Files

84 lines
2.0 KiB
Go

package chat
import (
"encoding/json"
"fmt"
"net/http"
"strconv"
"github.com/go-chi/chi/v5"
"github.com/yan1h/agent-coding-workflow/internal/infra/errs"
)
// streamMessages implements GET /api/v1/conversations/{id}/stream.
// It upgrades the connection to a Server-Sent Events stream and forwards
// SSEEvents produced by MessageService.Stream until the channel closes or
// the client disconnects.
func (h *Handler) streamMessages(w http.ResponseWriter, r *http.Request) {
uid, err := h.userID(r)
if err != nil {
writeErr(w, r, err)
return
}
convID, err := parseUUID(chi.URLParam(r, "id"))
if err != nil {
writeErr(w, r, err)
return
}
var since int64
if s := r.URL.Query().Get("since"); s != "" {
since, _ = strconv.ParseInt(s, 10, 64)
}
flusher, ok := w.(http.Flusher)
if !ok {
http.Error(w, "streaming unsupported", http.StatusInternalServerError)
return
}
w.Header().Set("Content-Type", "text/event-stream")
w.Header().Set("Cache-Control", "no-cache")
w.Header().Set("Connection", "keep-alive")
w.Header().Set("X-Accel-Buffering", "no")
w.WriteHeader(http.StatusOK)
ch, err := h.msgSvc.Stream(r.Context(), uid, convID, since)
if err != nil {
writeSSEError(w, flusher, err)
return
}
for {
select {
case <-r.Context().Done():
return
case ev, ok := <-ch:
if !ok {
return
}
writeSSE(w, flusher, ev)
}
}
}
// writeSSE writes a single SSE frame to w and flushes.
func writeSSE(w http.ResponseWriter, f http.Flusher, ev SSEEvent) {
data, _ := json.Marshal(ev.Data)
fmt.Fprintf(w, "id: %d\nevent: %s\ndata: %s\n\n", ev.ID, ev.Event, data)
f.Flush()
}
// writeSSEError writes an error event to the SSE stream and flushes.
func writeSSEError(w http.ResponseWriter, f http.Flusher, err error) {
code := errs.CodeInternal
msg := err.Error()
if ae, ok := errs.As(err); ok {
code = ae.Code
msg = ae.Message
}
payload := map[string]string{"code": string(code), "message": msg}
data, _ := json.Marshal(payload)
fmt.Fprintf(w, "event: error\ndata: %s\n\n", data)
f.Flush()
}