feat(wecom): send media via temp uploads

pkg/channels/wecom/media.go

@@ -4,7 +4,10 @@ import (
 	"context"
 	"crypto/aes"
 	"crypto/cipher"
+	"crypto/md5"
 	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
 	"fmt"
 	"io"
 	"mime"
@@ -13,12 +16,73 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
+	"time"
 
 	"github.com/h2non/filetype"
 
+	"github.com/sipeed/picoclaw/pkg/bus"
 	"github.com/sipeed/picoclaw/pkg/media"
 )
 
+const (
+	wecomOutboundMediaMaxBytes = 20 << 20
+	wecomOutboundImageMaxBytes = 2 << 20
+	wecomOutboundVoiceMaxBytes = 2 << 20
+	wecomOutboundVideoMaxBytes = 10 << 20
+	wecomUploadChunkMaxBytes   = 512 << 10
+	wecomUploadMaxChunks       = 100
+	wecomUploadMinBytes        = 5
+)
+
+type wecomOutboundMedia struct {
+	MsgType     string
+	MediaID     string
+	Title       string
+	Description string
+}
+
+func (m *wecomOutboundMedia) respondBody() wecomRespondMsgBody {
+	body := wecomRespondMsgBody{MsgType: m.MsgType}
+	switch m.MsgType {
+	case "file":
+		body.File = &wecomMediaRefContent{MediaID: m.MediaID}
+	case "image":
+		body.Image = &wecomMediaRefContent{MediaID: m.MediaID}
+	case "voice":
+		body.Voice = &wecomMediaRefContent{MediaID: m.MediaID}
+	case "video":
+		body.Video = &wecomVideoContent{
+			MediaID:     m.MediaID,
+			Title:       m.Title,
+			Description: m.Description,
+		}
+	}
+	return body
+}
+
+func (m *wecomOutboundMedia) sendBody(chatID string, chatType uint32) wecomSendMsgBody {
+	body := wecomSendMsgBody{
+		ChatID:   chatID,
+		ChatType: chatType,
+		MsgType:  m.MsgType,
+	}
+	switch m.MsgType {
+	case "file":
+		body.File = &wecomMediaRefContent{MediaID: m.MediaID}
+	case "image":
+		body.Image = &wecomMediaRefContent{MediaID: m.MediaID}
+	case "voice":
+		body.Voice = &wecomMediaRefContent{MediaID: m.MediaID}
+	case "video":
+		body.Video = &wecomVideoContent{
+			MediaID:     m.MediaID,
+			Title:       m.Title,
+			Description: m.Description,
+		}
+	}
+	return body
+}
+
 func decodeMediaAESKey(value string) ([]byte, error) {
 	if value == "" {
 		return nil, nil
@@ -227,12 +291,11 @@ func (c *WeComChannel) storeRemoteMedia(
 		return "", fmt.Errorf("download media returned HTTP %d", resp.StatusCode)
 	}
 
-	const maxSize = 20 << 20
+	data, err := io.ReadAll(io.LimitReader(resp.Body, wecomOutboundMediaMaxBytes+1))
-	data, err := io.ReadAll(io.LimitReader(resp.Body, maxSize+1))
 	if err != nil {
 		return "", fmt.Errorf("read media: %w", err)
 	}
-	if len(data) > maxSize {
+	if len(data) > wecomOutboundMediaMaxBytes {
 		return "", fmt.Errorf("media too large")
 	}
 
@@ -289,3 +352,447 @@ func (c *WeComChannel) storeRemoteMedia(
 	}
 	return ref, nil
 }
+
+func detectLocalWeComContentType(localPath, hint string) string {
+	contentType := normalizeWeComContentType(hint)
+	if !isGenericWeComContentType(contentType) {
+		return contentType
+	}
+
+	if kind, err := filetype.MatchFile(localPath); err == nil && kind != filetype.Unknown {
+		return normalizeWeComContentType(kind.MIME.Value)
+	}
+
+	if ext := strings.ToLower(filepath.Ext(localPath)); ext != "" {
+		if byExt := normalizeWeComContentType(mime.TypeByExtension(ext)); byExt != "" {
+			return byExt
+		}
+	}
+
+	file, err := os.Open(localPath)
+	if err != nil {
+		return contentType
+	}
+	defer file.Close()
+
+	buf := make([]byte, 512)
+	n, err := file.Read(buf)
+	if err != nil && err != io.EOF {
+		return contentType
+	}
+	if n == 0 {
+		return contentType
+	}
+	return normalizeWeComContentType(http.DetectContentType(buf[:n]))
+}
+
+func writeWeComTempFile(prefix, filename string, data []byte) (string, error) {
+	mediaDir := filepath.Join(os.TempDir(), "picoclaw_media")
+	if err := os.MkdirAll(mediaDir, 0o700); err != nil {
+		return "", fmt.Errorf("mkdir media dir: %w", err)
+	}
+
+	ext := strings.ToLower(filepath.Ext(filename))
+	tmpFile, err := os.CreateTemp(mediaDir, prefix+"-*"+ext)
+	if err != nil {
+		return "", fmt.Errorf("create temp file: %w", err)
+	}
+	tmpPath := tmpFile.Name()
+
+	if _, err := tmpFile.Write(data); err != nil {
+		_ = tmpFile.Close()
+		_ = os.Remove(tmpPath)
+		return "", fmt.Errorf("write temp file: %w", err)
+	}
+	if err := tmpFile.Close(); err != nil {
+		_ = os.Remove(tmpPath)
+		return "", fmt.Errorf("close temp file: %w", err)
+	}
+	return tmpPath, nil
+}
+
+func (c *WeComChannel) downloadRemoteMediaToTemp(
+	ctx context.Context,
+	resourceURL, fallbackName string,
+) (string, string, string, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, resourceURL, nil)
+	if err != nil {
+		return "", "", "", fmt.Errorf("create request: %w", err)
+	}
+
+	resp, err := c.mediaClient.Do(req)
+	if err != nil {
+		return "", "", "", fmt.Errorf("download media: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		body, _ := io.ReadAll(io.LimitReader(resp.Body, 1024))
+		return "", "", "", fmt.Errorf("download media returned HTTP %d: %s", resp.StatusCode, string(body))
+	}
+
+	data, err := io.ReadAll(io.LimitReader(resp.Body, wecomOutboundMediaMaxBytes+1))
+	if err != nil {
+		return "", "", "", fmt.Errorf("read media: %w", err)
+	}
+	if len(data) > wecomOutboundMediaMaxBytes {
+		return "", "", "", fmt.Errorf("media too large")
+	}
+
+	filename, contentType := detectWeComMediaMetadata(
+		data,
+		fallbackName,
+		resp.Header.Get("Content-Type"),
+		resourceURL,
+		resp.Header.Get("Content-Disposition"),
+	)
+	tmpPath, err := writeWeComTempFile("wecom-outbound", filename, data)
+	if err != nil {
+		return "", "", "", err
+	}
+	return tmpPath, filename, contentType, nil
+}
+
+func (c *WeComChannel) resolveOutboundPart(
+	ctx context.Context,
+	part bus.MediaPart,
+) (string, string, string, func(), error) {
+	cleanup := func() {}
+	filename := sanitizeWeComFilename(part.Filename)
+	contentType := normalizeWeComContentType(part.ContentType)
+	ref := strings.TrimSpace(part.Ref)
+
+	switch {
+	case ref == "":
+		return "", filename, contentType, cleanup, nil
+
+	case strings.HasPrefix(ref, "http://") || strings.HasPrefix(ref, "https://"):
+		localPath, name, ct, err := c.downloadRemoteMediaToTemp(ctx, ref, filename)
+		if err != nil {
+			return "", "", "", cleanup, err
+		}
+		return localPath, name, ct, func() { _ = os.Remove(localPath) }, nil
+
+	case strings.HasPrefix(ref, "media://"):
+		store := c.GetMediaStore()
+		if store == nil {
+			return "", "", "", cleanup, fmt.Errorf("no media store available")
+		}
+
+		localPath, meta, err := store.ResolveWithMeta(ref)
+		if err != nil {
+			return "", "", "", cleanup, err
+		}
+		if filename == "" {
+			filename = sanitizeWeComFilename(meta.Filename)
+		}
+		if contentType == "" {
+			contentType = normalizeWeComContentType(meta.ContentType)
+		}
+		if strings.HasPrefix(localPath, "http://") || strings.HasPrefix(localPath, "https://") {
+			tmpPath, name, ct, err := c.downloadRemoteMediaToTemp(ctx, localPath, filename)
+			if err != nil {
+				return "", "", "", cleanup, err
+			}
+			return tmpPath, name, ct, func() { _ = os.Remove(tmpPath) }, nil
+		}
+		if _, err := os.Stat(localPath); err != nil {
+			return "", "", "", cleanup, err
+		}
+		if filename == "" {
+			filename = sanitizeWeComFilename(filepath.Base(localPath))
+		}
+		if contentType == "" {
+			contentType = detectLocalWeComContentType(localPath, "")
+		}
+		return localPath, filename, contentType, cleanup, nil
+
+	case strings.HasPrefix(ref, "file://"):
+		u, err := url.Parse(ref)
+		if err != nil {
+			return "", "", "", cleanup, err
+		}
+		localPath := u.Path
+		if _, err := os.Stat(localPath); err != nil {
+			return "", "", "", cleanup, err
+		}
+		if filename == "" {
+			filename = sanitizeWeComFilename(filepath.Base(localPath))
+		}
+		if contentType == "" {
+			contentType = detectLocalWeComContentType(localPath, "")
+		}
+		return localPath, filename, contentType, cleanup, nil
+
+	default:
+		if _, err := os.Stat(ref); err != nil {
+			return "", "", "", cleanup, err
+		}
+		if filename == "" {
+			filename = sanitizeWeComFilename(filepath.Base(ref))
+		}
+		if contentType == "" {
+			contentType = detectLocalWeComContentType(ref, "")
+		}
+		return ref, filename, contentType, cleanup, nil
+	}
+}
+
+func canWeComSendImage(contentType, ext string, size int64) bool {
+	if size > wecomOutboundImageMaxBytes {
+		return false
+	}
+	switch normalizeWeComContentType(contentType) {
+	case "image/jpeg", "image/jpg", "image/png", "image/gif":
+		return true
+	}
+	switch strings.ToLower(ext) {
+	case ".jpg", ".jpeg", ".png", ".gif":
+		return true
+	default:
+		return false
+	}
+}
+
+func canWeComSendVoice(contentType, ext string, size int64) bool {
+	if size > wecomOutboundVoiceMaxBytes {
+		return false
+	}
+	contentType = normalizeWeComContentType(contentType)
+	return strings.Contains(contentType, "amr") || strings.EqualFold(ext, ".amr")
+}
+
+func canWeComSendVideo(contentType, ext string, size int64) bool {
+	if size > wecomOutboundVideoMaxBytes {
+		return false
+	}
+	return normalizeWeComContentType(contentType) == "video/mp4" || strings.EqualFold(ext, ".mp4")
+}
+
+func outboundWeComMediaKind(partType, filename, contentType string, size int64) string {
+	if size < wecomUploadMinBytes {
+		return ""
+	}
+
+	partType = strings.ToLower(strings.TrimSpace(partType))
+	contentType = normalizeWeComContentType(contentType)
+	ext := strings.ToLower(filepath.Ext(filename))
+
+	if partType == "file" {
+		if size <= wecomOutboundMediaMaxBytes {
+			return "file"
+		}
+		return ""
+	}
+
+	if (partType == "image" || partType == "") && canWeComSendImage(contentType, ext, size) {
+		return "image"
+	}
+	if (partType == "audio" || partType == "voice" || partType == "") && canWeComSendVoice(contentType, ext, size) {
+		return "voice"
+	}
+	if (partType == "video" || partType == "") && canWeComSendVideo(contentType, ext, size) {
+		return "video"
+	}
+	if size <= wecomOutboundMediaMaxBytes {
+		return "file"
+	}
+	return ""
+}
+
+func trimWeComBytes(value string, limit int) string {
+	value = strings.TrimSpace(value)
+	if limit <= 0 || len(value) <= limit {
+		return value
+	}
+	size := 0
+	var out strings.Builder
+	for _, r := range value {
+		width := len(string(r))
+		if size+width > limit {
+			break
+		}
+		size += width
+		out.WriteRune(r)
+	}
+	return out.String()
+}
+
+func ensureWeComOutboundFilename(filename, localPath, contentType string) string {
+	filename = sanitizeWeComFilename(filename)
+	if filename == "" {
+		filename = sanitizeWeComFilename(filepath.Base(localPath))
+	}
+	if filename == "" {
+		filename = "media"
+	}
+	if filepath.Ext(filename) == "" {
+		fallbackExt := inferMediaExt(contentType, strings.ToLower(filepath.Ext(localPath)))
+		if fallbackExt != "" {
+			filename += fallbackExt
+		}
+	}
+	filename = trimWeComBytes(filename, 256)
+	if filename == "" {
+		return "media"
+	}
+	return filename
+}
+
+func buildWeComVideoContent(mediaID, filename, description string) *wecomVideoContent {
+	title := strings.TrimSuffix(filename, filepath.Ext(filename))
+	title = trimWeComBytes(title, 64)
+	if title == "" {
+		title = "video"
+	}
+	description = trimWeComBytes(description, 512)
+	return &wecomVideoContent{
+		MediaID:     mediaID,
+		Title:       title,
+		Description: description,
+	}
+}
+
+func decodeWeComEnvelopeBody[T any](env wecomEnvelope) (T, error) {
+	var out T
+	if len(env.Body) == 0 {
+		return out, fmt.Errorf("wecom response body is empty")
+	}
+	if err := json.Unmarshal(env.Body, &out); err != nil {
+		return out, fmt.Errorf("decode wecom response body: %w", err)
+	}
+	return out, nil
+}
+
+func (c *WeComChannel) uploadOutboundMedia(
+	ctx context.Context,
+	localPath, filename, contentType string,
+	part bus.MediaPart,
+) (*wecomOutboundMedia, error) {
+	_ = ctx
+
+	contentType = detectLocalWeComContentType(localPath, contentType)
+	filename = ensureWeComOutboundFilename(filename, localPath, contentType)
+
+	data, err := os.ReadFile(localPath)
+	if err != nil {
+		return nil, fmt.Errorf("read media file: %w", err)
+	}
+	size := int64(len(data))
+	kind := outboundWeComMediaKind(part.Type, filename, contentType, size)
+	if kind == "" {
+		return nil, fmt.Errorf("unsupported wecom media type or size for %q", filename)
+	}
+
+	totalChunks := (len(data) + wecomUploadChunkMaxBytes - 1) / wecomUploadChunkMaxBytes
+	if totalChunks <= 0 || totalChunks > wecomUploadMaxChunks {
+		return nil, fmt.Errorf("wecom upload requires 1-%d chunks, got %d", wecomUploadMaxChunks, totalChunks)
+	}
+
+	sum := md5.Sum(data)
+	initEnv, err := c.sendCommandAck(wecomCommand{
+		Cmd:     wecomCmdUploadMediaInit,
+		Headers: wecomHeaders{ReqID: randomID(10)},
+		Body: wecomUploadMediaInitBody{
+			Type:        kind,
+			Filename:    filename,
+			TotalSize:   size,
+			TotalChunks: totalChunks,
+			MD5:         hex.EncodeToString(sum[:]),
+		},
+	}, wecomUploadTimeout)
+	if err != nil {
+		return nil, err
+	}
+	initResp, err := decodeWeComEnvelopeBody[wecomUploadMediaInitResponse](initEnv)
+	if err != nil {
+		return nil, err
+	}
+	if strings.TrimSpace(initResp.UploadID) == "" {
+		return nil, fmt.Errorf("wecom upload init returned empty upload_id")
+	}
+
+	for idx, offset := 0, 0; offset < len(data); idx, offset = idx+1, offset+wecomUploadChunkMaxBytes {
+		end := offset + wecomUploadChunkMaxBytes
+		if end > len(data) {
+			end = len(data)
+		}
+		if err := c.sendCommand(wecomCommand{
+			Cmd:     wecomCmdUploadMediaChunk,
+			Headers: wecomHeaders{ReqID: randomID(10)},
+			Body: wecomUploadMediaChunkBody{
+				UploadID:   initResp.UploadID,
+				ChunkIndex: idx,
+				Base64Data: base64.StdEncoding.EncodeToString(data[offset:end]),
+			},
+		}, wecomUploadTimeout); err != nil {
+			return nil, err
+		}
+	}
+
+	finishEnv, err := c.sendCommandAck(wecomCommand{
+		Cmd:     wecomCmdUploadMediaEnd,
+		Headers: wecomHeaders{ReqID: randomID(10)},
+		Body: wecomUploadMediaFinishBody{
+			UploadID: initResp.UploadID,
+		},
+	}, wecomUploadTimeout)
+	if err != nil {
+		return nil, err
+	}
+	finishResp, err := decodeWeComEnvelopeBody[wecomUploadMediaFinishResponse](finishEnv)
+	if err != nil {
+		return nil, err
+	}
+	if strings.TrimSpace(finishResp.MediaID) == "" {
+		return nil, fmt.Errorf("wecom upload finish returned empty media_id")
+	}
+
+	uploaded := &wecomOutboundMedia{
+		MsgType: kind,
+		MediaID: finishResp.MediaID,
+	}
+	if kind == "video" {
+		video := buildWeComVideoContent(finishResp.MediaID, filename, part.Caption)
+		uploaded.Title = video.Title
+		uploaded.Description = video.Description
+	}
+	return uploaded, nil
+}
+
+func fallbackWeComMediaText(part bus.MediaPart, kind, filename string) string {
+	var lines []string
+	if caption := strings.TrimSpace(part.Caption); caption != "" {
+		lines = append(lines, caption)
+	}
+
+	label := kind
+	if label == "" {
+		label = "media"
+	}
+	if filename != "" {
+		lines = append(lines, fmt.Sprintf("[%s: %s]", label, filename))
+	} else {
+		lines = append(lines, fmt.Sprintf("[%s attachment]", label))
+	}
+
+	ref := strings.TrimSpace(part.Ref)
+	if strings.HasPrefix(ref, "http://") || strings.HasPrefix(ref, "https://") {
+		lines = append(lines, ref)
+	}
+
+	return strings.Join(lines, "\n")
+}
+
+func (c *WeComChannel) resolveMediaRoute(chatID string) (wecomTurn, uint32, bool) {
+	if turn, ok := c.getTurn(chatID); ok {
+		if time.Since(turn.CreatedAt) <= wecomStreamMaxDuration {
+			return turn, turn.ChatType, true
+		}
+		c.deleteTurn(chatID)
+	}
+	if route, ok := c.routes.Get(chatID); ok {
+		return wecomTurn{ChatID: route.ChatID, ChatType: route.ChatType}, route.ChatType, false
+	}
+	return wecomTurn{ChatID: chatID}, 0, false
+}

pkg/channels/wecom/protocol.go

@@ -10,6 +10,9 @@ const (
 	wecomCmdEventCallback    = "aibot_event_callback"
 	wecomCmdRespondMsg       = "aibot_respond_msg"
 	wecomCmdSendMsg          = "aibot_send_msg"
+	wecomCmdUploadMediaInit  = "aibot_upload_media_init"
+	wecomCmdUploadMediaChunk = "aibot_upload_media_chunk"
+	wecomCmdUploadMediaEnd   = "aibot_upload_media_finish"
 	wecomMaxContentBytes     = 20480
 )
 
@@ -32,15 +35,26 @@ type wecomCommand struct {
 }
 
 type wecomSendMsgBody struct {
-	ChatID   string                `json:"chatid"`
+	ChatID       string                `json:"chatid"`
-	ChatType uint32                `json:"chat_type,omitempty"`
+	ChatType     uint32                `json:"chat_type,omitempty"`
-	MsgType  string                `json:"msgtype"`
+	MsgType      string                `json:"msgtype"`
-	Markdown *wecomMarkdownContent `json:"markdown,omitempty"`
+	Markdown     *wecomMarkdownContent `json:"markdown,omitempty"`
+	File         *wecomMediaRefContent `json:"file,omitempty"`
+	Image        *wecomMediaRefContent `json:"image,omitempty"`
+	Voice        *wecomMediaRefContent `json:"voice,omitempty"`
+	Video        *wecomVideoContent    `json:"video,omitempty"`
+	TemplateCard map[string]any        `json:"template_card,omitempty"`
 }
 
 type wecomRespondMsgBody struct {
-	MsgType string              `json:"msgtype"`
+	MsgType      string                `json:"msgtype"`
-	Stream  *wecomStreamContent `json:"stream,omitempty"`
+	Stream       *wecomStreamContent   `json:"stream,omitempty"`
+	Markdown     *wecomMarkdownContent `json:"markdown,omitempty"`
+	File         *wecomMediaRefContent `json:"file,omitempty"`
+	Image        *wecomMediaRefContent `json:"image,omitempty"`
+	Voice        *wecomMediaRefContent `json:"voice,omitempty"`
+	Video        *wecomVideoContent    `json:"video,omitempty"`
+	TemplateCard map[string]any        `json:"template_card,omitempty"`
 }
 
 type wecomStreamContent struct {
@@ -53,6 +67,44 @@ type wecomMarkdownContent struct {
 	Content string `json:"content"`
 }
 
+type wecomMediaRefContent struct {
+	MediaID string `json:"media_id"`
+}
+
+type wecomVideoContent struct {
+	MediaID     string `json:"media_id"`
+	Title       string `json:"title,omitempty"`
+	Description string `json:"description,omitempty"`
+}
+
+type wecomUploadMediaInitBody struct {
+	Type        string `json:"type"`
+	Filename    string `json:"filename"`
+	TotalSize   int64  `json:"total_size"`
+	TotalChunks int    `json:"total_chunks"`
+	MD5         string `json:"md5,omitempty"`
+}
+
+type wecomUploadMediaInitResponse struct {
+	UploadID string `json:"upload_id"`
+}
+
+type wecomUploadMediaChunkBody struct {
+	UploadID   string `json:"upload_id"`
+	ChunkIndex int    `json:"chunk_index"`
+	Base64Data string `json:"base64_data"`
+}
+
+type wecomUploadMediaFinishBody struct {
+	UploadID string `json:"upload_id"`
+}
+
+type wecomUploadMediaFinishResponse struct {
+	Type      string          `json:"type"`
+	MediaID   string          `json:"media_id"`
+	CreatedAt json.RawMessage `json:"created_at"`
+}
+
 type wecomIncomingMessage struct {
 	MsgID    string `json:"msgid"`
 	AIBotID  string `json:"aibotid"`

pkg/channels/wecom/wecom.go

@@ -23,6 +23,7 @@ import (
 const (
 	wecomConnectTimeout    = 15 * time.Second
 	wecomCommandTimeout    = 10 * time.Second
+	wecomUploadTimeout     = 30 * time.Second
 	wecomHeartbeatInterval = 30 * time.Second
 	wecomStreamMaxDuration = 5*time.Minute + 30*time.Second
 	wecomRouteTTL          = 30 * time.Minute
@@ -49,7 +50,7 @@ type WeComChannel struct {
 	recent      *recentMessageSet
 	routes      *reqIDStore
 	mediaClient *http.Client
-	commandSend func(wecomCommand, time.Duration) error
+	commandSend func(wecomCommand, time.Duration) (wecomEnvelope, error)
 }
 
 type wecomTurn struct {
@@ -187,22 +188,74 @@ func (c *WeComChannel) SendMedia(ctx context.Context, msg bus.OutboundMediaMessa
 	if !c.IsRunning() {
 		return channels.ErrNotRunning
 	}
-	var parts []string
+
+	route, chatType, hasTurn := c.resolveMediaRoute(msg.ChatID)
+	chatID := route.ChatID
+	if chatID == "" {
+		chatID = msg.ChatID
+	}
+
 	for _, part := range msg.Parts {
-		switch {
+		if strings.TrimSpace(part.Ref) == "" {
-		case part.Caption != "":
+			if caption := strings.TrimSpace(part.Caption); caption != "" {
-			parts = append(parts, part.Caption)
+				if err := c.sendActivePush(chatID, chatType, caption); err != nil {
-		case part.Filename != "":
+					return err
-			parts = append(parts, fmt.Sprintf("[media: %s]", part.Filename))
+				}
-		default:
+			}
-			parts = append(parts, "[media attachments are not yet supported]")
+			continue
+		}
+
+		localPath, filename, contentType, cleanup, err := c.resolveOutboundPart(ctx, part)
+		if err != nil {
+			return fmt.Errorf("wecom resolve media %q: %v: %w", part.Ref, err, channels.ErrSendFailed)
+		}
+
+		func() {
+			if cleanup != nil {
+				defer cleanup()
+			}
+
+			uploaded, uploadErr := c.uploadOutboundMedia(ctx, localPath, filename, contentType, part)
+			if uploadErr != nil {
+				logger.WarnCF("wecom", "Falling back to placeholder after media upload failure", map[string]any{
+					"chat_id":      chatID,
+					"ref":          part.Ref,
+					"filename":     filename,
+					"content_type": contentType,
+					"error":        uploadErr.Error(),
+				})
+				if hasTurn {
+					if finishErr := c.sendStreamChunk(route, true, ""); finishErr != nil {
+						err = finishErr
+						return
+					}
+					c.deleteTurn(msg.ChatID)
+					hasTurn = false
+				}
+				err = c.sendActivePush(chatID, chatType, fallbackWeComMediaText(part, "", filename))
+				return
+			}
+
+			if hasTurn {
+				err = c.sendTurnMedia(route, uploaded)
+				c.deleteTurn(msg.ChatID)
+				hasTurn = false
+			} else {
+				err = c.sendActiveMedia(chatID, chatType, uploaded)
+			}
+			if err != nil {
+				return
+			}
+			if caption := strings.TrimSpace(part.Caption); caption != "" {
+				err = c.sendActivePush(chatID, chatType, caption)
+			}
+		}()
+		if err != nil {
+			return err
 		}
 	}
-	return c.Send(ctx, bus.OutboundMessage{
+
-		Channel: msg.Channel,
+	return nil
-		ChatID:  msg.ChatID,
-		Content: strings.Join(parts, "\n"),
-	})
 }
 
 func (c *WeComChannel) connectLoop() {
@@ -620,6 +673,20 @@ func (c *WeComChannel) sendStreamChunk(turn wecomTurn, finish bool, content stri
 	}, wecomCommandTimeout)
 }
 
+func (c *WeComChannel) sendTurnMedia(turn wecomTurn, uploaded *wecomOutboundMedia) error {
+	if uploaded == nil {
+		return fmt.Errorf("wecom outbound media is nil: %w", channels.ErrSendFailed)
+	}
+	if err := c.sendCommand(wecomCommand{
+		Cmd:     wecomCmdRespondMsg,
+		Headers: wecomHeaders{ReqID: turn.ReqID},
+		Body:    uploaded.respondBody(),
+	}, wecomCommandTimeout); err != nil {
+		return err
+	}
+	return c.sendStreamChunk(turn, true, "")
+}
+
 func (c *WeComChannel) sendActivePush(chatID string, chatType uint32, content string) error {
 	if strings.TrimSpace(chatID) == "" {
 		return fmt.Errorf("empty chat ID: %w", channels.ErrSendFailed)
@@ -641,24 +708,57 @@ func (c *WeComChannel) sendActivePush(chatID string, chatType uint32, content st
 	return nil
 }
 
+func (c *WeComChannel) sendActiveMedia(chatID string, chatType uint32, uploaded *wecomOutboundMedia) error {
+	if strings.TrimSpace(chatID) == "" {
+		return fmt.Errorf("empty chat ID: %w", channels.ErrSendFailed)
+	}
+	if uploaded == nil {
+		return fmt.Errorf("wecom outbound media is nil: %w", channels.ErrSendFailed)
+	}
+	return c.sendCommand(wecomCommand{
+		Cmd:     wecomCmdSendMsg,
+		Headers: wecomHeaders{ReqID: randomID(10)},
+		Body:    uploaded.sendBody(chatID, chatType),
+	}, wecomCommandTimeout)
+}
+
 func (c *WeComChannel) sendCommand(cmd wecomCommand, timeout time.Duration) error {
+	_, err := c.sendCommandAck(cmd, timeout)
+	return err
+}
+
+func (c *WeComChannel) sendCommandAck(cmd wecomCommand, timeout time.Duration) (wecomEnvelope, error) {
 	if c.commandSend != nil {
 		return c.commandSend(cmd, timeout)
 	}
-	return c.writeCurrent(cmd, timeout)
+	return c.writeCurrentAck(cmd, timeout)
 }
 
 func (c *WeComChannel) writeCurrent(cmd wecomCommand, timeout time.Duration) error {
+	_, err := c.writeCurrentAck(cmd, timeout)
+	return err
+}
+
+func (c *WeComChannel) writeCurrentAck(cmd wecomCommand, timeout time.Duration) (wecomEnvelope, error) {
 	c.connMu.Lock()
 	conn := c.conn
 	c.connMu.Unlock()
 	if conn == nil {
-		return fmt.Errorf("wecom websocket not connected: %w", channels.ErrTemporary)
+		return wecomEnvelope{}, fmt.Errorf("wecom websocket not connected: %w", channels.ErrTemporary)
 	}
-	return c.writeAndWait(conn, cmd, timeout)
+	return c.writeAndWaitAck(conn, cmd, timeout)
 }
 
 func (c *WeComChannel) writeAndWait(conn *websocket.Conn, cmd wecomCommand, timeout time.Duration) error {
+	_, err := c.writeAndWaitAck(conn, cmd, timeout)
+	return err
+}
+
+func (c *WeComChannel) writeAndWaitAck(
+	conn *websocket.Conn,
+	cmd wecomCommand,
+	timeout time.Duration,
+) (wecomEnvelope, error) {
 	if cmd.Headers.ReqID == "" {
 		cmd.Headers.ReqID = randomID(10)
 	}
@@ -674,13 +774,13 @@ func (c *WeComChannel) writeAndWait(conn *websocket.Conn, cmd wecomCommand, time
 
 	data, err := json.Marshal(cmd)
 	if err != nil {
-		return fmt.Errorf("%w: %v", channels.ErrSendFailed, err)
+		return wecomEnvelope{}, fmt.Errorf("%w: %v", channels.ErrSendFailed, err)
 	}
 	c.connMu.Lock()
 	err = conn.WriteMessage(websocket.TextMessage, data)
 	c.connMu.Unlock()
 	if err != nil {
-		return fmt.Errorf("%w: %v", channels.ErrTemporary, err)
+		return wecomEnvelope{}, fmt.Errorf("%w: %v", channels.ErrTemporary, err)
 	}
 
 	timer := time.NewTimer(timeout)
@@ -688,13 +788,13 @@ func (c *WeComChannel) writeAndWait(conn *websocket.Conn, cmd wecomCommand, time
 	select {
 	case env := <-waitCh:
 		if env.ErrCode != 0 {
-			return fmt.Errorf("%w: wecom errcode=%d errmsg=%s", channels.ErrTemporary, env.ErrCode, env.ErrMsg)
+			return wecomEnvelope{}, fmt.Errorf("%w: wecom errcode=%d errmsg=%s", channels.ErrTemporary, env.ErrCode, env.ErrMsg)
 		}
-		return nil
+		return env, nil
 	case <-timer.C:
-		return fmt.Errorf("%w: timeout waiting for WeCom ack", channels.ErrTemporary)
+		return wecomEnvelope{}, fmt.Errorf("%w: timeout waiting for WeCom ack", channels.ErrTemporary)
 	case <-c.ctx.Done():
-		return c.ctx.Err()
+		return wecomEnvelope{}, c.ctx.Err()
 	}
 }
 

pkg/channels/wecom/wecom_test.go

@@ -2,13 +2,16 @@ package wecom
 
 import (
 	"context"
+	"encoding/json"
 	"errors"
+	"os"
 	"path/filepath"
 	"testing"
 	"time"
 
 	"github.com/sipeed/picoclaw/pkg/bus"
 	"github.com/sipeed/picoclaw/pkg/config"
+	"github.com/sipeed/picoclaw/pkg/media"
 )
 
 func TestDispatchIncoming_UsesActualChatIDAndStoresReqIDRoute(t *testing.T) {
@@ -18,9 +21,9 @@ func TestDispatchIncoming_UsesActualChatIDAndStoresReqIDRoute(t *testing.T) {
 	ch := newTestWeComChannel(t, messageBus)
 
 	var commands []wecomCommand
-	ch.commandSend = func(cmd wecomCommand, _ time.Duration) error {
+	ch.commandSend = func(cmd wecomCommand, _ time.Duration) (wecomEnvelope, error) {
 		commands = append(commands, cmd)
-		return nil
+		return wecomTestAck(nil), nil
 	}
 
 	msg := wecomIncomingMessage{
@@ -107,12 +110,12 @@ func TestSend_StreamFailureFallsBackToActualChatID(t *testing.T) {
 	}
 
 	var commands []wecomCommand
-	ch.commandSend = func(cmd wecomCommand, _ time.Duration) error {
+	ch.commandSend = func(cmd wecomCommand, _ time.Duration) (wecomEnvelope, error) {
 		commands = append(commands, cmd)
 		if len(commands) == 1 && cmd.Cmd == wecomCmdRespondMsg {
-			return errors.New("stream send failed")
+			return wecomEnvelope{}, errors.New("stream send failed")
 		}
-		return nil
+		return wecomTestAck(nil), nil
 	}
 
 	if err := ch.Send(context.Background(), bus.OutboundMessage{
@@ -152,6 +155,301 @@ func TestSend_StreamFailureFallsBackToActualChatID(t *testing.T) {
 	}
 }
 
+func TestSendMedia_SendsActiveImage(t *testing.T) {
+	t.Parallel()
+
+	ch := newTestWeComChannel(t, bus.NewMessageBus())
+	ch.SetRunning(true)
+
+	store := media.NewFileMediaStore()
+	ch.SetMediaStore(store)
+
+	imageData := wecomTestJPEGData(t)
+	imagePath := filepath.Join(t.TempDir(), "photo.jpg")
+	if err := os.WriteFile(imagePath, imageData, 0o600); err != nil {
+		t.Fatalf("WriteFile() error = %v", err)
+	}
+	ref, err := store.Store(imagePath, media.MediaMeta{
+		Filename:      "photo.jpg",
+		ContentType:   "image/jpeg",
+		Source:        "test",
+		CleanupPolicy: media.CleanupPolicyForgetOnly,
+	}, "scope-1")
+	if err != nil {
+		t.Fatalf("Store() error = %v", err)
+	}
+
+	var commands []wecomCommand
+	ch.commandSend = func(cmd wecomCommand, _ time.Duration) (wecomEnvelope, error) {
+		commands = append(commands, cmd)
+		switch cmd.Cmd {
+		case wecomCmdUploadMediaInit:
+			return wecomTestAck(wecomUploadMediaInitResponse{UploadID: "upload-1"}), nil
+		case wecomCmdUploadMediaEnd:
+			return wecomTestAck(wecomUploadMediaFinishResponse{
+				Type:    "image",
+				MediaID: "media-1",
+			}), nil
+		default:
+			return wecomTestAck(nil), nil
+		}
+	}
+
+	err = ch.SendMedia(context.Background(), bus.OutboundMediaMessage{
+		Channel: "wecom",
+		ChatID:  "chat-1",
+		Parts: []bus.MediaPart{{
+			Ref:         ref,
+			Type:        "image",
+			Filename:    "photo.jpg",
+			ContentType: "image/jpeg",
+		}},
+	})
+	if err != nil {
+		t.Fatalf("SendMedia() error = %v", err)
+	}
+
+	if len(commands) != 4 {
+		t.Fatalf("expected 4 commands, got %d", len(commands))
+	}
+	if commands[0].Cmd != wecomCmdUploadMediaInit {
+		t.Fatalf("first command = %q, want %q", commands[0].Cmd, wecomCmdUploadMediaInit)
+	}
+	initBody, ok := commands[0].Body.(wecomUploadMediaInitBody)
+	if !ok {
+		t.Fatalf("unexpected init body type %T", commands[0].Body)
+	}
+	if initBody.Type != "image" || initBody.Filename != "photo.jpg" || initBody.TotalChunks != 1 {
+		t.Fatalf("init body = %+v", initBody)
+	}
+	if commands[1].Cmd != wecomCmdUploadMediaChunk {
+		t.Fatalf("second command = %q, want %q", commands[1].Cmd, wecomCmdUploadMediaChunk)
+	}
+	chunkBody, ok := commands[1].Body.(wecomUploadMediaChunkBody)
+	if !ok {
+		t.Fatalf("unexpected chunk body type %T", commands[1].Body)
+	}
+	if chunkBody.UploadID != "upload-1" || chunkBody.ChunkIndex != 0 || chunkBody.Base64Data == "" {
+		t.Fatalf("chunk body = %+v", chunkBody)
+	}
+	if commands[2].Cmd != wecomCmdUploadMediaEnd {
+		t.Fatalf("third command = %q, want %q", commands[2].Cmd, wecomCmdUploadMediaEnd)
+	}
+	if commands[3].Cmd != wecomCmdSendMsg {
+		t.Fatalf("fourth command = %q, want %q", commands[3].Cmd, wecomCmdSendMsg)
+	}
+
+	body, ok := commands[3].Body.(wecomSendMsgBody)
+	if !ok {
+		t.Fatalf("unexpected send body type %T", commands[3].Body)
+	}
+	if body.MsgType != "image" || body.Image == nil {
+		t.Fatalf("send body = %+v", body)
+	}
+	if body.ChatID != "chat-1" {
+		t.Fatalf("send chatid = %q, want chat-1", body.ChatID)
+	}
+	if body.Image.MediaID != "media-1" {
+		t.Fatalf("image media_id = %q, want media-1", body.Image.MediaID)
+	}
+}
+
+func TestSendMedia_UsesTurnImageAndFinishesStream(t *testing.T) {
+	t.Parallel()
+
+	ch := newTestWeComChannel(t, bus.NewMessageBus())
+	ch.SetRunning(true)
+
+	store := media.NewFileMediaStore()
+	ch.SetMediaStore(store)
+
+	imageData := wecomTestJPEGData(t)
+	imagePath := filepath.Join(t.TempDir(), "reply.jpg")
+	if err := os.WriteFile(imagePath, imageData, 0o600); err != nil {
+		t.Fatalf("WriteFile() error = %v", err)
+	}
+	ref, err := store.Store(imagePath, media.MediaMeta{
+		Filename:      "reply.jpg",
+		ContentType:   "image/jpeg",
+		Source:        "test",
+		CleanupPolicy: media.CleanupPolicyForgetOnly,
+	}, "scope-2")
+	if err != nil {
+		t.Fatalf("Store() error = %v", err)
+	}
+
+	ch.queueTurn("chat-1", wecomTurn{
+		ReqID:     "req-1",
+		ChatID:    "chat-1",
+		ChatType:  1,
+		StreamID:  "stream-1",
+		CreatedAt: time.Now(),
+	})
+	if err := ch.routes.Put("chat-1", "req-1", 1, time.Hour); err != nil {
+		t.Fatalf("Put() error = %v", err)
+	}
+
+	var commands []wecomCommand
+	ch.commandSend = func(cmd wecomCommand, _ time.Duration) (wecomEnvelope, error) {
+		commands = append(commands, cmd)
+		switch cmd.Cmd {
+		case wecomCmdUploadMediaInit:
+			return wecomTestAck(wecomUploadMediaInitResponse{UploadID: "upload-2"}), nil
+		case wecomCmdUploadMediaEnd:
+			return wecomTestAck(wecomUploadMediaFinishResponse{
+				Type:    "image",
+				MediaID: "media-2",
+			}), nil
+		default:
+			return wecomTestAck(nil), nil
+		}
+	}
+
+	err = ch.SendMedia(context.Background(), bus.OutboundMediaMessage{
+		Channel: "wecom",
+		ChatID:  "chat-1",
+		Parts: []bus.MediaPart{{
+			Ref:         ref,
+			Type:        "image",
+			Filename:    "reply.jpg",
+			ContentType: "image/jpeg",
+		}},
+	})
+	if err != nil {
+		t.Fatalf("SendMedia() error = %v", err)
+	}
+
+	if len(commands) != 5 {
+		t.Fatalf("expected 5 commands, got %d", len(commands))
+	}
+	if commands[0].Cmd != wecomCmdUploadMediaInit {
+		t.Fatalf("first command = %+v", commands[0])
+	}
+	if commands[1].Cmd != wecomCmdUploadMediaChunk {
+		t.Fatalf("second command = %+v", commands[1])
+	}
+	if commands[2].Cmd != wecomCmdUploadMediaEnd {
+		t.Fatalf("third command = %+v", commands[2])
+	}
+	if commands[3].Cmd != wecomCmdRespondMsg || commands[3].Headers.ReqID != "req-1" {
+		t.Fatalf("fourth command = %+v", commands[3])
+	}
+	if commands[4].Cmd != wecomCmdRespondMsg || commands[4].Headers.ReqID != "req-1" {
+		t.Fatalf("fifth command = %+v", commands[4])
+	}
+
+	imageBody, ok := commands[3].Body.(wecomRespondMsgBody)
+	if !ok {
+		t.Fatalf("unexpected image body type %T", commands[3].Body)
+	}
+	if imageBody.MsgType != "image" || imageBody.Image == nil {
+		t.Fatalf("image body = %+v", imageBody)
+	}
+	if imageBody.Image.MediaID != "media-2" {
+		t.Fatalf("image media_id = %q, want media-2", imageBody.Image.MediaID)
+	}
+
+	streamBody, ok := commands[4].Body.(wecomRespondMsgBody)
+	if !ok {
+		t.Fatalf("unexpected finish body type %T", commands[4].Body)
+	}
+	if streamBody.MsgType != "stream" || streamBody.Stream == nil || !streamBody.Stream.Finish {
+		t.Fatalf("finish body = %+v", streamBody)
+	}
+
+	if _, ok := ch.getTurn("chat-1"); ok {
+		t.Fatal("expected turn to be removed after media send")
+	}
+}
+
+func TestSendMedia_SendsActiveFile(t *testing.T) {
+	t.Parallel()
+
+	ch := newTestWeComChannel(t, bus.NewMessageBus())
+	ch.SetRunning(true)
+
+	store := media.NewFileMediaStore()
+	ch.SetMediaStore(store)
+
+	filePath := filepath.Join(t.TempDir(), "report.pdf")
+	if err := os.WriteFile(filePath, []byte("%PDF-1.4"), 0o600); err != nil {
+		t.Fatalf("WriteFile() error = %v", err)
+	}
+	ref, err := store.Store(filePath, media.MediaMeta{
+		Filename:      "report.pdf",
+		ContentType:   "application/pdf",
+		Source:        "test",
+		CleanupPolicy: media.CleanupPolicyForgetOnly,
+	}, "scope-3")
+	if err != nil {
+		t.Fatalf("Store() error = %v", err)
+	}
+
+	var commands []wecomCommand
+	ch.commandSend = func(cmd wecomCommand, _ time.Duration) (wecomEnvelope, error) {
+		commands = append(commands, cmd)
+		switch cmd.Cmd {
+		case wecomCmdUploadMediaInit:
+			return wecomTestAck(wecomUploadMediaInitResponse{UploadID: "upload-3"}), nil
+		case wecomCmdUploadMediaEnd:
+			return wecomTestAck(wecomUploadMediaFinishResponse{
+				Type:    "file",
+				MediaID: "media-3",
+			}), nil
+		default:
+			return wecomTestAck(nil), nil
+		}
+	}
+
+	err = ch.SendMedia(context.Background(), bus.OutboundMediaMessage{
+		Channel: "wecom",
+		ChatID:  "chat-2",
+		Parts: []bus.MediaPart{{
+			Ref:         ref,
+			Type:        "file",
+			Filename:    "report.pdf",
+			ContentType: "application/pdf",
+		}},
+	})
+	if err != nil {
+		t.Fatalf("SendMedia() error = %v", err)
+	}
+
+	if len(commands) != 4 {
+		t.Fatalf("expected 4 commands, got %d", len(commands))
+	}
+	if commands[0].Cmd != wecomCmdUploadMediaInit {
+		t.Fatalf("first command = %q, want %q", commands[0].Cmd, wecomCmdUploadMediaInit)
+	}
+	initBody, ok := commands[0].Body.(wecomUploadMediaInitBody)
+	if !ok {
+		t.Fatalf("unexpected init body type %T", commands[0].Body)
+	}
+	if initBody.Type != "file" || initBody.Filename != "report.pdf" {
+		t.Fatalf("init body = %+v", initBody)
+	}
+	if commands[1].Cmd != wecomCmdUploadMediaChunk {
+		t.Fatalf("second command = %q, want %q", commands[1].Cmd, wecomCmdUploadMediaChunk)
+	}
+	if commands[2].Cmd != wecomCmdUploadMediaEnd {
+		t.Fatalf("third command = %q, want %q", commands[2].Cmd, wecomCmdUploadMediaEnd)
+	}
+	if commands[3].Cmd != wecomCmdSendMsg {
+		t.Fatalf("fourth command = %q, want %q", commands[3].Cmd, wecomCmdSendMsg)
+	}
+
+	body, ok := commands[3].Body.(wecomSendMsgBody)
+	if !ok {
+		t.Fatalf("unexpected body type %T", commands[3].Body)
+	}
+	if body.MsgType != "file" || body.File == nil {
+		t.Fatalf("body = %+v", body)
+	}
+	if body.File.MediaID != "media-3" {
+		t.Fatalf("file media_id = %q, want media-3", body.File.MediaID)
+	}
+}
+
 func newTestWeComChannel(t *testing.T, messageBus *bus.MessageBus) *WeComChannel {
 	t.Helper()
 
@@ -165,3 +463,46 @@ func newTestWeComChannel(t *testing.T, messageBus *bus.MessageBus) *WeComChannel
 	ch.routes = newReqIDStore(filepath.Join(t.TempDir(), "reqids.json"))
 	return ch
 }
+
+func wecomTestJPEGData(t *testing.T) []byte {
+	t.Helper()
+
+	const jpegBase64 = "/9j/4AAQSkZJRgABAQAAAQABAAD/2wBDAP//////////////////////////////////////////////////////////////////////////////////////" +
+		"//////////////////////////////////////////////////////////////////////////////////////////////2wBDAf//////////////////////////////////////////////////////////////////////////////////////" +
+		"//////////////////////////////////////////////////////////////////////////////////////////////wAARCAABAAEDASIAAhEBAxEB/8QAFQABAQAAAAAAAAAAAAAAAAAAAAb/xAAVEQEBAAAAAAAAAAAAAAAAAAAABf/aAAwDAQACEAMQAAAB6A//xAAVEAEBAAAAAAAAAAAAAAAAAAAAEf/aAAgBAQABBQJf/8QAFBEBAAAAAAAAAAAAAAAAAAAAEP/aAAgBAwEBPwF//8QAFBEBAAAAAAAAAAAAAAAAAAAAEP/aAAgBAgEBPwF//8QAFBABAAAAAAAAAAAAAAAAAAAAEP/aAAgBAQAGPwJf/8QAFBABAAAAAAAAAAAAAAAAAAAAEP/aAAgBAQABPyFf/9k="
+
+	return decodeTestBase64(t, jpegBase64)
+}
+
+func TestDecodeWeComUploadFinish_AcceptsNumericCreatedAt(t *testing.T) {
+	t.Parallel()
+
+	resp, err := decodeWeComEnvelopeBody[wecomUploadMediaFinishResponse](wecomEnvelope{
+		Body: json.RawMessage(`{"type":"file","media_id":"media-1","created_at":1380000000}`),
+	})
+	if err != nil {
+		t.Fatalf("decodeWeComEnvelopeBody() error = %v", err)
+	}
+	if resp.Type != "file" || resp.MediaID != "media-1" {
+		t.Fatalf("response = %+v", resp)
+	}
+	if string(resp.CreatedAt) != "1380000000" {
+		t.Fatalf("created_at = %s, want 1380000000", string(resp.CreatedAt))
+	}
+}
+
+func wecomTestAck(body any) wecomEnvelope {
+	var raw []byte
+	if body != nil {
+		encoded, err := json.Marshal(body)
+		if err != nil {
+			panic(err)
+		}
+		raw = encoded
+	}
+	return wecomEnvelope{
+		ErrCode: 0,
+		ErrMsg:  "ok",
+		Body:    raw,
+	}
+}