/*
 * Copyright (C) 2013 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.android.incallui;

import android.net.Uri;
import android.telecom.PhoneAccount;
import android.telephony.PhoneNumberUtils;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * Manages logging for the entire class.
 */
public class Log {

    // Generic tag for all In Call logging
    public static final String TAG = "InCall";

    public static final boolean DEBUG = android.util.Log.isLoggable(TAG, android.util.Log.DEBUG);
    public static final boolean VERBOSE = android.util.Log.isLoggable(TAG,
            android.util.Log.VERBOSE);
    public static final String TAG_DELIMETER = " - ";

    public static void d(String tag, String msg) {
        if (DEBUG) {
            android.util.Log.d(TAG, delimit(tag) + msg);
        }
    }

    public static void d(Object obj, String msg) {
        if (DEBUG) {
            android.util.Log.d(TAG, getPrefix(obj) + msg);
        }
    }

    public static void d(Object obj, String str1, Object str2) {
        if (DEBUG) {
            android.util.Log.d(TAG, getPrefix(obj) + str1 + str2);
        }
    }

    public static void v(Object obj, String msg) {
        if (VERBOSE) {
            android.util.Log.v(TAG, getPrefix(obj) + msg);
        }
    }

    public static void v(Object obj, String str1, Object str2) {
        if (VERBOSE) {
            android.util.Log.d(TAG, getPrefix(obj) + str1 + str2);
        }
    }

    public static void e(String tag, String msg, Exception e) {
        android.util.Log.e(TAG, delimit(tag) + msg, e);
    }

    public static void e(String tag, String msg) {
        android.util.Log.e(TAG, delimit(tag) + msg);
    }

    public static void e(Object obj, String msg, Exception e) {
        android.util.Log.e(TAG, getPrefix(obj) + msg, e);
    }

    public static void e(Object obj, String msg) {
        android.util.Log.e(TAG, getPrefix(obj) + msg);
    }

    public static void i(String tag, String msg) {
        android.util.Log.i(TAG, delimit(tag) + msg);
    }

    public static void i(Object obj, String msg) {
        android.util.Log.i(TAG, getPrefix(obj) + msg);
    }

    public static void w(Object obj, String msg) {
        android.util.Log.w(TAG, getPrefix(obj) + msg);
    }

    public static void wtf(Object obj, String msg) {
        android.util.Log.wtf(TAG, getPrefix(obj) + msg);
    }

    public static String piiHandle(Object pii) {
        if (pii == null || VERBOSE) {
            return String.valueOf(pii);
        }

        if (pii instanceof Uri) {
            Uri uri = (Uri) pii;

            // All Uri's which are not "tel" go through normal pii() method.
            if (!PhoneAccount.SCHEME_TEL.equals(uri.getScheme())) {
                return pii(pii);
            } else {
                pii = uri.getSchemeSpecificPart();
            }
        }

        String originalString = String.valueOf(pii);
        StringBuilder stringBuilder = new StringBuilder(originalString.length());
        for (char c : originalString.toCharArray()) {
            if (PhoneNumberUtils.isDialable(c)) {
                stringBuilder.append('*');
            } else {
                stringBuilder.append(c);
            }
        }
        return stringBuilder.toString();
    }

    /**
     * Redact personally identifiable information for production users.
     * If we are running in verbose mode, return the original string, otherwise
     * return a SHA-1 hash of the input string.
     */
    public static String pii(Object pii) {
        if (pii == null || VERBOSE) {
            return String.valueOf(pii);
        }
        return "[" + secureHash(String.valueOf(pii).getBytes()) + "]";
    }

    private static String secureHash(byte[] input) {
        MessageDigest messageDigest;
        try {
            messageDigest = MessageDigest.getInstance("SHA-1");
        } catch (NoSuchAlgorithmException e) {
            return null;
        }
        messageDigest.update(input);
        byte[] result = messageDigest.digest();
        return encodeHex(result);
    }

    private static String encodeHex(byte[] bytes) {
        StringBuffer hex = new StringBuffer(bytes.length * 2);

        for (int i = 0; i < bytes.length; i++) {
            int byteIntValue = bytes[i] & 0xff;
            if (byteIntValue < 0x10) {
                hex.append("0");
            }
            hex.append(Integer.toString(byteIntValue, 16));
        }

        return hex.toString();
    }

    private static String getPrefix(Object obj) {
        return (obj == null ? "" : (obj.getClass().getSimpleName() + TAG_DELIMETER));
    }

    private static String delimit(String tag) {
        return tag + TAG_DELIMETER;
    }
}