Start busting out reflection for GetFacet

cmd/eia-client/internal/util/util_reflect.go

@@ -14,6 +14,21 @@ import (
 	eiaapi "gitea.libretechconsulting.com/50W/eia-api-go/api"
 )
 
+type MethodSubs struct {
+	TypedParams        map[reflect.Type]reflect.Value // Replace field of specific type with value
+	NameParams         map[string]reflect.Value       // Replace field with specific name with value
+	NameContainsParams map[string]reflect.Value       // Replace fields with name containing string with value
+}
+
+var defaultMethodSubs = MethodSubs{
+	NameContainsParams: map[string]reflect.Value{
+		"route": reflect.ValueOf(strconv.Itoa(time.Now().AddDate(-1, 0, 0).Year())),
+	},
+}
+
+// func GetFacet(cmd *cobra.Command, route string) (*eiaapi.FacetOptionList, error) {
+// }
+
 func GetFacets(cmd *cobra.Command, route string) (*eiaapi.FacetOptionList, error) {
 	client, err := Client(cmd)
 	if err != nil {
@@ -29,49 +44,9 @@ func GetFacets(cmd *cobra.Command, route string) (*eiaapi.FacetOptionList, error
 		return nil, fmt.Errorf("method %q not found", route)
 	}
 
-	// Create a slice of reflect.Value for the method's arguments
+	args := prepMethodArgs(cmd.Context(), method, GetMethodSubs(cmd))
-	methodType := method.Type()
-	args := make([]reflect.Value, 0, methodType.NumIn())
-
-	// Populate arguments with zero values for their respective types
-	for i := 0; i < methodType.NumIn(); i++ {
-		argType := methodType.In(i)
-
-		// Don't supply request editor Fn args
-		if methodType.IsVariadic() && i == methodType.NumIn()-1 {
-			continue
-		}
-
-		if argType == reflect.TypeOf((*context.Context)(nil)).Elem() {
-			args = append(args, reflect.ValueOf(cmd.Context()))
-			continue
-		}
-
-		// Default to last year for Route1
-		if argType == reflect.TypeOf(eiaapi.Route1("1999")) {
-			lastYear := time.Now().AddDate(-1, 0, 0).Year()
-			args = append(args, reflect.ValueOf(eiaapi.Route1(strconv.Itoa(lastYear))))
-			continue
-		}
-
-		// Zero value of other stuff
-		args = append(args, reflect.Zero(argType))
-	}
-
-	results := method.Call(args)
-	if len(results) != 2 {
-		return nil, errors.New("unexpected response from get facet call")
-	}
-
-	var resp *http.Response
-	var ok bool
-	if resp, ok = results[0].Interface().(*http.Response); !ok {
-		return nil, errors.New("no or invalid response received from call")
-	}
-	if err := checkCallErr(results[1]); err != nil {
-		return nil, err
-	}
 
+	// 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)
@@ -82,6 +57,21 @@ func GetFacets(cmd *cobra.Command, route string) (*eiaapi.FacetOptionList, error
 		return nil, errors.New("unable to find parser for facet response")
 	}
 
+	// Perform the API call
+	results := method.Call(args)
+	if len(results) != 2 {
+		return nil, errors.New("unexpected response from get facet call")
+	}
+
+	// Prepare *http.Response, error
+	resp, err := getResponse(results)
+	if err != nil {
+		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")
@@ -116,6 +106,55 @@ func GetFacets(cmd *cobra.Command, route string) (*eiaapi.FacetOptionList, error
 	return facetOptions.Response, nil
 }
 
+// Given an API method, replaces any named fields with the provided value
+// from the subs map, otherwise uses built-in logic for common fields
+// such as a context.Context. Skips request editor funcs
+func prepMethodArgs(ctx context.Context, method reflect.Value, _ MethodSubs) []reflect.Value {
+	// Create a slice of reflect.Value for the method's arguments
+	methodType := method.Type()
+	args := make([]reflect.Value, 0, methodType.NumIn())
+
+	// Populate arguments with zero values for their respective types
+	for i := 0; i < methodType.NumIn(); i++ {
+		argType := methodType.In(i)
+
+		// Don't supply request editor Fn args
+		if methodType.IsVariadic() && i == methodType.NumIn()-1 {
+			continue
+		}
+
+		if argType == reflect.TypeOf((*context.Context)(nil)).Elem() {
+			args = append(args, reflect.ValueOf(ctx))
+			continue
+		}
+
+		// Default to last year for Route1
+		if argType == reflect.TypeOf(eiaapi.Route1("1999")) {
+			lastYear := time.Now().AddDate(-1, 0, 0).Year()
+			args = append(args, reflect.ValueOf(eiaapi.Route1(strconv.Itoa(lastYear))))
+			continue
+		}
+
+		// Zero value of other stuff
+		args = append(args, reflect.Zero(argType))
+	}
+
+	return args
+}
+
+func getResponse(responses []reflect.Value) (*http.Response, error) {
+	resp, ok := responses[0].Interface().(*http.Response)
+	if !ok {
+		return nil, errors.New("no or invalid response received from call")
+	}
+
+	if err := checkCallErr(responses[1]); err != nil {
+		return nil, err
+	}
+
+	return resp, nil
+}
+
 func checkCallErr(val reflect.Value) error {
 	var err error
 	var ok bool
@@ -128,3 +167,11 @@ func checkCallErr(val reflect.Value) error {
 
 	return err
 }
+
+func GetMethodSubs(cmd *cobra.Command) MethodSubs {
+	subs := defaultMethodSubs
+
+	subs.TypedParams[reflect.TypeOf(context.Background())] = reflect.ValueOf(cmd.Context())
+
+	return subs
+}