/*
 *  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
 *
 *      https://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.util;

import java.io.File;

import org.apache.tools.ant.ProjectComponent;
import org.apache.tools.ant.types.Path;
import org.apache.tools.ant.types.Reference;
import org.apache.tools.ant.types.ResourceCollection;
import org.apache.tools.ant.types.resources.Union;

A class to help in creating, setting and getting script runners.
/**
 * A class to help in creating, setting and getting script runners.
 */
public class ScriptRunnerHelper {
    private ClasspathUtils.Delegate cpDelegate = null;
    private File    srcFile;
    private String  encoding;
    private String  manager = "auto";
    private String  language;
    private String  text;
    private boolean compiled = false;
    private boolean setBeans = true;
    private ProjectComponent projectComponent;
    private ClassLoader scriptLoader = null;
    private Union resources = new Union();

    
Set the project component associated with this helper.
Params:
component – the project component that owns this helper./**
     * Set the project component associated with this helper.
     * @param component the project component that owns this helper.
     */
    public void setProjectComponent(ProjectComponent component) {
        this.projectComponent = component;
    }

    
Create and set text on a script.
Returns:
the created or reused script runner./**
     * Create and set text on a script.
     * @return the created or reused script runner.
     */
    public ScriptRunnerBase getScriptRunner() {
        ScriptRunnerBase runner = getRunner();
        runner.setCompiled(compiled);

        if (encoding != null) {
            // set it first, because runner.setSrc() loads immediately the file
            runner.setEncoding(encoding);
        }
        if (srcFile != null) {
            runner.setSrc(srcFile);
        }
        if (text != null) {
            runner.addText(text);
        }
        if (resources != null) {
            runner.loadResources(resources);
        }
        if (setBeans) {
            runner.bindToComponent(projectComponent);
        } else {
            runner.bindToComponentMinimum(projectComponent);
        }
        return runner;
    }

    
Classpath to be used when searching for classes and resources.
Returns:
an empty Path instance to be configured by Ant./**
     * Classpath to be used when searching for classes and resources.
     *
     * @return an empty Path instance to be configured by Ant.
     */
    public Path createClasspath() {
        return getClassPathDelegate().createClasspath();
    }

    
Set the classpath to be used when searching for classes and resources.
Params:
classpath – an Ant Path object containing the search path./**
     * Set the classpath to be used when searching for classes and resources.
     *
     * @param classpath an Ant Path object containing the search path.
     */
    public void setClasspath(Path classpath) {
        getClassPathDelegate().setClasspath(classpath);
    }

    
Set the classpath by reference.
Params:
r – a Reference to a Path instance to be used as the classpath
         value./**
     * Set the classpath by reference.
     *
     * @param r a Reference to a Path instance to be used as the classpath
     *          value.
     */
    public void setClasspathRef(Reference r) {
        getClassPathDelegate().setClasspathref(r);
    }

    
Load the script from an external file; optional.
Params:
file – the file containing the script source./**
     * Load the script from an external file; optional.
     *
     * @param file the file containing the script source.
     */
    public void setSrc(File file) {
        this.srcFile = file;
    }

    
Get the external script file; optional.
Returns:
the file containing the script source.
Since:
Ant 1.10.2/**
     * Get the external script file; optional.
     * @return the file containing the script source.
     * @since Ant 1.10.2
     */
    public File getSrc() {
        return srcFile;
    }

    
Set the encoding of the script from an external file; optional.
Params:
encoding – the encoding of the file containing the script source.
Since:
Ant 1.10.2/**
     * Set the encoding of the script from an external file; optional.
     *
     * @param encoding the encoding of the file containing the script source.
     * @since Ant 1.10.2
     */
    public void setEncoding(String encoding) {
        this.encoding = encoding;
    }

    
Get the external file encoding.
Returns:
the encoding of the file containing the script source.
Since:
Ant 1.10.2/**
     * Get the external file encoding.
     * @return the encoding of the file containing the script source.
     * @since Ant 1.10.2
     */
    public String getEncoding() {
        return encoding;
    }

    
Add script text.
Params:
text – a component of the script text to be added./**
     * Add script text.
     *
     * @param text a component of the script text to be added.
     */
    public void addText(String text) {
        this.text = text;
    }

    
Defines the script manager - defaults to "auto".
Params:
manager – the scripting manager - "bsf" or "javax" or "auto"/**
     * Defines the script manager - defaults to "auto".
     *
     * @param manager the scripting manager - "bsf" or "javax" or "auto"
     */
    public void setManager(String manager) {
        this.manager = manager;
    }

    
Defines the language (required).
Params:
language – the scripting language name for the script./**
     * Defines the language (required).
     *
     * @param language the scripting language name for the script.
     */
    public void setLanguage(String language) {
        this.language = language;
    }

    
Get the language.
Returns:
the scripting language./**
     * Get the language.
     * @return the scripting language.
     */
    public String getLanguage() {
        return language;
    }

    
Enable the compilation of the script if possible.
If this is true and the compilation feature is available in
the script engine, the script is compiled before the first
evaluation, and should be cached for future evaluations.
Otherwise, the script is evaluated each time.
The default is false.
Params:
compiled – the value to set./**
     * Enable the compilation of the script if possible.
     * If this is true and the compilation feature is available in
     * the script engine, the script is compiled before the first
     * evaluation, and should be cached for future evaluations.
     * Otherwise, the script is evaluated each time.
     * The default is false.
     *
     * @param compiled the value to set.
     */
    public void setCompiled(boolean compiled) {
        this.compiled = compiled;
    }

    
Get the compilation feature.
Returns:
the compilation feature./**
     * Get the compilation feature.
     * @return the compilation feature.
     */
    public boolean getCompiled() {
        return this.compiled;
    }

    
Set the setbeans attribute.
If this is true, <script> will create variables in the
script instance for all
properties, targets and references of the current project.
It this is false, only the project and self variables will
be set.
The default is true.
Params:
setBeans – the value to set./**
     * Set the setbeans attribute.
     * If this is true, &lt;script&gt; will create variables in the
     * script instance for all
     * properties, targets and references of the current project.
     * It this is false, only the project and self variables will
     * be set.
     * The default is true.
     * @param setBeans the value to set.
     */
    public void setSetBeans(boolean setBeans) {
        this.setBeans = setBeans;
    }

    
Used when called by scriptdef.
Params:
loader – the loader used by scriptdef./**
     * Used when called by scriptdef.
     * @param loader the loader used by scriptdef.
     */
    public void setClassLoader(ClassLoader loader) {
        scriptLoader = loader;
    }

    private synchronized ClassLoader generateClassLoader() {
        if (scriptLoader != null) {
            return scriptLoader;
        }
        if (cpDelegate == null) {
            scriptLoader = getClass().getClassLoader();
            return scriptLoader;
        }
        scriptLoader = cpDelegate.getClassLoader();
        return scriptLoader;
    }

    private ClasspathUtils.Delegate getClassPathDelegate() {
        if (cpDelegate == null) {
            if (projectComponent == null) {
                throw new IllegalStateException("Can't access classpath without a project component");
            }
            cpDelegate = ClasspathUtils.getDelegate(projectComponent);
        }
        return cpDelegate;
    }

    
Get a script runner.
/**
     * Get a script runner.
     */
    private ScriptRunnerBase getRunner() {
        return new ScriptRunnerCreator(projectComponent.getProject()).createRunner(
                manager, language, generateClassLoader());
    }

    
Add any source resource.
Params:
resource – source of script
Since:
Ant 1.7.1/**
     * Add any source resource.
     *
     * @param resource source of script
     * @since Ant 1.7.1
     */
    public void add(ResourceCollection resource) {
        resources.add(resource);
    }
}