/**

* Jooby https://jooby.io

* Apache License Version 2.0 https://jooby.io/LICENSE.txt

* Copyright 2014 Edgar Espina

*/

package io.jooby;

import io.jooby.internal.FileAsset;

import io.jooby.internal.JarAsset;

import io.jooby.internal.URLAsset;

import javax.annotation.Nonnull;

import java.io.IOException;

import java.io.InputStream;

import java.net.JarURLConnection;

import java.net.URISyntaxException;

import java.net.URL;

import java.nio.ByteBuffer;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.util.Base64;

/**

* Represent an static resource file. Asset from file system and classpath are supported.

*

* @author edgar

* @since 2.0.0

*/

public interface Asset extends AutoCloseable {

/**

* Creates a file system asset.

*

* @param resource File resource.

* @return File resource asset.

*/

static Asset create(@Nonnull Path resource) {

return new FileAsset(resource);

}

/**

* Creates a URL asset with the given path.

* @param path Asset path.

* @param resource Asset URL.

* @return URL asset.

*/

static Asset create(@Nonnull String path, @Nonnull URL resource) {

try {

if ("jar".equals(resource.getProtocol())) {

return new JarAsset((JarURLConnection) resource.openConnection());

}

if ("file".equals(resource.getProtocol())) {

return create(Paths.get(resource.toURI()));

}

return new URLAsset(resource, path);

} catch (IOException | URISyntaxException x) {

throw SneakyThrows.propagate(x);

}

}

/**

* @return Asset size (in bytes) or <code>-1</code> if undefined.

*/

long getSize();

/**

* @return The last modified date if possible or -1 when isn't.

*/

long getLastModified();

/**

* @return True if the asset is a directory (when possible).

*/

boolean isDirectory();

/**

* Computes a weak e-tag value from asset.

*

* @return A weak e-tag.

*/

default @Nonnull String getEtag() {

StringBuilder b = new StringBuilder(32);

b.append("W/\"");

Base64.Encoder encoder = Base64.getEncoder();

int hashCode = hashCode();

long lastModified = getLastModified();

long length = getSize();

ByteBuffer buffer = ByteBuffer.allocate(Long.BYTES);

buffer.putLong(lastModified ^ hashCode);

b.append(Long.toHexString(lastModified ^ hashCode));

buffer.clear();

buffer.putLong(length ^ hashCode);

b.append(encoder.encodeToString(buffer.array()));

b.append('"');

return b.toString();

}

/**

* @return Asset media type.

*/

@Nonnull

MediaType getContentType();

/**

* @return Asset content.

*/

InputStream stream();

}