com.github.jlangch.venice.impl.util.markdown.block.CodeBlockParser Maven / Gradle / Ivy

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 *
 *
 * Copyright 2017-2024 Venice
 *
 * 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.github.jlangch.venice.impl.util.markdown.block;

import com.github.jlangch.venice.impl.reader.LineReader;
import com.github.jlangch.venice.impl.util.StringUtil;


public class CodeBlockParser {

    public CodeBlockParser(final LineReader reader) {
        this.reader = reader;
    }

    public CodeBlock parse() {
        if (reader.eof()) {
            return new CodeBlock();
        }

        String line = reader.peek();

        if (CodeBlockParser.isBlockStart(line)) {
            reader.consume();

            final int indentLen = parseIndent(line);
            final String language = parseLanguage(line);

            final CodeBlock block = new CodeBlock(language);

            while(!reader.eof()) {
                line = reader.peek();
                reader.consume();

                if (isFence(line)) {
                    break;
                }
                else {
                    block.addLine(removeIndent(StringUtil.trimRight(line), indentLen));
                }
            }

            block.parseChunks();
            return block;
        }
        else {
            return new CodeBlock();
        }
    }

    public static boolean isBlockStart(final String line) {
        return isFence(line);
    }

    private static boolean isFence(final String line) {
        return line.matches(" *```.*");
    }

    private static String parseLanguage(final String line) {
        return StringUtil.removeStart(line.trim(), "```").trim();
    }

    private static int parseIndent(final String line) {
        return StringUtil.indexNotOf(line, " ", 0);
    }

    private static String removeIndent(final String line, final int indent) {
        if (indent == 0 ) {
            return line;
        }
        else {
            final int lineIndent = Math.min(parseIndent(line), indent);
            return lineIndent == 0 ? line : line.substring(lineIndent);
        }
    }


    private final LineReader reader;
}