/*
    * Copyright (C) 2011 the original author or authors.
    *
    * 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.codehaus.gmavenplus.mojo;
  
  import org.apache.maven.artifact.DependencyResolutionRequiredException;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugins.annotations.Mojo;
  import org.apache.maven.plugins.annotations.Parameter;
  import org.apache.maven.plugins.annotations.ResolutionScope;
  import org.codehaus.gmavenplus.model.internal.Version;
  import org.codehaus.gmavenplus.util.FileUtils;
  import org.codehaus.gmavenplus.util.NoExitSecurityManager;
  
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.Reader;
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.net.MalformedURLException;
  import java.net.URL;
  
  import static org.codehaus.gmavenplus.util.ReflectionUtils.findConstructor;
  import static org.codehaus.gmavenplus.util.ReflectionUtils.findMethod;
  import static org.codehaus.gmavenplus.util.ReflectionUtils.invokeConstructor;
  import static org.codehaus.gmavenplus.util.ReflectionUtils.invokeMethod;
  
  
  /**
   * Executes Groovy scripts (in the pom or external), bound to the current project.
   * Note that this mojo requires Groovy >= 1.5.0.
   * Note that it references the plugin classloader to pull in dependencies Groovy didn't include
   * (for things like Ant for AntBuilder, Ivy for @grab, and Jansi for Groovysh).
   *
   * @author Keegan Witt
   * @since 1.0-beta-1
   */
  @Mojo(name = "execute", requiresDependencyResolution = ResolutionScope.TEST, threadSafe = true)
  public class ExecuteMojo extends AbstractToolsMojo {
  
      /**
       * Groovy 4.0.0-RC-1 version.
       */
      protected static final Version GROOVY_4_0_0_RC_1 = new Version(4, 0, 0, "RC-1");
  
      /**
       * Groovy 1.7.0 version.
       */
      protected static final Version GROOVY_1_7_0 = new Version(1, 7, 0);
  
      /**
       * Groovy scripts to run (in order). Can be a script body, a {@link java.net.URL URL} to a script
       * (local or remote), or a filename.
       */
      @Parameter(required = true)
      protected String[] scripts;
  
      /**
       * Whether to continue executing remaining scripts when a script fails.
       */
      @Parameter(defaultValue = "false")
      protected boolean continueExecuting;
  
      /**
       * The encoding of script files.
       *
       * @since 1.0-beta-2
       */
      @Parameter(defaultValue = "${project.build.sourceEncoding}")
      protected String sourceEncoding;
  
      /**
       * Flag to allow script execution to be skipped.
       *
       * @since 1.9.1
       */
      @Parameter(defaultValue = "false")
      protected boolean skipScriptExecution;
  
      /**
       * Executes this mojo.
       *
       * @throws MojoExecutionException If an unexpected problem occurs (causes a "BUILD ERROR" message to be displayed)
      */
     @Override
     public void execute() throws MojoExecutionException {
         doExecute();
     }
 
     /**
      * Does the actual execution.
      *
      * @throws MojoExecutionException If an unexpected problem occurs (causes a "BUILD ERROR" message to be displayed)
      */
     protected synchronized void doExecute() throws MojoExecutionException {
         if (skipScriptExecution) {
             getLog().info("Skipping script execution because ${skipScriptExecution} was set to true.");
             return;
         }
 
         if (scripts == null || scripts.length == 0) {
             getLog().info("No scripts specified for execution. Skipping.");
             return;
         }
 
         try {
             setupClassWrangler(project.getTestClasspathElements(), includeClasspath);
         } catch (MalformedURLException e) {
             throw new MojoExecutionException("Unable to add project test dependencies to classpath.", e);
         } catch (DependencyResolutionRequiredException e) {
             throw new MojoExecutionException("Test dependencies weren't resolved.", e);
         }
 
         logPluginClasspath();
         classWrangler.logGroovyVersion(mojoExecution.getMojoDescriptor().getGoal());
 
         try {
             getLog().debug("Project test classpath:\n" + project.getTestClasspathElements());
         } catch (DependencyResolutionRequiredException e) {
             getLog().debug("Unable to log project test classpath");
         }
 
         if (groovyVersionSupportsAction()) {
             final SecurityManager sm = System.getSecurityManager();
             try {
                 if (!allowSystemExits) {
                     System.setSecurityManager(new NoExitSecurityManager());
                 }
 
                 // get classes we need with reflection
                 Class<?> groovyShellClass = classWrangler.getClass("groovy.lang.GroovyShell");
 
                 // create a GroovyShell to run scripts in
                 Object shell = setupShell(groovyShellClass);
 
                 // run the scripts
                 executeScripts(groovyShellClass, shell);
             } catch (ClassNotFoundException e) {
                 throw new MojoExecutionException("Unable to get a Groovy class from classpath (" + e.getMessage() + "). Do you have Groovy as a compile dependency in your project or the plugin?", e);
             } catch (InvocationTargetException e) {
                 throw new MojoExecutionException("Error occurred while calling a method on a Groovy class from classpath.", e);
             } catch (InstantiationException e) {
                 throw new MojoExecutionException("Error occurred while instantiating a Groovy class from classpath.", e);
             } catch (IllegalAccessException e) {
                 throw new MojoExecutionException("Unable to access a method on a Groovy class from classpath.", e);
             } finally {
                 if (!allowSystemExits) {
                     System.setSecurityManager(sm);
                 }
             }
         } else {
             getLog().error("Your Groovy version (" + classWrangler.getGroovyVersionString() + ") doesn't support script execution. The minimum version of Groovy required is " + minGroovyVersion + ". Skipping script execution.");
         }
     }
 
     /**
      * Instantiates a new groovy.lang.GroovyShell object.
      *
      * @param groovyShellClass the groovy.lang.GroovyShell class
      * @return a new groovy.lang.GroovyShell object
      * @throws InvocationTargetException when a reflection invocation needed for shell configuration cannot be completed
      * @throws IllegalAccessException    when a method needed for shell configuration cannot be accessed
      * @throws InstantiationException    when a class needed for shell configuration cannot be instantiated
      * @throws ClassNotFoundException    when a class needed for shell configuration cannot be found
      */
     protected Object setupShell(final Class<?> groovyShellClass) throws InvocationTargetException, IllegalAccessException, InstantiationException, ClassNotFoundException {
         Object shell;
         if (sourceEncoding != null) {
             Class<?> compilerConfigurationClass = classWrangler.getClass("org.codehaus.groovy.control.CompilerConfiguration");
             Object compilerConfiguration = invokeConstructor(findConstructor(compilerConfigurationClass));
             invokeMethod(findMethod(compilerConfigurationClass, "setSourceEncoding", String.class), compilerConfiguration, sourceEncoding);
             shell = invokeConstructor(findConstructor(groovyShellClass, ClassLoader.class, compilerConfigurationClass), classWrangler.getClassLoader(), compilerConfiguration);
         } else {
             shell = invokeConstructor(findConstructor(groovyShellClass, ClassLoader.class), classWrangler.getClassLoader());
         }
         initializeProperties();
         Method setProperty = findMethod(groovyShellClass, "setProperty", String.class, Object.class);
         if (bindPropertiesToSeparateVariables) {
             for (Object k : properties.keySet()) {
                 invokeMethod(setProperty, shell, k, properties.get(k));
             }
         } else {
             if (groovyOlderThan(GROOVY_4_0_0_RC_1)) {
                 invokeMethod(setProperty, shell, "properties", properties);
             } else {
                 throw new IllegalArgumentException("properties is a read-only property in Groovy " + GROOVY_4_0_0_RC_1 + " and later.");
             }
         }
 
         return shell;
     }
 
     /**
      * Executes the configured scripts.
      *
      * @param groovyShellClass the groovy.lang.GroovyShell class
      * @param shell            a groovy.lag.GroovyShell object
      * @throws InvocationTargetException when a reflection invocation needed for script execution cannot be completed
      * @throws IllegalAccessException    when a method needed for script execution cannot be accessed
      * @throws MojoExecutionException    when an exception occurred during script execution (causes a "BUILD ERROR" message to be displayed)
      */
     protected void executeScripts(final Class<?> groovyShellClass, final Object shell) throws InvocationTargetException, IllegalAccessException, MojoExecutionException {
         int scriptNum = 1;
         for (String script : scripts) {
             try {
                 // TODO: try as file first, then as URL?
                 try {
                     // it's a URL to a script
                     executeScriptFromUrl(groovyShellClass, shell, script);
                 } catch (MalformedURLException e) {
                     // it's not a URL to a script, try as a filename
                     File scriptFile = new File(script);
                     if (scriptFile.isFile()) {
                         getLog().info("Running Groovy script from " + scriptFile.getCanonicalPath() + ".");
                         Method evaluateFile = findMethod(groovyShellClass, "evaluate", File.class);
                         invokeMethod(evaluateFile, shell, scriptFile);
                     } else {
                         // it's neither a filename or URL, treat as a script body
                         Method evaluateString = findMethod(groovyShellClass, "evaluate", String.class);
                         invokeMethod(evaluateString, shell, script);
                     }
                 }
             } catch (IOException ioe) {
                 if (continueExecuting) {
                     getLog().error("An Exception occurred while executing script " + scriptNum + ". Continuing to execute remaining scripts.", ioe);
                 } else {
                     throw new MojoExecutionException("An Exception occurred while executing script " + scriptNum + ".", ioe);
                 }
             }
             scriptNum++;
         }
     }
 
     /**
      * Executes a script at a URL location.
      *
      * @param groovyShellClass the GroovyShell class
      * @param shell            a groovy.lag.GroovyShell object
      * @param script           the script URL to execute
      * @throws IOException               when the stream can't be opened on the URL
      * @throws InvocationTargetException when a reflection invocation needed for script execution cannot be completed
      * @throws IllegalAccessException    when a method needed for script execution cannot be accessed
      */
     protected void executeScriptFromUrl(Class<?> groovyShellClass, Object shell, String script) throws IOException, InvocationTargetException, IllegalAccessException {
         URL url = new URL(script);
         getLog().info("Running Groovy script from " + url + ".");
         if (groovyAtLeast(GROOVY_1_7_0)) {
             Method evaluateUrlWithReader = findMethod(groovyShellClass, "evaluate", Reader.class);
             BufferedReader reader = null;
             try {
                 if (sourceEncoding != null) {
                     reader = new BufferedReader(new InputStreamReader(url.openStream(), sourceEncoding));
                 } else {
                     reader = new BufferedReader(new InputStreamReader(url.openStream()));
                 }
                 invokeMethod(evaluateUrlWithReader, shell, reader);
             } finally {
                 FileUtils.closeQuietly(reader);
             }
         } else {
             Method evaluateUrlWithStream = findMethod(groovyShellClass, "evaluate", InputStream.class);
             InputStream inputStream = null;
             try {
                 if (sourceEncoding != null) {
                     getLog().warn("Source encoding does not apply to Groovy versions previous to 1.7.0, ignoring.");
                 }
                 inputStream = url.openStream();
                 invokeMethod(evaluateUrlWithStream, shell, inputStream);
             } finally {
                 FileUtils.closeQuietly(inputStream);
             }
         }
     }
 
 }