SupportedFormatsAdoc.java

/*
 * 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.apache.tika.cli;

import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;

import org.apache.tika.mime.MediaType;
import org.apache.tika.parser.CompositeParser;
import org.apache.tika.parser.ParseContext;
import org.apache.tika.parser.Parser;
import org.apache.tika.parser.ParserDecorator;
import org.apache.tika.parser.ocr.TesseractOCRConfig;

/**
 * Renders the leaf parsers of a composite and their media types as an AsciiDoc
 * list for the docs' Supported Formats page. Output is fully sorted so a
 * checked-in copy can be diffed against a fresh render.
 */
final class SupportedFormatsAdoc {

    static final String HEADER = "//\n" +
            "// Licensed to the Apache Software Foundation (ASF) under one or more\n" +
            "// contributor license agreements.  See the NOTICE file distributed with\n" +
            "// this work for additional information regarding copyright ownership.\n" +
            "// The ASF licenses this file to You under the Apache License, Version 2.0\n" +
            "// (the \"License\"); you may not use this file except in compliance with\n" +
            "// the License.  You may obtain a copy of the License at\n" +
            "//\n" +
            "//     http://www.apache.org/licenses/LICENSE-2.0\n" +
            "//\n" +
            "// Unless required by applicable law or agreed to in writing, software\n" +
            "// distributed under the License is distributed on an \"AS IS\" BASIS,\n" +
            "// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n" +
            "// See the License for the specific language governing permissions and\n" +
            "// limitations under the License.\n" +
            "//\n" +
            "\n" +
            "// Generated by `tika-app --list-parser-details-adoc`. Do not edit by hand;\n" +
            "// regenerate and commit. TikaCLITest fails when this file is stale.\n";

    private SupportedFormatsAdoc() {
    }

    static String render(Parser root) {
        // Tesseract only advertises types when the binary is installed; hide it so
        // the output does not depend on the generating machine.
        ParseContext context = new ParseContext();
        TesseractOCRConfig noOcr = new TesseractOCRConfig();
        noOcr.setSkipOcr(true);
        context.set(TesseractOCRConfig.class, noOcr);

        Map<String, Set<String>> byClass = new TreeMap<>();
        collect(root, context, byClass);

        StringBuilder sb = new StringBuilder(HEADER).append('\n');
        for (Map.Entry<String, Set<String>> e : byClass.entrySet()) {
            String fqn = e.getKey();
            int dot = fqn.lastIndexOf('.');
            sb.append("* `").append(fqn, 0, dot + 1).append("` link:{tika-javadoc-url}/")
                    .append(fqn.replace('.', '/')).append(".html[").append(fqn.substring(dot + 1))
                    .append("]\n");
            for (String type : e.getValue()) {
                sb.append("** `").append(type).append("`\n");
            }
        }
        return sb.toString();
    }

    private static void collect(Parser p, ParseContext context, Map<String, Set<String>> byClass) {
        while (p instanceof ParserDecorator) {
            p = ((ParserDecorator) p).getWrappedParser();
        }
        if (p instanceof CompositeParser) {
            for (Parser child : ((CompositeParser) p).getAllComponentParsers()) {
                collect(child, context, byClass);
            }
            return;
        }
        Set<MediaType> supported = p.getSupportedTypes(context);
        if (supported.isEmpty()) {
            return;
        }
        Set<String> types = byClass.computeIfAbsent(p.getClass().getName(), k -> new TreeSet<>());
        for (MediaType mt : supported) {
            types.add(mt.toString());
        }
    }
}