/*******************************************************************************
 * Copyright (c) 2000, 2007 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
 *
 
 *******************************************************************************/
package org.eclipse.dltk.core.search;

import org.eclipse.core.resources.IResource;
import org.eclipse.dltk.core.IModelElement;
import org.eclipse.dltk.internal.core.ModelElement;


/**
 * A search match represents the result of a search query.
 * 
 * Search matches may be accurate (<code>A_ACCURATE</code>) or they might be
 * merely potential matches (<code>A_INACCURATE</code>). The latter occurs when
 * a compile-time problem prevents the search engine from completely resolving
 * the match.
 * <p>
 * This class is intended to be instantiated and subclassed by clients.
 * </p>
 * 
 * @see SearchEngine#search(SearchPattern, SearchParticipant[], IJavaSearchScope, SearchRequestor, org.eclipse.core.runtime.IProgressMonitor)
	 *
 */
public class SearchMatch {
	
	/**
	 * The search result corresponds an exact match of the search pattern.
	 * 
	 * @see #getAccuracy()
	 */
	public static final int A_ACCURATE = 0;

	/**
	 * The search result is potentially a match for the search pattern,
	 * but the search engine is unable to fully check it (for example, because
	 * there are errors in the code or the buildpath are not correctly set).
	 * 
	 * @see #getAccuracy()
	 */
	public static final int A_INACCURATE = 1;

	private Object element;
	private int length;
	private int offset;

	private int accuracy;
	private SearchParticipant participant;	
	private IResource resource;

	private boolean insideDocComment = false;
	
	// store the rule used while reporting the match
	private int rule = SearchPattern.R_FULL_MATCH |
								SearchPattern.R_EQUIVALENT_MATCH |
								SearchPattern.R_ERASURE_MATCH;
	
	// store other necessary information
	private boolean raw = false;
	private boolean implicit = false;

	/**
	 * Creates a new search match.
	 * <p>
	 * Note that <code>isInsideDocComment()</code> defaults to false.
	 * </p>
	 * 
	 * @param element the element that encloses or corresponds to the match,
	 * or <code>null</code> if none
	 * @param accuracy one of {@link #A_ACCURATE} or {@link #A_INACCURATE}
	 * @param offset the offset the match starts at, or -1 if unknown
	 * @param length the length of the match, or -1 if unknown
	 * @param participant the search participant that created the match
	 * @param resource the resource of the element, or <code>null</code> if none
	 */
	public SearchMatch(
			IModelElement element,
			int accuracy,
			int offset,  
			int length,
			SearchParticipant participant, 
			IResource resource) {
		this.element = element;
		this.offset = offset;
		this.length = length;
		this.accuracy = accuracy & A_INACCURATE;
		if (accuracy > A_INACCURATE) {
			this.rule = accuracy & ~A_INACCURATE; // accuracy may have also some rule information
		}
		this.participant = participant;
		this.resource = resource;
	}

	/**
	 * Returns the accuracy of this search match.
	 * 
	 * @return one of {@link #A_ACCURATE} or {@link #A_INACCURATE}
	 */
	public final int getAccuracy() {
		return this.accuracy;
	}

	/**
	 * Returns the element of this search match.
	 * In case of a reference match, this is the inner-most enclosing element of the reference.
	 * In case of a declaration match, this is the declaration.
	 * 
	 * @return the element of the search match, or <code>null</code> if none
	 */
	public final Object getElement() {
		return this.element;
	}

	/**
	 * Returns the length of this search match.
	 * 
	 * @return the length of this search match, or -1 if unknown
	 */
	public final int getLength() {
		return this.length;
	}
	
	/**
	 * Returns the offset of this search match.
	 * 
	 * @return the offset of this search match, or -1 if unknown
	 */
	public final int getOffset() {
		return this.offset;
	}
	
	/**
	 * Returns the search participant which issued this search match.
	 * 
	 * @return the participant which issued this search match
	 */
	public final SearchParticipant getParticipant() {
		return this.participant;
	}
	
	/**
	 * Returns the resource containing this search match.
	 * 
	 * @return the resource of the match, or <code>null</code> if none
	 */
	public final IResource getResource() {
		return this.resource;
	}

	/**
	 * Returns the rule used while creating the match.
	 * 
	 * @return one of {@link SearchPattern#R_FULL_MATCH}, {@link SearchPattern#R_EQUIVALENT_MATCH}
	 * 	or {@link SearchPattern#R_ERASURE_MATCH}
	 *
	 */
	public final int getRule() {
		return this.rule;
	}

	/**
	 * Returns whether match element is compatible with searched pattern or not.
	 * Note that equivalent matches are also erasure ones.
	 * 
	 * @return <code>true</code> if match element is compatible 
	 * 				<code>false</code> otherwise
	 *
	 */
	public final boolean isEquivalent() {
		return isErasure() && (this.rule & SearchPattern.R_EQUIVALENT_MATCH) != 0;
	}

	/**
	 * Returns whether match element only has same erasure than searched pattern or not.
	 * Note that this is always true for both generic and non-generic element as soon
	 * as the accuracy is accurate.
	 * 
	 * @return <code>true</code> if match element has same erasure
	 * 				<code>false</code> otherwise
	 *
	 */
	public final boolean isErasure() {
		return (this.rule & SearchPattern.R_ERASURE_MATCH) != 0;
	}

	/**
	 * Returns whether element matches exactly searched pattern or not.
	 * Note that exact matches are also erasure and equivalent ones.
	 * 
	 * @return <code>true</code> if match is exact
	 * 				<code>false</code> otherwise
	 *
	 */
	public final boolean isExact() {
		return isEquivalent() && (this.rule & SearchPattern.R_FULL_MATCH) != 0;
	}

	/**
	 * Returns whether the associated element is implicit or not.
	 * 
	 * Note that this piece of information is currently only implemented
	 * for implicit member pair value in annotation.
	 * 
	 * @return <code>true</code> if this match is associated to an implicit
	 * element and <code>false</code> otherwise
	 *
	 */
	public final boolean isImplicit() {
		return this.implicit;
	}

	/**
	 * Returns whether the associated element is a raw type/method or not.
	 * 
	 * @return <code>true</code> if this match is associated to a raw
	 * type or method and <code>false</code> otherwise
	 *
	 */
	public final boolean isRaw() {
		return this.raw;
	}

	/**
	 * Returns whether this search match is inside a doc comment of a script 
	 * source file.
	 * 
	 * @return <code>true</code> if this search match is inside a doc
	 * comment, and <code>false</code> otherwise
	 */
	public final boolean isInsideDocComment() {
		// default is outside a doc comment
		return this.insideDocComment;
	}

	/**
	 * Sets the accuracy of this match.
	 * 
	 * @param accuracy one of {@link #A_ACCURATE} or {@link #A_INACCURATE}
	 */
	public final void setAccuracy (int accuracy) {
		this.accuracy = accuracy;
	}

	/**
	 * Sets the element of this search match.
	 * 
	 * @param element the element that encloses or corresponds to the match,
	 * or <code>null</code> if none
	 */
	public final void setElement (Object element) {
		this.element = element;
	}

	/**
	 * Sets whether this search match is inside a doc comment of a script 
	 * source file.
	 * 
	 * @param insideDoc <code>true</code> if this search match is inside a doc
	 * comment, and <code>false</code> otherwise
	 */
	public final void setInsideDocComment (boolean insideDoc) {
		this.insideDocComment = insideDoc;
	}

	/**
	 * Sets whether the associated element is implicit or not.
	 * Typically, this is the case when match is on an implicit constructor
	 * or an implicit member pair value in annotation.
	 * 
	 * @param implicit <code>true</code> if this match is associated to an implicit
	 * element and <code>false</code> otherwise
	 *
	 */
	public final void setImplicit(boolean implicit) {
		this.implicit = implicit;
	}

	/**
	 * Sets the length of this search match.
	 * 
	 * @param length the length of the match, or -1 if unknown
	 */
	public final void setLength(int length) {
		this.length = length;
	}
	
	/**
	 * Sets the offset of this search match.
	 * 
	 * @param offset the offset the match starts at, or -1 if unknown
	 */
	public final void setOffset(int offset) {
		this.offset = offset;
	}

	/**
	 * Sets the participant of this match.
	 * 
	 * @param participant the search participant that created this match
	 */
	public final void setParticipant (SearchParticipant participant) {
		this.participant = participant;
	}

	/**
	 * Sets the resource of this match.
	 * 
	 * @param resource the resource of the match, or <code>null</code> if none
	 */
	public final void setResource (IResource resource) {
		this.resource = resource;
	}

	/**
	 * Set the rule used while reporting the match.
	 * 
	 * @param rule one of {@link SearchPattern#R_FULL_MATCH}, {@link SearchPattern#R_EQUIVALENT_MATCH}
	 * 	or {@link SearchPattern#R_ERASURE_MATCH}
	 *
	 */
	public final void setRule(int rule) {
		this.rule = rule;
	}

	/**
	 * Set whether the associated element is a raw type/method or not.
	 * 
	 * @param raw <code>true</code> if this search match is associated to a raw
	 * type or method and <code>false</code> otherwise
	 *
	 */
	public final void setRaw(boolean raw) {
		this.raw = raw;
	}

	/* (non-javadoc)
	 * @see java.lang.Object#toString()
	 */
	public String toString() {
		StringBuffer buffer = new StringBuffer();
		buffer.append("Search match"); //$NON-NLS-1$
		buffer.append("\n  accuracy="); //$NON-NLS-1$
		buffer.append(this.accuracy == A_ACCURATE ? "ACCURATE" : "INACCURATE"); //$NON-NLS-1$ //$NON-NLS-2$
		buffer.append("\n  rule="); //$NON-NLS-1$
		if ((this.rule & SearchPattern.R_FULL_MATCH) != 0) {
			buffer.append("EXACT"); //$NON-NLS-1$
		} else if ((this.rule & SearchPattern.R_EQUIVALENT_MATCH) != 0) {
			buffer.append("EQUIVALENT"); //$NON-NLS-1$
		} else if ((this.rule & SearchPattern.R_ERASURE_MATCH) != 0) {
			buffer.append("ERASURE"); //$NON-NLS-1$
		}
		buffer.append("\n  raw="); //$NON-NLS-1$
		buffer.append(this.raw);
		buffer.append("\n  offset="); //$NON-NLS-1$
		buffer.append(this.offset);
		buffer.append("\n  length="); //$NON-NLS-1$
		buffer.append(this.length);
		if (this.element != null) {
			buffer.append("\n  element="); //$NON-NLS-1$
			buffer.append(((ModelElement)getElement()).toStringWithAncestors());
		}
		buffer.append("\n"); //$NON-NLS-1$
		return buffer.toString();
	}
}
