/**

* 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.ClassPathAssetSource;

import io.jooby.internal.FileDiskAssetSource;

import io.jooby.internal.FolderDiskAssetSource;

import javax.annotation.Nonnull;

import javax.annotation.Nullable;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.InputStream;

import java.nio.file.Files;

import java.nio.file.Path;

import java.util.Arrays;

import java.util.List;

import java.util.Properties;

/**

* An asset source is a collection or provider of {@link Asset}. There are two implementations:

*

* <ul>

* <li>File system: using {@link #create(Path)}.</li>

* <li>Classpath/URL: using {@link #create(ClassLoader, String)}.</li>

* </ul>

*/

public interface AssetSource {

/**

* Resolve an asset using the given path.

*

* @param path Path to look for.

* @return An asset or <code>null</code>.

*/

@Nullable Asset resolve(@Nonnull String path);

/**

* Classpath asset source. Useful for resolving files from classpath

* (including jar files).

*

* @param loader Class loader.

* @param location Classpath location. For security reasons root of classpath <code>/</code> is

* disallowed.

* @return An asset source.

*/

static @Nonnull AssetSource create(@Nonnull ClassLoader loader, @Nonnull String location) {

return new ClassPathAssetSource(loader, location);

}

/**

* Creates a webjar asset source. Usage:

*

* <ul>

* <li>Add a webjar to your project, for example swagger-ui</li>

* <li>Create and add an asset handler:

* <pre>{@code

*

* asset("/path/*", AssetSource.webjar(getClassLoader(), "swagger-ui"));

*

* }</pre>

* </li>

* </ul>

*

* @param loader Class loader.

* @param name Web asset name.

* @return A webjar source.

*/

static @Nonnull AssetSource webjars(@Nonnull ClassLoader loader, @Nonnull String name) {

List<String> location = Arrays.asList(

"META-INF/maven/org.webjars/" + name + "/pom.properties",

"META-INF/maven/org.webjars.npm/" + name + "/pom.properties"

);

String versionPath = location.stream().filter(it -> loader.getResource(it) != null)

.findFirst()

.orElseThrow(() -> SneakyThrows.propagate(new FileNotFoundException(location.toString())));

try (InputStream in = loader.getResourceAsStream(versionPath)) {

Properties properties = new Properties();

properties.load(in);

String version = properties.getProperty("version");

String source = "/META-INF/resources/webjars/" + name + "/" + version;

return new ClassPathAssetSource(loader, source);

} catch (IOException x) {

throw SneakyThrows.propagate(x);

}

}

/**

* Creates a source from given location. Assets are resolved from file system.

*

* @param location Asset directory.

* @return A new file system asset source.

*/

static @Nonnull AssetSource create(@Nonnull Path location) {

Path absoluteLocation = location.toAbsolutePath();

if (Files.isDirectory(absoluteLocation)) {

return new FolderDiskAssetSource(absoluteLocation);

} else if (Files.isRegularFile(location)) {

return new FileDiskAssetSource(location);

}

throw SneakyThrows.propagate(new FileNotFoundException(location.toAbsolutePath().toString()));

}

}