Subversion Repositories SmartDukaan

/*
 *      Copyright 2005 stat4j.org
 *
 *   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 net.sourceforge.stat4j;

import java.util.Date;



/**
 * Name:                Threshold.java
 * Date:                Sep 6, 2004
 * Description:
 * 
 * A preset limit that may be applied to a statstic so
 * as to trigger an alert.
 * 
 * 
 * @see Alert
 * 
 * @author Lara D'Abreo
 */
public final class Threshold {

        //Threshold operators
        public interface Operators {
        
                public final static String LESS_THAN_OR_EQUAL = "<=";
                public final static String GREATER_THAN_OR_EQUAL = ">=";
                public final static String EQUAL_TO = "==";
                public final static String NOT_EQUAL_TO = "!=";
                public final static String GREATER_THAN = ">";
                public final static String LESS_THAN = "<";
        

                public final static String[] ALL_OPS =new String[] 
                        {
                                LESS_THAN_OR_EQUAL,
                                GREATER_THAN_OR_EQUAL,
                                EQUAL_TO,
                                NOT_EQUAL_TO,
                                GREATER_THAN,
                                LESS_THAN,
                                };

        }


        protected String operator;
        protected double limit;
        

        public Threshold() {
        }

        /**
         * Evaluate if rule is triggered
         * @param reading
         * @return
         */
        public boolean isTriggered(double value) {

                if (operator == null)
                        return false;

                if (operator.equals(Operators.EQUAL_TO)) {
                        return value == limit;
                } else if (operator.equals(Operators.NOT_EQUAL_TO)) {
                        return value != limit;
                } else if (operator.equals(Operators.GREATER_THAN)) {
                        return value > limit;
                } else if (operator.equals(Operators.GREATER_THAN_OR_EQUAL)) {
                        Date currentDate = new Date();
                        if(currentDate.getHours()>1 && currentDate.getHours()<5) {
                                return value >= limit/5;
                        } else if(currentDate.getHours()<=23 && currentDate.getHours()>6) {
                                return value >= limit;
                        } else {
                                return value >= limit/2;
                        }
                } else if (operator.equals(Operators.LESS_THAN)) {
                        return value < limit;
                } else if (operator.equals(Operators.LESS_THAN_OR_EQUAL)) {
                        return value <= limit;
                }
                return false;
        }

        


        public static Threshold toThreshold(String str) {
                if (str == null)
                        return null;
                if (str.length() == 0)
                        return null;
                        
                 try {
                                int idx = -1;String op= null;
                                for (int i = 0; i < Operators.ALL_OPS.length; ++i) {
                                        String opstr = Operators.ALL_OPS[i];
                                        idx= str.indexOf(opstr);
                                        if (idx >= 0) {
                                                op = opstr;
                                                break;                                          
                                        } //fi
                                }//rof
                                
                                // mo operator found
                                if (idx == -1) return null;

                                // value
                                String valueStr = str.substring(idx+op.length());
                                double value = Double.parseDouble(valueStr);
                                
                                Threshold rule = new Threshold();
                                rule.setOperator(op);
                                rule.setValue(value);
                        
                                return rule;

                        } catch (Exception e) {
                                return null;
                        }

        }
        

        /**
         * @param string
         */
        public void setOperator(String string) {
                operator = string;
        }

        /**
         * @param d
         */
        public void setValue(double d) {
                limit = d;
        }
        
        public String toString() {
                return operator + limit;
        }

}