gradle/helper.gradle

import java.nio.file.Path
import java.nio.file.Paths
import java.nio.file.Files
import java.text.MessageFormat


class UpdateLibrariesTask extends DefaultTask {
	Path directory
	List<Map> libraries
	Set<String> manualLibraries = new HashSet<>();

	@TaskAction
	def update() {
		Set<String> librariesNames = new HashSet<>()

		libraries.each({
			String url = it.get("url")
			String libraryName = it.get("name")

			librariesNames.add(libraryName)

			Path libraryFile = directory.resolve(libraryName)
			if (Files.notExists(libraryFile)) {
				logger.lifecycle(MessageFormat.format("Downloading library {0} from {1}", libraryName, url))
				ant.get(src: url, dest: libraryFile)
			} else {
				logger.lifecycle(MessageFormat.format("Skipping download of library {0} because it already exists", libraryName))
			}
		})

		Files.list(directory)
		.filter({
			String filename = it.getFileName().toString()
			!librariesNames.contains(filename) && !manualLibraries.contains(filename)
		})
		.each({
			logger.lifecycle(MessageFormat.format("Deleting old library {0}", it.getFileName()))
			Files.delete(it)
		})
	}

}

ext.UpdateLibrariesTask = UpdateLibrariesTask


class BuildLibraryTask extends DefaultTask {
	Path targetDirectory
	String targetLibraryName
	String builderUrl
	String[] buildCommand
	Map<String, String> buildEnv = new HashMap<>()
	String[] builtLibraryName
	String builderName = "library_builder"

	def getBuildDirectory() {
		return getProject().buildDir.toPath().toAbsolutePath().resolve("libraries").resolve(targetLibraryName)
	}

	def getBuilderPath() {
		return getBuildDirectory().resolve(builderName)
	}

	@TaskAction
	def update() {
		Path libraryFile = targetDirectory.resolve(targetLibraryName)
		Path buildDirectory = getBuildDirectory()
		Files.createDirectories(buildDirectory)
		if (Files.notExists(libraryFile)) {
			logger.lifecycle(MessageFormat.format("Building library {0} from {1}", targetLibraryName, builderUrl))

			ant.get(src: builderUrl, dest: getBuilderPath())

			Map<String, String> finalBuildEnv = new HashMap<String, String>();
			finalBuildEnv.putAll(System.getenv());
			finalBuildEnv.putAll(buildEnv)
			getProject().exec {
				workingDir = buildDirectory.toFile()
				commandLine = Arrays.asList(buildCommand)
				environment = finalBuildEnv
			}

			Path builtLibraryFile = buildDirectory
			for (String builtLibraryElementName : builtLibraryName) {
				builtLibraryFile = builtLibraryFile.resolve(builtLibraryElementName)
			}
			Files.copy(builtLibraryFile, libraryFile)
			buildDirectory.toFile().deleteDir()

			logger.lifecycle(MessageFormat.format("Successfully built library {0}", targetLibraryName))
		} else {
			logger.lifecycle(MessageFormat.format("Skipping building of library {0} because it already exists", targetLibraryName))
		}
	}
}

ext.BuildLibraryTask = BuildLibraryTask