/*

 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

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

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.jpackage.internal;

import java.io.*;

import java.nio.charset.StandardCharsets;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.StandardCopyOption;

import java.text.MessageFormat;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import java.util.Optional;

import java.util.stream.Collectors;

import java.util.stream.Stream;

import static jdk.jpackage.internal.StandardBundlerParam.RESOURCE_DIR;

import jdk.jpackage.internal.resources.ResourceLocator;

/**

 * Resource file that may have the default value supplied by jpackage. It can be

 * overridden by a file from resource directory set with {@code --resource-dir}

 * jpackage parameter.

 *

 * Resource has default name and public name. Default name is the name of a file

 * in {@code jdk.jpackage.internal.resources} package that provides the default

 * value of the resource.

 *

 * Public name is a path relative to resource directory to a file with custom

 * value of the resource.

 *

 * Use #setPublicName to set the public name.

 *

 * If #setPublicName was not called, name of file passed in #saveToFile function

 * will be used as a public name.

 *

 * Use #setExternal to set arbitrary file as a source of resource. If non-null

 * value was passed in #setExternal call that value will be used as a path to file

 * to copy in the destination file passed in #saveToFile function call.

 */

final class OverridableResource {

    OverridableResource(String defaultName) {

        this.defaultName = defaultName;

    }

    OverridableResource setSubstitutionData(Map<String, String> v) {

        if (v != null) {

            // Disconnect `v`

            substitutionData = new HashMap<>(v);

        } else {

            substitutionData = null;

        }

        return this;

    }

    OverridableResource setCategory(String v) {

        category = v;

        return this;

    }

    String getCategory() {

        return category;

    }

    OverridableResource setResourceDir(Path v) {

        resourceDir = v;

        return this;

    }

    OverridableResource setResourceDir(File v) {

        return setResourceDir(toPath(v));

    }

    /**

     * Set name of file to look for in resource dir.

     *

     * @return this

     */

    OverridableResource setPublicName(Path v) {

        publicName = v;

        return this;

    }

    OverridableResource setPublicName(String v) {

        return setPublicName(Path.of(v));

    }

    OverridableResource setExternal(Path v) {

        externalPath = v;

        return this;

    }

    OverridableResource setExternal(File v) {

        return setExternal(toPath(v));

    }

    void saveToFile(Path dest) throws IOException {

        final String printableCategory;

        if (category != null) {

            printableCategory = String.format("[%s]", category);

        } else {

            printableCategory = "";

        }

        if (externalPath != null && externalPath.toFile().exists()) {

            Log.verbose(MessageFormat.format(I18N.getString(

                    "message.using-custom-resource-from-file"),

                    printableCategory,

                    externalPath.toAbsolutePath().normalize()));

            try (InputStream in = Files.newInputStream(externalPath)) {

                processResourceStream(in, dest);

            }

            return;

        }

        final Path resourceName = Optional.ofNullable(publicName).orElse(

                dest.getFileName());

        if (resourceDir != null) {

            final Path customResource = resourceDir.resolve(resourceName);

            if (customResource.toFile().exists()) {

                Log.verbose(MessageFormat.format(I18N.getString(

                        "message.using-custom-resource"), printableCategory,

                        resourceDir.normalize().toAbsolutePath().relativize(

                                customResource.normalize().toAbsolutePath())));

                try (InputStream in = Files.newInputStream(customResource)) {

                    processResourceStream(in, dest);

                }

                return;

            }

        }

        if (defaultName != null) {

            Log.verbose(MessageFormat.format(

                    I18N.getString("message.using-default-resource"),

                    defaultName, printableCategory, resourceName));

            try (InputStream in = readDefault(defaultName)) {

                processResourceStream(in, dest);

            }

        }

    }

    void saveToFile(File dest) throws IOException {

        saveToFile(dest.toPath());

    }

    static InputStream readDefault(String resourceName) {

        return ResourceLocator.class.getResourceAsStream(resourceName);

    }

    static OverridableResource createResource(String defaultName,

            Map<String, ? super Object> params) {

        return new OverridableResource(defaultName).setResourceDir(

                RESOURCE_DIR.fetchFrom(params));

    }

    private static List<String> substitute(Stream<String> lines,

            Map<String, String> substitutionData) {

        return lines.map(line -> {

            String result = line;

            for (var entry : substitutionData.entrySet()) {

                result = result.replace(entry.getKey(), Optional.ofNullable(

                        entry.getValue()).orElse(""));

            }

            return result;

        }).collect(Collectors.toList());

    }

    private static Path toPath(File v) {

        if (v != null) {

            return v.toPath();

        }

        return null;

    }

    private void processResourceStream(InputStream rawResource, Path dest)

            throws IOException {

        if (substitutionData == null) {

            Files.createDirectories(dest.getParent());

            Files.copy(rawResource, dest, StandardCopyOption.REPLACE_EXISTING);

        } else {

            // Utf8 in and out

            try (BufferedReader reader = new BufferedReader(

                    new InputStreamReader(rawResource, StandardCharsets.UTF_8))) {

                Files.createDirectories(dest.getParent());

                Files.write(dest, substitute(reader.lines(), substitutionData));

            }

        }

    }

    private Map<String, String> substitutionData;

    private String category;

    private Path resourceDir;

    private Path publicName;

    private Path externalPath;

    private final String defaultName;

}