/*******************************************************************************
 * Copyright (c) 2005, 2010 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
 *     Jens Lukowski/Innoopract - initial renaming/restructuring
 *     
 *******************************************************************************/

package org.eclipse.wst.sse.ui.internal.contentassist;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Set;

import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.contentassist.IContentAssistSubjectControl;
import org.eclipse.jface.contentassist.ISubjectControlContentAssistProcessor;
import org.eclipse.jface.contentassist.ISubjectControlContextInformationPresenter;
import org.eclipse.jface.contentassist.ISubjectControlContextInformationValidator;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.TextPresentation;
import org.eclipse.jface.text.contentassist.ICompletionProposal;
import org.eclipse.jface.text.contentassist.IContentAssistProcessor;
import org.eclipse.jface.text.contentassist.IContextInformation;
import org.eclipse.jface.text.contentassist.IContextInformationExtension;
import org.eclipse.jface.text.contentassist.IContextInformationPresenter;
import org.eclipse.jface.text.contentassist.IContextInformationValidator;
import org.eclipse.swt.graphics.Image;
import org.eclipse.wst.sse.ui.contentassist.StructuredContentAssistProcessor;
import org.eclipse.wst.sse.ui.internal.IReleasable;
import org.eclipse.wst.sse.ui.internal.Logger;

/**
 * <p>A processor that aggregates the proposals of multiple other processors.
 * When proposals are requested, the contained processors are queried in the
 * order they were added to the compound object. Copied from
 * org.eclipse.jdt.internal.ui.text.CompoundContentAssistProcessor.
 * Modification was made to add a dispose() method.</p>
 */
public class CompoundContentAssistProcessor implements IContentAssistProcessor, ISubjectControlContentAssistProcessor, IReleasable {

	/** the compound processors */
	private final Set fProcessors = new LinkedHashSet();
	
	/** Aggregated error message from the compound processors */
	private String fErrorMessage;

	/**
	 * Creates a new instance.
	 */
	public CompoundContentAssistProcessor() {
	}

	/**
	 * Creates a new instance with one child processor.
	 * 
	 * @param processor
	 *            the processor to add
	 */
	public CompoundContentAssistProcessor(IContentAssistProcessor processor) {
		add(processor);
	}

	/**
	 * Adds a processor to this compound processor.
	 * 
	 * @param processor
	 *            the processor to add
	 */
	public void add(IContentAssistProcessor processor) {
		Assert.isNotNull(processor);
		fProcessors.add(processor);
	}
	
	/**
	 * @param processor check to see if this {@link IContentAssistProcessor} is one
	 * in this compound processor.
	 * 
	 * @return <code>true</code> if this compound processor contains the given processor,
	 * <code>false</code> otherwise
	 */
	public boolean containsProcessor(IContentAssistProcessor processor) {
		return fProcessors.contains(processor);
	}

	/**
	 * Removes a processor from this compound processor.
	 * 
	 * @param processor
	 *            the processor to remove
	 */
	public void remove(IContentAssistProcessor processor) {
		fProcessors.remove(processor);
	}

	/**
	 * Creates a new instance and adds all specified processors.
	 * 
	 * @param processors
	 */
	public CompoundContentAssistProcessor(IContentAssistProcessor[] processors) {
		for (int i = 0; i < processors.length; i++) {
			add(processors[i]);
		}
	}

	/*
	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#computeCompletionProposals(org.eclipse.jface.text.ITextViewer,
	 *      int)
	 */
	public ICompletionProposal[] computeCompletionProposals(ITextViewer viewer, int documentOffset) {
		fErrorMessage = null;
		List ret = new LinkedList();
		for (Iterator it = fProcessors.iterator(); it.hasNext();) {
			IContentAssistProcessor p = (IContentAssistProcessor) it.next();
			try {
				// isolate calls to each processor
				ICompletionProposal[] proposals = p.computeCompletionProposals(viewer, documentOffset);
				if (proposals != null && proposals.length > 0) {
					ret.addAll(Arrays.asList(proposals));
					fErrorMessage = null; // Hide previous errors
				}
				else {
					if (fErrorMessage == null && ret.isEmpty()) {
						String errorMessage = p.getErrorMessage();
						if (errorMessage != null) {
							fErrorMessage = errorMessage;
						}
					}
				}
			}
			catch (Exception e) {
				Logger.logException(e);
			}
		}
		return (ICompletionProposal[]) ret.toArray(new ICompletionProposal[ret.size()]);
	}

	/**
	 * {@inheritDoc}
	 * <p>
	 * The returned objects are wrapper objects around the real information
	 * containers.
	 * </p>
	 * 
	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#computeContextInformation(org.eclipse.jface.text.ITextViewer,
	 *      int)
	 */
	public IContextInformation[] computeContextInformation(ITextViewer viewer, int documentOffset) {
		fErrorMessage = null;
		List ret = new LinkedList();
		for (Iterator it = fProcessors.iterator(); it.hasNext();) {
			IContentAssistProcessor p = (IContentAssistProcessor) it.next();
			IContextInformation[] informations = p.computeContextInformation(viewer, documentOffset);
			if (informations != null && informations.length > 0) {
				for (int i = 0; i < informations.length; i++)
					ret.add(new WrappedContextInformation(informations[i], p));
				fErrorMessage = null; // Hide previous errors
			} else {
				if (fErrorMessage == null && ret.isEmpty()) {
					String errorMessage = p.getErrorMessage();
					if (errorMessage != null) {
						fErrorMessage = errorMessage;
					}
				}
			}
		}
		return (IContextInformation[]) ret.toArray(new IContextInformation[ret.size()]);
	}

	/*
	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getCompletionProposalAutoActivationCharacters()
	 */
	public char[] getCompletionProposalAutoActivationCharacters() {
		Set ret = new LinkedHashSet();
		for (Iterator it = fProcessors.iterator(); it.hasNext();) {
			IContentAssistProcessor p = (IContentAssistProcessor) it.next();
			char[] chars = p.getCompletionProposalAutoActivationCharacters();
			if (chars != null)
				for (int i = 0; i < chars.length; i++)
					ret.add(new Character(chars[i]));
		}

		char[] chars = new char[ret.size()];
		int i = 0;
		for (Iterator it = ret.iterator(); it.hasNext(); i++) {
			Character ch = (Character) it.next();
			chars[i] = ch.charValue();
		}
		return chars;
	}

	/*
	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getContextInformationAutoActivationCharacters()
	 */
	public char[] getContextInformationAutoActivationCharacters() {
		Set ret = new LinkedHashSet();
		for (Iterator it = fProcessors.iterator(); it.hasNext();) {
			IContentAssistProcessor p = (IContentAssistProcessor) it.next();
			char[] chars = p.getContextInformationAutoActivationCharacters();
			if (chars != null)
				for (int i = 0; i < chars.length; i++)
					ret.add(new Character(chars[i]));
		}

		char[] chars = new char[ret.size()];
		int i = 0;
		for (Iterator it = ret.iterator(); it.hasNext(); i++) {
			Character ch = (Character) it.next();
			chars[i] = ch.charValue();
		}
		return chars;
	}

	/**
	 * Returns the error message of one of
	 * contained processor if any, or <code>null</code> if no processor has an
	 * error message.
	 * 
	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getErrorMessage()
	 * @return {@inheritDoc}
	 */
	public String getErrorMessage() {
		return fErrorMessage;
	}

	/**
	 * {@inheritDoc}
	 * <p>
	 * The returned validator is a wrapper around the validators provided by
	 * the child processors.
	 * </p>
	 * 
	 * @see org.eclipse.jface.text.contentassist.IContentAssistProcessor#getContextInformationValidator()
	 */
	public IContextInformationValidator getContextInformationValidator() {
		boolean hasValidator = false;
		boolean hasPresenter = false;
		boolean hasExtension = false;

		Iterator itp = fProcessors.iterator();
		while (itp.hasNext() && (!hasPresenter || !hasExtension)) {
			IContentAssistProcessor p = (IContentAssistProcessor) itp.next();
			IContextInformationValidator v = p.getContextInformationValidator();
			if (v != null) {
				hasValidator = true;
				if (v instanceof IContextInformationPresenter) {
					hasPresenter = true;
				}
				if (v instanceof ISubjectControlContextInformationPresenter || v instanceof ISubjectControlContextInformationValidator) {
					hasExtension = true;
				}
			}
		}

		CompoundContentAssistValidator validator = null;
		if (hasPresenter && hasExtension)
			validator = new CompoundContentAssistValidatorPresenterEx();
		else if (hasPresenter)
			validator = new CompoundContentAssistValidatorPresenter();
		else if (hasExtension)
			validator = new CompoundContentAssistValidatorEx();
		else if (hasValidator)
			validator = new CompoundContentAssistValidator();

		if (validator != null)
			for (Iterator it = fProcessors.iterator(); it.hasNext();) {
				IContentAssistProcessor p = (IContentAssistProcessor) it.next();
				IContextInformationValidator v = p.getContextInformationValidator();
				if (v != null)
					validator.add(v);
			}

		return validator;
	}

	/*
	 * @see ISubjectControlContentAssistProcessor#computeCompletionProposals(IContentAssistSubjectControl,
	 *      int)
	 */
	public ICompletionProposal[] computeCompletionProposals(IContentAssistSubjectControl contentAssistSubjectControl, int documentOffset) {
		fErrorMessage = null;
		List ret = new LinkedList();
		for (Iterator it = fProcessors.iterator(); it.hasNext();) {
			Object o = it.next();
			if (o instanceof ISubjectControlContentAssistProcessor) {
				ISubjectControlContentAssistProcessor p = (ISubjectControlContentAssistProcessor) o;
				ICompletionProposal[] proposals = p.computeCompletionProposals(contentAssistSubjectControl, documentOffset);
				if (proposals != null && proposals.length > 0) {
					ret.addAll(Arrays.asList(proposals));
					fErrorMessage = null; // Hide previous errors
				} else {
					if (fErrorMessage == null && ret.isEmpty()) {
						String errorMessage = p.getErrorMessage();
						if (errorMessage != null) {
							fErrorMessage = errorMessage;
						}
					}
				}
			}
		}

		return (ICompletionProposal[]) ret.toArray(new ICompletionProposal[ret.size()]);
	}

	/**
	 * {@inheritDoc}
	 * <p>
	 * The returned objects are wrapper objects around the real information
	 * containers.
	 * </p>
	 * 
	 * @see org.eclipse.jface.contentassist.ISubjectControlContentAssistProcessor#computeContextInformation(org.eclipse.jface.text.contentassist.IContentAssistSubject,
	 *      int)
	 */
	public IContextInformation[] computeContextInformation(IContentAssistSubjectControl contentAssistSubjectControl, int documentOffset) {
		fErrorMessage = null;
		List ret = new LinkedList();
		for (Iterator it = fProcessors.iterator(); it.hasNext();) {
			Object o = it.next();
			if (o instanceof ISubjectControlContentAssistProcessor) {
				ISubjectControlContentAssistProcessor p = (ISubjectControlContentAssistProcessor) o;
				IContextInformation[] informations = p.computeContextInformation(contentAssistSubjectControl, documentOffset);
				if (informations != null && informations.length > 0) {
					for (int i = 0; i < informations.length; i++)
						ret.add(new WrappedContextInformation(informations[i], p));
					fErrorMessage = null; // Hide previous errors
				} else {
					if (fErrorMessage == null && ret.isEmpty()) {
						String errorMessage = p.getErrorMessage();
						if (errorMessage != null) {
							fErrorMessage = errorMessage;
						}
					}
				}
			}
		}
		return (IContextInformation[]) ret.toArray(new IContextInformation[ret.size()]);
	}

	/**
	 * Dispose of any content assist processors that need disposing
	 * @deprecated use {@link #release()}
	 */
	public void dispose() {
		this.release();
	}
	
	public void install(ITextViewer viewer) {
		for (Iterator it = fProcessors.iterator(); it.hasNext();) {
			IContentAssistProcessor p = (IContentAssistProcessor) it.next();
			if (p instanceof StructuredContentAssistProcessor) {
				((StructuredContentAssistProcessor) p).install(viewer);
			}
		}
	}

	/**
	 * @see org.eclipse.wst.sse.ui.internal.IReleasable#release()
	 */
	public void release() {
		// go through list of content assist processors and dispose
		for (Iterator it = fProcessors.iterator(); it.hasNext();) {
			IContentAssistProcessor p = (IContentAssistProcessor) it.next();
			if (p instanceof IReleasable) {
				((IReleasable) p).release();
			}
		}
	}
	
	private static class WrappedContextInformation implements IContextInformation, IContextInformationExtension {
		private IContextInformation fInfo;
		private IContentAssistProcessor fProcessor;

		WrappedContextInformation(IContextInformation info, IContentAssistProcessor processor) {
			fInfo = info;
			fProcessor = processor;
		}

		/*
		 * @see java.lang.Object#equals(java.lang.Object)
		 */
		public boolean equals(Object obj) {
			return fInfo.equals(obj);
		}

		/*
		 * @see org.eclipse.jface.text.contentassist.IContextInformation#getContextDisplayString()
		 */
		public String getContextDisplayString() {
			return fInfo.getContextDisplayString();
		}

		/*
		 * @see org.eclipse.jface.text.contentassist.IContextInformation#getImage()
		 */
		public Image getImage() {
			return fInfo.getImage();
		}

		/*
		 * @see org.eclipse.jface.text.contentassist.IContextInformation#getInformationDisplayString()
		 */
		public String getInformationDisplayString() {
			return fInfo.getInformationDisplayString();
		}

		/*
		 * @see java.lang.Object#hashCode()
		 */
		public int hashCode() {
			return fInfo.hashCode();
		}

		/*
		 * @see java.lang.Object#toString()
		 */
		public String toString() {
			return fInfo.toString();
		}

		IContentAssistProcessor getProcessor() {
			return fProcessor;
		}

		IContextInformation getContextInformation() {
			return fInfo;
		}

		public int getContextInformationPosition() {
			int position = -1;
			if (fInfo instanceof IContextInformationExtension)
				position = ((IContextInformationExtension)fInfo).getContextInformationPosition();
			return position;
		}
	}
	
	private static class CompoundContentAssistValidator implements IContextInformationValidator {
		List fValidators = new ArrayList();
		IContextInformationValidator fValidator;

		void add(IContextInformationValidator validator) {
			fValidators.add(validator);
		}

		/*
		 * @see org.eclipse.jface.text.contentassist.IContextInformationValidator#install(org.eclipse.jface.text.contentassist.IContextInformation,
		 *      org.eclipse.jface.text.ITextViewer, int)
		 */
		public void install(IContextInformation info, ITextViewer viewer, int documentPosition) {
			// install either the validator in the info, or all validators
			fValidator = getValidator(info);
			IContextInformation realInfo = getContextInformation(info);
			if (fValidator != null)
				fValidator.install(realInfo, viewer, documentPosition);
			else {
				for (Iterator it = fValidators.iterator(); it.hasNext();) {
					IContextInformationValidator v = (IContextInformationValidator) it.next();
					v.install(realInfo, viewer, documentPosition);
				}
			}
		}

		IContextInformationValidator getValidator(IContextInformation info) {
			if (info instanceof WrappedContextInformation) {
				WrappedContextInformation wrap = (WrappedContextInformation) info;
				return wrap.getProcessor().getContextInformationValidator();
			}

			return null;
		}

		IContextInformation getContextInformation(IContextInformation info) {
			IContextInformation realInfo = info;
			if (info instanceof WrappedContextInformation) {
				WrappedContextInformation wrap = (WrappedContextInformation) info;
				realInfo = wrap.getContextInformation();
			}

			return realInfo;
		}

		/*
		 * @see org.eclipse.jface.text.contentassist.IContextInformationValidator#isContextInformationValid(int)
		 */
		public boolean isContextInformationValid(int documentPosition) {
			// use either the validator in the info, or all validators
			boolean isValid = false;
			if (fValidator != null)
				isValid = fValidator.isContextInformationValid(documentPosition);
			else {
				for (Iterator it = fValidators.iterator(); it.hasNext();) {
					IContextInformationValidator v = (IContextInformationValidator) it.next();
					isValid |= v.isContextInformationValid(documentPosition);
				}
			}
			return isValid;
		}

	}

	private static class CompoundContentAssistValidatorPresenter extends CompoundContentAssistValidator implements IContextInformationPresenter {
		public boolean updatePresentation(int offset, TextPresentation presentation) {
			// use either the validator in the info, or all validators
			boolean presentationUpdated = false;
			if (fValidator instanceof IContextInformationPresenter)
				presentationUpdated = ((IContextInformationPresenter) fValidator).updatePresentation(offset, presentation);
			else {
				for (Iterator it = fValidators.iterator(); it.hasNext();) {
					IContextInformationValidator v = (IContextInformationValidator) it.next();
					if (v instanceof IContextInformationPresenter)
						presentationUpdated |= ((IContextInformationPresenter) v).updatePresentation(offset, presentation);
				}
			}
			return presentationUpdated;
		}
	}

	private static class CompoundContentAssistValidatorEx extends CompoundContentAssistValidator implements ISubjectControlContextInformationValidator {
		/*
		 * @see ISubjectControlContextInformationValidator#install(IContextInformation,
		 *      IContentAssistSubjectControl, int)
		 */
		public void install(IContextInformation info, IContentAssistSubjectControl contentAssistSubjectControl, int documentPosition) {
			// install either the validator in the info, or all validators
			fValidator = getValidator(info);
			IContextInformation realInfo = getContextInformation(info);
			if (fValidator instanceof ISubjectControlContextInformationValidator)
				((ISubjectControlContextInformationValidator) fValidator).install(realInfo, contentAssistSubjectControl, documentPosition);
			else {
				for (Iterator it = fValidators.iterator(); it.hasNext();) {
					if (it.next() instanceof ISubjectControlContextInformationValidator)
						((ISubjectControlContextInformationValidator) it.next()).install(realInfo, contentAssistSubjectControl, documentPosition);
				}
			}
		}

	}

	private static class CompoundContentAssistValidatorPresenterEx extends CompoundContentAssistValidatorPresenter implements ISubjectControlContextInformationPresenter, ISubjectControlContextInformationValidator {
		/*
		 * @see ISubjectControlContextInformationPresenter#install(IContextInformation,
		 *      IContentAssistSubjectControl, int)
		 */
		public void install(IContextInformation info, IContentAssistSubjectControl contentAssistSubjectControl, int documentPosition) {
			// install either the validator in the info, or all validators
			fValidator = getValidator(info);
			IContextInformation realInfo = getContextInformation(info);

			if (fValidator instanceof ISubjectControlContextInformationValidator)
				((ISubjectControlContextInformationValidator) fValidator).install(realInfo, contentAssistSubjectControl, documentPosition);
			else {
				for (Iterator it = fValidators.iterator(); it.hasNext();) {
					if (it.next() instanceof ISubjectControlContextInformationValidator)
						((ISubjectControlContextInformationValidator) it.next()).install(realInfo, contentAssistSubjectControl, documentPosition);
				}
			}
		}

	}
}