/*
 * Copyright (C) 2007 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 android.util;

import java.io.PrintWriter;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Locale;

Various utilities for debugging and logging.
/**
 * <p>Various utilities for debugging and logging.</p>
 */
public class DebugUtils {
    
@hide
/** @hide */ public DebugUtils() {}

    
Filters objects against the ANDROID_OBJECT_FILTER
environment variable. This environment variable can filter objects
based on their class name and attribute values.
Here is the syntax for ANDROID_OBJECT_FILTER:
ClassName@attribute1=value1@attribute2=value2...
Examples:

Select TextView instances: TextView
Select TextView instances of text "Loading" and bottom offset of 22:
TextView@text=Loading.*@bottom=22

The class name and the values are regular expressions.
This class is useful for debugging and logging purpose:
if (DEBUG) {
  if (DebugUtils.isObjectSelected(childView) && LOGV_ENABLED) {
    Log.v(TAG, "Object " + childView + " logged!");
  }
}

NOTE: This method is very expensive as it relies
heavily on regular expressions and reflection. Calls to this method
should always be stripped out of the release binaries and avoided
as much as possible in debug mode.
Params:
object – any object to match against the ANDROID_OBJECT_FILTER
       environement variable
Returns:
true if object is selected by the ANDROID_OBJECT_FILTER
        environment variable, false otherwise/**
     * <p>Filters objects against the <code>ANDROID_OBJECT_FILTER</code>
     * environment variable. This environment variable can filter objects
     * based on their class name and attribute values.</p>
     *
     * <p>Here is the syntax for <code>ANDROID_OBJECT_FILTER</code>:</p>
     *
     * <p><code>ClassName@attribute1=value1@attribute2=value2...</code></p>
     *
     * <p>Examples:</p>
     * <ul>
     * <li>Select TextView instances: <code>TextView</code></li>
     * <li>Select TextView instances of text "Loading" and bottom offset of 22:
     * <code>TextView@text=Loading.*@bottom=22</code></li>
     * </ul>
     *
     * <p>The class name and the values are regular expressions.</p>
     *
     * <p>This class is useful for debugging and logging purpose:</p>
     * <pre>
     * if (DEBUG) {
     *   if (DebugUtils.isObjectSelected(childView) && LOGV_ENABLED) {
     *     Log.v(TAG, "Object " + childView + " logged!");
     *   }
     * }
     * </pre>
     *
     * <p><strong>NOTE</strong>: This method is very expensive as it relies
     * heavily on regular expressions and reflection. Calls to this method
     * should always be stripped out of the release binaries and avoided
     * as much as possible in debug mode.</p>
     *
     * @param object any object to match against the ANDROID_OBJECT_FILTER
     *        environement variable
     * @return true if object is selected by the ANDROID_OBJECT_FILTER
     *         environment variable, false otherwise
     */
    public static boolean isObjectSelected(Object object) {
        boolean match = false;
        String s = System.getenv("ANDROID_OBJECT_FILTER");
        if (s != null && s.length() > 0) {
            String[] selectors = s.split("@");
            // first selector == class name
            if (object.getClass().getSimpleName().matches(selectors[0])) {
                // check potential attributes
                for (int i = 1; i < selectors.length; i++) {
                    String[] pair = selectors[i].split("=");
                    Class<?> klass = object.getClass();
                    try {
                        Method declaredMethod = null;
                        Class<?> parent = klass;
                        do {
                            declaredMethod = parent.getDeclaredMethod("get" +
                                    pair[0].substring(0, 1).toUpperCase(Locale.ROOT) +
                                    pair[0].substring(1),
                                    (Class[]) null);
                        } while ((parent = klass.getSuperclass()) != null &&
                                declaredMethod == null);

                        if (declaredMethod != null) {
                            Object value = declaredMethod
                                    .invoke(object, (Object[])null);
                            match |= (value != null ?
                                    value.toString() : "null").matches(pair[1]);
                        }
                    } catch (NoSuchMethodException e) {
                        e.printStackTrace();
                    } catch (IllegalAccessException e) {
                        e.printStackTrace();
                    } catch (InvocationTargetException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
        return match;
    }

    
@hide
/** @hide */
    public static void buildShortClassTag(Object cls, StringBuilder out) {
        if (cls == null) {
            out.append("null");
        } else {
            String simpleName = cls.getClass().getSimpleName();
            if (simpleName == null || simpleName.isEmpty()) {
                simpleName = cls.getClass().getName();
                int end = simpleName.lastIndexOf('.');
                if (end > 0) {
                    simpleName = simpleName.substring(end+1);
                }
            }
            out.append(simpleName);
            out.append('{');
            out.append(Integer.toHexString(System.identityHashCode(cls)));
        }
    }

    
@hide
/** @hide */
    public static void printSizeValue(PrintWriter pw, long number) {
        float result = number;
        String suffix = "";
        if (result > 900) {
            suffix = "KB";
            result = result / 1024;
        }
        if (result > 900) {
            suffix = "MB";
            result = result / 1024;
        }
        if (result > 900) {
            suffix = "GB";
            result = result / 1024;
        }
        if (result > 900) {
            suffix = "TB";
            result = result / 1024;
        }
        if (result > 900) {
            suffix = "PB";
            result = result / 1024;
        }
        String value;
        if (result < 1) {
            value = String.format("%.2f", result);
        } else if (result < 10) {
            value = String.format("%.1f", result);
        } else if (result < 100) {
            value = String.format("%.0f", result);
        } else {
            value = String.format("%.0f", result);
        }
        pw.print(value);
        pw.print(suffix);
    }

    
@hide
/** @hide */
    public static String sizeValueToString(long number, StringBuilder outBuilder) {
        if (outBuilder == null) {
            outBuilder = new StringBuilder(32);
        }
        float result = number;
        String suffix = "";
        if (result > 900) {
            suffix = "KB";
            result = result / 1024;
        }
        if (result > 900) {
            suffix = "MB";
            result = result / 1024;
        }
        if (result > 900) {
            suffix = "GB";
            result = result / 1024;
        }
        if (result > 900) {
            suffix = "TB";
            result = result / 1024;
        }
        if (result > 900) {
            suffix = "PB";
            result = result / 1024;
        }
        String value;
        if (result < 1) {
            value = String.format("%.2f", result);
        } else if (result < 10) {
            value = String.format("%.1f", result);
        } else if (result < 100) {
            value = String.format("%.0f", result);
        } else {
            value = String.format("%.0f", result);
        }
        outBuilder.append(value);
        outBuilder.append(suffix);
        return outBuilder.toString();
    }

    
Use prefixed constants (static final values) on given class to turn value
into human-readable string.
@hide
/**
     * Use prefixed constants (static final values) on given class to turn value
     * into human-readable string.
     *
     * @hide
     */
    public static String valueToString(Class<?> clazz, String prefix, int value) {
        for (Field field : clazz.getDeclaredFields()) {
            final int modifiers = field.getModifiers();
            if (Modifier.isStatic(modifiers) && Modifier.isFinal(modifiers)
                    && field.getType().equals(int.class) && field.getName().startsWith(prefix)) {
                try {
                    if (value == field.getInt(null)) {
                        return constNameWithoutPrefix(prefix, field);
                    }
                } catch (IllegalAccessException ignored) {
                }
            }
        }
        return Integer.toString(value);
    }

    
Use prefixed constants (static final values) on given class to turn flags
into human-readable string.
@hide
/**
     * Use prefixed constants (static final values) on given class to turn flags
     * into human-readable string.
     *
     * @hide
     */
    public static String flagsToString(Class<?> clazz, String prefix, int flags) {
        final StringBuilder res = new StringBuilder();
        boolean flagsWasZero = flags == 0;

        for (Field field : clazz.getDeclaredFields()) {
            final int modifiers = field.getModifiers();
            if (Modifier.isStatic(modifiers) && Modifier.isFinal(modifiers)
                    && field.getType().equals(int.class) && field.getName().startsWith(prefix)) {
                try {
                    final int value = field.getInt(null);
                    if (value == 0 && flagsWasZero) {
                        return constNameWithoutPrefix(prefix, field);
                    }
                    if ((flags & value) != 0) {
                        flags &= ~value;
                        res.append(constNameWithoutPrefix(prefix, field)).append('|');
                    }
                } catch (IllegalAccessException ignored) {
                }
            }
        }
        if (flags != 0 || res.length() == 0) {
            res.append(Integer.toHexString(flags));
        } else {
            res.deleteCharAt(res.length() - 1);
        }
        return res.toString();
    }

    private static String constNameWithoutPrefix(String prefix, Field field) {
        return field.getName().substring(prefix.length());
    }
}