/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.oozie.util;

import java.util.Date;
import java.util.List;
import java.util.TimeZone;

import org.apache.commons.lang.StringUtils;
import org.quartz.CronExpression;
import java.text.ParseException;

/**
 * Utility class to check common parameter preconditions.
 */
public class ParamChecker {

    /**
     * Check that a value is not null. If null throws an IllegalArgumentException.
     *
     * @param obj value.
     * @param name parameter name for the exception message.
     * @return the given value.
     */
    public static <T> T notNull(T obj, String name) {
        if (obj == null) {
            throw new IllegalArgumentException(name + " cannot be null");
        }
        return obj;
    }

    /**
     * Check that a list is not null and that none of its elements is null. If null or if the list has emtpy elements
     * throws an IllegalArgumentException.
     *
     * @param list the list of strings.
     * @param name parameter name for the exception message.
     * @return the given list.
     */
    public static <T> List<T> notNullElements(List<T> list, String name) {
        notNull(list, name);
        for (int i = 0; i < list.size(); i++) {
            notNull(list.get(i), XLog.format("list [{0}] element [{1}]", name, i));
        }
        return list;
    }

    /**
     * Check that a string is not null and not empty. If null or emtpy throws an IllegalArgumentException.
     *
     * @param str value.
     * @param name parameter name for the exception message.
     * @return the given value.
     */
    public static String notEmpty(String str, String name) {
        return notEmpty(str, name, null);
    }

    /**
     * Check that a string is not null and not empty. If null or emtpy throws an IllegalArgumentException.
     *
     * @param str value.
     * @param name parameter name for the exception message.
     * @param info additional information to be printed with the exception message
     * @return the given value.
     */
    public static String notEmpty(String str, String name, String info) {
        if (str == null) {
            throw new IllegalArgumentException(name + " cannot be null" + (info == null ? "" : ", " + info));
        }
        if (str.length() == 0) {
            throw new IllegalArgumentException(name + " cannot be empty" + (info == null ? "" : ", " + info));
        }
        return str;
    }

    /**
     * Check that a list is not null and that none of its elements is null. If null or if the list has emtpy elements
     * throws an IllegalArgumentException.
     *
     * @param list the list of strings.
     * @param name parameter name for the exception message.
     * @return the given list.
     */
    public static List<String> notEmptyElements(List<String> list, String name) {
        notNull(list, name);
        for (int i = 0; i < list.size(); i++) {
            notEmpty(list.get(i), XLog.format("list [{0}] element [{1}]", name, i));
        }
        return list;
    }

    private static final int MAX_NODE_NAME_LEN = 50;

    /**
     * Check that the given string is a valid action name [a-zA-Z_][0-9a-zA-Z_\-]* and not longer than 50 chars.
     *
     * @param actionName string to validate is a token.
     * @return the given string.
     */
    public static String validateActionName(String actionName) {
        ParamChecker.notEmpty(actionName, "action name");
        if (actionName.length() > MAX_NODE_NAME_LEN) {
            throw new IllegalArgumentException(XLog.format("name [{0}] must be {1} chars or less", actionName,
                                                           MAX_NODE_NAME_LEN));
        }

        char c = actionName.charAt(0);
        if (!(c >= 'A' && c <= 'Z') && !(c >= 'a' && c <= 'z') && !(c == '_')) {
            throw new IllegalArgumentException(XLog.format("name [{0}], must start with [A-Za-z_]", actionName));
        }
        for (int i = 1; i < actionName.length(); i++) {
            c = actionName.charAt(i);
            if (!(c >= '0' && c <= '9') && !(c >= 'A' && c <= 'Z') && !(c >= 'a' && c <= 'z')
                    && !(c == '_' || c == '-')) {
                throw new IllegalArgumentException(XLog.format("name [{0}] must be [A-Za-z_][0-9A-Za-z_]*", actionName));
            }
        }
        return actionName;
    }

    /**
     * Return if the specified token is a valid Java identifier.
     *
     * @param token string to validate if it is a valid Java identifier.
     * @return if the specified token is a valid Java identifier.
     */
    public static boolean isValidIdentifier(String token) {
        ParamChecker.notEmpty(token, "identifier");
        for (int i = 0; i < token.length(); i++) {
            char c = token.charAt(i);
            if (!(c >= '0' && c <= '9') && !(c >= 'A' && c <= 'Z') && !(c >= 'a' && c <= 'z') && !(c == '_')) {
                return false;
            }
            if (i == 0 && (c >= '0' && c <= '9')) {
                return false;
            }
        }
        return true;
    }

    /**
     * Check whether the value is greater than or equals 0.
     *
     * @param value : value to test
     * @param name : Name of the parameter
     * @return If the value is > 0, return the value. Otherwise throw IllegalArgumentException
     */
    public static int checkGTZero(int value, String name) {
        if (value <= 0) {
            throw new IllegalArgumentException(XLog.format("parameter [{0}] = [{1}] must be greater than zero", name,
                                                           value));
        }
        return value;
    }

    /**
     * Check whether the value is greater than or equals to 0.
     *
     * @param value : value to test
     * @param name : Name of the parameter
     * @return If the value is >= 0, return the value. Otherwise throw IllegalArgumentException
     */
    public static int checkGEZero(int value, String name) {
        if (value < 0) {
            throw new IllegalArgumentException(XLog.format(
                    "parameter [{0}] = [{1}] must be greater than or equals zero", name, value));
        }
        return value;
    }

    /**
     * Check whether the value is less than or equal to 0.
     *
     * @param value : value to test
     * @param name : Name of the parameter
     * @return If the value is <= 0, return the value. Otherwise throw IllegalArgumentException
     */
    public static int checkLEZero(int value, String name) {
        if (value > 0) {
            throw new IllegalArgumentException(XLog.format(
                    "parameter [{0}] = [{1}] must be less than or equal to zero", name, value));
        }
        return value;
    }

    /**
     * Check whether the value is Integer.
     *
     * @param value : value to test
     * @param name : Name of the parameter
     * @return If the value is integer, return the value. Otherwise throw IllegalArgumentException
     */
    public static int checkInteger(String val, String name) {
        int ret;
        try {
            ret = Integer.parseInt(val);
        }
        catch (NumberFormatException nex) {
            throw new IllegalArgumentException(XLog.format(
                    "parameter [{0}] = [{1}]  must be an integer. Parsing error {2}", name, val, nex.getMessage(), nex));
        }
        return ret;
    }

    /**
     * Check whether a value is a valid coordinator frequency.
     *
     * @param value : value to test
     * @return If the value is a valid frequency, return the frequency, Otherwise throw IllegalArgumentException
     */
    public static String checkFrequency(String val) {
        try {
            Integer.parseInt(val);
        }
        catch (NumberFormatException ex) {
            try {
                // this part is necessary since Quartz
                // doesn't support for specifying both a day-of-week
                // and a day-of-month parameter, nor does it support
                // using "?" in both fields, but we don't want to
                // expose it to users.
                String[] cronArray1 = val.split(" ");
                String[] cronArray2 = val.split(" ");

                if (cronArray1.length != 5) {
                    throw new IllegalArgumentException(XLog.format(
                            "parameter [{0}] = [{1}]  must have 5 bit fields. Parsing error {2}", "frequency",
                            val, ex.getMessage(), ex));
                }

                if (!cronArray1[4].trim().equals("?")) {
                    cronArray1[2] = "?";
                }

                if (!cronArray2[2].trim().equals("?")) {
                    cronArray2[4] = "?";
                }

                new CronExpression("0 " + StringUtils.join(cronArray1, " "));
                new CronExpression("0 " + StringUtils.join(cronArray2, " "));
            }
            catch (ParseException pex) {
                throw new IllegalArgumentException(XLog.format(
                        "parameter [{0}] = [{1}]  must be an integer or a cron syntax. Parsing error {2}", "frequency",
                        val, ex.getMessage(), ex));
            }
        }
        return val;
    }
    /**
     * Check whether the value is Oozie processing timezone data format.
     *
     * @param value : value to test
     * @param name : Name of the parameter
     * @return If the value is in Oozie processing timezone date format, return the value.
     * Otherwise throw IllegalArgumentException
     */
    public static Date checkDateOozieTZ(String date, String name) {
        Date ret;
        try {
            ret = DateUtils.parseDateOozieTZ(date);
        }
        catch (Exception ex) {
            throw new IllegalArgumentException(XLog.format(
                    "parameter [{0}] = [{1}] must be Date in {2} format ({3})."
                            + " Parsing error {4}", name, date, DateUtils.getOozieProcessingTimeZone().getID(),
                    DateUtils.getOozieTimeMask(), ex));
        }
        return ret;
    }

    /**
     * Check whether the value mention correct Timezone.
     *
     * @param value : value to test
     * @param name : Name of the parameter
     * @return If the value is correct TZ return the value. Otherwise throw IllegalArgumentException
     */
    public static TimeZone checkTimeZone(String tzStr, String name) {
        TimeZone tz;
        try {
            tz = DateUtils.getTimeZone(tzStr);
        }
        catch (Exception ex) {
            throw new IllegalArgumentException(XLog.format("parameter [{0}] = [{1}] must be a valid TZ."
                    + " Parsing error {2}", name, tzStr, ex.getMessage(), ex));
        }
        return tz;
    }

    /**
     * Check whether an item is a member of an array of string
     *
     * @param item : item to test
     * @param members : List of items in string
     * @param name : Name of the parameter
     * @return If the item is in the member return true. Otherwise throw IllegalArgumentException
     */
    public static boolean isMember(String item, String[] members, String name) {
        for (int i = 0; i < members.length; i++) {
            if (members[i].equals(item)) {
                return true;
            }
        }
        // Error case
        StringBuilder buff = new StringBuilder();
        for (int i = 0; i < members.length; i++) {
            buff.append(members[i]).append(", ");
        }
        throw new IllegalArgumentException(XLog.format("parameter [{0}] = [{1}] " + "must be in the list {2}", name,
                                                       item, buff.toString()));
    }
}