/*
    * 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;
  
  import java.nio.charset.StandardCharsets;
  import java.util.Arrays;
  import java.util.Base64;
  
  import org.htmlunit.Page;
  import org.htmlunit.WebWindow;
  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.background.BackgroundJavaScriptFactory;
  import org.htmlunit.javascript.background.JavaScriptJob;
  import org.htmlunit.util.StringUtils;
  
  /**
   * The implementation of {@code WindowOrWorkerGlobalScope}
   * to be used by the implementers of the mixin.
   *
   * @author Ronald Brill
   * @author Rural Hunter
   * @author Lai Quang Duong
   */
  public final class WindowOrWorkerGlobalScopeMixin {
  
      /**
       * The minimum delay that can be used with setInterval() or setTimeout(). Browser minimums are
       * usually in the 10ms to 15ms range, but there's really no reason for us to waste that much time.
       * <a href="http://jsninja.com/Timers#Minimum_Timer_Delay_and_Reliability">
       * http://jsninja.com/Timers#Minimum_Timer_Delay_and_Reliability</a>
       */
      private static final int MIN_TIMER_DELAY = 1;
  
      private WindowOrWorkerGlobalScopeMixin() {
          super();
      }
  
      /**
       * Decodes a string of data which has been encoded using base-64 encoding.
       * @param encodedData the encoded string
       * @param scriptable the HtmlUnitScriptable
       * @return the decoded value
       */
      public static String atob(final String encodedData, final HtmlUnitScriptable scriptable) {
          final String withoutWhitespace = StringUtils.replaceChars(encodedData, " \t\r\n\u000c", "");
          final byte[] bytes = withoutWhitespace.getBytes(StandardCharsets.ISO_8859_1);
          try {
              return new String(Base64.getDecoder().decode(bytes), StandardCharsets.ISO_8859_1);
          }
          catch (final IllegalArgumentException e) {
              throw JavaScriptEngine.asJavaScriptException(
                      scriptable,
                      "Failed to execute atob(): " + e.getMessage(),
                      org.htmlunit.javascript.host.dom.DOMException.INVALID_CHARACTER_ERR);
          }
      }
  
      /**
       * Creates a base-64 encoded ASCII string from a string of binary data.
       * @param stringToEncode string to encode
       * @param scriptable the HtmlUnitScriptable
       * @return the encoded string
       */
      public static String btoa(final String stringToEncode, final HtmlUnitScriptable scriptable) {
          final int l = stringToEncode.length();
          for (int i = 0; i < l; i++) {
              if (stringToEncode.charAt(i) > 255) {
                  throw JavaScriptEngine.asJavaScriptException(
                          scriptable,
                          "Function btoa supports only latin1 characters",
                          org.htmlunit.javascript.host.dom.DOMException.INVALID_CHARACTER_ERR);
              }
          }
  
          final byte[] bytes = stringToEncode.getBytes(StandardCharsets.ISO_8859_1);
          try {
              return new String(Base64.getEncoder().encode(bytes), StandardCharsets.UTF_8);
          }
          catch (final IllegalArgumentException e) {
              throw JavaScriptEngine.asJavaScriptException(
                     scriptable,
                     "Failed to execute btoa(): " + e.getMessage(),
                     org.htmlunit.javascript.host.dom.DOMException.INVALID_CHARACTER_ERR);
         }
     }
 
     /**
      * Sets a chunk of JavaScript to be invoked at some specified time later.
      * The invocation occurs only if the window is opened after the delay
      * and does not contain an other page than the one that originated the setTimeout.
      *
      * @see <a href="https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/setTimeout">
      *     MDN web docs</a>
      *
      * @param context the JavaScript context
      * @param thisObj the scriptable
      * @param args the arguments passed into the method
      * @param function the function
      * @return the id of the created timer
      */
     public static Object setTimeout(final Context context, final Scriptable thisObj,
             final Object[] args, final Function function) {
         if (args.length < 1) {
             throw JavaScriptEngine.typeError("Function not provided");
         }
 
         final int timeout = JavaScriptEngine.toInt32((args.length > 1) ? args[1] : JavaScriptEngine.UNDEFINED);
         final Object[] params = (args.length > 2)
                 ? Arrays.copyOfRange(args, 2, args.length)
                 : JavaScriptEngine.EMPTY_ARGS;
         return setTimeoutIntervalImpl((Window) thisObj, args[0], timeout, true, params);
     }
 
     /**
      * Sets a chunk of JavaScript to be invoked each time a specified number of milliseconds has elapsed.
      *
      * @see <a href="https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/setInterval">
      *     MDN web docs</a>
      * @param context the JavaScript context
      * @param thisObj the scriptable
      * @param args the arguments passed into the method
      * @param function the function
      * @return the id of the created interval
      */
     public static Object setInterval(final Context context, final Scriptable thisObj,
             final Object[] args, final Function function) {
         if (args.length < 1) {
             throw JavaScriptEngine.typeError("Function not provided");
         }
 
         final int timeout = JavaScriptEngine.toInt32((args.length > 1) ? args[1] : JavaScriptEngine.UNDEFINED);
         final Object[] params = (args.length > 2)
                 ? Arrays.copyOfRange(args, 2, args.length)
                 : JavaScriptEngine.EMPTY_ARGS;
         return setTimeoutIntervalImpl((Window) thisObj, args[0], timeout, false, params);
     }
 
     /**
      * Queues a microtask to be executed.
      *
      * @see <a href="https://developer.mozilla.org/en-US/docs/Web/API/queueMicrotask">
      *     MDN web docs</a>
      * @param thisObj the scriptable
      * @param args the arguments passed into the method
      * @return undefined
      */
     public static Object queueMicrotask(final Scriptable thisObj, final Object[] args) {
         if (args.length < 1) {
             throw JavaScriptEngine.typeError("At least 1 argument required");
         }
         if (!(args[0] instanceof Function)) {
             throw JavaScriptEngine.typeError("Argument 1 is not callable");
         }
 
         final Function callback = (Function) args[0];
         final VarScope scope = ScriptableObject.getTopLevelScope(thisObj.getParentScope());
         final Context cx = Context.getCurrentContext();
         cx.enqueueMicrotask(() -> {
             try {
                 callback.call(cx, scope, thisObj, JavaScriptEngine.EMPTY_ARGS);
             }
             catch (final Exception e) {
                 // uncaught exception in a microtask must not prevent remaining microtasks from running.
             }
         });
 
         return JavaScriptEngine.UNDEFINED;
     }
 
     private static int setTimeoutIntervalImpl(final Window window, final Object code,
             int timeout, final boolean isTimeout, final Object[] params) {
         if (timeout < MIN_TIMER_DELAY) {
             timeout = MIN_TIMER_DELAY;
         }
 
         final WebWindow webWindow = window.getWebWindow();
         final Page page = (Page) window.getDomNodeOrNull();
         Integer period = null;
         if (!isTimeout) {
             period = timeout;
         }
 
         if (code instanceof String s) {
             final String description = "window.set"
                                         + (isTimeout ? "Timeout" : "Interval")
                                         + "(" + s + ", " + timeout + ")";
             final JavaScriptJob job = BackgroundJavaScriptFactory.theFactory().
                     createJavaScriptJob(timeout, period, description, webWindow, s);
             return webWindow.getJobManager().addJob(job, page);
         }
 
         if (code instanceof Function f) {
             final String functionName;
             if (f instanceof FunctionObject object) {
                 functionName = object.getFunctionName();
             }
             else {
                 functionName = String.valueOf(f); // can this happen?
             }
 
             final String description = "window.set"
                                         + (isTimeout ? "Timeout" : "Interval")
                                         + "(" + functionName + ", " + timeout + ")";
             final JavaScriptJob job = BackgroundJavaScriptFactory.theFactory().
                     createJavaScriptJob(timeout, period, description, webWindow, f, params);
             return webWindow.getJobManager().addJob(job, page);
         }
 
         throw JavaScriptEngine.reportRuntimeError("Unknown type for function.");
     }
 }