/*
 * Copyright  2000,2002-2004 The Apache Software Foundation
 *
 *  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 org.apache.tools.ant.types;

import java.util.Vector;
import org.apache.tools.ant.BuildException;

/**
 * Wrapper for environment variables.
 *
 */
public class Environment {

    /**
     * a vector of type Enviromment.Variable
     * @see Variable
     */
    protected Vector variables;

    /**
     * representation of a single env value
     */
    public static class Variable {

        /**
         * env key and value pair; everything gets expanded to a string
         * during assignment
         */
        private String key, value;

        /**
         * Constructor for variable
         *
         */
        public Variable() {
            super();
        }

        /**
         * set the key
         * @param key string
         */
        public void setKey(String key) {
            this.key = key;
        }

        /**
         * set the value
         * @param value string value
         */
        public void setValue(String value) {
            this.value = value;
        }

        /**
         * key accessor
         * @return key
         */
        public String getKey() {
            return this.key;
        }

        /**
         * value accessor
         * @return value
         */
        public String getValue() {
            return this.value;
        }

        /**
         * stringify path and assign to the value.
         * The value will contain all path elements separated by the appropriate
         * separator
         * @param path path
         */
        public void setPath(Path path) {
            this.value = path.toString();
        }

        /**
         * get the absolute path of a file and assign it to the value
         * @param file file to use as the value
         */
        public void setFile(java.io.File file) {
            this.value = file.getAbsolutePath();
        }

        /**
         * get the assigment string
         * This is not ready for insertion into a property file without following
         * the escaping rules of the properties class.
         * @return a string of the form key=value.
         * @throws BuildException if key or value are unassigned
         */
        public String getContent() throws BuildException {
            if (key == null || value == null) {
                throw new BuildException("key and value must be specified "
                    + "for environment variables.");
            }
            StringBuffer sb = new StringBuffer(key.trim());
            sb.append("=").append(value.trim());
            return sb.toString();
        }
    }

    /**
     * constructor
     */
    public Environment() {
        variables = new Vector();
    }

    /**
     * add a variable.
     * Validity checking is <i>not</i> performed at this point. Duplicates
     * are not caught either.
     * @param var new variable.
     */
    public void addVariable(Variable var) {
        variables.addElement(var);
    }

    /**
     * get the variable list as an array
     * @return array of key=value assignment strings
     * @throws BuildException if any variable is misconfigured
     */
    public String[] getVariables() throws BuildException {
        if (variables.size() == 0) {
            return null;
        }
        String[] result = new String[variables.size()];
        for (int i = 0; i < result.length; i++) {
            result[i] = ((Variable) variables.elementAt(i)).getContent();
        }
        return result;
    }
}