/*******************************************************************************
 * Copyright (c) 2004, 2005 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jdt.internal.debug.core.logicalstructures;

import java.text.MessageFormat;

import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.debug.core.DebugEvent;
import org.eclipse.debug.core.DebugException;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.ILogicalStructureType;
import org.eclipse.debug.core.IStatusHandler;
import org.eclipse.debug.core.model.IDebugTarget;
import org.eclipse.debug.core.model.ISourceLocator;
import org.eclipse.debug.core.model.IThread;
import org.eclipse.debug.core.model.IValue;
import org.eclipse.debug.core.sourcelookup.ISourceLookupDirector;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.debug.core.IJavaClassType;
import org.eclipse.jdt.debug.core.IJavaDebugTarget;
import org.eclipse.jdt.debug.core.IJavaInterfaceType;
import org.eclipse.jdt.debug.core.IJavaObject;
import org.eclipse.jdt.debug.core.IJavaReferenceType;
import org.eclipse.jdt.debug.core.IJavaStackFrame;
import org.eclipse.jdt.debug.core.IJavaThread;
import org.eclipse.jdt.debug.core.IJavaType;
import org.eclipse.jdt.debug.core.IJavaValue;
import org.eclipse.jdt.debug.core.IJavaVariable;
import org.eclipse.jdt.debug.eval.IAstEvaluationEngine;
import org.eclipse.jdt.debug.eval.ICompiledExpression;
import org.eclipse.jdt.debug.eval.IEvaluationListener;
import org.eclipse.jdt.debug.eval.IEvaluationResult;
import org.eclipse.jdt.internal.debug.core.JDIDebugPlugin;
import org.eclipse.jdt.internal.debug.core.model.JDIReferenceType;

public class JavaLogicalStructure implements ILogicalStructureType {


	// stack frame context provider
	public static final int INFO_EVALUATION_STACK_FRAME = 111;
	private static IStatus fgNeedStackFrame = new Status(IStatus.INFO, JDIDebugPlugin.getUniqueIdentifier(), INFO_EVALUATION_STACK_FRAME, "Provides thread context for an evaluation", null); //$NON-NLS-1$
	private static IStatusHandler fgStackFrameProvider;

	/**
	 * Fully qualified type name.
	 */
	private String fType;
	/**
	 * Indicate if this java logical structure should be used on object
	 * instance of subtype of the specified type.
	 */
	private boolean fSubtypes;
	/**
	 * Code snippet to evaluate to create the logical value.
	 */
	private String fValue;
	/**
	 * Description of the logical structure.
	 */
	private String fDescription;
	/**
	 * Name and associated code snippet of the variables of the logical value.
	 */
	private String[][] fVariables;
	/**
	 * The plugin identifier of the plugin which contributed this logical structure
     * or <code>null</code> if this structure was defined by the user.
	 */
    private String fContributingPluginId= null;
	
	/**
	 * Performs the evaluations.
	 */
	private class EvaluationBlock implements IEvaluationListener {
		
		private IJavaObject fEvaluationValue;
		private IJavaReferenceType fEvaluationType;
		private IJavaThread fThread;
		private IAstEvaluationEngine fEvaluationEngine;
		private IEvaluationResult fResult;

		public EvaluationBlock(IJavaObject value, IJavaReferenceType type, IJavaThread thread, IAstEvaluationEngine evaluationEngine) {
			fEvaluationValue= value;
			fEvaluationType= type;
			fThread= thread;
			fEvaluationEngine= evaluationEngine;
		}

		/* (non-Javadoc)
		 * @see org.eclipse.jdt.debug.eval.IEvaluationListener#evaluationComplete(org.eclipse.jdt.debug.eval.IEvaluationResult)
		 */
		public void evaluationComplete(IEvaluationResult result) {
			synchronized(this) {
				fResult= result;
				this.notify();
			}
		}

		public IJavaValue evaluate(String snippet) throws DebugException {
			ICompiledExpression compiledExpression= fEvaluationEngine.getCompiledExpression(snippet, fEvaluationType);
			if (compiledExpression.hasErrors()) {
				String[] errorMessages = compiledExpression.getErrorMessages();
                log(errorMessages);
				return new JavaStructureErrorValue(errorMessages, fEvaluationValue);
			}
			fResult= null;
			fEvaluationEngine.evaluateExpression(compiledExpression, fEvaluationValue, fThread, this, DebugEvent.EVALUATION_IMPLICIT, false);
			synchronized(this) {
				if (fResult == null) {
					try {
						this.wait();
					} catch (InterruptedException e) {
					}
				}
			}
			if (fResult == null) {
				return new JavaStructureErrorValue(LogicalStructuresMessages.JavaLogicalStructure_1, fEvaluationValue); //$NON-NLS-1$
			}
			if (fResult.hasErrors()) {
				DebugException exception = fResult.getException();
				String message;
				if (exception != null) {
                    if (isContributed()) {
                        JDIDebugPlugin.log(exception);
                    }
					message= MessageFormat.format(LogicalStructuresMessages.JavaLogicalStructure_2, new String[] { exception.getMessage() }); //$NON-NLS-1$
				} else {
                    log(fResult.getErrorMessages());
					message= LogicalStructuresMessages.JavaLogicalStructure_3; //$NON-NLS-1$
				}
				return new JavaStructureErrorValue(message, fEvaluationValue);
			}
			return fResult.getValue();
		}
        
        /**
         * Logs the given error messages if this logical structure was contributed
         * via extension.
         */
        private void log(String[] messages) {
            if (isContributed()) {
                StringBuffer log= new StringBuffer();
                for (int i = 0; i < messages.length; i++) {
                    log.append(messages[i]).append('\n');
                }
                JDIDebugPlugin.log(new Status(IStatus.ERROR, JDIDebugPlugin.getUniqueIdentifier(), IStatus.ERROR, log.toString(),null));
            }
        }
	}

	/**
	 * Constructor from parameters.
	 */
	public JavaLogicalStructure(String type, boolean subtypes, String value, String description, String[][] variables) {
		fType= type;
		fSubtypes= subtypes;
		fValue= value;
		fDescription= description;
		fVariables= variables;
	}

	/**
	 * Constructor from configuration element.
	 */
	public JavaLogicalStructure(IConfigurationElement configurationElement) throws CoreException {
		fType= configurationElement.getAttribute("type"); //$NON-NLS-1$
		if (fType == null) {
			throw new CoreException(new Status(IStatus.ERROR, JDIDebugPlugin.getUniqueIdentifier(), JDIDebugPlugin.INTERNAL_ERROR, LogicalStructuresMessages.JavaLogicalStructures_0, null)); //$NON-NLS-1$
		}
		fSubtypes= Boolean.valueOf(configurationElement.getAttribute("subtypes")).booleanValue(); //$NON-NLS-1$
		fValue= configurationElement.getAttribute("value"); //$NON-NLS-1$
		fDescription= configurationElement.getAttribute("description"); //$NON-NLS-1$
		if (fDescription == null) {
			throw new CoreException(new Status(IStatus.ERROR, JDIDebugPlugin.getUniqueIdentifier(), JDIDebugPlugin.INTERNAL_ERROR, LogicalStructuresMessages.JavaLogicalStructures_4, null)); //$NON-NLS-1$
		}
		IConfigurationElement[] variableElements= configurationElement.getChildren("variable"); //$NON-NLS-1$
		if (fValue== null && variableElements.length == 0) {
			throw new CoreException(new Status(IStatus.ERROR, JDIDebugPlugin.getUniqueIdentifier(), JDIDebugPlugin.INTERNAL_ERROR, LogicalStructuresMessages.JavaLogicalStructures_1, null)); //$NON-NLS-1$
		}
		fVariables= new String[variableElements.length][2];
		for (int j= 0; j < fVariables.length; j++) {
			String variableName= variableElements[j].getAttribute("name"); //$NON-NLS-1$
			if (variableName == null) {
				throw new CoreException(new Status(IStatus.ERROR, JDIDebugPlugin.getUniqueIdentifier(), JDIDebugPlugin.INTERNAL_ERROR, LogicalStructuresMessages.JavaLogicalStructures_2, null)); //$NON-NLS-1$
			}
			fVariables[j][0]= variableName;
			String variableValue= variableElements[j].getAttribute("value"); //$NON-NLS-1$
			if (variableValue == null) {
				throw new CoreException(new Status(IStatus.ERROR, JDIDebugPlugin.getUniqueIdentifier(), JDIDebugPlugin.INTERNAL_ERROR, LogicalStructuresMessages.JavaLogicalStructures_3, null)); //$NON-NLS-1$
			}
			fVariables[j][1]= variableValue;
		}
        fContributingPluginId= configurationElement.getNamespace();
	}
	
	/**
	 * @see org.eclipse.debug.core.model.ILogicalStructureTypeDelegate#providesLogicalStructure(IValue)
	 */
	public boolean providesLogicalStructure(IValue value) {
		if (!(value instanceof IJavaObject)) {
			return false;
		}
		return getType((IJavaObject) value) != null;
	}

	/**
	 * @see org.eclipse.debug.core.model.ILogicalStructureTypeDelegate#getLogicalStructure(IValue)
	 */
	public IValue getLogicalStructure(IValue value) {
		if (!(value instanceof IJavaObject)) {
			return null;
		}
		IJavaObject javaValue= (IJavaObject) value;
		try {
			IJavaReferenceType type = getType(javaValue);
			if (type == null) {
				return null;
			}
			IJavaStackFrame stackFrame= getStackFrame(javaValue);
			if (stackFrame == null) {
				return null;
			}
			
			// find the project the snippets will be compiled in.
			ISourceLocator locator= javaValue.getLaunch().getSourceLocator();
			Object sourceElement= null;
			if (locator instanceof ISourceLookupDirector) {
				if (type instanceof JDIReferenceType) {
					String[] sourcePaths= ((JDIReferenceType) type).getSourcePaths(null);
					if (sourcePaths.length > 0) {
						sourceElement= ((ISourceLookupDirector) locator).getSourceElement(sourcePaths[0]);
					}
				}
				if (!(sourceElement instanceof IJavaElement) && sourceElement instanceof IAdaptable) {
					sourceElement = ((IAdaptable)sourceElement).getAdapter(IJavaElement.class);
				}
			}
			if (sourceElement == null) {
				sourceElement = locator.getSourceElement(stackFrame);
				if (!(sourceElement instanceof IJavaElement) && sourceElement instanceof IAdaptable) {
					sourceElement = ((IAdaptable)sourceElement).getAdapter(IJavaElement.class);
				}
			}
			IJavaProject project= null;
			if (sourceElement instanceof IJavaElement) {
				project= ((IJavaElement) sourceElement).getJavaProject();
			} else if (sourceElement instanceof IResource) {
				IJavaProject resourceProject = JavaCore.create(((IResource)sourceElement).getProject());
				if (resourceProject.exists()) {
					project= resourceProject;
				}
			}
			if (project == null) {
				return null;
			}
			
			IAstEvaluationEngine evaluationEngine= JDIDebugPlugin.getDefault().getEvaluationEngine(project, (IJavaDebugTarget)stackFrame.getDebugTarget());
			
			EvaluationBlock evaluationBlock= new EvaluationBlock(javaValue, type, (IJavaThread)stackFrame.getThread(), evaluationEngine);
			if (fValue == null) {
				// evaluate each variable
				IJavaVariable[] variables= new IJavaVariable[fVariables.length];
				for (int i= 0; i < fVariables.length; i++) {
					variables[i]= new JDIPlaceholderVariable(fVariables[i][0], evaluationBlock.evaluate(fVariables[i][1]));
				}
				return new LogicalObjectStructureValue(javaValue, variables);
			}
			// evaluate the logical value
			return evaluationBlock.evaluate(fValue);

		} catch (CoreException e) {
			JDIDebugPlugin.log(e);
		}
		return null;
	}
	
	private IJavaReferenceType getType(IJavaObject value) {
		try {
			IJavaType type= value.getJavaType();
			if (!(type instanceof IJavaClassType)) {
				return null;
			}
			IJavaClassType classType= (IJavaClassType) type;
			if (classType.getName().equals(fType)) {
				// found the type
				return classType;
			}
			if (!fSubtypes) {
				// if not checking the subtypes, stop here
				return null;
			}
			IJavaClassType superClass= classType.getSuperclass();
			while (superClass != null) {
				if (superClass.getName().equals(fType)) {
					// found the type, it's a super class
					return superClass;
				}
				superClass= superClass.getSuperclass();
			}
			IJavaInterfaceType[] superInterfaces= classType.getAllInterfaces();
			for (int i= 0; i < superInterfaces.length; i++) {
				if (superInterfaces[i].getName().equals(fType)) {
					// found the type, it's a super interface
					return superInterfaces[i];
				}
			}
		} catch (DebugException e) {
			JDIDebugPlugin.log(e);
			return null;
		}
		return null;
	}

	/**
	 * Return the current stack frame context, or a valid stack frame for the given value.
	 */
	private IJavaStackFrame getStackFrame(IValue value) throws CoreException {
		IStatusHandler handler = getStackFrameProvider();
		if (handler != null) {
			IJavaStackFrame stackFrame = (IJavaStackFrame)handler.handleStatus(fgNeedStackFrame, value);
			if (stackFrame != null) {
				return stackFrame;
			}
		}
		IDebugTarget target = value.getDebugTarget();
		IJavaDebugTarget javaTarget = (IJavaDebugTarget) target.getAdapter(IJavaDebugTarget.class);
		if (javaTarget != null) {
			IThread[] threads = javaTarget.getThreads();
			for (int i = 0; i < threads.length; i++) {
				IThread thread = threads[i];
				if (thread.isSuspended()) {
					return (IJavaStackFrame)thread.getTopStackFrame();
				}
			}
		}
		return null;
	}
	
	private static IStatusHandler getStackFrameProvider() {
		if (fgStackFrameProvider == null) {
			fgStackFrameProvider = DebugPlugin.getDefault().getStatusHandler(fgNeedStackFrame);
		}
		return fgStackFrameProvider;
	}
	
	/**
	 * Returns if this logical structure should be used for subtypes too.
	 */
	public boolean isSubtypes() {
		return fSubtypes;
	}
	
	/**
	 * Sets if this logical structure should be used for subtypes or not.
	 */
	public void setSubtypes(boolean subtypes) {
		fSubtypes = subtypes;
	}
	
	/**
	 * Returns the name of the type this logical structure should be used for.
	 */
	public String getQualifiedTypeName() {
		return fType;
	}
	/**
	 * Sets the name of the type this logical structure should be used for.
	 */
	public void setType(String type) {
		fType = type;
	}
	/**
	 * Returns the code snippet to use to generate the logical structure.
	 */
	public String getValue() {
		return fValue;
	}
	/**
	 * Sets the code snippet to use to generate the logical structure.
	 */
	public void setValue(String value) {
		fValue = value;
	}
	/**
	 * Returns the variables of this logical structure.
	 */
	public String[][] getVariables() {
		return fVariables;
	}
	/**
	 * Sets the variables of this logical structure.
	 */
	public void setVariables(String[][] variables) {
		fVariables = variables;
	}
	/**
	 * Set the description of this logical structure.
	 */
	public void setDescription(String description) {
		fDescription = description;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.debug.core.model.ILogicalStructureTypeDelegate2#getDescription(org.eclipse.debug.core.model.IValue)
	 */
	public String getDescription(IValue value) {
		return getDescription();
	}
	
    /* (non-Javadoc)
     * @see org.eclipse.debug.core.ILogicalStructureType#getDescription()
     */
    public String getDescription() {
		return fDescription;
	}
    
    /**
     * Indicates if this logical structure was contributed by a plug-in
     * or defined by a user.
     */
    public boolean isContributed() {
        return fContributingPluginId != null;
    }
	
	/**
     * Returns the plugin identifier of the plugin which contributed this logical
     * structure or <code>null</code> if this structure was defined by the user.
     * @return the plugin identifier of the plugin which contributed this
     *  structure or <code>null</code>
	 */
    public String getContributingPluginId() {
        return fContributingPluginId;
    }

	/* (non-Javadoc)
	 * @see org.eclipse.debug.core.ILogicalStructureType#getId()
	 */
	public String getId() {
		return JDIDebugPlugin.getUniqueIdentifier() + fType + fDescription;
	}

}
