/*
    * Copyright 2021-2022 The OSHI Project Contributors
    * SPDX-License-Identifier: MIT
    */
   package oshi.driver.mac;
   
   import static oshi.jna.platform.mac.CoreGraphics.kCGNullWindowID;
   import static oshi.jna.platform.mac.CoreGraphics.kCGWindowListExcludeDesktopElements;
   import static oshi.jna.platform.mac.CoreGraphics.kCGWindowListOptionAll;
  import static oshi.jna.platform.mac.CoreGraphics.kCGWindowListOptionOnScreenOnly;
  
  import java.awt.Rectangle;
  import java.util.ArrayList;
  import java.util.List;
  
  import com.sun.jna.Pointer;
  import com.sun.jna.platform.mac.CoreFoundation.CFArrayRef;
  import com.sun.jna.platform.mac.CoreFoundation.CFBooleanRef;
  import com.sun.jna.platform.mac.CoreFoundation.CFDictionaryRef;
  import com.sun.jna.platform.mac.CoreFoundation.CFNumberRef;
  import com.sun.jna.platform.mac.CoreFoundation.CFStringRef;
  
  import oshi.annotation.concurrent.ThreadSafe;
  import oshi.jna.platform.mac.CoreGraphics;
  import oshi.jna.platform.mac.CoreGraphics.CGRect;
  import oshi.software.os.OSDesktopWindow;
  import oshi.util.FormatUtil;
  import oshi.util.platform.mac.CFUtil;
  
  /**
   * Utility to query desktop windows
   */
  @ThreadSafe
  public final class WindowInfo {
  
      private WindowInfo() {
      }
  
      /**
       * Gets windows on the operating system's GUI desktop.
       *
       * @param visibleOnly Whether to restrict the list to only windows visible to the user.
       * @return A list of {@link oshi.software.os.OSDesktopWindow} objects representing the desktop windows.
       */
      public static List<OSDesktopWindow> queryDesktopWindows(boolean visibleOnly) {
          CFArrayRef windowInfo = CoreGraphics.INSTANCE.CGWindowListCopyWindowInfo(
                  visibleOnly ? kCGWindowListOptionOnScreenOnly | kCGWindowListExcludeDesktopElements
                          : kCGWindowListOptionAll,
                  kCGNullWindowID);
          int numWindows = windowInfo.getCount();
          // Prepare a list to return
          List<OSDesktopWindow> windowList = new ArrayList<>();
          // Set up keys for dictionary lookup
          CFStringRef kCGWindowIsOnscreen = CFStringRef.createCFString("kCGWindowIsOnscreen");
          CFStringRef kCGWindowNumber = CFStringRef.createCFString("kCGWindowNumber");
          CFStringRef kCGWindowOwnerPID = CFStringRef.createCFString("kCGWindowOwnerPID");
          CFStringRef kCGWindowLayer = CFStringRef.createCFString("kCGWindowLayer");
          CFStringRef kCGWindowBounds = CFStringRef.createCFString("kCGWindowBounds");
          CFStringRef kCGWindowName = CFStringRef.createCFString("kCGWindowName");
          CFStringRef kCGWindowOwnerName = CFStringRef.createCFString("kCGWindowOwnerName");
          try {
              // Populate the list
              for (int i = 0; i < numWindows; i++) {
                  // For each array element, get the dictionary
                  Pointer result = windowInfo.getValueAtIndex(i);
                  CFDictionaryRef windowRef = new CFDictionaryRef(result);
                  // Now get information from the dictionary.
                  result = windowRef.getValue(kCGWindowIsOnscreen); // Optional key, check for null
                  boolean visible = result == null || new CFBooleanRef(result).booleanValue();
                  if (!visibleOnly || visible) {
                      result = windowRef.getValue(kCGWindowNumber); // kCFNumberSInt64Type
                      long windowNumber = new CFNumberRef(result).longValue();
  
                      result = windowRef.getValue(kCGWindowOwnerPID); // kCFNumberSInt64Type
                      long windowOwnerPID = new CFNumberRef(result).longValue();
  
                      result = windowRef.getValue(kCGWindowLayer); // kCFNumberIntType
                      int windowLayer = new CFNumberRef(result).intValue();
  
                      result = windowRef.getValue(kCGWindowBounds);
                      try (CGRect rect = new CGRect()) {
                          CoreGraphics.INSTANCE.CGRectMakeWithDictionaryRepresentation(new CFDictionaryRef(result), rect);
                          Rectangle windowBounds = new Rectangle(FormatUtil.roundToInt(rect.origin.x),
                                  FormatUtil.roundToInt(rect.origin.y), FormatUtil.roundToInt(rect.size.width),
                                  FormatUtil.roundToInt(rect.size.height));
                          // Note: the Quartz name returned by this field is rarely used
                          result = windowRef.getValue(kCGWindowName); // Optional key, check for null
                          String windowName = CFUtil.cfPointerToString(result, false);
                          // This is the program running the window, use as name if name blank or add in
                          // parenthesis
                          result = windowRef.getValue(kCGWindowOwnerName); // Optional key, check for null
                          String windowOwnerName = CFUtil.cfPointerToString(result, false);
                          if (windowName.isEmpty()) {
                              windowName = windowOwnerName;
                          } else {
                              windowName = windowName + "(" + windowOwnerName + ")";
                          }
  
                          windowList.add(new OSDesktopWindow(windowNumber, windowName, windowOwnerName, windowBounds,
                                 windowOwnerPID, windowLayer, visible));
                     }
                 }
             }
         } finally {
             // CF references from "Copy" or "Create" must be released
             kCGWindowIsOnscreen.release();
             kCGWindowNumber.release();
             kCGWindowOwnerPID.release();
             kCGWindowLayer.release();
             kCGWindowBounds.release();
             kCGWindowName.release();
             kCGWindowOwnerName.release();
             windowInfo.release();
         }
 
         return windowList;
     }
 }