/**
 * Copyright 2011-2021 Asakusa Framework Team.
 *
 * Licensed 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 com.asakusafw.utils.java.parser.javadoc;

import java.util.ArrayList;

import com.asakusafw.utils.java.internal.parser.javadoc.ir.IrDocBlock;
import com.asakusafw.utils.java.internal.parser.javadoc.ir.IrDocFragment;
import com.asakusafw.utils.java.internal.parser.javadoc.ir.IrDocSimpleName;
import com.asakusafw.utils.java.internal.parser.javadoc.ir.IrDocText;
import com.asakusafw.utils.java.internal.parser.javadoc.ir.JavadocToken;
import com.asakusafw.utils.java.internal.parser.javadoc.ir.JavadocTokenKind;

/**
 * An implementation of {@link JavadocBaseParser} which parses {@code param} blocks.
 */
public class ParamBlockParser extends AcceptableJavadocBlockParser {

    /**
     * Creates a new instance.
     */
    public ParamBlockParser() {
        super("param"); //$NON-NLS-1$
    }

    /**
     * Creates a new instance.
     * @param tagName the first acceptable tag name
     * @param tagNames the rest acceptable tag names
     */
    public ParamBlockParser(String tagName, String... tagNames) {
        super(tagName, tagNames);
    }

    @Override
    public IrDocBlock parse(String tag, JavadocScanner scanner) throws JavadocParseException {
        ArrayList<IrDocFragment> fragments = new ArrayList<>();

        IrDocSimpleName name = fetchSimpleName(scanner);
        if (name != null) {
            fragments.add(name);
        } else {
            consumeIfTypeParameter(scanner, fragments);
        }

        fragments.addAll(fetchRestFragments(scanner));
        fragments.trimToSize();
        return newBlock(tag, fragments);
    }

    private void consumeIfTypeParameter(JavadocScanner scanner, ArrayList<IrDocFragment> fragments) {
        JavadocTokenStream stream = new DefaultJavadocTokenStream(scanner);
        stream.mark();
        JavadocToken first = stream.nextToken();
        if (first.getKind() != JavadocTokenKind.LESS) {
            stream.rewind();
            return;
        }
        JavadocToken second = stream.nextToken();
        if (second.getKind() != JavadocTokenKind.IDENTIFIER) {
            stream.rewind();
            return;
        }
        JavadocToken third = stream.nextToken();
        if (third.getKind() != JavadocTokenKind.GREATER) {
            stream.rewind();
            return;
        }

        stream.discard();

        IrDocText open = new IrDocText(first.getText());
        open.setLocation(first.getLocation());

        IrDocSimpleName name = new IrDocSimpleName(second.getText());
        name.setLocation(second.getLocation());

        IrDocText close = new IrDocText(third.getText());
        close.setLocation(third.getLocation());

        fragments.add(open);
        fragments.add(name);
        fragments.add(close);
    }
}
