/*
    * Copyright 2025 The OSHI Project Contributors
    * SPDX-License-Identifier: MIT
    */
   package oshi.driver.windows.registry;
   
   import com.sun.jna.platform.win32.Advapi32Util;
   import com.sun.jna.platform.win32.Win32Exception;
   import com.sun.jna.platform.win32.WinNT;
  import com.sun.jna.platform.win32.WinReg;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import oshi.software.os.ApplicationInfo;
  import oshi.util.ParseUtil;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.LinkedHashMap;
  import java.util.LinkedHashSet;
  import java.util.Map;
  import java.util.Set;
  import java.util.Arrays;
  
  public final class InstalledAppsData {
      private static final Logger LOG = LoggerFactory.getLogger(InstalledAppsData.class);
  
      private InstalledAppsData() {
      }
  
      private static final Map<WinReg.HKEY, List<String>> REGISTRY_PATHS = new HashMap<>();
      private static final int[] ACCESS_FLAGS = { WinNT.KEY_WOW64_64KEY, WinNT.KEY_WOW64_32KEY };
  
      static {
          REGISTRY_PATHS.put(WinReg.HKEY_LOCAL_MACHINE,
                  Arrays.asList("SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall",
                          "SOFTWARE\\WOW6432Node\\Microsoft\\Windows\\CurrentVersion\\Uninstall"));
  
          REGISTRY_PATHS.put(WinReg.HKEY_CURRENT_USER,
                  Arrays.asList("SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall"));
      }
  
      public static List<ApplicationInfo> queryInstalledApps() {
          Set<ApplicationInfo> appInfoSet = new LinkedHashSet<>();
  
          // Iterate through both HKLM and HKCU paths
          for (Map.Entry<WinReg.HKEY, List<String>> entry : REGISTRY_PATHS.entrySet()) {
              WinReg.HKEY rootKey = entry.getKey();
              List<String> uninstallPaths = entry.getValue();
  
              for (String registryPath : uninstallPaths) {
                  for (int accessFlag : ACCESS_FLAGS) {
                      String[] keys = Advapi32Util.registryGetKeys(rootKey, registryPath, accessFlag);
                      for (String key : keys) {
                          String fullPath = registryPath + "\\" + key;
                          try {
                              String name = getRegistryValueOrUnknown(rootKey, fullPath, "DisplayName", accessFlag);
                              if (name == null) {
                                  continue;
                              }
                              String version = getRegistryValueOrUnknown(rootKey, fullPath, "DisplayVersion", accessFlag);
                              String publisher = getRegistryValueOrUnknown(rootKey, fullPath, "Publisher", accessFlag);
                              String installDate = getRegistryValueOrUnknown(rootKey, fullPath, "InstallDate",
                                      accessFlag);
                              String installLocation = getRegistryValueOrUnknown(rootKey, fullPath, "InstallLocation",
                                      accessFlag);
                              String installSource = getRegistryValueOrUnknown(rootKey, fullPath, "InstallSource",
                                      accessFlag);
  
                              long installDateEpoch = ParseUtil.parseDateToEpoch(installDate, "yyyyMMdd");
  
                              Map<String, String> additionalInfo = new LinkedHashMap<>();
                              additionalInfo.put("installLocation", installLocation);
                              additionalInfo.put("installSource", installSource);
  
                              ApplicationInfo app = new ApplicationInfo(name, version, publisher, installDateEpoch,
                                      additionalInfo);
                              appInfoSet.add(app);
                          } catch (Win32Exception e) {
                              // Skip keys that are inaccessible or have missing values
                          }
                      }
                  }
              }
          }
  
          return new ArrayList<>(appInfoSet);
      }
  
      private static String getRegistryValueOrUnknown(WinReg.HKEY rootKey, String path, String key, int accessFlag) {
          try {
              String value = Advapi32Util.registryGetStringValue(rootKey, path, key, accessFlag);
              if (value != null && !value.trim().isEmpty()) {
                  return value;
              }
          } catch (Win32Exception e) {
              LOG.trace("Unable to access " + path + " with flag " + accessFlag + ": " + e.getMessage());
          }
          return null;
     }
 }