import os from stone.backend import CodeBackend from stone.ir import ( is_void_type, is_struct_type ) from go_helpers import ( HEADER, fmt_type, fmt_var, generate_doc, ) class GoClientBackend(CodeBackend): def generate(self, api): for namespace in api.namespaces.values(): if len(namespace.routes) > 0: self._generate_client(namespace) def _generate_client(self, namespace): file_name = os.path.join(self.target_folder_path, namespace.name, 'client.go') with self.output_to_relative_path(file_name): self.emit_raw(HEADER) self.emit() self.emit('package %s' % namespace.name) self.emit() self.emit('// Client interface describes all routes in this namespace') with self.block('type Client interface'): for route in namespace.routes: generate_doc(self, route) self.emit(self._generate_route_signature(namespace, route)) self.emit() self.emit('type apiImpl dropbox.Context') for route in namespace.routes: self._generate_route(namespace, route) self.emit('// New returns a Client implementation for this namespace') with self.block('func New(c dropbox.Config) Client'): self.emit('ctx := apiImpl(dropbox.NewContext(c))') self.emit('return &ctx') def _generate_route_signature(self, namespace, route): req = fmt_type(route.arg_data_type, namespace) res = fmt_type(route.result_data_type, namespace, use_interface=True) fn = fmt_var(route.name) style = route.attrs.get('style', 'rpc') arg = '' if is_void_type(route.arg_data_type) else 'arg {req}' ret = '(err error)' if is_void_type(route.result_data_type) else \ '(res {res}, err error)' signature = '{fn}(' + arg + ') ' + ret if style == 'download': signature = '{fn}(' + arg + \ ') (res {res}, content io.ReadCloser, err error)' elif style == 'upload': signature = '{fn}(' + arg + ', content io.Reader) ' + ret if is_void_type(route.arg_data_type): signature = '{fn}(content io.Reader) ' + ret return signature.format(fn=fn, req=req, res=res) def _generate_route(self, namespace, route): out = self.emit fn = fmt_var(route.name) err = fmt_type(route.error_data_type, namespace) out('//%sAPIError is an error-wrapper for the %s route' % (fn, route.name)) with self.block('type {fn}APIError struct'.format(fn=fn)): out('dropbox.APIError') out('EndpointError {err} `json:"error"`'.format(err=err)) out() signature = 'func (dbx *apiImpl) ' + self._generate_route_signature( namespace, route) with self.block(signature): if route.deprecated is not None: out('log.Printf("WARNING: API `%s` is deprecated")' % fn) if route.deprecated.by is not None: out('log.Printf("Use API `%s` instead")' % fmt_var(route.deprecated.by.name)) out() out('cli := dbx.Client') out() self._generate_request(namespace, route) self._generate_post() self._generate_response(route) ok_check = 'if resp.StatusCode == http.StatusOK' if fn == "Download": ok_check += ' || resp.StatusCode == http.StatusPartialContent' with self.block(ok_check): self._generate_result(route) self._generate_error_handling(route) out() def _generate_request(self, namespace, route): out = self.emit auth = route.attrs.get('auth', '') host = route.attrs.get('host', 'api') style = route.attrs.get('style', 'rpc') body = 'nil' if not is_void_type(route.arg_data_type): out('dbx.Config.LogDebug("arg: %v", arg)') out('b, err := json.Marshal(arg)') with self.block('if err != nil'): out('return') out() if host != 'content': body = 'bytes.NewReader(b)' if style == 'upload': body = 'content' headers = {} if not is_void_type(route.arg_data_type): if host == 'content' or style in ['upload', 'download']: headers["Dropbox-API-Arg"] = "string(b)" else: headers["Content-Type"] = '"application/json"' if style == 'upload': headers["Content-Type"] = '"application/octet-stream"' out('headers := map[string]string{') for k, v in sorted(headers.items()): out('\t"{}": {},'.format(k, v)) out('}') if fmt_var(route.name) == "Download": out('for k, v := range arg.ExtraHeaders { headers[k] = v }') if auth != 'noauth' and auth != 'team': with self.block('if dbx.Config.AsMemberID != ""'): out('headers["Dropbox-API-Select-User"] = dbx.Config.AsMemberID') out() authed = 'false' if auth == 'noauth' else 'true' out('req, err := (*dropbox.Context)(dbx).NewRequest("{}", "{}", {}, "{}", "{}", headers, {})'.format( host, style, authed, namespace.name, route.name, body)) with self.block('if err != nil'): out('return') out('dbx.Config.LogInfo("req: %v", req)') out() def _generate_post(self): out = self.emit out('resp, err := cli.Do(req)') with self.block('if err != nil'): out('return') out() out('dbx.Config.LogInfo("resp: %v", resp)') def _generate_response(self, route): out = self.emit style = route.attrs.get('style', 'rpc') if style == 'download': out('body := []byte(resp.Header.Get("Dropbox-API-Result"))') out('content = resp.Body') else: out('defer resp.Body.Close()') with self.block('body, err := ioutil.ReadAll(resp.Body);' 'if err != nil'): out('return') out() out('dbx.Config.LogDebug("body: %v", body)') def _generate_error_handling(self, route): out = self.emit style = route.attrs.get('style', 'rpc') with self.block('if resp.StatusCode == http.StatusConflict'): # If style was download, body was assigned to a header. # Need to re-read the response body to parse the error if style == 'download': out('defer resp.Body.Close()') with self.block('body, err = ioutil.ReadAll(resp.Body);' 'if err != nil'): out('return') out('var apiError %sAPIError' % fmt_var(route.name)) with self.block('err = json.Unmarshal(body, &apiError);' 'if err != nil'): out('return') out('err = apiError') out('return') out('var apiError dropbox.APIError') with self.block("if resp.StatusCode == http.StatusBadRequest || " "resp.StatusCode == http.StatusInternalServerError"): out('apiError.ErrorSummary = string(body)') out('err = apiError') out('return') with self.block('err = json.Unmarshal(body, &apiError);' 'if err != nil'): out('return') out('err = apiError') out('return') def _generate_result(self, route): out = self.emit if is_struct_type(route.result_data_type) and \ route.result_data_type.has_enumerated_subtypes(): out('var tmp %sUnion' % fmt_var(route.result_data_type.name, export=False)) with self.block('err = json.Unmarshal(body, &tmp);' 'if err != nil'): out('return') with self.block('switch tmp.Tag'): for t in route.result_data_type.get_enumerated_subtypes(): with self.block('case "%s":' % t.name, delim=(None, None)): self.emit('res = tmp.%s' % fmt_var(t.name)) elif not is_void_type(route.result_data_type): with self.block('err = json.Unmarshal(body, &res);' 'if err != nil'): out('return') out() out('return')