/**
 * Copyright (c) 2011, Google Inc.
 *
 * 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.android.mail.utils;

import android.net.Uri;
import android.text.TextUtils;
import android.util.Log;

import com.google.common.annotations.VisibleForTesting;

import java.util.List;
import java.util.regex.Pattern;

public class LogUtils {

    public static final String TAG = LogTag.getLogTag();

    // "GMT" + "+" or "-" + 4 digits
    private static final Pattern DATE_CLEANUP_PATTERN_WRONG_TIMEZONE =
            Pattern.compile("GMT([-+]\\d{4})$");

    private static final String ACCOUNT_PREFIX = "account:";

    /**
     * Priority constant for the println method; use LogUtils.v.
     */
    public static final int VERBOSE = Log.VERBOSE;

    /**
     * Priority constant for the println method; use LogUtils.d.
     */
    public static final int DEBUG = Log.DEBUG;

    /**
     * Priority constant for the println method; use LogUtils.i.
     */
    public static final int INFO = Log.INFO;

    /**
     * Priority constant for the println method; use LogUtils.w.
     */
    public static final int WARN = Log.WARN;

    /**
     * Priority constant for the println method; use LogUtils.e.
     */
    public static final int ERROR = Log.ERROR;

    /**
     * Used to enable/disable logging that we don't want included in
     * production releases.  This should be set to DEBUG for production releases, and VERBOSE for
     * internal builds.
     */
    // STOPSHIP: ship with DEBUG set
    private static final int MAX_ENABLED_LOG_LEVEL = VERBOSE;

    private static Boolean sDebugLoggingEnabledForTests = null;

    /**
     * Enable debug logging for unit tests.
     */
    @VisibleForTesting
    public static void setDebugLoggingEnabledForTests(boolean enabled) {
        setDebugLoggingEnabledForTestsInternal(enabled);
    }

    protected static void setDebugLoggingEnabledForTestsInternal(boolean enabled) {
        sDebugLoggingEnabledForTests = Boolean.valueOf(enabled);
    }

    /**
     * Returns true if the build configuration prevents debug logging.
     */
    @VisibleForTesting
    public static boolean buildPreventsDebugLogging() {
        return MAX_ENABLED_LOG_LEVEL > VERBOSE;
    }

    /**
     * Returns a boolean indicating whether debug logging is enabled.
     */
    protected static boolean isDebugLoggingEnabled(String tag) {
        if (buildPreventsDebugLogging()) {
            return false;
        }
        if (sDebugLoggingEnabledForTests != null) {
            return sDebugLoggingEnabledForTests.booleanValue();
        }
        return Log.isLoggable(tag, Log.DEBUG) || Log.isLoggable(TAG, Log.DEBUG);
    }

    /**
     * Returns a String for the specified content provider uri.  This will do
     * sanitation of the uri to remove PII if debug logging is not enabled.
     */
    public static String contentUriToString(final Uri uri) {
        return contentUriToString(TAG, uri);
    }

    /**
     * Returns a String for the specified content provider uri.  This will do
     * sanitation of the uri to remove PII if debug logging is not enabled.
     */
    public static String contentUriToString(String tag, Uri uri) {
        if (isDebugLoggingEnabled(tag)) {
            // Debug logging has been enabled, so log the uri as is
            return uri.toString();
        } else {
            // Debug logging is not enabled, we want to remove the email address from the uri.
            List<String> pathSegments = uri.getPathSegments();

            Uri.Builder builder = new Uri.Builder()
                    .scheme(uri.getScheme())
                    .authority(uri.getAuthority())
                    .query(uri.getQuery())
                    .fragment(uri.getFragment());

            // This assumes that the first path segment is the account
            final String account = pathSegments.get(0);

            builder = builder.appendPath(sanitizeAccountName(account));
            for (int i = 1; i < pathSegments.size(); i++) {
                builder.appendPath(pathSegments.get(i));
            }
            return builder.toString();
        }
    }

    /**
     * Sanitizes an account name.  If debug logging is not enabled, a sanitized name
     * is returned.
     */
    public static String sanitizeAccountName(String accountName) {
        if (TextUtils.isEmpty(accountName)) {
            return "";
        }

        return ACCOUNT_PREFIX + sanitizeName(TAG, accountName);
    }

    public static String sanitizeName(final String tag, final String name) {
        if (TextUtils.isEmpty(name)) {
            return "";
        }

        if (isDebugLoggingEnabled(tag)) {
            return name;
        }

        return String.valueOf(name.hashCode());
    }

    /**
     * Checks to see whether or not a log for the specified tag is loggable at the specified level.
     */
    public static boolean isLoggable(String tag, int level) {
        if (MAX_ENABLED_LOG_LEVEL > level) {
            return false;
        }
        return Log.isLoggable(tag, level) || Log.isLoggable(TAG, level);
    }

    /**
     * Send a {@link #VERBOSE} log message.
     * @param tag Used to identify the source of a log message.  It usually identifies
     *        the class or activity where the log call occurs.
     * @param format the format string (see {@link java.util.Formatter#format})
     * @param args
     *            the list of arguments passed to the formatter. If there are
     *            more arguments than required by {@code format},
     *            additional arguments are ignored.
     */
    public static int v(String tag, String format, Object... args) {
        if (isLoggable(tag, VERBOSE)) {
            return Log.v(tag, String.format(format, args));
        }
        return 0;
    }

    /**
     * Send a {@link #VERBOSE} log message.
     * @param tag Used to identify the source of a log message.  It usually identifies
     *        the class or activity where the log call occurs.
     * @param tr An exception to log
     * @param format the format string (see {@link java.util.Formatter#format})
     * @param args
     *            the list of arguments passed to the formatter. If there are
     *            more arguments than required by {@code format},
     *            additional arguments are ignored.
     */
    public static int v(String tag, Throwable tr, String format, Object... args) {
        if (isLoggable(tag, VERBOSE)) {
            return Log.v(tag, String.format(format, args), tr);
        }
        return 0;
    }

    /**
     * Send a {@link #DEBUG} log message.
     * @param tag Used to identify the source of a log message.  It usually identifies
     *        the class or activity where the log call occurs.
     * @param format the format string (see {@link java.util.Formatter#format})
     * @param args
     *            the list of arguments passed to the formatter. If there are
     *            more arguments than required by {@code format},
     *            additional arguments are ignored.
     */
    public static int d(String tag, String format, Object... args) {
        if (isLoggable(tag, DEBUG)) {
            return Log.d(tag, String.format(format, args));
        }
        return 0;
    }

    /**
     * Send a {@link #DEBUG} log message.
     * @param tag Used to identify the source of a log message.  It usually identifies
     *        the class or activity where the log call occurs.
     * @param tr An exception to log
     * @param format the format string (see {@link java.util.Formatter#format})
     * @param args
     *            the list of arguments passed to the formatter. If there are
     *            more arguments than required by {@code format},
     *            additional arguments are ignored.
     */
    public static int d(String tag, Throwable tr, String format, Object... args) {
        if (isLoggable(tag, DEBUG)) {
            return Log.d(tag, String.format(format, args), tr);
        }
        return 0;
    }

    /**
     * Send a {@link #INFO} log message.
     * @param tag Used to identify the source of a log message.  It usually identifies
     *        the class or activity where the log call occurs.
     * @param format the format string (see {@link java.util.Formatter#format})
     * @param args
     *            the list of arguments passed to the formatter. If there are
     *            more arguments than required by {@code format},
     *            additional arguments are ignored.
     */
    public static int i(String tag, String format, Object... args) {
        if (isLoggable(tag, INFO)) {
            return Log.i(tag, String.format(format, args));
        }
        return 0;
    }

    /**
     * Send a {@link #INFO} log message.
     * @param tag Used to identify the source of a log message.  It usually identifies
     *        the class or activity where the log call occurs.
     * @param tr An exception to log
     * @param format the format string (see {@link java.util.Formatter#format})
     * @param args
     *            the list of arguments passed to the formatter. If there are
     *            more arguments than required by {@code format},
     *            additional arguments are ignored.
     */
    public static int i(String tag, Throwable tr, String format, Object... args) {
        if (isLoggable(tag, INFO)) {
            return Log.i(tag, String.format(format, args), tr);
        }
        return 0;
    }

    /**
     * Send a {@link #WARN} log message.
     * @param tag Used to identify the source of a log message.  It usually identifies
     *        the class or activity where the log call occurs.
     * @param format the format string (see {@link java.util.Formatter#format})
     * @param args
     *            the list of arguments passed to the formatter. If there are
     *            more arguments than required by {@code format},
     *            additional arguments are ignored.
     */
    public static int w(String tag, String format, Object... args) {
        if (isLoggable(tag, WARN)) {
            return Log.w(tag, String.format(format, args));
        }
        return 0;
    }

    /**
     * Send a {@link #WARN} log message.
     * @param tag Used to identify the source of a log message.  It usually identifies
     *        the class or activity where the log call occurs.
     * @param tr An exception to log
     * @param format the format string (see {@link java.util.Formatter#format})
     * @param args
     *            the list of arguments passed to the formatter. If there are
     *            more arguments than required by {@code format},
     *            additional arguments are ignored.
     */
    public static int w(String tag, Throwable tr, String format, Object... args) {
        if (isLoggable(tag, WARN)) {
            return Log.w(tag, String.format(format, args), tr);
        }
        return 0;
    }

    /**
     * Send a {@link #ERROR} log message.
     * @param tag Used to identify the source of a log message.  It usually identifies
     *        the class or activity where the log call occurs.
     * @param format the format string (see {@link java.util.Formatter#format})
     * @param args
     *            the list of arguments passed to the formatter. If there are
     *            more arguments than required by {@code format},
     *            additional arguments are ignored.
     */
    public static int e(String tag, String format, Object... args) {
        if (isLoggable(tag, ERROR)) {
            return Log.e(tag, String.format(format, args));
        }
        return 0;
    }

    /**
     * Send a {@link #ERROR} log message.
     * @param tag Used to identify the source of a log message.  It usually identifies
     *        the class or activity where the log call occurs.
     * @param tr An exception to log
     * @param format the format string (see {@link java.util.Formatter#format})
     * @param args
     *            the list of arguments passed to the formatter. If there are
     *            more arguments than required by {@code format},
     *            additional arguments are ignored.
     */
    public static int e(String tag, Throwable tr, String format, Object... args) {
        if (isLoggable(tag, ERROR)) {
            return Log.e(tag, String.format(format, args), tr);
        }
        return 0;
    }

    /**
     * What a Terrible Failure: Report a condition that should never happen.
     * The error will always be logged at level ASSERT with the call stack.
     * Depending on system configuration, a report may be added to the
     * {@link android.os.DropBoxManager} and/or the process may be terminated
     * immediately with an error dialog.
     * @param tag Used to identify the source of a log message.  It usually identifies
     *        the class or activity where the log call occurs.
     * @param format the format string (see {@link java.util.Formatter#format})
     * @param args
     *            the list of arguments passed to the formatter. If there are
     *            more arguments than required by {@code format},
     *            additional arguments are ignored.
     */
    public static int wtf(String tag, String format, Object... args) {
        return Log.wtf(tag, String.format(format, args), new Error());
    }

    /**
     * What a Terrible Failure: Report a condition that should never happen.
     * The error will always be logged at level ASSERT with the call stack.
     * Depending on system configuration, a report may be added to the
     * {@link android.os.DropBoxManager} and/or the process may be terminated
     * immediately with an error dialog.
     * @param tag Used to identify the source of a log message.  It usually identifies
     *        the class or activity where the log call occurs.
     * @param tr An exception to log
     * @param format the format string (see {@link java.util.Formatter#format})
     * @param args
     *            the list of arguments passed to the formatter. If there are
     *            more arguments than required by {@code format},
     *            additional arguments are ignored.
     */
    public static int wtf(String tag, Throwable tr, String format, Object... args) {
        return Log.wtf(tag, String.format(format, args), tr);
    }


    /**
     * Try to make a date MIME(RFC 2822/5322)-compliant.
     *
     * It fixes:
     * - "Thu, 10 Dec 09 15:08:08 GMT-0700" to "Thu, 10 Dec 09 15:08:08 -0700"
     *   (4 digit zone value can't be preceded by "GMT")
     *   We got a report saying eBay sends a date in this format
     */
    public static String cleanUpMimeDate(String date) {
        if (TextUtils.isEmpty(date)) {
            return date;
        }
        date = DATE_CLEANUP_PATTERN_WRONG_TIMEZONE.matcher(date).replaceFirst("$1");
        return date;
    }


    public static String byteToHex(int b) {
        return byteToHex(new StringBuilder(), b).toString();
    }

    public static StringBuilder byteToHex(StringBuilder sb, int b) {
        b &= 0xFF;
        sb.append("0123456789ABCDEF".charAt(b >> 4));
        sb.append("0123456789ABCDEF".charAt(b & 0xF));
        return sb;
    }

}