Fix #35506: allow to override lang strings

Author: LEDfan

src/main/java/eu/openanalytics/containerproxy/ContainerProxyApplication.java

@@ -212,12 +212,6 @@ public static Properties getDefaultProperties() {
         properties.put("springdoc.api-docs.enabled", false);
         properties.put("springdoc.swagger-ui.enabled", false);
 
-        // Internationalization
-        // ====================
-        properties.put("spring.messages.basename", "messages,cp_messages");
-        // use MessageFormat for all messages: single quotes must be escaped in every message
-        properties.put("spring.messages.always-use-message-format", "true");
-
         return properties;
     }
 

src/main/java/eu/openanalytics/containerproxy/util/CustomMessageSource.java

@@ -20,42 +20,94 @@
  */
 package eu.openanalytics.containerproxy.util;
 
-import org.springframework.boot.autoconfigure.context.MessageSourceAutoConfiguration;
-import org.springframework.boot.autoconfigure.context.MessageSourceProperties;
-import org.springframework.boot.context.properties.EnableConfigurationProperties;
-import org.springframework.context.MessageSource;
-import org.springframework.context.MessageSourceResolvable;
-import org.springframework.context.NoSuchMessageException;
+import eu.openanalytics.containerproxy.service.LanguageService;
+import org.apache.commons.lang3.StringUtils;
+import org.jspecify.annotations.Nullable;
+import org.springframework.boot.context.properties.bind.Bindable;
+import org.springframework.boot.context.properties.bind.Binder;
+import org.springframework.context.support.AbstractMessageSource;
+import org.springframework.context.support.ResourceBundleMessageSource;
+import org.springframework.core.env.Environment;
 import org.springframework.stereotype.Component;
-import org.thymeleaf.util.StringUtils;
 
 import javax.annotation.Nonnull;
+import java.text.MessageFormat;
+import java.util.HashMap;
 import java.util.Locale;
+import java.util.Map;
+import java.util.ResourceBundle;
+import java.util.stream.Collectors;
 
 @Component("messageSource")
-@EnableConfigurationProperties(MessageSourceProperties.class)
-public class CustomMessageSource implements MessageSource {
+public class CustomMessageSource extends AbstractMessageSource {
 
-    private MessageSource delegate;
+    private static final String PROP_PROXY_TRANSLATION_OVERRIDES = "proxy.translation-overrides";
+    private final Map<String, Map<String, String>> translationOverrides = new HashMap<>();
+    private final Map<String, Map<String, MessageFormat>> translationOverridesMessageFormat = new HashMap<>();
 
-    public CustomMessageSource(MessageSourceProperties properties) {
-        MessageSourceAutoConfiguration autoConfiguration = new MessageSourceAutoConfiguration();
-        this.delegate = autoConfiguration.messageSource(properties);
+    public CustomMessageSource(Environment environment, LanguageService languageService) {
+        ResourceBundleMessageSource parentMessageSource = new CapitalizedMessageSource();
+        parentMessageSource.setBasenames("messages", "cp_messages");
+        parentMessageSource.setAlwaysUseMessageFormat(true);
+        setParentMessageSource(parentMessageSource);
+
+        // read overridden translations from config file
+        for (String language : languageService.getEnabledLanguages().keySet()) {
+            Map<String, String> messages = getTranslationOverrides(environment, language);
+            translationOverrides.put(language, messages);
+            translationOverridesMessageFormat.put(language, convertToMessageFormat(messages, language));
+        }
     }
 
     @Override
-    public String getMessage(@Nonnull String code, Object[] args, String defaultMessage, @Nonnull Locale locale) {
-        return StringUtils.capitalize(delegate.getMessage(code, args, defaultMessage, locale));
+    protected @Nullable String resolveCodeWithoutArguments(@Nonnull String code, @Nonnull Locale locale) {
+        if (translationOverrides.containsKey(locale.getLanguage())) {
+            return translationOverrides.get(locale.getLanguage()).get(code);
+        }
+        return null;
     }
 
     @Override
-    public String getMessage(@Nonnull String code, Object[] args, @Nonnull Locale locale) throws NoSuchMessageException {
-        return StringUtils.capitalize(delegate.getMessage(code, args, locale));
+    protected @Nullable MessageFormat resolveCode(@Nonnull String code, @Nonnull Locale locale) {
+        if (translationOverrides.containsKey(locale.getLanguage())) {
+            return translationOverridesMessageFormat.get(locale.getLanguage()).get(code);
+        }
+        return null;
     }
 
-    @Override
-    public String getMessage(@Nonnull MessageSourceResolvable resolvable, @Nonnull Locale locale) throws NoSuchMessageException {
-        return StringUtils.capitalize(delegate.getMessage(resolvable, locale));
+    private Map<String, String> getTranslationOverrides(Environment environment, String language) {
+        return Binder.get(environment)
+            .bind(PROP_PROXY_TRANSLATION_OVERRIDES + "." + language, Bindable.mapOf(String.class, String.class))
+            .orElse(new HashMap<>());
+    }
+
+    private Map<String, MessageFormat> convertToMessageFormat(Map<String, String> messages, String language) {
+        Locale locale = Locale.forLanguageTag(language);
+        return messages.entrySet().stream().collect(Collectors.toMap(
+            Map.Entry::getKey,
+            e -> new MessageFormat(StringUtils.capitalize(e.getValue()), locale))
+        );
+    }
+
+    private static class CapitalizedMessageSource extends ResourceBundleMessageSource {
+
+        /**
+         * Capitalizes the first letter of each string. Because this low-level method
+         * is overridden, the strings are still properly cached.
+         *
+         * @param bundle the ResourceBundle to perform the lookup in
+         * @param key    the key to look up
+         * @return the associated value, or {@code null} if none
+         */
+        @Override
+        protected @Nullable String getStringOrNull(@Nonnull ResourceBundle bundle, @Nonnull String key) {
+            String result = super.getStringOrNull(bundle, key);
+            if (result != null) {
+                return StringUtils.capitalize(result);
+            }
+            return null;
+        }
+
     }
 
 }