/jira3-script-plugin/src/main/java/com/google/code/jira/script/workflow/ScriptWorkflowUtils.java

package com.google.code.jira.script.workflow;



import java.util.Iterator;

import java.util.List;

import java.util.Map;



import javax.script.Invocable;

import javax.script.ScriptEngine;

import javax.script.ScriptEngineFactory;

import javax.script.ScriptEngineManager;

import javax.script.ScriptException;



import org.apache.log4j.Category;



import com.atlassian.core.user.UserUtils;

import com.atlassian.jira.issue.Issue;

import com.opensymphony.user.EntityNotFoundException;

import com.opensymphony.user.User;

import com.opensymphony.workflow.WorkflowContext;

import com.opensymphony.workflow.WorkflowException;



public class ScriptWorkflowUtils {



	public static final String ISSUE_KEY = "issue";



	public static final String ORIGINAL_ISSUE_KEY = "originalissueobject";



	public static final String CONTEXT_KEY = "context";



	public static final String SCRIPT_NAME = "scriptName";



	public static final String ENGINE_NAME = "engineName";



	public static final String SCRIPT_CONTENT = "scriptContent";



	public static final Issue getIssue(Map transientArgs) {

		return (Issue) transientArgs.get(ISSUE_KEY);

	}



	public static final Issue getOriginalIssue(Map transientArgs) {

		return (Issue) transientArgs.get(ORIGINAL_ISSUE_KEY);

	}



	public static final User getCaller(Map transientArgs) {

		WorkflowContext context = (WorkflowContext) transientArgs.get(CONTEXT_KEY);

		String username = context.getCaller();



		try {

			return UserUtils.getUser(username);

		} catch (EntityNotFoundException e) {

			return null;

		}

	}



	public static String getScriptName(Map args) {

		return (String) args.get(SCRIPT_NAME);

	}



	public static String getEngineName(Map args) {

		return (String) args.get(ENGINE_NAME);

	}



	public static String getScriptContent(Map args) {

		return (String) args.get(SCRIPT_CONTENT);

	}



	public static ScriptEngine getEngine(Map args) throws WorkflowException {

		String engineName = getEngineName(args);

		if (engineName == null) {

			throw new WorkflowException("Missing parameter: engine name.");

		}



		// Loads the engine

		ScriptEngineManager manager = new ScriptEngineManager();

		List factories = manager.getEngineFactories();

		if (factories == null || factories.size() == 0) {

			throw new WorkflowException("No engines found! Please check your JVM version and configuration.");

		}



		ScriptEngine engine = null;

		for (Iterator iterator = factories.iterator(); iterator.hasNext();) {

			ScriptEngineFactory factory = (ScriptEngineFactory) iterator.next();

			if (engineName.equals(factory.getEngineName())) {

				engine = factory.getScriptEngine();

				break;

			}

		}



		if (engine == null) {

			throw new WorkflowException("No script engine found associate with the name " + engineName + ".");

		}



		return engine;

	}



	public static Object executeScript(Map transientVars, Map args, Category log) throws WorkflowException {

		// Obtains the issue and the caller

		Issue issue = getIssue(transientVars);

		Issue originalIssue = getOriginalIssue(transientVars);

		User caller = getCaller(transientVars);



		// Obtains the script engine and the script content

		ScriptEngine engine = getEngine(args);

		String scriptContent = getScriptContent(args);



		try {

			engine.eval(scriptContent);

			engine.put("issue", issue);

			engine.put("originalissue", originalIssue);

			engine.put("caller", caller);

			engine.put("log", log);



			Invocable invocable = (Invocable) engine;

			return invocable.invokeFunction("execute", null);

		} catch (ScriptException e) {

			throw new WorkflowException("Error evaluating script.", e);

		} catch (NoSuchMethodException e) {

			throw new WorkflowException("The method execute() has not been found.", e);

		}

	}

}