Refactored configuration to make sections less code intensive to add

internal/config/config.go

@@ -18,9 +18,8 @@ package config
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
-	"maps"
+	"log/slog"
 	"reflect"
 	"strings"
 
@@ -31,65 +30,37 @@ import (
 const EnvPrefix string = "JOBSEARCH"
 const EtcConfigPath string = "/etc/job-search"
 
+// Each field's cfg tag must match the section's JSCK* constant.
 type JobSearchConfig struct {
-	Logging JobSearchConfigLogging
+	Logging  JobSearchConfigLogging  `cfg:"logging"`
 }
 
-// Default configuration
+// Default configuration, taken from the default struct tags
 func LoadDefaultConfig() {
-	conf := JobSearchConfig{
-		Logging: defaultConfigLogging(),
+	var conf JobSearchConfig
+	if err := applyDefaults(&conf); err != nil {
+		panic(fmt.Sprintf("config: %v", err))
 	}
 	LoadToViper(conf)
 }
 
-// Converts configuration to a map
-func (conf JobSearchConfig) Map() map[string]any {
-	confMap := map[string]any{}
-	confMap["logging"] = conf.Logging.Map()
-	return confMap
-}
+func (c JobSearchConfig) Map() map[string]any { return mapOf(c) }
 
-// Converts configuration to a flat dotted format
-func (conf JobSearchConfig) Flatten() map[string]any {
-	confFlat := map[string]any{}
-	maps.Copy(confFlat, conf.Logging.Flatten())
-	return confFlat
-}
+func (c JobSearchConfig) Flatten() map[string]any { return flattenOf("", c) }
 
-// Returns the expected type of a configuration key value
 func (c JobSearchConfig) TypeOf(key string) (reflect.Kind, error) {
-	keyParts := strings.Split(key, ".")
-	switch keyParts[0] {
-	case "logging":
-		return c.Logging.TypeOf(strings.Join(keyParts[1:], "."))
-	default:
-		return reflect.Invalid, errors.New("unknown configuration key")
-	}
+	return typeOf(c, key)
 }
 
-// Returns the expected type of a configuration value
 func (c JobSearchConfig) ValueOf(key string) (any, error) {
-	keyParts := strings.Split(key, ".")
-	switch keyParts[0] {
-	case "logging":
-		return c.Logging.ValueOf(strings.Join(keyParts[1:], "."))
-	default:
-		return nil, errors.New("unknown configuration key")
-	}
+	return valueOf(c, key)
 }
 
-// Returns the expected type of a configuration value
 func (c *JobSearchConfig) SetValue(key string, value any) error {
-	keyParts := strings.Split(key, ".")
-	switch keyParts[0] {
-	case "logging":
-		return c.Logging.SetValue(strings.Join(keyParts[1:], "."), value)
-	default:
-		return errors.New("unknown configuration key")
-	}
+	return setValue(c, key, value)
 }
 
+// Utility method for loading a configuration from Viper
 func LoadFromViper(conf *JobSearchConfig) {
 	keys := viper.AllKeys()
 	for idx := range keys {
@@ -105,10 +76,13 @@ func LoadFromViper(conf *JobSearchConfig) {
 			conf.SetValue(key, viper.GetInt(key))
 		case reflect.Bool:
 			conf.SetValue(key, viper.GetBool(key))
+		default:
+			slog.Error(fmt.Sprintf("unknown key type: %s", keyType))
 		}
 	}
 }
 
+// Utility method for loading a configuration into Viper as defaults
 func LoadToViper(conf JobSearchConfig) {
 	flatMap := conf.Flatten()
 	for key := range flatMap {
@@ -121,7 +95,7 @@ func (conf JobSearchConfig) String() string {
 	var sb strings.Builder
 	for k, v := range conf.Flatten() {
 		typ, _ := conf.TypeOf(k)
-		sb.WriteString(fmt.Sprint(k, " = ", v, " <", typ, ">"))
+		sb.WriteString(fmt.Sprint(k, " = ", v, " <", typ, ">\n"))
 	}
 	return sb.String()
 }