/**

 * Back 2 Browser Bytecode Translator

 * Copyright (C) 2012 Jaroslav Tulach <jaroslav.tulach@apidesign.org>

 *

 * This program is free software: you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation, version 2 of the License.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program. Look for COPYING file in the top folder.

 * If not, see http://opensource.org/licenses/GPL-2.0.

 */

package org.apidesign.bck2brwsr.ide.editor;

import com.sun.source.tree.AnnotationTree;

import com.sun.source.tree.ExpressionTree;

import com.sun.source.tree.LiteralTree;

import com.sun.source.tree.MethodTree;

import com.sun.source.tree.Tree.Kind;

import com.sun.source.tree.VariableTree;

import com.sun.source.util.TreePath;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.List;

import org.netbeans.api.java.lexer.JavaTokenId;

import static org.netbeans.api.java.lexer.JavaTokenId.BLOCK_COMMENT;

import static org.netbeans.api.java.lexer.JavaTokenId.JAVADOC_COMMENT;

import static org.netbeans.api.java.lexer.JavaTokenId.LINE_COMMENT;

import static org.netbeans.api.java.lexer.JavaTokenId.WHITESPACE;

import org.netbeans.api.java.source.CompilationInfo;

import org.netbeans.api.java.source.TreeMaker;

import org.netbeans.api.lexer.Token;

import org.netbeans.api.lexer.TokenSequence;

import org.netbeans.spi.editor.hints.ErrorDescription;

import org.netbeans.spi.editor.hints.Fix;

import org.netbeans.spi.java.hints.ErrorDescriptionFactory;

import org.netbeans.spi.java.hints.Hint;

import org.netbeans.spi.java.hints.HintContext;

import org.netbeans.spi.java.hints.JavaFix;

import org.netbeans.spi.java.hints.TriggerTreeKind;

import org.openide.util.NbBundle.Messages;

@Hint(displayName = "#DN_JSNI2JavaScriptBody", description = "#DESC_JSNI2JavaScriptBody", category = "general")

@Messages({

    "DN_JSNI2JavaScriptBody=JSNI to @JavaScriptBody",

    "DESC_JSNI2JavaScriptBody=JSNI to @JavaScriptBody"

})

public class JSNI2JavaScriptBody {

    @TriggerTreeKind(Kind.METHOD)

    @Messages("ERR_JSNI2JavaScriptBody=Can convert JSNI to @JavaScriptBody")

    public static ErrorDescription computeWarning(final HintContext ctx) {

        Token<JavaTokenId> token = findBlockToken(ctx.getInfo(), ctx.getPath(), ctx);

        if (token == null) {

            return null;

        }

        Fix fix = new FixImpl(ctx.getInfo(), ctx.getPath()).toEditorFix();

        return ErrorDescriptionFactory.forName(ctx, ctx.getPath(), Bundle.ERR_JSNI2JavaScriptBody(), fix);

    }

    private static Token<JavaTokenId> findBlockToken(CompilationInfo info, TreePath path, HintContext ctx) {

        int end = (int) info.getTrees().getSourcePositions().getEndPosition(path.getCompilationUnit(), path.getLeaf());

        TokenSequence<JavaTokenId> ts = info.getTokenHierarchy().tokenSequence(JavaTokenId.language());

        if (ts == null) return null;

        ts.move(end);

        if ((ctx != null && ctx.isCanceled()) || !ts.movePrevious() || ts.token().id() != JavaTokenId.SEMICOLON) return null;

        OUTER: while (ts.movePrevious()) {

            if (ctx != null && ctx.isCanceled()) return null;

            switch (ts.token().id()) {

                case WHITESPACE: break;

                case LINE_COMMENT: break;

                case JAVADOC_COMMENT: break;

                case BLOCK_COMMENT:

                    final CharSequence tok = ts.token().text();

                    final int l = tok.length(); 

                    if (l > 4 

                        && tok.subSequence(0, 4).toString().equals("/*-{") // NOI18N

                        && tok.subSequence(l - 4, l).toString().equals("}-*/") // NOI18N

                    ) {

                        return ts.offsetToken();

                    }

                    break;

                default:

                    break OUTER;

            }

        }

        return null;

    }

    private static final class FixImpl extends JavaFix {

        public FixImpl(CompilationInfo info, TreePath tp) {

            super(info, tp);

        }

        @Override

        @Messages("FIX_JSNI2JavaScriptBody=Convert JSNI to @JavaScriptBody")

        protected String getText() {

            return Bundle.FIX_JSNI2JavaScriptBody();

        }

        @Override

        protected void performRewrite(TransformationContext ctx) {

            Token<JavaTokenId> jsniComment = findBlockToken(ctx.getWorkingCopy(), ctx.getPath(), null);

            if (jsniComment == null) {

                //XXX: warn?

                return ;

            }

            JsniCommentTokenizer tok = new JsniCommentTokenizer();

            ManglingSink ms = new ManglingSink();

            final CharSequence cmnt = jsniComment.text();

            tok.process(cmnt.subSequence(4, cmnt.length() - 4), ms);

            TreeMaker make = ctx.getWorkingCopy().getTreeMaker();

            MethodTree mt = (MethodTree) ctx.getPath().getLeaf();

            List<LiteralTree> params = new ArrayList<LiteralTree>();

            for (VariableTree p : mt.getParameters()) {

                params.add(make.Literal(p.getName().toString()));

            }

            AnnotationTree jsBody = make.Annotation(make.QualIdent("org.apidesign.bck2brwsr.core.JavaScriptBody"),

                Arrays.<ExpressionTree>asList(

                    make.Assignment(make.Identifier("args"), make.NewArray(null, Collections.<ExpressionTree>emptyList(), params)),

                    make.Assignment(make.Identifier("body"), make.Literal(ms.out.toString()))

                )

            );

            ctx.getWorkingCopy().rewrite(mt.getModifiers(), make.addModifiersAnnotation(mt.getModifiers(), jsBody));

        }

    }

}