import org.gradle.plugins.ide.eclipse.model.Library
import org.gradle.plugins.ide.eclipse.model.ProjectDependency
import org.gradle.plugins.ide.eclipse.model.SourceFolder

apply plugin: 'eclipse'

eclipse.jdt {
	sourceCompatibility = 17
	targetCompatibility = 17
}

// Replace classpath entries with project dependencies (GRADLE-1116)
// https://issues.gradle.org/browse/GRADLE-1116
eclipse.classpath.file.whenMerged { classpath ->
	def regexp = /.*?\/([^\/]+)\/build\/([^\/]+\/)+(?:main|test)/ // only match those that end in main or test (avoids removing necessary entries like build/classes/jaxb)
	def projectOutputDependencies = classpath.entries.findAll { entry -> entry.path =~ regexp }
	projectOutputDependencies.each { entry ->
		def matcher = (entry.path =~ regexp)
		if (matcher) {
			def projectName = matcher[0][1]
			def path = "/${projectName}"
			if (!classpath.entries.find { e -> e instanceof ProjectDependency && e.path == path }) {
				def recursiveDependency = entry.path.matches('.+/' + projectName + '/build/([^/]+/)+(?:main|test)')
				// Avoid recursive dependency on current project.
				if (!recursiveDependency) {
					classpath.entries.add(new ProjectDependency(path))
				}
			}
			classpath.entries.remove(entry)
		}
	}

	// Remove any remaining direct depencencies on JARs in the build/libs folder
	// except the repack JARs.
	classpath.entries.removeAll { entry -> (entry.path =~ /(?!.*?repack.*\.jar).*?\/([^\/]+)\/build\/libs\/[^\/]+\.jar/) }
}

// Use separate main/test outputs (prevents WTP from packaging test classes)
eclipse.classpath.defaultOutputDir = file(project.name + '/bin/eclipse')
eclipse.classpath.file.beforeMerged { classpath ->
	classpath.entries.findAll{ it instanceof SourceFolder }.each {
		if (it.output.startsWith('bin/')) {
			it.output = null
		}
	}
}
eclipse.classpath.file.whenMerged {
	entries.findAll{ it instanceof SourceFolder }.each {
		it.output = 'bin/' + it.path.split('/')[1]
	}
}

// Ensure project dependencies come after 3rd-party libs (SPR-11836)
// https://jira.spring.io/browse/SPR-11836
eclipse.classpath.file.whenMerged {
	entries.findAll { it instanceof ProjectDependency }.each {
		// delete from original position
		entries.remove(it)
		// append to end of classpath
		entries.add(it)
	}
}

// Remove recursive project dependencies
eclipse.classpath.file.whenMerged {
	entries.findAll { it instanceof ProjectDependency && it.path == ('/' + project.name) }.each {
		entries.remove(it)
	}
}

// Since an Eclipse project supports only a single Java compliance level, projects
// that use the multiReleaseJar plugin are configured with a single Java baseline
// within Eclipse. By default, the highest multi-release version is used (such as
// Java 24 for spring-core), so that the corresponding sources can be developed
// and tested within Eclipse. A different baseline can be configured via the
// "eclipseJavaBaseline" project property: for example, -PeclipseJavaBaseline=17.
// Multi-release source folders for versions above the baseline are not configured
// as source folders in Eclipse (the sources themselves remain untouched), and types
// which are overridden by a multi-release source folder are excluded from lower
// source folders in Eclipse.
def javaBaseline = 17

def multiReleaseVersions = {
	sourceSets.names.findAll { it ==~ /java\d+/ }.collect { (it - 'java') as int }
}

def eclipseJavaBaseline = {
	def releaseVersions = multiReleaseVersions()
	if (releaseVersions.isEmpty()) {
		return javaBaseline
	}
	return (project.hasProperty('eclipseJavaBaseline') ?
			(project.property('eclipseJavaBaseline') as int) : releaseVersions.max())
}

// Return the Java version of the supplied source folder: 0 for "src/main/java",
// 21 for "src/main/java21", or null if it is not a Java source folder.
def javaVersionOf = { SourceFolder folder ->
	def matcher = (folder.path =~ /^src\/(main|test)\/java(\d*)$/)
	if (!matcher.matches()) {
		return null
	}
	return (matcher.group(2) ? (matcher.group(2) as int) : 0)
}

// Return the paths of all Java source files in the supplied directory, relative to
// that directory: for example, "org/springframework/core/task/VirtualThreadDelegate.java"
// for "src/main/java21/org/springframework/core/task/VirtualThreadDelegate.java".
def relativeJavaFiles = { String dir ->
	def root = file(dir).toPath()
	return fileTree(dir).matching { include '**/*.java' }.collect {
		root.relativize(it.toPath()).toString().replace('\\', '/')
	}
}

// Remove existing source folders, since their exclusion patterns depend on the
// configured baseline and would otherwise result in duplicate entries.
eclipse.classpath.file.beforeMerged { classpath ->
	if (!multiReleaseVersions().isEmpty()) {
		classpath.entries.removeAll { it instanceof SourceFolder }
	}
}

eclipse.jdt.file.whenMerged { jdt ->
	def baseline = JavaVersion.toVersion(eclipseJavaBaseline())
	jdt.sourceCompatibility = baseline
	jdt.targetCompatibility = baseline
}

eclipse.classpath.file.whenMerged { classpath ->
	def baseline = eclipseJavaBaseline()

	// Remove Gradle output for multi-release source sets, such as
	// "build/classes/java/java21".
	classpath.entries.removeAll { it.path =~ /build\/classes\/[^\/]+\/java\d+(Test)?$/ }

	// Remove classpath entries for multi-release source folders above the baseline.
	classpath.entries.removeAll {
		it instanceof SourceFolder && (javaVersionOf(it) ?: 0) > baseline
	}

	// Mark multi-release test source folders (such as "src/test/java21") as test
	// sources, since they share the output folder with "src/test/java".
	classpath.entries.findAll { it instanceof SourceFolder && it.path ==~ /src\/test\/java\d+/ }.each {
		it.entryAttributes['test'] = 'true'
	}

	// Exclude types from lower source folders which are overridden in higher ones.
	['main', 'test'].each { scope ->
		def sourceFolders = classpath.entries.findAll {
			it instanceof SourceFolder && it.path.startsWith("src/${scope}/") &&
					javaVersionOf(it) != null
		}
		sourceFolders.each { folder ->
			def overriddenTypes = sourceFolders
					.findAll { javaVersionOf(it) > javaVersionOf(folder) }
					.collectMany { relativeJavaFiles(it.path) }
					.findAll { file("${folder.path}/${it}").exists() }
			if (!overriddenTypes.isEmpty()) {
				folder.excludes = (folder.excludes + overriddenTypes).unique()
			}
		}

		// Place higher source folders before lower ones, so that the debugger's source
		// lookup finds overriding types before excluded ones.
		def multiReleaseFolders = sourceFolders.findAll { javaVersionOf(it) > 0 }
				.sort { -javaVersionOf(it) }
		def baseFolder = sourceFolders.find { javaVersionOf(it) == 0 }
		if (baseFolder != null && !multiReleaseFolders.isEmpty()) {
			classpath.entries.removeAll(multiReleaseFolders)
			classpath.entries.addAll(classpath.entries.indexOf(baseFolder), multiReleaseFolders)
		}
	}
}

// Remove classpath entries for non-existent libraries added by the multiReleaseJar
// plugin, such as "spring-core/build/classes/kotlin/java21".
eclipse.classpath.file.whenMerged {
	entries.findAll { it instanceof Library && !file(it.path).exists() }.each {
		entries.remove(it)
	}
}

// Include project specific settings
tasks.register('eclipseSettings', Copy) {
	from rootProject.files(
		'src/eclipse/org.eclipse.core.resources.prefs',
		'src/eclipse/org.eclipse.jdt.core.prefs',
		'src/eclipse/org.eclipse.jdt.ui.prefs')
	into project.file('.settings/')
	outputs.upToDateWhen { false }
}

tasks.register('cleanEclipseSettings', Delete) {
	delete project.file('.settings/org.eclipse.core.resources.prefs')
	delete project.file('.settings/org.eclipse.jdt.core.prefs')
	delete project.file('.settings/org.eclipse.jdt.ui.prefs')
}

tasks['eclipse'].dependsOn(eclipseSettings)
tasks['eclipseJdt'].dependsOn(eclipseSettings)
tasks['cleanEclipse'].dependsOn(cleanEclipseSettings)