#789: implement uninstall of IDEasy

cli/src/main/java/com/devonfw/tools/ide/commandlet/UninstallCommandlet.java

@@ -2,6 +2,7 @@
 
 import com.devonfw.tools.ide.context.IdeContext;
 import com.devonfw.tools.ide.property.ToolProperty;
+import com.devonfw.tools.ide.tool.IdeasyCommandlet;
 import com.devonfw.tools.ide.tool.ToolCommandlet;
 
 /**
@@ -21,7 +22,7 @@ public UninstallCommandlet(IdeContext context) {
 
     super(context);
     addKeyword(getName());
-    this.tools = add(new ToolProperty("", true, true, "tool"));
+    this.tools = add(new ToolProperty("", false, true, "tool"));
   }
 
   @Override
@@ -33,7 +34,18 @@ public String getName() {
   @Override
   public void run() {
 
-    for (int i = 0; i < this.tools.getValueCount(); i++) {
+    int valueCount = this.tools.getValueCount();
+    if (valueCount == 0) {
+      if (!this.context.isForceMode()) {
+        this.context.askToContinue("Sub-command uninstall without any further arguments will perform the entire uninstallation of IDEasy.\n"
+            + "Since this is typically not to be called manually, you may have forgotten to specify the tool to install as extra argument.\n"
+            + "The current command will uninstall IDEasy from your computer. Are you sure?");
+      }
+      IdeasyCommandlet ideasy = new IdeasyCommandlet(this.context);
+      ideasy.uninstallIdeasy();
+      return;
+    }
+    for (int i = 0; i < valueCount; i++) {
       ToolCommandlet toolCommandlet = this.tools.getValue(i);
       if (toolCommandlet.getInstalledVersion() != null) {
         toolCommandlet.uninstall();

cli/src/main/java/com/devonfw/tools/ide/common/SimpleSystemPath.java

@@ -0,0 +1,85 @@
+package com.devonfw.tools.ide.common;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.function.Predicate;
+
+/**
+ * Represents the PATH variable in a structured way. Similar to {@link SystemPath} but much simper: It just tokenizes the PATH into a {@link java.util.List} of
+ * {@link String}s.
+ */
+public class SimpleSystemPath {
+
+  private final char separator;
+
+  private final List<String> entries;
+
+  private SimpleSystemPath(char separator, List<String> entries) {
+
+    super();
+    this.separator = separator;
+    this.entries = entries;
+  }
+
+  /**
+   * @return the entries of this PATH as a mutable {@link List}.
+   */
+  public List<String> getEntries() {
+
+    return this.entries;
+  }
+
+  /**
+   * Remove all entries from this PATH that match the given {@link Predicate}.
+   *
+   * @param filter the {@link Predicate} {@link Predicate#test(Object) deciding} what to filter and remove.
+   */
+  public void removeEntries(Predicate<String> filter) {
+
+    Iterator<String> iterator = this.entries.iterator();
+    while (iterator.hasNext()) {
+      String entry = iterator.next();
+      if (filter.test(entry)) {
+        iterator.remove();
+      }
+    }
+  }
+
+  @Override
+  public String toString() {
+
+    StringBuilder sb = new StringBuilder();
+    boolean first = true;
+    for (String entry : this.entries) {
+      if (first) {
+        first = false;
+      } else {
+        sb.append(this.separator);
+      }
+      sb.append(entry);
+    }
+    return sb.toString();
+  }
+
+  /**
+   * @param path the entire PATH as {@link String},
+   * @param separator the separator character.
+   * @return the {@link SimpleSystemPath}.
+   */
+  public static SimpleSystemPath of(String path, char separator) {
+
+    List<String> entries = new ArrayList<>();
+    int start = 0;
+    int len = path.length();
+    while (start < len) {
+      int end = path.indexOf(separator, start);
+      if (end < 0) {
+        end = len;
+      }
+      entries.add(path.substring(start, end));
+      start = end + 1;
+    }
+    return new SimpleSystemPath(separator, entries);
+  }
+}

cli/src/main/java/com/devonfw/tools/ide/os/WindowsHelper.java

@@ -14,6 +14,11 @@ public interface WindowsHelper {
    */
   void setUserEnvironmentValue(String key, String value);
 
+  /**
+   * @param key the name of the environment variable to remove.
+   */
+  void removeUserEnvironmentValue(String key);
+
   /**
    * @param key the name of the environment variable.
    * @return the value of the environment variable in the users context.

cli/src/main/java/com/devonfw/tools/ide/os/WindowsHelperImpl.java

@@ -3,6 +3,7 @@
 import java.util.List;
 
 import com.devonfw.tools.ide.context.IdeContext;
+import com.devonfw.tools.ide.log.IdeLogLevel;
 import com.devonfw.tools.ide.process.ProcessMode;
 import com.devonfw.tools.ide.process.ProcessResult;
 
@@ -33,6 +34,16 @@ public void setUserEnvironmentValue(String key, String value) {
     assert (result.isSuccessful());
   }
 
+  @Override
+  public void removeUserEnvironmentValue(String key) {
+    ProcessResult result = this.context.newProcess().executable("reg").addArgs("delete", HKCU_ENVIRONMENT, "/v", key, "/f").run(ProcessMode.DEFAULT_CAPTURE);
+    if (result.isSuccessful()) {
+      this.context.debug("Removed environment variable {}", key);
+    } else {
+      result.log(IdeLogLevel.WARNING, this.context);
+    }
+  }
+
   @Override
   public String getUserEnvironmentValue(String key) {
 

cli/src/main/java/com/devonfw/tools/ide/tool/IdeasyCommandlet.java

@@ -9,6 +9,7 @@
 
 import com.devonfw.tools.ide.cli.CliException;
 import com.devonfw.tools.ide.commandlet.UpgradeMode;
+import com.devonfw.tools.ide.common.SimpleSystemPath;
 import com.devonfw.tools.ide.common.Tag;
 import com.devonfw.tools.ide.context.IdeContext;
 import com.devonfw.tools.ide.io.FileAccess;
@@ -33,6 +34,10 @@ public class IdeasyCommandlet extends MvnBasedLocalToolCommandlet {
 
   /** The {@link #getName() tool name}. */
   public static final String TOOL_NAME = "ideasy";
+  public static final String BASHRC = ".bashrc";
+  public static final String ZSHRC = ".zshrc";
+  public static final String IDE_BIN = "\\_ide\\bin";
+  public static final String IDE_INSTALLATION_BIN = "\\_ide\\installation\\bin";
 
   private final UpgradeMode mode;
 
@@ -168,44 +173,49 @@ public void installIdeasy(Path cwd) {
       fileAccess.copy(installationArtifact, ideasyVersionPath);
     }
     fileAccess.symlink(ideasyVersionPath, installationPath);
-    addToShellRc(".bashrc", ideRoot, null);
-    addToShellRc(".zshrc", ideRoot, "autoload -U +X bashcompinit && bashcompinit");
+    addToShellRc(BASHRC, ideRoot, null);
+    addToShellRc(ZSHRC, ideRoot, "autoload -U +X bashcompinit && bashcompinit");
     installIdeasyWindowsEnv(ideRoot, installationPath);
     this.context.success("IDEasy has been installed successfully on your system.");
     this.context.warning("IDEasy has been setup for new shells but it cannot work in your current shell(s).\n"
         + "Reboot or open a new terminal to make it work.");
   }
 
   private void installIdeasyWindowsEnv(Path ideRoot, Path installationPath) {
-    if (this.context.getSystemInfo().isWindows()) {
-      WindowsHelper helper = WindowsHelper.get(this.context);
-      helper.setUserEnvironmentValue(IdeVariables.IDE_ROOT.getName(), ideRoot.toString());
-      String userPath = helper.getUserEnvironmentValue(IdeVariables.PATH.getName());
-      if (userPath == null) {
-        this.context.error("Could not read user PATH from registry!");
+    if (!this.context.getSystemInfo().isWindows()) {
+      return;
+    }
+    WindowsHelper helper = WindowsHelper.get(this.context);
+    helper.setUserEnvironmentValue(IdeVariables.IDE_ROOT.getName(), ideRoot.toString());
+    String userPath = helper.getUserEnvironmentValue(IdeVariables.PATH.getName());
+    if (userPath == null) {
+      this.context.error("Could not read user PATH from registry!");
+    } else {
+      this.context.info("Found user PATH={}", userPath);
+      Path ideasyBinPath = installationPath.resolve("bin");
+      SimpleSystemPath path = SimpleSystemPath.of(userPath, ';');
+      if (path.getEntries().isEmpty()) {
+        this.context.warning("ATTENTION:\n"
+            + "Your user specific PATH variable seems to be empty.\n"
+            + "You can double check this by pressing [Windows][r] and launch the program SystemPropertiesAdvanced.\n"
+            + "Then click on 'Environment variables' and check if 'PATH' is set in the 'user variables' from the upper list.\n"
+            + "In case 'PATH' is defined there non-empty and you get this message, please abort and give us feedback:\n"
+            + "https://github.com/devonfw/IDEasy/issues\n"
+            + "Otherwise all is correct and you can continue.");
+        this.context.askToContinue("Are you sure you want to override your PATH?");
       } else {
-        this.context.info("Found user PATH={}", userPath);
-        Path ideasyBinPath = installationPath.resolve("bin");
-        userPath = removeObsoleteEntryFromWindowsPath(userPath);
-        if (userPath.isEmpty()) {
-          this.context.warning("ATTENTION:\n"
-              + "Your user specific PATH variable seems to be empty.\n"
-              + "You can double check this by pressing [Windows][r] and launch the program SystemPropertiesAdvanced.\n"
-              + "Then click on 'Environment variables' and check if 'PATH' is set in the 'user variables' from the upper list.\n"
-              + "In case 'PATH' is defined there non-empty and you get this message, please abort and give us feedback:\n"
-              + "https://github.com/devonfw/IDEasy/issues\n"
-              + "Otherwise all is correct and you can continue.");
-          this.context.askToContinue("Are you sure you want to override your PATH?");
-          userPath = ideasyBinPath.toString();
-        } else {
-          userPath = userPath + ";" + ideasyBinPath;
-        }
-        helper.setUserEnvironmentValue(IdeVariables.PATH.getName(), userPath);
+        path.removeEntries(s -> s.endsWith(IDE_BIN));
       }
+      path.getEntries().add(ideasyBinPath.toString());
+      helper.setUserEnvironmentValue(IdeVariables.PATH.getName(), path.toString());
     }
   }
 
   static String removeObsoleteEntryFromWindowsPath(String userPath) {
+    return removeEntryFromWindowsPath(userPath, IDE_BIN);
+  }
+
+  static String removeEntryFromWindowsPath(String userPath, String suffix) {
     int len = userPath.length();
     int start = 0;
     while ((start >= 0) && (start < len)) {
@@ -214,7 +224,7 @@ static String removeObsoleteEntryFromWindowsPath(String userPath) {
         end = len;
       }
       String entry = userPath.substring(start, end);
-      if (entry.endsWith("\\_ide\\bin")) {
+      if (entry.endsWith(suffix)) {
         String prefix = "";
         int offset = 1;
         if (start > 0) {
@@ -224,7 +234,7 @@ static String removeObsoleteEntryFromWindowsPath(String userPath) {
         if (end == len) {
           return prefix;
         } else {
-          return prefix + userPath.substring(end + offset);
+          return removeEntryFromWindowsPath(prefix + userPath.substring(end + offset), suffix);
         }
       }
       start = end + 1;
@@ -240,11 +250,34 @@ static String removeObsoleteEntryFromWindowsPath(String userPath) {
    */
   private void addToShellRc(String filename, Path ideRoot, String extraLine) {
 
-    this.context.info("Configuring IDEasy in {}", filename);
+    modifyShellRc(filename, ideRoot, true, extraLine);
+  }
+
+  private void removeFromShellRc(String filename, Path ideRoot) {
+
+    modifyShellRc(filename, ideRoot, false, null);
+  }
+
+  /**
+   * Adds ourselves to the shell RC (run-commands) configuration file.
+   *
+   * @param filename the name of the RC file.
+   * @param ideRoot the IDE_ROOT {@link Path}.
+   */
+  private void modifyShellRc(String filename, Path ideRoot, boolean add, String extraLine) {
+
+    if (add) {
+      this.context.info("Configuring IDEasy in {}", filename);
+    } else {
+      this.context.info("Removing IDEasy from {}", filename);
+    }
     Path rcFile = this.context.getUserHome().resolve(filename);
     FileAccess fileAccess = this.context.getFileAccess();
     List<String> lines = fileAccess.readFileLines(rcFile);
     if (lines == null) {
+      if (!add) {
+        return;
+      }
       lines = new ArrayList<>();
     } else {
       // since it is unspecified if the returned List may be immutable we want to get sure
@@ -263,14 +296,17 @@ private void addToShellRc(String filename, Path ideRoot, String extraLine) {
         extraLine = null;
       }
     }
-    if (extraLine != null) {
-      lines.add(extraLine);
-    }
-    if (!this.context.getSystemInfo().isWindows()) {
-      lines.add("export IDE_ROOT=\"" + WindowsPathSyntax.MSYS.format(ideRoot) + "\"");
+    if (add) {
+      if (extraLine != null) {
+        lines.add(extraLine);
+      }
+      if (!this.context.getSystemInfo().isWindows()) {
+        lines.add("export IDE_ROOT=\"" + WindowsPathSyntax.MSYS.format(ideRoot) + "\"");
+      }
+      lines.add(BASH_CODE_SOURCE_FUNCTIONS);
     }
-    lines.add(BASH_CODE_SOURCE_FUNCTIONS);
     fileAccess.writeFileLines(lines, rcFile);
+    this.context.debug("Successfully updated {}", filename);
   }
 
   private static boolean isObsoleteRcLine(String line) {
@@ -317,4 +353,47 @@ private Path determineIdeRoot(Path cwd) {
     return ideRoot;
   }
 
+  /**
+   * Uninstalls IDEasy entirely from the system.
+   */
+  public void uninstallIdeasy() {
+
+    Path ideRoot = this.context.getIdeRoot();
+    removeFromShellRc(BASHRC, ideRoot);
+    removeFromShellRc(ZSHRC, ideRoot);
+    Path idePath = this.context.getIdePath();
+    uninstallIdeasyWindowsEnv(ideRoot);
+    this.context.info("Finally deleting {}", idePath);
+    this.context.getFileAccess().delete(idePath); // TODO prevent Windows file locks
+    this.context.success("IDEasy has been uninstalled from your system.");
+    this.context.interaction("ATTENTION:\n"
+        + "In order to prevent data-loss, we do not delete your projects and git repositories!\n"
+        + "To entirely get rid of IDEasy, also check your IDE_ROOT folder at:\n"
+        + "{}", ideRoot);
+  }
+
+  private void uninstallIdeasyWindowsEnv(Path ideRoot) {
+    if (!this.context.getSystemInfo().isWindows()) {
+      return;
+    }
+    WindowsHelper helper = WindowsHelper.get(this.context);
+    helper.removeUserEnvironmentValue(IdeVariables.IDE_ROOT.getName());
+    String userPath = helper.getUserEnvironmentValue(IdeVariables.PATH.getName());
+    if (userPath == null) {
+      this.context.error("Could not read user PATH from registry!");
+    } else {
+      this.context.info("Found user PATH={}", userPath);
+      String newUserPath = userPath;
+      if (!userPath.isEmpty()) {
+        SimpleSystemPath path = SimpleSystemPath.of(userPath, ';');
+        path.removeEntries(s -> s.endsWith(IDE_BIN) || s.endsWith(IDE_INSTALLATION_BIN));
+        newUserPath = path.toString();
+      }
+      if (newUserPath.equals(userPath)) {
+        this.context.error("Could not find IDEasy in PATH:\n{}", userPath);
+      } else {
+        helper.setUserEnvironmentValue(IdeVariables.PATH.getName(), newUserPath);
+      }
+    }
+  }
 }