feat: multiple oauth providers (#355)

* feat: add flag decoder (candidate)

* refactor: finalize flags decoder

* feat: add env decoder

* feat: add oauth config parsing logic

* feat: implement backend logic for multiple oauth providers

* feat: implement multiple oauth providers in the frontend

* feat: add some default icons

* chore: add credits for parser

* feat: style oauth auto redirect screen

* fix: bot suggestions

* refactor: rework decoders using simpler and more efficient pattern

* refactor: rework oauth name database migration

internal/utils/decoders/decoders.go

@@ -0,0 +1,81 @@
+package decoders
+
+import (
+	"reflect"
+	"strings"
+	"tinyauth/internal/config"
+)
+
+func NormalizeKeys(keys map[string]string, rootName string, sep string) map[string]string {
+	normalized := make(map[string]string)
+	knownKeys := getKnownKeys()
+
+	for k, v := range keys {
+		var finalKey []string
+		var suffix string
+		var camelClientName string
+		var camelField string
+
+		finalKey = append(finalKey, rootName)
+		finalKey = append(finalKey, "providers")
+		cebabKey := strings.ToLower(k)
+
+		for _, known := range knownKeys {
+			if strings.HasSuffix(cebabKey, strings.ReplaceAll(known, "-", sep)) {
+				suffix = known
+				break
+			}
+		}
+
+		if suffix == "" {
+			continue
+		}
+
+		clientNameParts := strings.Split(strings.TrimPrefix(strings.TrimSuffix(cebabKey, sep+strings.ReplaceAll(suffix, "-", sep)), "providers"+sep), sep)
+
+		for i, p := range clientNameParts {
+			if i == 0 {
+				camelClientName += p
+				continue
+			}
+			if p == "" {
+				continue
+			}
+			camelClientName += strings.ToUpper(string([]rune(p)[0])) + string([]rune(p)[1:])
+		}
+
+		finalKey = append(finalKey, camelClientName)
+
+		filedParts := strings.Split(suffix, "-")
+
+		for i, p := range filedParts {
+			if i == 0 {
+				camelField += p
+				continue
+			}
+			if p == "" {
+				continue
+			}
+			camelField += strings.ToUpper(string([]rune(p)[0])) + string([]rune(p)[1:])
+		}
+
+		finalKey = append(finalKey, camelField)
+		normalized[strings.Join(finalKey, ".")] = v
+	}
+
+	return normalized
+}
+
+func getKnownKeys() []string {
+	var known []string
+
+	p := config.OAuthServiceConfig{}
+	v := reflect.ValueOf(p)
+	typeOfP := v.Type()
+
+	for field := range typeOfP.NumField() {
+		known = append(known, typeOfP.Field(field).Tag.Get("key"))
+	}
+
+	return known
+}