/*******************************************************************************
 * Copyright (c) 2000, 2019 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *   Jesper Kamstrup Linnet (eclipse@kamstrup-linnet.dk) - initial API and implementation
 *          (report 36180: Callers/Callees view)
 *   Stephan Herrmann (stephan@cs.tu-berlin.de):
 *          - bug 75800: [call hierarchy] should allow searches for fields
 *   Red Hat Inc. - modified to use CallHierarchyCore instance
 *******************************************************************************/
package org.eclipse.jdt.internal.corext.callhierarchy;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.StringTokenizer;

import org.eclipse.jface.preference.IPreferenceStore;

import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IMember;
import org.eclipse.jdt.core.IMethod;
import org.eclipse.jdt.core.ITypeRoot;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.core.dom.ASTParser;
import org.eclipse.jdt.core.dom.CompilationUnit;
import org.eclipse.jdt.core.search.IJavaSearchScope;

import org.eclipse.jdt.internal.corext.dom.IASTSharedValues;

import org.eclipse.jdt.internal.ui.JavaPlugin;
import org.eclipse.jdt.internal.ui.util.StringMatcher;

public class CallHierarchy {
    private static final String PREF_USE_IMPLEMENTORS= "PREF_USE_IMPLEMENTORS"; //$NON-NLS-1$
    private static final String PREF_USE_FILTERS = "PREF_USE_FILTERS"; //$NON-NLS-1$
    private static final String PREF_FILTERS_LIST = "PREF_FILTERS_LIST"; //$NON-NLS-1$
    private static final String PREF_FILTER_TESTCODE= "PREF_FILTER_TESTCODE"; //$NON-NLS-1$

    private static final String DEFAULT_IGNORE_FILTERS = "java.*,javax.*"; //$NON-NLS-1$
    private static CallHierarchy fgInstance;
    private CallHierarchyCore fgCallHierarchyCore;
    private StringMatcher[] fFilters;

    private CallHierarchy() {
        fgCallHierarchyCore = CallHierarchyCore.getDefault();
    }

    public static CallHierarchy getDefault() {
        if (fgInstance == null) {
            fgInstance = new CallHierarchy();
        }

        return fgInstance;
    }

    public boolean isSearchUsingImplementorsEnabled() {
        IPreferenceStore settings = JavaPlugin.getDefault().getPreferenceStore();

        return settings.getBoolean(PREF_USE_IMPLEMENTORS);
    }

    public void setSearchUsingImplementorsEnabled(boolean enabled) {
        IPreferenceStore settings = JavaPlugin.getDefault().getPreferenceStore();

        settings.setValue(PREF_USE_IMPLEMENTORS, enabled);
    }

    public boolean isFilterTestCode() {
        IPreferenceStore settings = JavaPlugin.getDefault().getPreferenceStore();

        return settings.getBoolean(PREF_FILTER_TESTCODE);
    }

    public void setFilterTestCode(boolean enabled) {
        IPreferenceStore settings = JavaPlugin.getDefault().getPreferenceStore();

        settings.setValue(PREF_FILTER_TESTCODE, enabled);
    }


    public Collection<IJavaElement> getImplementingMethods(IMethod method) {
        return fgCallHierarchyCore.getImplementingMethods(method);
    }

    public Collection<IJavaElement> getInterfaceMethods(IMethod method) {
        return fgCallHierarchyCore.getInterfaceMethods(method);
    }

    public MethodWrapper[] getCallerRoots(IMember[] members) {
        return fgCallHierarchyCore.getCallerRoots(members);
    }

    public MethodWrapper[] getCalleeRoots(IMember[] members) {
        return fgCallHierarchyCore.getCalleeRoots(members);
    }

    public static CallLocation getCallLocation(Object element) {
        return CallHierarchyCore.getCallLocation(element);
    }

    public IJavaSearchScope getSearchScope() {
        return fgCallHierarchyCore.getSearchScope();
    }

    public void setSearchScope(IJavaSearchScope searchScope) {
        fgCallHierarchyCore.setSearchScope(searchScope);
    }

	/**
	 * Checks whether the fully qualified name is ignored by the set filters.
	 *
	 * @param fullyQualifiedName the fully qualified name
	 *
	 * @return <code>true</code> if the fully qualified name is ignored
	 */
    public boolean isIgnored(String fullyQualifiedName) {
        if ((getIgnoreFilters() != null) && (getIgnoreFilters().length > 0)) {
            for (int i = 0; i < getIgnoreFilters().length; i++) {
                String fullyQualifiedName1 = fullyQualifiedName;

                if (getIgnoreFilters()[i].match(fullyQualifiedName1)) {
                    return true;
                }
            }
        }

        return false;
    }

    public boolean isFilterEnabled() {
        IPreferenceStore settings = JavaPlugin.getDefault().getPreferenceStore();
        return settings.getBoolean(PREF_USE_FILTERS);
    }

    public void setFilterEnabled(boolean filterEnabled) {
        IPreferenceStore settings = JavaPlugin.getDefault().getPreferenceStore();
        settings.setValue(PREF_USE_FILTERS, filterEnabled);
    }

    /**
     * Returns the current filters as a string.
     * @return returns the filters
     */
    public String getFilters() {
        IPreferenceStore settings = JavaPlugin.getDefault().getPreferenceStore();

        return settings.getString(PREF_FILTERS_LIST);
    }

    public void setFilters(String filters) {
        fFilters = null;

        IPreferenceStore settings = JavaPlugin.getDefault().getPreferenceStore();
        settings.setValue(PREF_FILTERS_LIST, filters);
    }

    /**
     * Returns filters for packages which should not be included in the search results.
     *
     * @return StringMatcher[]
     */
    private StringMatcher[] getIgnoreFilters() {
        if (fFilters == null) {
            String filterString = null;

            if (isFilterEnabled()) {
                filterString = getFilters();

                if (filterString == null) {
                    filterString = DEFAULT_IGNORE_FILTERS;
                }
            }

            if (filterString != null) {
                fFilters = parseList(filterString);
            } else {
                fFilters = null;
            }
        }

        return fFilters;
    }

    public static boolean arePossibleInputElements(List<?> elements) {
        return CallHierarchyCore.arePossibleInputElements(elements);
	}

	/**
	 * Parses the comma separated string into an array of {@link StringMatcher} objects.
	 *
	 * @param listString the string to parse
	 * @return an array of {@link StringMatcher} objects
	 */
    private static StringMatcher[] parseList(String listString) {
        List<StringMatcher> list = new ArrayList<>(10);
        StringTokenizer tokenizer = new StringTokenizer(listString, ","); //$NON-NLS-1$

        while (tokenizer.hasMoreTokens()) {
            String textFilter = tokenizer.nextToken().trim();
            list.add(new StringMatcher(textFilter, false, false));
        }

        return list.toArray(new StringMatcher[list.size()]);
    }

    static CompilationUnit getCompilationUnitNode(IMember member, boolean resolveBindings) {
    	ITypeRoot typeRoot= member.getTypeRoot();
        try {
	    	if (typeRoot.exists() && typeRoot.getBuffer() != null) {
				ASTParser parser= ASTParser.newParser(IASTSharedValues.SHARED_AST_LEVEL);
				parser.setSource(typeRoot);
				parser.setResolveBindings(resolveBindings);
				return (CompilationUnit) parser.createAST(null);
	    	}
        } catch (JavaModelException e) {
            JavaPlugin.log(e);
        }
        return null;
    }

    public static boolean isPossibleInputElement(Object element){
        return CallHierarchyCore.isPossibleInputElement(element);
    }
}