another mention @NAME when the name is
-// known, and the own number and LID become OWN, so that they never go to the
-// log.
-func (w *WhatsApp) message(ctx context.Context, event *events.Message) (WhatsAppChat, WhatsAppMessage, bool) {
-	w.mutex.Lock()
-	device := w.device
-	own := slices.Clone(w.own)
 	w.mutex.Unlock()
 
-	info := event.Info
-	chatJID := info.Chat.ToNonAD()
-	switch {
-	case device == nil:
-	case event.IsEdit, info.Edit != "", event.IsEphemeral, event.IsViewOnce, event.SourceWebMsg != nil:
-	case chatJID.Server != types.DefaultUserServer && chatJID.Server != types.HiddenUserServer && chatJID.Server != types.GroupServer:
-	case slices.Contains(own, chatJID.User):
-	default:
-		return w.text(ctx, device, own, event)
-	}
-
-	return WhatsAppChat{}, WhatsAppMessage{}, false
-}
-
-// text returns the chat and the batch message of event, a message that the
-// batches take when it has text.
-func (w *WhatsApp) text(ctx context.Context, device *store.Device, own []string, event *events.Message) (WhatsAppChat, WhatsAppMessage, bool) {
-	info := event.Info
-	text := event.Message.GetConversation()
-	extended := event.Message.GetExtendedTextMessage()
-	if text == "" {
-		text = extended.GetText()
-	}
-
-	if strings.TrimSpace(text) == "" {
-		return WhatsAppChat{}, WhatsAppMessage{}, false
+	if line != "" {
+		w.logger.Log(ctx, level, line, attrs...)
 	}
 
-	contextInfo := extended.GetContextInfo()
-	message := WhatsAppMessage{
-		ID:   info.ID,
-		Time: info.Timestamp,
-		Mine: info.IsFromMe,
-	}
-
-	if !message.Mine {
-		message.Sender = whatsappContactName(ctx, device, info.Sender, info.PushName)
-	}
-
-	for _, mentioned := range contextInfo.GetMentionedJID() {
-		jid, err := types.ParseJID(mentioned)
-		switch {
-		case err != nil:
-		case slices.Contains(own, jid.User):
-			message.Mention = true
-			text = strings.ReplaceAll(text, "@"+jid.User, "@you")
-		default:
-			text = strings.ReplaceAll(text, "@"+jid.User, "@"+whatsappContactName(ctx, device, jid, ""))
-		}
-	}
-
-	participant, err := types.ParseJID(contextInfo.GetParticipant())
-	message.Reply = err == nil && slices.Contains(own, participant.User)
-
-	for _, id := range own {
-		text = strings.ReplaceAll(text, id, "OWN")
-	}
-
-	message.Text = text
-	chatJID := info.Chat.ToNonAD()
-	chat := WhatsAppChat{
-		ID:    chatJID.String(),
-		Group: chatJID.Server == types.GroupServer,
-	}
-
-	if !chat.Group {
-		push := info.PushName
-		if message.Mine {
-			push = ""
-		}
-
-		chat.Name = whatsappContactName(ctx, device, chatJID, push)
-	}
-
-	return chat, message, true
-}
-
-// caughtUpBy ends the catch-up of the connection with the number catchups, when
-// no later connection started a new one.
-func (w *WhatsApp) caughtUpBy(catchups int) {
-	w.mutex.Lock()
-	defer w.mutex.Unlock()
-
-	if w.catchups == catchups {
-		w.endCatchup()
-	}
-}
-
-// endCatchup ends a running catch-up and wakes Run, which logs all batches. The
-// caller holds the mutex.
-func (w *WhatsApp) endCatchup() {
-	if !w.catchingUp {
-		return
-	}
-
-	w.catchingUp = false
-	w.caughtUp = true
-	if w.catchupTimer != nil {
-		w.catchupTimer.Stop()
+	if notice != "" {
+		w.broadcast(notice)
 	}
 
-	select {
-	case w.wake <- struct{}{}:
-	default:
-	}
+	return true
 }
 
 // disconnectedLong gives the notice of a long disconnection, unless the
 // disconnection with the number disconnections ended.
 func (w *WhatsApp) disconnectedLong(disconnections int) {
 	w.mutex.Lock()
+
 	long := !w.closed && w.linked && !w.connected && !w.noticed && w.disconnections == disconnections
 	if long {
 		w.noticed = true
@@ -1184,6 +1024,7 @@ func (w *WhatsApp) disconnectedLong(disconnections int) {
 // broadcast gives text as a notice to all clients.
 func (w *WhatsApp) broadcast(text string) {
 	w.mutex.Lock()
+
 	notify := w.notify
 	closed := w.closed
 	w.mutex.Unlock()
@@ -1201,100 +1042,17 @@ func (w *WhatsApp) redact(text string) string {
 	w.mutex.Lock()
 	defer w.mutex.Unlock()
 
-	for _, id := range w.own {
-		text = strings.ReplaceAll(text, id, "OWN")
-	}
-
-	return text
+	return whatsappRedact(w.own, text)
 }
 
-// Send sends text to chat, the ID of a private chat or a group, and returns the
-// answer of the tool. id names the send: a call with an id that has a record
-// gives the answer of the record and sends nothing, and the same id with
-// another chat or text is an error. The record "sending" is durable before the
-// send, so a stop of the daemon during the send gives an answer that the result
-// is unknown, and not a second send. A disconnected WhatsApp sends nothing and
-// makes no record.
-func (w *WhatsApp) Send(ctx context.Context, id, chat, text string) (string, error) {
-	w.mutex.Lock()
-	linked := w.linked
-	device := w.device
-	client := w.client
-	connected := w.connected
-	own := slices.Clone(w.own)
-	w.mutex.Unlock()
-
-	if !linked {
-		return whatsappNotLinked, nil
-	}
-
-	jid, err := whatsappSendCheck(id, chat, text, own)
-	if err != nil {
-		return "", err
-	}
-
-	digest := sha256.Sum256([]byte(text))
-	record := WhatsAppSend{
-		ID:     id,
-		Chat:   chat,
-		Digest: hex.EncodeToString(digest[:]),
-		State:  whatsappSending,
-		Time:   w.clock(),
-	}
-
-	held, found := w.state.Send(id)
-	switch {
-	case found && (held.Chat != record.Chat || held.Digest != record.Digest):
-		return "", fmt.Errorf("the id %s belongs to another message: give a new id for each message", id)
-	case found && held.State == whatsappSending:
-		return "The send with this id started, but its result is unknown, because the daemon stopped during it. Ask the user to look at the chat in WhatsApp before you send the message again with a new id.", nil
-	case found:
-		return held.Answer + " This is the answer of the first call with this id: nothing was sent again.", nil
-	case client == nil || !connected:
-		return "", errors.New("WhatsApp is disconnected, so nothing was sent: try again later")
-	}
-
-	record.MessageID = client.GenerateMessageID()
-	err = w.state.PutSend(record)
-	if err != nil {
-		return "", err
-	}
-
-	sendCtx, cancel := context.WithTimeout(ctx, whatsappSendTime)
-	defer cancel()
-
-	response, err := client.SendMessage(sendCtx, jid, &waE2E.Message{
-		Conversation: new(text),
-	}, whatsmeow.SendRequestExtra{
-		ID: record.MessageID,
-	})
-
-	record.State = whatsappSent
-	if err != nil {
-		record.State = whatsappFailed
-		record.Answer = "The send failed: " + w.redact(err.Error()) + "."
-	} else {
-		name := w.groupName(ctx, jid.String())
-		if jid.Server != types.GroupServer {
-			name = whatsappContactName(ctx, device, jid, "")
-		}
-
-		record.Answer = "Sent to " + name + " at " + response.Timestamp.In(w.clock().Location()).Format("15:04") + "."
-	}
-
-	err = w.state.PutSend(record)
-	if err != nil {
-		return "", err
-	}
-
-	return record.Answer, nil
-}
-
-// WhatsAppMatch is one contact or group of Find.
-type WhatsAppMatch struct {
-	id   string
-	name string
-	kind string
+// WhatsAppLink is a copy of the link of the device at one time, for the parts
+// of WhatsApp that do not own it: the groups, the batches, find, and send.
+type WhatsAppLink struct {
+	linked    bool
+	device    *store.Device
+	client    WhatsAppClient
+	connected bool
+	own       []string
 }
 
 // WhatsAppRequest is a pair or unlink command for Run, with the function that
@@ -1305,14 +1063,24 @@ type WhatsAppRequest struct {
 	answer func(text string)
 }
 
+// whatsappSetDeviceProps sets the device properties that the library sends at
+// the pairing. They are global values of the library, so the daemon sets them
+// once before any client exists. The phone shows the linked device with the
+// name OneChat and a desktop icon only when the platform type is known.
+func whatsappSetDeviceProps() {
+	store.SetOSInfo("OneChat", [3]uint32{0, 1, 0})
+
+	store.DeviceProps.PlatformType = waCompanionReg.DeviceProps_DESKTOP.Enum()
+}
+
 // whatsappNewClient returns the client of the library for device, with handle
-// as its event handler. The client tries again after a failed first connection,
-// acknowledges a message only after handle returns true, and downloads no old
-// history. The phone shows the device with the name OneChat.
+// as its event handler. Run owns failed starting connections of linked devices,
+// so only an unlinked device enables the initial retry of the library for
+// pairing. The library still retries a lost connection. The client acknowledges
+// a message only after handle returns true, and downloads no old history.
 func whatsappNewClient(device *store.Device, handle func(event any) bool) WhatsAppClient {
-	store.SetOSInfo("OneChat", [3]uint32{0, 1, 0})
 	client := whatsmeow.NewClient(device, waLog.Noop)
-	client.InitialAutoReconnect = true
+	client.InitialAutoReconnect = device.ID == nil
 	client.SynchronousAck = true
 	client.ManualHistorySyncDownload = true
 	client.AddEventHandlerWithSuccessStatus(handle)
@@ -1362,68 +1130,10 @@ func whatsappContactName(ctx context.Context, device *store.Device, jid types.JI
 	}
 }
 
-// whatsappFold returns text in lower case with no accents and no space at its
-// ends, so that names match with no regard to case and accents.
-func whatsappFold(text string) string {
-	folded, _, err := transform.String(transform.Chain(norm.NFD, runes.Remove(runes.In(unicode.Mn)), norm.NFC), text)
-	if err != nil {
-		folded = text
-	}
-
-	return strings.ToLower(strings.TrimSpace(folded))
-}
-
-// whatsappFindAnswer returns the answer of Find for name with matches. Without
-// groups, the answer says that it has no groups.
-func whatsappFindAnswer(name string, matches []WhatsAppMatch, groups bool) string {
-	slices.SortFunc(matches, func(a, b WhatsAppMatch) int {
-		return cmp.Or(strings.Compare(whatsappFold(a.name), whatsappFold(b.name)), strings.Compare(a.id, b.id))
-	})
-
-	var lines []string
-	for _, match := range matches[:min(len(matches), whatsappFindMatches)] {
-		lines = append(lines, match.id+" | "+match.name+" | "+match.kind)
-	}
-
-	if len(matches) == 0 {
-		lines = append(lines, "No contact or group has a name with \""+name+"\".")
-	}
-
-	if len(matches) > whatsappFindMatches {
-		lines = append(lines, fmt.Sprintf("%d more: give a longer part of the name.", len(matches)-whatsappFindMatches))
-	}
-
-	if !groups {
-		lines = append(lines, "The groups are not in this answer, because WhatsApp is disconnected.")
-	}
-
-	return strings.Join(lines, "\n")
-}
-
-// whatsappSendCheck returns the JID of chat, and an error when id, chat, or
-// text cannot go to a send. The chat is a private chat or a group, and not the
-// chat of the user with itself.
-func whatsappSendCheck(id, chat, text string, own []string) (types.JID, error) {
-	jid, err := types.ParseJID(chat)
-	switch {
-	case strings.TrimSpace(id) == "" || len(id) > whatsappSendIDBytes:
-		return types.EmptyJID, fmt.Errorf("the id must have 1 to %d bytes", whatsappSendIDBytes)
-	case strings.TrimSpace(text) == "" || len(text) > whatsappSendBytes:
-		return types.EmptyJID, fmt.Errorf("the text must have 1 to %d bytes", whatsappSendBytes)
-	case err != nil || jid.User == "" || jid != jid.ToNonAD() || jid.String() != chat:
-		return types.EmptyJID, fmt.Errorf("%q is not the ID of a WhatsApp chat: find the ID with whatsapp_find", chat)
-	case jid.Server != types.DefaultUserServer && jid.Server != types.HiddenUserServer && jid.Server != types.GroupServer:
-		return types.EmptyJID, fmt.Errorf("%q is not a private chat or a group", chat)
-	case slices.Contains(own, jid.User):
-		return types.EmptyJID, errors.New("this is the chat of the user with itself: send to another chat")
-	}
-
-	return jid, nil
-}
-
 // whatsappOwnIDs returns the own number and the own LID that are not empty.
 func whatsappOwnIDs(ids ...string) []string {
 	var own []string
+
 	for _, id := range ids {
 		if id != "" {
 			own = append(own, id)
@@ -1433,6 +1143,15 @@ func whatsappOwnIDs(ids ...string) []string {
 	return own
 }
 
+// whatsappRedact replaces each of the own IDs own in text with OWN.
+func whatsappRedact(own []string, text string) string {
+	for _, id := range own {
+		text = strings.ReplaceAll(text, id, "OWN")
+	}
+
+	return text
+}
+
 // whatsappSessionAddress returns the SQLite address of the session database at
 // path, with foreign keys on, as the library needs, and a wait for a busy
 // database.