/*
 * 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.tomee.website;

import org.apache.openejb.loader.IO;
import org.apache.openejb.util.Join;

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class Docs {

    private final Sources sources;

    public Docs(final Sources sources) {
        this.sources = sources;
    }

    public void prepare(final Source source) {
        final File srcDocs = new File(source.getDir(), "docs");
        final File destDocs = sources.getJbakeContentDestFor(source, "docs"); //target/jbake/<tomeeBranch>/docs

        if (!srcDocs.exists()) return;

        try {
            IO.copyDirectory(srcDocs, destDocs);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

        try {
            Files.walk(destDocs.toPath())
                    .filter(path -> path.toFile().isFile())
                    .filter(path -> path.toFile().getName().endsWith(".mdtext"))
                    .forEach(path -> renameMdtextFile(path.toFile()));

        } catch (Exception e) {
            throw new RuntimeException(e);
        }

        final List<Doc> docs;
        try {
            docs = Files.walk(destDocs.toPath())
                    .filter(path -> path.toFile().isFile())
                    .filter(this::isRendered)
                    .map(Path::toFile)
                    .map(path -> toLink(destDocs, path))
                    .collect(Collectors.toList());
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

        docs.stream()
                .peek(JbakeHeaders::addJbakeHeader)
                .forEach(FixMarkdown::process);
        ;

        GroupedIndex.process(destDocs, "docsindex");
    }

    private void renameMdtextFile(final File file) {
        final File newName = new File(file.getParentFile(), file.getName().replace(".mdtext", ".md"));
        if (!file.renameTo(newName)) {
            throw new IllegalStateException("Couldn't rename: " + file.getAbsolutePath() + "\n  to: " + newName.getAbsolutePath());
        }
    }

    private boolean hasIndex(final File destDocs) {
        return Stream.of(destDocs.listFiles())
                .filter(File::isFile)
                .filter(file -> file.getName().startsWith("index."))
                .filter(Docs::isRendered)
                .findFirst().isPresent();
    }

    private void buildIndex(final File destDocs, final List<Doc> docs) {
        try {
            final List<String> links = docs.stream()
                    .map(Doc::toAdoc)
                    .collect(Collectors.toList());

            final StringBuilder index = new StringBuilder();
            index.append(":jbake-type: page\n")
                    .append(":jbake-status: published\n")
                    .append(":jbake-title: Documentation\n")
                    .append("\n")
                    .append("Documentation\n\n")
            ;

            index.append(Join.join("\n", links));

            IO.copy(IO.read(index.toString()), new File(destDocs, "index.adoc"));

        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    private Doc toLink(final File base, final File file) {
        final String href = href(base, file);

        final String name = href.replace(".html", "");
        return new Doc(href, name, file);
    }

    public static String href(final File base, final File file) {
        final String relativePath = relativePath(base, file);
        return Docs.simpleName(relativePath) + ".html";
    }

    public static String relativePath(final File base, final File file) {
        final int baseLength = base.getAbsolutePath().length() + 1;

        return file.getAbsolutePath().substring(baseLength);
    }

    public static class Doc {
        private final String href;
        private final String name;
        private final File source;

        public Doc(final String href, final String name, final File source) {
            this.href = href;
            this.name = name;
            this.source = source;
        }

        public File getSource() {
            return source;
        }

        public String getHref() {
            return href;
        }

        public String getName() {
            return name;
        }

        public String toAdoc() {
            return " - link:" + href + "[" + name + "]";
        }
    }

    private boolean isRendered(final Path path) {
        final File file = path.toFile();
        return isRendered(file);
    }

    public static boolean isRendered(final File file) {
        final String name = file.getName();
        for (final String extension : extensions) {
            if (name.endsWith(extension)) return true;
        }
        return false;
    }

    private static final String[] extensions = {".html", ".asciidoc", ".adoc", ".ad", ".md"};

    public static String simpleName(final File file) {
        final String name = file.getName();

        return simpleName(name);
    }

    public static String simpleName(final String name) {
        for (final String extension : extensions) {
            if (name.endsWith(extension)) return name.replace(extension, "");
        }

        throw new IllegalStateException("Unknown extension: " + name);
    }
}