/*
 * Copyright (c) 2018-2019. Developed by Hedgecode.
 *
 * 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 org.hedgecode.chess.img;

import java.awt.image.BufferedImage;
import java.net.URI;
import java.net.URISyntaxException;
import java.nio.file.DirectoryStream;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.HashMap;
import java.util.Map;

import org.hedgecode.chess.img.fs.FileSystemDetector;
import org.hedgecode.chess.img.fs.FileSystemContractor;

/**
 * Abstract common image loader with type state of saved resources.
 *
 * @author Dmitry Samoshin aka gotty
 */
public abstract class AbstractImageLoader implements ImageLoader {

    private static final String IMAGES_DIR =
            ImageConstants.RESOURCE_ROOT_DIR.concat(ImageConstants.RESOURCE_IMAGES_DIR);

    private static final int DEF_IMAGE_SIZE = 100;

    private Type loadType;

    private URI imageResourceUri;

    public AbstractImageLoader() {
        loadType = Type.STATELESS;
        try {
            if (FileSystemDetector.detectJar(getImageResourceUri())) {
                loadType = Type.STATEFUL;
            }
        } catch (ImageException ignored) {
        }
    }

    protected abstract void clear();

    @Override
    public Type loadType() {
        return loadType;
    }

    protected void setLoadType(Type loadType) {
        if (Type.STATELESS.equals(loadType)) {
            clear();
        }
        this.loadType = loadType;
    }

    protected URI getImageResourceUri() throws ImageException {
        if (imageResourceUri == null) {
            try {
                imageResourceUri = getClass().getResource(IMAGES_DIR).toURI();
            } catch (URISyntaxException e) {
                throw new ImageException("image.unable.access.resource");
            }
        }
        return imageResourceUri;
    }

    protected Map<String, BufferedImage> loadImages(String imagesPath, ImageFilter filter)
            throws ImageException
    {
        return loadImages(imagesPath, filter, DEF_IMAGE_SIZE);
    }

    protected Map<String, BufferedImage> loadImages(String imagesPath, ImageFilter filter, int size)
            throws ImageException
    {
        Map<String, BufferedImage> images = new HashMap<>();
        try (FileSystemContractor fsc = FileSystemDetector.detect(getImageResourceUri())) {
            try (DirectoryStream<Path> ds =
                         Files.newDirectoryStream(
                                 fsc.getPath(imagesPath), filter
                         )
            ) {
                ImageFormatShaper formatShaper = ImageFormatShaper.getInstance();
                for (Path file : ds) {
                    String fileName = file.getFileName().toString();
                    String baseName = FilenameUtils.getBaseName(fileName).toLowerCase();
                    String imageFormat = FilenameUtils.getExtension(fileName).toLowerCase();
                    images.put(
                            baseName,
                            formatShaper.shape(
                                    imageFormat,
                                    fsc.getResourceAsStream(file),
                                    size
                            )
                    );
                }
            }
        } catch (Exception e) {
            throw new ImageException("image.unable.access.resource", e.getMessage());
        }
        return images;
    }

}