Implement get route subcommand

pkg/eia/eia_reflection.go

@@ -36,8 +36,50 @@ var defaultMethodSubs = MethodSubs{
 	},
 }
 
+func (client *Client) GetRoute(ctx context.Context, route string, subs *MethodSubs) (
+	*eiaapi.FinalRoute, error,
+) {
+	eiaClient := reflect.ValueOf(client)
+
+	// Get the method for describing this facet
+	method := eiaClient.MethodByName(route)
+	if !method.IsValid() {
+		return nil, fmt.Errorf("method %s not found", route)
+	}
+
+	parser, err := getParser(route)
+	if err != nil {
+		return nil, err
+	}
+
+	args := prepMethodArgs(method, route, subs)
+	results := method.Call(args)
+	resp, err := getResponse(results)
+	if err != nil {
+		return nil, err
+	}
+
+	result, err := parseResponse(parser, resp)
+	if err != nil {
+		return nil, err
+	}
+
+	desc, ok := result.Interface().(*eiaapi.FinalRouteResponseContainer)
+	if !ok {
+		return nil, errors.New("indescribable route returned")
+	}
+
+	if desc.Response == nil {
+		return nil, errors.New("no route response received")
+	}
+
+	return desc.Response.Response, nil
+}
+
 // Given an API route and a facet ID, retrieve information about the facet
-func (client *Client) GetFacet(ctx context.Context, route string, facet string, subs *MethodSubs) (*eiaapi.FacetDetails, error) {
+func (client *Client) GetFacet(ctx context.Context, route string, facet string, subs *MethodSubs) (
+	*eiaapi.FacetDetails, error,
+) {
 	eiaClient := reflect.ValueOf(client)
 
 	// Get the method for describing this facet
@@ -52,14 +94,9 @@ func (client *Client) GetFacet(ctx context.Context, route string, facet string,
 	args := prepMethodArgs(method, methodName, subs)
 
 	// Prepare a parser func for our facet response
-	parserFunc, exists := eiaapi.ParseFunctionsMap[fmt.Sprintf("Parse%sResponse", methodName)]
-	if !exists {
-		return nil, fmt.Errorf("parser func for %s not found", route)
-	}
-
-	parser := reflect.ValueOf(parserFunc)
-	if !parser.IsValid() {
-		return nil, errors.New("unable to find parser for facet response")
+	parser, err := getParser(methodName)
+	if err != nil {
+		return nil, err
 	}
 
 	results := method.Call(args)
@@ -68,29 +105,12 @@ func (client *Client) GetFacet(ctx context.Context, route string, facet string,
 		return nil, err
 	}
 
-	results = parser.Call([]reflect.Value{reflect.ValueOf(resp)})
-	if len(results) != 2 {
-		return nil, errors.New("unexpected response while parsing facet response")
-	}
-	if err := checkCallErr(results[1]); err != nil {
+	result, err := parseResponse(parser, resp)
+	if err != nil {
 		return nil, err
 	}
 
-	result := results[0]
-	if result.Kind() == reflect.Ptr {
-		result = result.Elem()
-	}
-
-	if result.Kind() != reflect.Struct {
-		return nil, fmt.Errorf("unexpected parse result kind %s", result.Kind().String())
-	}
-
-	field := result.FieldByName("JSON200")
-	if !field.IsValid() {
-		return nil, errors.New("invalid facet data field in response")
-	}
-
-	facetDetails, ok := field.Interface().(*eiaapi.FacetDetailsContainer)
+	facetDetails, ok := result.Interface().(*eiaapi.FacetDetailsContainer)
 	if !ok {
 		return nil, errors.New("response does not contain facet details")
 	}
@@ -103,7 +123,9 @@ func (client *Client) GetFacet(ctx context.Context, route string, facet string,
 }
 
 // Return a list of facets given a named route
-func (client *Client) GetFacets(ctx context.Context, route string, subs *MethodSubs) (*eiaapi.FacetOptionList, error) {
+func (client *Client) GetFacets(ctx context.Context, route string, subs *MethodSubs) (
+	*eiaapi.FacetOptionList, error,
+) {
 	eiaClient := reflect.ValueOf(client)
 
 	// Get the method by name
@@ -115,14 +137,9 @@ func (client *Client) GetFacets(ctx context.Context, route string, subs *MethodS
 	args := prepMethodArgs(method, route, subs)
 
 	// Prepare a parser func for our facet response
-	parserFunc, exists := eiaapi.ParseFunctionsMap[fmt.Sprintf("Parse%sResponse", route)]
-	if !exists {
-		return nil, fmt.Errorf("parser func for %s not found", route)
-	}
-
-	parser := reflect.ValueOf(parserFunc)
-	if !parser.IsValid() {
-		return nil, errors.New("unable to find parser for facet response")
+	parser, err := getParser(route)
+	if err != nil {
+		return nil, err
 	}
 
 	// Perform the API call
@@ -137,32 +154,12 @@ func (client *Client) GetFacets(ctx context.Context, route string, subs *MethodS
 		return nil, err
 	}
 
-	// Call the parser with our response, then extract the JSON200 response,
-	// and return the expected FacetOptiionsList from the container
-
-	results = parser.Call([]reflect.Value{reflect.ValueOf(resp)})
-	if len(results) != 2 {
-		return nil, errors.New("unexpected response while parsing facet response")
-	}
-	if err := checkCallErr(results[1]); err != nil {
+	result, err := parseResponse(parser, resp)
+	if err != nil {
 		return nil, err
 	}
 
-	result := results[0]
-	if result.Kind() == reflect.Ptr {
-		result = result.Elem()
-	}
-
-	if result.Kind() != reflect.Struct {
-		return nil, fmt.Errorf("unexpected parse result kind %s", result.Kind().String())
-	}
-
-	field := result.FieldByName("JSON200")
-	if !field.IsValid() {
-		return nil, errors.New("invalid facet data field in response")
-	}
-
-	facetOptions, ok := field.Interface().(*eiaapi.FacetOptionListContainer)
+	facetOptions, ok := result.Interface().(*eiaapi.FacetOptionListContainer)
 	if !ok {
 		return nil, errors.New("response does not contain facet options")
 	}
@@ -266,6 +263,34 @@ func prepMethodArgs(method reflect.Value, name string, subs *MethodSubs) []refle
 	return args
 }
 
+func parseResponse(parser reflect.Value, resp *http.Response) (reflect.Value, error) {
+	var result reflect.Value
+
+	results := parser.Call([]reflect.Value{reflect.ValueOf(resp)})
+	if len(results) != 2 {
+		return result, errors.New("unexpected response while parsing response")
+	}
+	if err := checkCallErr(results[1]); err != nil {
+		return result, err
+	}
+
+	result = results[0]
+	if result.Kind() == reflect.Ptr {
+		result = result.Elem()
+	}
+
+	if result.Kind() != reflect.Struct {
+		return result, fmt.Errorf("unexpected parse result kind %s", result.Kind().String())
+	}
+
+	field := result.FieldByName("JSON200")
+	if !field.IsValid() {
+		return result, errors.New("invalid facet data field in response")
+	}
+
+	return field, nil
+}
+
 func getResponse(responses []reflect.Value) (*http.Response, error) {
 	resp, ok := responses[0].Interface().(*http.Response)
 	if !ok {
@@ -279,6 +304,20 @@ func getResponse(responses []reflect.Value) (*http.Response, error) {
 	return resp, nil
 }
 
+func getParser(forMethod string) (reflect.Value, error) {
+	parserFunc, exists := eiaapi.ParseFunctionsMap[fmt.Sprintf("Parse%sResponse", forMethod)]
+	if !exists {
+		return reflect.Value{}, fmt.Errorf("parser func for %s not found", forMethod)
+	}
+
+	parser := reflect.ValueOf(parserFunc)
+	if !parser.IsValid() {
+		return reflect.Value{}, errors.New("unable to find parser for facet response")
+	}
+
+	return parser, nil
+}
+
 func checkCallErr(val reflect.Value) error {
 	var err error
 	var ok bool