/*
    * Copyright (c) 2002-2026 Gargoyle Software Inc.
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    * https://www.apache.org/licenses/LICENSE-2.0
    *
    * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.htmlunit.javascript.host.intl;
  
  import java.util.IllformedLocaleException;
  import java.util.List;
  
  import org.apache.commons.lang3.LocaleUtils;
  import org.htmlunit.corejs.javascript.Context;
  import org.htmlunit.corejs.javascript.Function;
  import org.htmlunit.corejs.javascript.FunctionObject;
  import org.htmlunit.corejs.javascript.Scriptable;
  import org.htmlunit.corejs.javascript.ScriptableObject;
  import org.htmlunit.corejs.javascript.VarScope;
  import org.htmlunit.javascript.HtmlUnitScriptable;
  import org.htmlunit.javascript.JavaScriptEngine;
  import org.htmlunit.javascript.configuration.JsxClass;
  import org.htmlunit.javascript.configuration.JsxConstructor;
  import org.htmlunit.javascript.configuration.JsxFunction;
  import org.htmlunit.javascript.configuration.JsxGetter;
  import org.htmlunit.javascript.configuration.JsxSymbolConstant;
  
  /**
   * A JavaScript object for Intl.Locale.
   *
   * @author Lai Quang Duong
   * @author Ronald Brill
   *
   * @see <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Intl/Locale">MDN Documentation</a>
   */
  @JsxClass
  public class Locale extends HtmlUnitScriptable {
  
      /** Symbol.toStringTag support. */
      @JsxSymbolConstant
      public static final String TO_STRING_TAG = "Intl.Locale";
  
      private static final List<String> ALLOWED_HOUR_CYCLES = List.of("h11", "h12", "h23", "h24");
      private static final List<String> ALLOWED_CASE_FIRSTS = List.of("upper", "lower", "false");
  
      private java.util.Locale locale_;
      private String language_;
      private String script_;
      private String region_;
      private String calendar_;
      private String collation_;
      private String numberingSystem_;
      private String caseFirst_;
      private String hourCycle_;
      private boolean numeric_;
  
      /**
       * Default constructor.
       */
      public Locale() {
          super();
      }
  
      private Locale(final java.util.Locale locale) {
          super();
          locale_ = locale;
          language_ = locale.getLanguage();
          if (!locale.getScript().isEmpty()) {
              script_ = locale.getScript();
          }
          if (!locale.getCountry().isEmpty()) {
              region_ = locale.getCountry();
          }
          if (locale.hasExtensions()) {
              calendar_ = locale.getUnicodeLocaleType("ca");
              collation_ = locale.getUnicodeLocaleType("co");
              numberingSystem_ = locale.getUnicodeLocaleType("nu");
              caseFirst_ = locale.getUnicodeLocaleType("kf");
              hourCycle_ = locale.getUnicodeLocaleType("hc");
              numeric_ = Boolean.parseBoolean(locale.getUnicodeLocaleType("kn"));
          }
      }
  
      /**
       * JavaScript constructor.
       * @param cx the current context
       * @param scope the scope
       * @param args the arguments
       * @param ctorObj the constructor function
       * @param inNewExpr whether called via new
       * @return the new Locale instance
       */
     @JsxConstructor
     public static Scriptable jsConstructor(final Context cx, final VarScope scope,
             final Object[] args, final Function ctorObj, final boolean inNewExpr) {
         if (args.length == 0 || JavaScriptEngine.isUndefined(args[0])) {
             throw JavaScriptEngine.typeError("Invalid element in locales argument");
         }
 
         final String languageTag = JavaScriptEngine.toString(args[0]);
         if (languageTag.isEmpty()) {
             throw JavaScriptEngine.rangeError("Invalid language tag: ");
         }
 
         java.util.Locale locale;
         try {
             locale = new java.util.Locale.Builder()
                     .setLanguageTag(languageTag)
                     .build();
         }
         catch (final IllformedLocaleException e) {
             throw JavaScriptEngine.rangeError("Invalid language tag: " + languageTag);
         }
 
         // Override by options if present
         if (args.length > 1 && !JavaScriptEngine.isUndefined(args[1])) {
             locale = overrideExistingWithOptions(locale, ScriptableObject.ensureScriptableObject(args[1]));
         }
 
         final Locale l = new Locale(locale);
         l.setParentScope(getTopLevelScope(scope));
         l.setPrototype(((FunctionObject) ctorObj).getClassPrototype());
         return l;
     }
 
     private static java.util.Locale overrideExistingWithOptions(
             final java.util.Locale existing, final ScriptableObject options) {
         final java.util.Locale.Builder builder = new java.util.Locale.Builder().setLocale(existing);
 
         setStringOption(builder, options, "language");
         setStringOption(builder, options, "script");
         setStringOption(builder, options, "region");
         setUnicodeKeyword(builder, options, "calendar", "ca", null);
         setUnicodeKeyword(builder, options, "collation", "co", null);
         setUnicodeKeyword(builder, options, "numberingSystem", "nu", null);
         setUnicodeKeyword(builder, options, "caseFirst", "kf", ALLOWED_CASE_FIRSTS);
         setUnicodeKeyword(builder, options, "hourCycle", "hc", ALLOWED_HOUR_CYCLES);
 
         final Object numeric = ScriptableObject.getProperty(options, "numeric");
         if (numeric != Scriptable.NOT_FOUND && !JavaScriptEngine.isUndefined(numeric)) {
             final boolean isNumeric = numeric instanceof Boolean ? (Boolean) numeric : true;
             builder.setUnicodeLocaleKeyword("kn", Boolean.toString(isNumeric));
         }
 
         return builder.build();
     }
 
     private static void setStringOption(final java.util.Locale.Builder builder,
             final ScriptableObject options, final String optionName) {
         final Object value = ScriptableObject.getProperty(options, optionName);
         if (value == Scriptable.NOT_FOUND || JavaScriptEngine.isUndefined(value)) {
             return;
         }
         try {
             final String s = JavaScriptEngine.toString(value);
             switch (optionName) {
                 case "language":
                     builder.setLanguage(s);
                     break;
                 case "script":
                     builder.setScript(s);
                     break;
                 case "region":
                     builder.setRegion(s);
                     break;
                 default:
                     break;
             }
         }
         catch (final Exception e) {
             throw JavaScriptEngine.rangeError("Invalid value for option \"" + optionName + "\"");
         }
     }
 
     private static void setUnicodeKeyword(final java.util.Locale.Builder builder,
             final ScriptableObject options, final String optionName, final String unicodeKey,
             final List<String> allowedValues) {
         final Object value = ScriptableObject.getProperty(options, optionName);
         if (value == Scriptable.NOT_FOUND || JavaScriptEngine.isUndefined(value)) {
             return;
         }
         final String s;
         try {
             s = JavaScriptEngine.toString(value);
         }
         catch (final Exception e) {
             throw JavaScriptEngine.rangeError("Invalid value for option \"" + optionName + "\"");
         }
         if (allowedValues != null && !allowedValues.contains(s)) {
             throw JavaScriptEngine.rangeError("Invalid value for option \"" + optionName + "\"");
         }
         builder.setUnicodeLocaleKeyword(unicodeKey, s);
     }
 
     /**
      * Returns the language subtag.
      * @return the language
      */
     @JsxGetter
     public Object getLanguage() {
         return language_ != null ? language_ : JavaScriptEngine.UNDEFINED;
     }
 
     /**
      * Returns the script subtag.
      * @return the script
      */
     @JsxGetter
     public Object getScript() {
         return script_ != null ? script_ : JavaScriptEngine.UNDEFINED;
     }
 
     /**
      * Returns the region subtag.
      * @return the region
      */
     @JsxGetter
     public Object getRegion() {
         return region_ != null ? region_ : JavaScriptEngine.UNDEFINED;
     }
 
     /**
      * Returns the calendar type.
      * @return the calendar type
      */
     @JsxGetter
     public Object getCalendar() {
         return calendar_ != null ? calendar_ : JavaScriptEngine.UNDEFINED;
     }
 
     /**
      * Returns the collation type.
      * @return the collation type
      */
     @JsxGetter
     public Object getCollation() {
         return collation_ != null ? collation_ : JavaScriptEngine.UNDEFINED;
     }
 
     /**
      * Returns the numbering system.
      * @return the numbering system
      */
     @JsxGetter
     public Object getNumberingSystem() {
         return numberingSystem_ != null ? numberingSystem_ : JavaScriptEngine.UNDEFINED;
     }
 
     /**
      * Returns the case first setting.
      * @return the case first setting
      */
     @JsxGetter
     public Object getCaseFirst() {
         return caseFirst_ != null ? caseFirst_ : JavaScriptEngine.UNDEFINED;
     }
 
     /**
      * Returns the hour cycle.
      * @return the hour cycle
      */
     @JsxGetter
     public Object getHourCycle() {
         return hourCycle_ != null ? hourCycle_ : JavaScriptEngine.UNDEFINED;
     }
 
     /**
      * Returns whether numeric sorting is used.
      * @return whether numeric sorting is used
      */
     @JsxGetter
     public boolean isNumeric() {
         return numeric_;
     }
 
     /**
      * Returns the base name (without Unicode extensions).
      * @return the base name (without Unicode extensions)
      */
     @JsxGetter
     public Object getBaseName() {
         final String variant = locale_.getVariant().replace("_", "-");
         return language_
                 + (script_ != null ? "-" + script_ : "")
                 + (region_ != null ? "-" + region_ : "")
                 + (!variant.isEmpty() ? "-" + variant : "");
     }
 
     /**
      * Returns a Locale with maximized subtags.
      * @return a new Locale instance with maximized subtags
      */
     @JsxFunction
     public Locale maximize() {
         final String region;
         if (region_ != null) {
             region = region_;
         }
         else {
             final java.util.List<java.util.Locale> locales =
                     LocaleUtils.countriesByLanguage(language_);
             if (!locales.isEmpty()) {
                 region = locales.get(0).getCountry();
             }
             else {
                 region = null;
             }
         }
 
         final java.util.Locale locale = new java.util.Locale.Builder()
                 .setLanguage(language_)
                 .setScript(script_)
                 .setRegion(region)
                 .setExtension('u', locale_.getExtension('u'))
                 .build();
 
         final Locale l = new Locale(locale);
         l.setParentScope(getTopLevelScope(getParentScope()));
         l.setPrototype(this.getPrototype());
         return l;
     }
 
     /**
      * Returns a Locale with minimized subtags.
      * @return a new Locale instance with minimized subtags
      */
     @JsxFunction
     public Locale minimize() {
         final java.util.Locale locale = new java.util.Locale.Builder()
                 .setLanguage(language_)
                 .setExtension('u', locale_.getExtension('u'))
                 .build();
 
         final Locale l = new Locale(locale);
         l.setParentScope(getTopLevelScope(getParentScope()));
         l.setPrototype(this.getPrototype());
         return l;
     }
 
     /**
      * Returns the locale's Unicode locale identifier string.
      * @return the locale's Unicode locale identifier string
      */
     @JsxFunction(functionName = "toString")
     public String jsToString() {
         if (locale_ == null) {
             return super.toString();
         }
         return locale_.toLanguageTag();
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public Object getDefaultValue(final Class<?> hint) {
         if (getPrototype() != null && (String.class.equals(hint) || hint == null)) {
             return jsToString();
         }
         return super.getDefaultValue(hint);
     }
 }