func()

in sumdb/internal/sumweb/server.go [64:170]
100 lines of code
21 McCabe index (conditional complexity)

func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	ctx, err := h.Server.NewContext(r)
	if err != nil {
		http.Error(w, err.Error(), 500)
		return
	}

	switch {
	default:
		http.NotFound(w, r)

	case strings.HasPrefix(r.URL.Path, "/lookup/"):
		mod := strings.TrimPrefix(r.URL.Path, "/lookup/")
		if !modVerRE.MatchString(mod) {
			http.Error(w, "invalid module@version syntax", http.StatusBadRequest)
			return
		}
		i := strings.Index(mod, "@")
		encPath, encVers := mod[:i], mod[i+1:]
		path, err := decodePath(encPath)
		if err != nil {
			reportError(w, r, err)
			return
		}
		vers, err := decodeVersion(encVers)
		if err != nil {
			reportError(w, r, err)
			return
		}
		id, err := h.Server.Lookup(ctx, path+"@"+vers)
		if err != nil {
			reportError(w, r, err)
			return
		}
		records, err := h.Server.ReadRecords(ctx, id, 1)
		if err != nil {
			// This should never happen - the lookup says the record exists.
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		if len(records) != 1 {
			http.Error(w, "invalid record count returned by ReadRecords", http.StatusInternalServerError)
			return
		}
		msg, err := tlog.FormatRecord(id, records[0])
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		signed, err := h.Server.Signed(ctx)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		w.Header().Set("Content-Type", "text/plain; charset=UTF-8")
		w.Write(msg)
		w.Write(signed)

	case r.URL.Path == "/latest":
		data, err := h.Server.Signed(ctx)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}
		w.Header().Set("Content-Type", "text/plain; charset=UTF-8")
		w.Write(data)

	case strings.HasPrefix(r.URL.Path, "/tile/"):
		t, err := tlog.ParseTilePath(r.URL.Path[1:])
		if err != nil {
			http.Error(w, "invalid tile syntax", http.StatusBadRequest)
			return
		}
		if t.L == -1 {
			// Record data.
			start := t.N << uint(t.H)
			records, err := h.Server.ReadRecords(ctx, start, int64(t.W))
			if err != nil {
				reportError(w, r, err)
				return
			}
			if len(records) != t.W {
				http.Error(w, "invalid record count returned by ReadRecords", http.StatusInternalServerError)
				return
			}
			var data []byte
			for i, text := range records {
				msg, err := tlog.FormatRecord(start+int64(i), text)
				if err != nil {
					http.Error(w, err.Error(), http.StatusInternalServerError)
				}
				data = append(data, msg...)
			}
			w.Header().Set("Content-Type", "text/plain; charset=UTF-8")
			w.Write(data)
			return
		}

		data, err := h.Server.ReadTileData(ctx, t)
		if err != nil {
			reportError(w, r, err)
			return
		}
		w.Header().Set("Content-Type", "application/octet-stream")
		w.Write(data)
	}
}