pgm: Move non commands into a util package

These aren't executed from the command line.  To keep our package
namespace cleaner, hide them under pgm.util.

Change-Id: If9d64f2a28ae1fd26c2177f44c2ec4e2a2751467
Signed-off-by: Shawn O. Pearce <sop@google.com>

gerrit-pgm/src/main/java/com/google/gerrit/pgm/util/ConsoleUI.java

@@ -0,0 +1,238 @@
+// Copyright (C) 2009 The Android Open Source Project
+//
+// 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
+//
+// http://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 com.google.gerrit.pgm.util;
+
+import static org.eclipse.jgit.util.StringUtils.equalsIgnoreCase;
+
+import java.io.Console;
+import java.lang.reflect.InvocationTargetException;
+
+/** Console based interaction with the invoking user. */
+public abstract class ConsoleUI {
+  /** Get a UI instance, assuming interactive mode. */
+  public static ConsoleUI getInstance() {
+    return getInstance(false);
+  }
+
+  /** Get a UI instance, possibly forcing batch mode. */
+  public static ConsoleUI getInstance(final boolean batchMode) {
+    Console console = batchMode ? null : System.console();
+    return console != null ? new Interactive(console) : new Batch();
+  }
+
+  /** Constructs an exception indicating the user aborted the operation. */
+  protected static Die abort() {
+    return new Die("aborted by user");
+  }
+
+  /** Obtain all values from an enumeration. */
+  @SuppressWarnings("unchecked")
+  protected static <T extends Enum<?>> T[] all(final T value) {
+    try {
+      return (T[]) value.getClass().getMethod("values").invoke(null);
+    } catch (IllegalArgumentException e) {
+      throw new IllegalArgumentException("Cannot obtain enumeration values", e);
+    } catch (SecurityException e) {
+      throw new IllegalArgumentException("Cannot obtain enumeration values", e);
+    } catch (IllegalAccessException e) {
+      throw new IllegalArgumentException("Cannot obtain enumeration values", e);
+    } catch (InvocationTargetException e) {
+      throw new IllegalArgumentException("Cannot obtain enumeration values", e);
+    } catch (NoSuchMethodException e) {
+      throw new IllegalArgumentException("Cannot obtain enumeration values", e);
+    }
+  }
+
+  /** @return true if this is a batch UI that has no user interaction. */
+  public abstract boolean isBatch();
+
+  /** Display a header message before a series of prompts. */
+  public abstract void header(String fmt, Object... args);
+
+  /** Request the user to answer a yes/no question. */
+  public abstract boolean yesno(String fmt, Object... args);
+
+  /** Prints a message asking the user to let us know when its safe to continue. */
+  public abstract void waitForUser();
+
+  /** Prompt the user for a string, suggesting a default, and returning choice. */
+  public final String readString(String def, String fmt, Object... args) {
+    if (def != null && def.isEmpty()) {
+      def = null;
+    }
+    return readStringImpl(def, fmt, args);
+  }
+
+  /** Prompt the user for a string, suggesting a default, and returning choice. */
+  protected abstract String readStringImpl(String def, String fmt,
+      Object... args);
+
+  /** Prompt the user for a password, returning the string; null if blank. */
+  public abstract String password(String fmt, Object... args);
+
+  /** Prompt the user to make a choice from an enumeration's values. */
+  public abstract <T extends Enum<?>> T readEnum(T def, String fmt,
+      Object... args);
+
+
+  private static class Interactive extends ConsoleUI {
+    private final Console console;
+
+    Interactive(final Console console) {
+      this.console = console;
+    }
+
+    @Override
+    public boolean isBatch() {
+      return false;
+    }
+
+    @Override
+    public boolean yesno(String fmt, Object... args) {
+      final String prompt = String.format(fmt, args);
+      for (;;) {
+        final String yn = console.readLine("%-30s [y/n]? ", prompt);
+        if (yn == null) {
+          throw abort();
+        }
+        if (yn.equalsIgnoreCase("y") || yn.equalsIgnoreCase("yes")) {
+          return true;
+        }
+        if (yn.equalsIgnoreCase("n") || yn.equalsIgnoreCase("no")) {
+          return false;
+        }
+      }
+    }
+
+    @Override
+    public void waitForUser() {
+      if (console.readLine("Press enter to continue ") == null) {
+        throw abort();
+      }
+    }
+
+    @Override
+    protected String readStringImpl(String def, String fmt, Object... args) {
+      final String prompt = String.format(fmt, args);
+      String r;
+      if (def != null) {
+        r = console.readLine("%-30s [%s]: ", prompt, def);
+      } else {
+        r = console.readLine("%-30s : ", prompt);
+      }
+      if (r == null) {
+        throw abort();
+      }
+      r = r.trim();
+      if (r.isEmpty()) {
+        return def;
+      }
+      return r;
+    }
+
+    @Override
+    public String password(String fmt, Object... args) {
+      final String prompt = String.format(fmt, args);
+      for (;;) {
+        final char[] a1 = console.readPassword("%-30s : ", prompt);
+        if (a1 == null) {
+          throw abort();
+        }
+
+        final char[] a2 = console.readPassword("%30s : ", "confirm password");
+        if (a2 == null) {
+          throw abort();
+        }
+
+        final String s1 = new String(a1);
+        final String s2 = new String(a2);
+        if (!s1.equals(s2)) {
+          console.printf("error: Passwords did not match; try again\n");
+          continue;
+        }
+        return !s1.isEmpty() ? s1 : null;
+      }
+    }
+
+    @Override
+    public <T extends Enum<?>> T readEnum(T def, String fmt, Object... args) {
+      final String prompt = String.format(fmt, args);
+      final T[] options = all(def);
+      for (;;) {
+        String r = console.readLine("%-30s [%s/?]: ", prompt, def.toString());
+        if (r == null) {
+          throw abort();
+        }
+        r = r.trim();
+        if (r.isEmpty()) {
+          return def;
+        }
+        for (final T e : options) {
+          if (equalsIgnoreCase(e.toString(), r)) {
+            return e;
+          }
+        }
+        if (!"?".equals(r)) {
+          console.printf("error: '%s' is not a valid choice\n", r);
+        }
+        console.printf("       Supported options are:\n");
+        for (final T e : options) {
+          console.printf("         %s\n", e.toString().toLowerCase());
+        }
+      }
+    }
+
+    @Override
+    public void header(String fmt, Object... args) {
+      fmt = fmt.replaceAll("\n", "\n*** ");
+      console.printf("\n*** " + fmt + "\n*** \n\n", args);
+    }
+  }
+
+  private static class Batch extends ConsoleUI {
+    @Override
+    public boolean isBatch() {
+      return true;
+    }
+
+    @Override
+    public boolean yesno(String fmt, Object... args) {
+      return true;
+    }
+
+    @Override
+    protected String readStringImpl(String def, String fmt, Object... args) {
+      return def;
+    }
+
+    @Override
+    public void waitForUser() {
+    }
+
+    @Override
+    public String password(String fmt, Object... args) {
+      return null;
+    }
+
+    @Override
+    public <T extends Enum<?>> T readEnum(T def, String fmt, Object... args) {
+      return def;
+    }
+
+    @Override
+    public void header(String fmt, Object... args) {
+    }
+  }
+}