/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF licenses this file
 *  to you under the Apache License, Version 2.0 (the
 *  "License"); you may not use this file except in compliance
 *  with the License.  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing,
 *  software distributed under the License is distributed on an
 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 *  KIND, either express or implied.  See the License for the
 *  specific language governing permissions and limitations
 *  under the License.
 */
package org.codehaus.groovy.tools.groovydoc;

import antlr.collections.AST;
import org.codehaus.groovy.antlr.GroovySourceAST;
import org.codehaus.groovy.antlr.LineColumn;
import org.codehaus.groovy.antlr.SourceBuffer;
import org.codehaus.groovy.antlr.parser.GroovyTokenTypes;
import org.codehaus.groovy.antlr.treewalker.VisitorAdapter;
import org.codehaus.groovy.control.ResolveVisitor;
import org.codehaus.groovy.groovydoc.*;
import org.codehaus.groovy.runtime.DefaultGroovyMethods;

import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class SimpleGroovyClassDocAssembler extends VisitorAdapter implements GroovyTokenTypes {
    private static final String FS = "/";
    private static final Pattern PREV_JAVADOC_COMMENT_PATTERN = Pattern.compile("(?s)/\\*\\*(.*?)\\*/");
    private final Stack<GroovySourceAST> stack;
    private Map<String, GroovyClassDoc> classDocs;
    private List<String> importedClassesAndPackages;
    private Map<String, String> aliases;
    private List<LinkArgument> links;
    private Properties properties;
    private SimpleGroovyFieldDoc currentFieldDoc;
    private SourceBuffer sourceBuffer;
    private String packagePath;
    private LineColumn lastLineCol;
    private boolean insideEnum;
    private Map<String, SimpleGroovyClassDoc> foundClasses;
    private boolean isGroovy;
    private boolean deferSetup;
    private String className;

    public SimpleGroovyClassDocAssembler(String packagePath, String file, SourceBuffer sourceBuffer, List<LinkArgument> links, Properties properties, boolean isGroovy) {
        this.sourceBuffer = sourceBuffer;
        this.packagePath = packagePath;
        this.links = links;
        this.properties = properties;
        this.isGroovy = isGroovy;

        stack = new Stack<GroovySourceAST>();
        classDocs = new HashMap<String, GroovyClassDoc>();
        className = file;
        if (file != null) {
            // todo: replace this simple idea of default class name
            int idx = file.lastIndexOf(".");
            className = file.substring(0, idx);
        }

        deferSetup = packagePath.equals("DefaultPackage");
        importedClassesAndPackages = new ArrayList<String>();
        aliases = new HashMap<String, String>();
        if (!deferSetup) setUpImports(packagePath, links, isGroovy, className);
        lastLineCol = new LineColumn(1, 1);
    }

    private void setUpImports(String packagePath, List<LinkArgument> links, boolean isGroovy, String className) {
        importedClassesAndPackages.add(packagePath + "/*");  // everything in this package
        if (isGroovy) {
            for (String pkg : ResolveVisitor.DEFAULT_IMPORTS) {
                importedClassesAndPackages.add(pkg.replace('.', '/') + "*");
            }
        } else {
            importedClassesAndPackages.add("java/lang/*");
        }
        SimpleGroovyClassDoc currentClassDoc = new SimpleGroovyClassDoc(importedClassesAndPackages, aliases, className, links);
        currentClassDoc.setFullPathName(packagePath + FS + className);
        currentClassDoc.setGroovy(isGroovy);
        classDocs.put(currentClassDoc.getFullPathName(), currentClassDoc);
    }

    public Map<String, GroovyClassDoc> getGroovyClassDocs() {
        postProcessClassDocs();
        return classDocs;
    }

    @Override
    public void visitInterfaceDef(GroovySourceAST t, int visit) {
        visitClassDef(t, visit);
    }

    @Override
    public void visitTraitDef(GroovySourceAST t, int visit) {
        visitClassDef(t, visit);
    }

    @Override
    public void visitEnumDef(GroovySourceAST t, int visit) {
        visitClassDef(t, visit);
        SimpleGroovyClassDoc currentClassDoc = getCurrentOrTopLevelClassDoc(t);
        if (visit == CLOSING_VISIT && currentClassDoc != null) {
            adjustForAutomaticEnumMethods(currentClassDoc);
        }
    }

    @Override
    public void visitAnnotationDef(GroovySourceAST t, int visit) {
        visitClassDef(t, visit);
    }

    @Override
    public void visitClassDef(GroovySourceAST t, int visit) {
        if (visit == OPENING_VISIT) {
            SimpleGroovyClassDoc parent = getCurrentClassDoc();
            String shortName = getIdentFor(t);
            String className = shortName;
            if (parent != null && isNested() && !insideAnonymousInnerClass()) {
                className = parent.name() + "." + className;
            } else {
                foundClasses = new HashMap<String, SimpleGroovyClassDoc>();
            }
            SimpleGroovyClassDoc current = (SimpleGroovyClassDoc) classDocs.get(packagePath + FS + className);
            if (current == null) {
                current = new SimpleGroovyClassDoc(importedClassesAndPackages, aliases, className, links);
                current.setGroovy(isGroovy);
            }
            current.setRawCommentText(getJavaDocCommentsBeforeNode(t));
            current.setFullPathName(packagePath + FS + current.name());
            current.setTokenType(t.getType());
            current.setNameWithTypeArgs(getIdentPlusTypeArgsFor(t));
            processAnnotations(t, current);
            processModifiers(t, current);
            classDocs.put(current.getFullPathName(), current);
            foundClasses.put(shortName, current);
            if (parent != null) {
                parent.addNested(current);
                current.setOuter(parent);
            }
        }
    }

    @Override
    public void visitPackageDef(GroovySourceAST t, int visit) {
        if (visit == OPENING_VISIT && deferSetup) {
            String packageWithSlashes = extractImportPath(t);
            setUpImports(packageWithSlashes, links, isGroovy, className);
        }
    }

    @Override
    public void visitImport(GroovySourceAST t, int visit) {
        if (visit == OPENING_VISIT) {
            String importTextWithSlashesInsteadOfDots = extractImportPath(t);

            GroovySourceAST child = t.childOfType(LITERAL_as);
            if (child != null)  {
                String alias = child.childOfType(DOT).getNextSibling().getText();

                child = child.childOfType(DOT);
                importTextWithSlashesInsteadOfDots = recurseDownImportBranch(child);

                aliases.put(alias, importTextWithSlashesInsteadOfDots);
            }

            importedClassesAndPackages.add(importTextWithSlashesInsteadOfDots);
        }
    }

// TODO is this needed so we can click through on default values?
//    @Override
//    public void visitStaticImport(GroovySourceAST t, int visit) {
//        if (visit == OPENING_VISIT) {
//            // TODO
//            String importTextWithSlashesInsteadOfDots = extractImportPath(t);
//            System.out.println(currentClassDoc.name() + " has static import: " + importTextWithSlashesInsteadOfDots);
//        }
//    }

    @Override
    public void visitExtendsClause(GroovySourceAST t, int visit) {
        SimpleGroovyClassDoc currentClassDoc = getCurrentClassDoc();
        if (visit == OPENING_VISIT) {
            for (GroovySourceAST superClassNode : findTypeNames(t)) {
                String superClassName = extractName(superClassNode);
                if (currentClassDoc.isInterface()) {
                    currentClassDoc.addInterfaceName(superClassName);
                } else {
                    currentClassDoc.setSuperClassName(superClassName);
                }
            }
        }
    }

    @Override
    public void visitImplementsClause(GroovySourceAST t, int visit) {
        if (visit == OPENING_VISIT) {
            for (GroovySourceAST classNode : findTypeNames(t)) {
                getCurrentClassDoc().addInterfaceName(extractName(classNode));
            }
        }
    }

    private static List<GroovySourceAST> findTypeNames(GroovySourceAST t) {
        List<GroovySourceAST> types = new ArrayList<GroovySourceAST>();
        for (AST child = t.getFirstChild(); child != null; child = child.getNextSibling()) {
            GroovySourceAST groovySourceAST = (GroovySourceAST) child;
            if (groovySourceAST.getType() == TYPE) {
                types.add((GroovySourceAST) groovySourceAST.getFirstChild());
            } else {
                types.add(groovySourceAST);
            }
        }
        return types;
    }

    @Override
    public void visitCtorIdent(GroovySourceAST t, int visit) {
        if (visit == OPENING_VISIT && !insideEnum && !insideAnonymousInnerClass()) {
            SimpleGroovyClassDoc currentClassDoc = getCurrentClassDoc();
            SimpleGroovyConstructorDoc currentConstructorDoc = new SimpleGroovyConstructorDoc(currentClassDoc.name(), currentClassDoc);
            currentConstructorDoc.setRawCommentText(getJavaDocCommentsBeforeNode(t));
            processModifiers(t, currentConstructorDoc);
            addParametersTo(t, currentConstructorDoc);
            processAnnotations(t, currentConstructorDoc);
            currentClassDoc.add(currentConstructorDoc);
        }
    }

    @Override
    public void visitMethodDef(GroovySourceAST t, int visit) {
        if (visit == OPENING_VISIT && !insideEnum && !insideAnonymousInnerClass()) {
            SimpleGroovyClassDoc currentClassDoc = getCurrentClassDoc();
            if (currentClassDoc == null) {
                // assume we have a script
                if ("true".equals(properties.getProperty("processScripts", "true"))) {
                    currentClassDoc = new SimpleGroovyClassDoc(importedClassesAndPackages, aliases, className, links);
                    currentClassDoc.setFullPathName(packagePath + FS + className);
                    currentClassDoc.setPublic(true);
                    currentClassDoc.setScript(true);
                    currentClassDoc.setGroovy(isGroovy);
                    currentClassDoc.setSuperClassName("groovy/lang/Script");
                    if ("true".equals(properties.getProperty("includeMainForScripts", "true"))) {
                        currentClassDoc.add(createMainMethod(currentClassDoc));
                    }
                    classDocs.put(currentClassDoc.getFullPathName(), currentClassDoc);
                    if (foundClasses == null) {
                        foundClasses = new HashMap<String, SimpleGroovyClassDoc>();
                    }
                    foundClasses.put(className, currentClassDoc);
                } else {
                    return;
                }
            }
            SimpleGroovyMethodDoc currentMethodDoc = createMethod(t, currentClassDoc);
            currentClassDoc.add(currentMethodDoc);
        }
    }

    private SimpleGroovyMethodDoc createMethod(GroovySourceAST t, SimpleGroovyClassDoc currentClassDoc) {
        String methodName = getIdentFor(t);
        SimpleGroovyMethodDoc currentMethodDoc = new SimpleGroovyMethodDoc(methodName, currentClassDoc);
        currentMethodDoc.setRawCommentText(getJavaDocCommentsBeforeNode(t));
        processModifiers(t, currentMethodDoc);
        currentMethodDoc.setReturnType(new SimpleGroovyType(getTypeOrDefault(t)));
        addParametersTo(t, currentMethodDoc);
        processAnnotations(t, currentMethodDoc);
        return currentMethodDoc;
    }

    private static GroovyMethodDoc createMainMethod(SimpleGroovyClassDoc currentClassDoc) {
        SimpleGroovyMethodDoc mainMethod = new SimpleGroovyMethodDoc("main", currentClassDoc);
        mainMethod.setPublic(true);
        mainMethod.setStatic(true);
        mainMethod.setCommentText("Implicit main method for Groovy Scripts");
        mainMethod.setFirstSentenceCommentText(mainMethod.commentText());
        SimpleGroovyParameter args = new SimpleGroovyParameter("args");
        GroovyType argsType = new SimpleGroovyType("java.lang.String[]");
        args.setType(argsType);
        mainMethod.add(args);
        GroovyType returnType = new SimpleGroovyType("void");
        mainMethod.setReturnType(returnType);
        return mainMethod;
    }

    @Override
    public void visitAnnotationFieldDef(GroovySourceAST t, int visit) {
        if (isGroovy && visit == OPENING_VISIT) {
            // TODO shouldn't really be treating annotation fields as methods - remove this hack
            SimpleGroovyClassDoc currentClassDoc = getCurrentClassDoc();
            SimpleGroovyMethodDoc currentMethodDoc = createMethod(t, currentClassDoc);
            String defaultText = getDefaultValue(t);
            if (defaultText != null) {
                String orig = currentMethodDoc.getRawCommentText();
                currentMethodDoc.setRawCommentText(orig + "\n* @default " + defaultText);
            }
            currentClassDoc.add(currentMethodDoc);
        } else if (visit == OPENING_VISIT) {
//        if (visit == OPENING_VISIT) {
            visitVariableDef(t, visit);
            String defaultText = getDefaultValue(t);
            if (isGroovy) {
                currentFieldDoc.setPublic(true);
            }
            if (defaultText != null) {
                currentFieldDoc.setConstantValueExpression(defaultText);
                String orig = currentFieldDoc.getRawCommentText();
                currentFieldDoc.setRawCommentText(orig + "\n* @default " + defaultText);
            }
        }
    }

    @Override
    public void visitEnumConstantDef(GroovySourceAST t, int visit) {
        if (visit == OPENING_VISIT) {
            SimpleGroovyClassDoc currentClassDoc = getCurrentClassDoc();
            insideEnum = true;
            String enumConstantName = getIdentFor(t);
            SimpleGroovyFieldDoc currentEnumConstantDoc = new SimpleGroovyFieldDoc(enumConstantName, currentClassDoc);
            currentEnumConstantDoc.setRawCommentText(getJavaDocCommentsBeforeNode(t));
            processModifiers(t, currentEnumConstantDoc);
            String typeName = getTypeNodeAsText(t.childOfType(TYPE), currentClassDoc.getTypeDescription());
            currentEnumConstantDoc.setType(new SimpleGroovyType(typeName));
            currentClassDoc.addEnumConstant(currentEnumConstantDoc);
        } else if (visit == CLOSING_VISIT) {
            insideEnum = false;
        }
    }

    @Override
    public void visitVariableDef(GroovySourceAST t, int visit) {
        if (visit == OPENING_VISIT && !insideAnonymousInnerClass() && isFieldDefinition()) {
            SimpleGroovyClassDoc currentClassDoc = getCurrentClassDoc();
            if (currentClassDoc != null) {
                String fieldName = getIdentFor(t);
                currentFieldDoc = new SimpleGroovyFieldDoc(fieldName, currentClassDoc);
                currentFieldDoc.setRawCommentText(getJavaDocCommentsBeforeNode(t));
                boolean isProp = processModifiers(t, currentFieldDoc);
                currentFieldDoc.setType(new SimpleGroovyType(getTypeOrDefault(t)));
                processAnnotations(t, currentFieldDoc);
                if (isProp) {
                    currentClassDoc.addProperty(currentFieldDoc);
                } else {
                    currentClassDoc.add(currentFieldDoc);
                }
            }
        }
    }

    @Override
    public void visitAssign(GroovySourceAST t, int visit) {
        gobbleComments(t, visit);
    }

    @Override
    public void visitMethodCall(GroovySourceAST t, int visit) {
        gobbleComments(t, visit);
    }

    private void gobbleComments(GroovySourceAST t, int visit) {
        if (visit == OPENING_VISIT) {
            SimpleGroovyClassDoc currentClassDoc = getCurrentClassDoc();
            if (currentClassDoc == null || currentClassDoc.isScript()) {
                if (t.getLine() > lastLineCol.getLine() ||
                        (t.getLine() == lastLineCol.getLine() && t.getColumn() > lastLineCol.getColumn())) {
                    getJavaDocCommentsBeforeNode(t);
                    // not normally set for non-major types but appropriate for a script
                    lastLineCol = new LineColumn(t.getLine(), t.getColumn());
                }
            }
        }
    }

    // Step through ClassDocs and tie up loose ends
    private void postProcessClassDocs() {
        for (GroovyClassDoc groovyClassDoc : classDocs.values()) {
            SimpleGroovyClassDoc classDoc = (SimpleGroovyClassDoc) groovyClassDoc;

            // potentially add default constructor to class docs (but not interfaces)
            if (classDoc.isClass()) {
                GroovyConstructorDoc[] constructors = classDoc.constructors();
                if (constructors != null && constructors.length == 0) { // add default constructor to doc
                    // name of class for the constructor
                    GroovyConstructorDoc constructorDoc = new SimpleGroovyConstructorDoc(classDoc.name(), classDoc);
                    // don't forget to tell the class about this default constructor.
                    classDoc.add(constructorDoc);
                }
            }
        }
    }

    private boolean isNested() {
        return getCurrentClassDoc() != null;
    }

    private static boolean isTopLevelConstruct(GroovySourceAST node) {
        if (node == null) return false;
        int type = node.getType();
        return type == CLASS_DEF || type == INTERFACE_DEF || type == TRAIT_DEF || type == ANNOTATION_DEF || type == ENUM_DEF;
    }

    private static void adjustForAutomaticEnumMethods(SimpleGroovyClassDoc currentClassDoc) {
        SimpleGroovyMethodDoc valueOf = new SimpleGroovyMethodDoc("valueOf", currentClassDoc);
        valueOf.setRawCommentText("Returns the enum constant of this type with the specified name.");
        SimpleGroovyParameter parameter = new SimpleGroovyParameter("name");
        parameter.setTypeName("String");
        valueOf.add(parameter);
        valueOf.setReturnType(new SimpleGroovyType(currentClassDoc.name()));
        currentClassDoc.add(valueOf);

        SimpleGroovyMethodDoc values = new SimpleGroovyMethodDoc("values", currentClassDoc);
        values.setRawCommentText("Returns an array containing the constants of this enum type, in the order they are declared.");
        values.setReturnType(new SimpleGroovyType(currentClassDoc.name() + "[]"));
        currentClassDoc.add(values);
    }

    private String extractImportPath(GroovySourceAST t) {
        return recurseDownImportBranch(getImportPathDotType(t));
    }

    private static GroovySourceAST getImportPathDotType(GroovySourceAST t) {
        GroovySourceAST child = t.childOfType(DOT);
        if (child == null) {
            child = t.childOfType(IDENT);
        }
        return child;
    }

    private String recurseDownImportBranch(GroovySourceAST t) {
        if (t != null) {
            if (t.getType() == DOT) {
                GroovySourceAST firstChild = (GroovySourceAST) t.getFirstChild();
                GroovySourceAST secondChild = (GroovySourceAST) firstChild.getNextSibling();
                return (recurseDownImportBranch(firstChild) + "/" + recurseDownImportBranch(secondChild));
            }
            if (t.getType() == IDENT) {
                return t.getText();
            }
            if (t.getType() == STAR) {
                return t.getText();
            }
        }
        return "";
    }

    private void addAnnotationRef(SimpleGroovyProgramElementDoc node, GroovySourceAST t) {
        GroovySourceAST classNode = t.childOfType(IDENT);
        if (classNode != null) {
            node.addAnnotationRef(new SimpleGroovyAnnotationRef(extractName(classNode), getChildTextFromSource(t).trim()));
        }
    }

    private void addAnnotationRef(SimpleGroovyParameter node, GroovySourceAST t) {
        GroovySourceAST classNode = t.childOfType(IDENT);
        if (classNode != null) {
            node.addAnnotationRef(new SimpleGroovyAnnotationRef(extractName(classNode), getChildTextFromSource(t).trim()));
        }
    }

    private void addAnnotationRefs(SimpleGroovyProgramElementDoc node, List<GroovySourceAST> nodes) {
        for (GroovySourceAST t : nodes) {
            addAnnotationRef(node, t);
        }
    }

    private void processAnnotations(GroovySourceAST t, SimpleGroovyProgramElementDoc node) {
        GroovySourceAST modifiers = t.childOfType(MODIFIERS);
        if (modifiers != null) {
            addAnnotationRefs(node, modifiers.childrenOfType(ANNOTATION));
        }
    }

    // hack warning! fragile! TODO find a better way
    private String getDefaultValue(GroovySourceAST t) {
        GroovySourceAST child = (GroovySourceAST) t.getFirstChild();
        if (t.getNumberOfChildren() != 4) return null;
        for (int i = 1; i < t.getNumberOfChildren(); i++) {
            child = (GroovySourceAST) child.getNextSibling();
        }
        GroovySourceAST nodeToProcess = child;
        if (child.getType() != ANNOTATION_ARRAY_INIT && child.getNumberOfChildren() > 0) {
            nodeToProcess = (GroovySourceAST) child.getFirstChild();
        }
        return getChildTextFromSource(nodeToProcess, ";");
    }

    private String getChildTextFromSource(GroovySourceAST child) {
        return sourceBuffer.getSnippet(
                new LineColumn(child.getLine(), child.getColumn()),
                new LineColumn(child.getLineLast(), child.getColumnLast()));
    }

    private String getChildTextFromSource(GroovySourceAST child, String tokens) {
        String text = sourceBuffer.getSnippet(
                new LineColumn(child.getLine(), child.getColumn()),
                new LineColumn(child.getLine() + 1, 0));
        StringTokenizer st = new StringTokenizer(text, tokens);
        return st.nextToken();
    }

    private boolean isFieldDefinition() {
        GroovySourceAST parentNode = getParentNode();
        return parentNode != null && parentNode.getType() == OBJBLOCK;
    }

    private boolean insideAnonymousInnerClass() {
        GroovySourceAST grandParentNode = getGrandParentNode();
        return grandParentNode != null && grandParentNode.getType() == LITERAL_new;
    }

    // return true if a property is found
    private boolean processModifiers(GroovySourceAST t, SimpleGroovyAbstractableElementDoc memberOrClass) {
        GroovySourceAST modifiers = t.childOfType(MODIFIERS);
        boolean hasNonPublicVisibility = false;
        boolean hasPublicVisibility = false;
        if (modifiers != null) {
            AST currentModifier = modifiers.getFirstChild();
            while (currentModifier != null) {
                int type = currentModifier.getType();
                switch (type) {
                    case LITERAL_public:
                        memberOrClass.setPublic(true);
                        hasPublicVisibility = true;
                        break;
                    case LITERAL_protected:
                        memberOrClass.setProtected(true);
                        hasNonPublicVisibility = true;
                        break;
                    case LITERAL_private:
                        memberOrClass.setPrivate(true);
                        hasNonPublicVisibility = true;
                        break;
                    case LITERAL_static:
                        memberOrClass.setStatic(true);
                        break;
                    case FINAL:
                        memberOrClass.setFinal(true);
                        break;
                    case ABSTRACT:
                        memberOrClass.setAbstract(true);
                        break;
                }
                currentModifier = currentModifier.getNextSibling();
            }
            if (!hasNonPublicVisibility && isGroovy && !(memberOrClass instanceof GroovyFieldDoc)) {
                // in groovy, methods and classes are assumed public, unless informed otherwise
                if (isPackageScope(modifiers)) {
                    memberOrClass.setPackagePrivate(true);
                    hasNonPublicVisibility = true;
                } else {
                    memberOrClass.setPublic(true);
                }
            } else if (!hasNonPublicVisibility && !hasPublicVisibility && !isGroovy) {
                if (insideInterface(memberOrClass) || insideAnnotationDef(memberOrClass)) {
                    memberOrClass.setPublic(true);
                } else {
                    memberOrClass.setPackagePrivate(true);
                }
            }
            if (memberOrClass instanceof GroovyFieldDoc && isGroovy && !hasNonPublicVisibility & !hasPublicVisibility) {
                if (isPackageScope(modifiers)) {
                    memberOrClass.setPackagePrivate(true);
                    hasNonPublicVisibility = true;
                }
            }
            if (memberOrClass instanceof GroovyFieldDoc && !hasNonPublicVisibility && !hasPublicVisibility && isGroovy) return true;
        } else if (isGroovy && !(memberOrClass instanceof GroovyFieldDoc)) {
            // in groovy, methods and classes are assumed public, unless informed otherwise
            memberOrClass.setPublic(true);
        } else if (!isGroovy) {
            if (insideInterface(memberOrClass) || insideAnnotationDef(memberOrClass)) {
                memberOrClass.setPublic(true);
            } else {
                memberOrClass.setPackagePrivate(true);
            }
        }
        return memberOrClass instanceof GroovyFieldDoc && isGroovy && !hasNonPublicVisibility & !hasPublicVisibility;
    }

    private boolean isPackageScope(GroovySourceAST modifiers) {
        List<String> names = getAnnotationNames(modifiers);
        return names.contains("groovy/transform/PackageScope") || names.contains("PackageScope");
    }

    private List<String> getAnnotationNames(GroovySourceAST modifiers) {
        List<String> annotationNames = new ArrayList<String>();
        List<GroovySourceAST> annotations = modifiers.childrenOfType(ANNOTATION);
        for (GroovySourceAST annotation : annotations) {
            annotationNames.add(buildName((GroovySourceAST) annotation.getFirstChild()));
        }
        return annotationNames;
    }

    private boolean insideInterface(SimpleGroovyAbstractableElementDoc memberOrClass) {
        SimpleGroovyClassDoc current = getCurrentClassDoc();
        if (current == null || current == memberOrClass) return false;
        return current.isInterface();
    }

    private boolean insideAnnotationDef(SimpleGroovyAbstractableElementDoc memberOrClass) {
        SimpleGroovyClassDoc current = getCurrentClassDoc();
        if (current == null || current == memberOrClass) return false;
        return current.isAnnotationType();
    }

    // todo - If no comment before node, then get comment from same node on parent class - ouch!

    private String getJavaDocCommentsBeforeNode(GroovySourceAST t) {
        String result = "";
        LineColumn thisLineCol = new LineColumn(t.getLine(), t.getColumn());
        String text = sourceBuffer.getSnippet(lastLineCol, thisLineCol);
        if (text != null) {
            Matcher m = PREV_JAVADOC_COMMENT_PATTERN.matcher(text);
            if (m.find()) {
                result = m.group(1);
            }
        }
        if (isMajorType(t)) {
            lastLineCol = thisLineCol;
        }
        return result;
    }

    private static boolean isMajorType(GroovySourceAST t) {
        if (t == null) return false;
        int tt = t.getType();
        return tt == CLASS_DEF || tt == TRAIT_DEF || tt == INTERFACE_DEF || tt == METHOD_DEF || tt == ANNOTATION_DEF || tt == ENUM_DEF ||
                tt == VARIABLE_DEF || tt == ANNOTATION_FIELD_DEF || tt == ENUM_CONSTANT_DEF || tt == CTOR_IDENT;
    }

    private static String getText(GroovySourceAST node) {
        String returnValue = null;
        if (node != null) {
            returnValue = node.getText();
        }
        return returnValue;
    }

    // preempt resolve as info is partially available here (star imports won't match here)
    private String extractName(GroovySourceAST typeNode) {
        String typeName = buildName(typeNode);
        if (!typeName.contains("/")) {
            String slashName = "/" + typeName;
            // Groovy currently resolves this to last found so traverse in reverse order
            for (int i = importedClassesAndPackages.size() - 1; i >= 0; i--) {
                String name = importedClassesAndPackages.get(i);
                if (name.endsWith(slashName)) {
                    typeName = name;
                    break;
                }
            }
        }
        return typeName;
    }

    private String buildName(GroovySourceAST t) {
        if (t != null) {
            if (t.getType() == DOT) {
                GroovySourceAST firstChild = (GroovySourceAST) t.getFirstChild();
                GroovySourceAST secondChild = (GroovySourceAST) firstChild.getNextSibling();
                return (buildName(firstChild) + "/" + buildName(secondChild));
            }
            if (t.getType() == IDENT) {
                return t.getText();
            }
        }
        return "";
    }

    private String getTypeOrDefault(GroovySourceAST t) {
        GroovySourceAST typeNode = t.childOfType(TYPE);
        return getTypeNodeAsText(typeNode, "def");
    }

    private String getTypeNodeAsText(GroovySourceAST typeNode, String defaultText) {
        // TODO refactor to retain richer type information rather than converting to String
        if (typeNode == null) {
            return defaultText;
        }
        if (typeNode.getType() == TYPE) {
            return getAsText(typeNode, defaultText);
        } else if (typeNode.getType() == TYPE_ARGUMENT) {
            return getTypeNodeAsText((GroovySourceAST) typeNode.getFirstChild(), defaultText);
        } else if (typeNode.getType() == WILDCARD_TYPE) {
            AST next = typeNode.getNextSibling();
            if (next == null && typeNode.getFirstChild() != null) {
                // Java2Groovy produces a slightly different tree structure (TODO fix converter or java.g instead?)
                next = typeNode.getFirstChild();
            }
            if (next == null) return "?";
            String boundType = getTypeNodeAsText((GroovySourceAST) next.getFirstChild(), defaultText);
            if (next.getType() == TYPE_UPPER_BOUNDS) return "? extends " + boundType;
            if (next.getType() == TYPE_LOWER_BOUNDS) return "? super " + boundType;
        } else if (typeNode.getType() == IDENT) {
            return getAsTextCurrent(typeNode, defaultText);
        }
        return defaultText;
    }

    private String getAsText(GroovySourceAST typeNode, String defaultText) {
        GroovySourceAST child = (GroovySourceAST) typeNode.getFirstChild();
        return getAsTextCurrent(child, defaultText);
    }

    private String getAsTextCurrent(GroovySourceAST node, String defaultText) {
        if (node == null) return defaultText;
        switch (node.getType()) {
            // literals
            case LITERAL_boolean:
                return "boolean";
            case LITERAL_byte:
                return "byte";
            case LITERAL_char:
                return "char";
            // note: LITERAL_def never created
            case LITERAL_double:
                return "double";
            case LITERAL_float:
                return "float";
            case LITERAL_int:
                return "int";
            case LITERAL_long:
                return "long";
            case LITERAL_short:
                return "short";
            case LITERAL_void:
                return "void";
            case ARRAY_DECLARATOR:
                String componentType = getAsText(node, defaultText);
                if (!componentType.equals("def")) return componentType + "[]";
                return "java/lang/Object[]";
            // identifiers
            case IDENT:
                StringBuilder ident = new StringBuilder();
                ident.append(node.getText());
                GroovySourceAST identChild = (GroovySourceAST) node.getFirstChild();
                getTypeArguments(identChild, ident, defaultText);
                return ident.toString();
            case DOT:
                StringBuilder dot = new StringBuilder();
                GroovySourceAST dotChild = (GroovySourceAST) node.getFirstChild();
                while (dotChild != null) {
                    if (dotChild.getType() == IDENT || dotChild.getType() == DOT) {
                        if (dot.length() > 0) dot.append("/");
                        dot.append(getAsTextCurrent(dotChild, defaultText));
                    } else if (dotChild.getType() == TYPE_ARGUMENTS) {
                        getTypeArguments(dotChild, dot, defaultText);
                    }
                    dotChild = (GroovySourceAST) dotChild.getNextSibling();
                }
                return dot.toString();
        }
        return defaultText;
    }

    private void getTypeArguments(GroovySourceAST child, StringBuilder result, String defaultText) {
        if (child != null && child.getType() == TYPE_ARGUMENTS && child.getNumberOfChildren() > 0) {
            result.append("<");
            GroovySourceAST typeArgumentsNext = (GroovySourceAST) child.getFirstChild();
            List<String> typeArgumentParts = new ArrayList<String>();
            while (typeArgumentsNext != null) {
                if (typeArgumentsNext.getType() == TYPE_ARGUMENT && typeArgumentsNext.getNumberOfChildren() > 0) {
                    typeArgumentParts.add(getTypeNodeAsText((GroovySourceAST) typeArgumentsNext.getFirstChild(), defaultText));
                }
                typeArgumentsNext = (GroovySourceAST) typeArgumentsNext.getNextSibling();
            }
            result.append(DefaultGroovyMethods.join(typeArgumentParts, ", "));
            result.append(">");
        }
    }

    private void getTypeParameters(GroovySourceAST child, StringBuilder result, String defaultText) {
        if (child != null && child.getType() == TYPE_PARAMETERS && child.getNumberOfChildren() > 0) {
            result.append("<");
            GroovySourceAST typeParametersNext = (GroovySourceAST) child.getFirstChild();
            List<String> typeParameterParts = new ArrayList<String>();
            while (typeParametersNext != null) {
                if (typeParametersNext.getType() == TYPE_PARAMETER && typeParametersNext.getNumberOfChildren() > 0) {
                    typeParameterParts.add(getTypeNodeAsText((GroovySourceAST) typeParametersNext.getFirstChild(), defaultText));
                }
                typeParametersNext = (GroovySourceAST) typeParametersNext.getNextSibling();
            }
            result.append(DefaultGroovyMethods.join(typeParameterParts, ", "));
            result.append(">");
        }
    }

    private void addParametersTo(GroovySourceAST t, SimpleGroovyExecutableMemberDoc executableMemberDoc) {
        // parameters
        GroovySourceAST parametersNode = t.childOfType(PARAMETERS);
        if (parametersNode != null && parametersNode.getNumberOfChildren() > 0) {
            GroovySourceAST currentNode = (GroovySourceAST) parametersNode.getFirstChild();
            while (currentNode != null) {
                String parameterTypeName = getTypeOrDefault(currentNode);
                String parameterName = getText(currentNode.childOfType(IDENT));
                SimpleGroovyParameter parameter = new SimpleGroovyParameter(parameterName);
                parameter.setVararg(currentNode.getType() == VARIABLE_PARAMETER_DEF);
                parameter.setTypeName(parameterTypeName);
                GroovySourceAST modifiers = currentNode.childOfType(MODIFIERS);
                if (modifiers != null) {
                    List<GroovySourceAST> annotations = modifiers.childrenOfType(ANNOTATION);
                    for (GroovySourceAST a : annotations) {
                        addAnnotationRef(parameter, a);
                    }
                }
                executableMemberDoc.add(parameter);
                if (currentNode.getNumberOfChildren() == 4) {
                    handleDefaultValue(currentNode, parameter);
                }
                currentNode = (GroovySourceAST) currentNode.getNextSibling();
            }
        }
    }

    private void handleDefaultValue(GroovySourceAST currentNode, SimpleGroovyParameter parameter) {
        GroovySourceAST paramPart = (GroovySourceAST) currentNode.getFirstChild();
        for (int i = 1; i < currentNode.getNumberOfChildren(); i++) {
            paramPart = (GroovySourceAST) paramPart.getNextSibling();
        }
        GroovySourceAST nodeToProcess = paramPart;
        if (paramPart.getNumberOfChildren() > 0) {
            nodeToProcess = (GroovySourceAST) paramPart.getFirstChild();
        }
        // hack warning!
        // TODO handle , and ) when they occur within Strings
        parameter.setDefaultValue(getChildTextFromSource(nodeToProcess, ",)"));
    }

    public void push(GroovySourceAST t) {
        stack.push(t);
    }

    public GroovySourceAST pop() {
        if (!stack.empty()) {
            return stack.pop();
        }
        return null;
    }

    private GroovySourceAST getParentNode() {
        GroovySourceAST parentNode = null;
        GroovySourceAST currentNode = stack.pop();
        if (!stack.empty()) {
            parentNode = stack.peek();
        }
        stack.push(currentNode);
        return parentNode;
    }

    private GroovySourceAST getGrandParentNode() {
        GroovySourceAST grandParentNode = null;
        GroovySourceAST parentNode;
        GroovySourceAST currentNode = stack.pop();
        if (!stack.empty()) {
            parentNode = stack.pop();
            if (!stack.empty()) {
                grandParentNode = stack.peek();
            }
            stack.push(parentNode);
        }
        stack.push(currentNode);
        return grandParentNode;
    }

    private SimpleGroovyClassDoc getCurrentOrTopLevelClassDoc(GroovySourceAST node) {
        SimpleGroovyClassDoc current = getCurrentClassDoc();
        if (current != null) return current;
        return foundClasses.get(getIdentFor(node));
    }

    private SimpleGroovyClassDoc getCurrentClassDoc() {
        if (stack.isEmpty()) return null;
        GroovySourceAST node = getParentNode();
        if (isTopLevelConstruct(node)) return foundClasses.get(getIdentFor(node));
        GroovySourceAST saved = stack.pop();
        SimpleGroovyClassDoc result = getCurrentClassDoc();
        stack.push(saved);
        return result;
    }

    private static String getIdentFor(GroovySourceAST gpn) {
        return gpn.childOfType(IDENT).getText();
    }

    private String getIdentPlusTypeArgsFor(GroovySourceAST gpn) {
        GroovySourceAST groovySourceAST = gpn.childOfType(IDENT);
        StringBuilder ident = new StringBuilder();
        ident.append(groovySourceAST.getText());
        GroovySourceAST typeParams = (GroovySourceAST) groovySourceAST.getNextSibling();
        getTypeParameters(typeParams, ident, "def");
        return ident.toString();
    }
}
