// Defines tasks for building the VDL tool and generating VDL files.

package io.v.vdl

import org.gradle.api.Plugin
import org.gradle.api.Project
import org.gradle.api.file.FileCollection
import org.gradle.api.tasks.Copy
import org.gradle.api.tasks.Delete
import org.gradle.api.tasks.Exec

class VdlPlugin implements Plugin<Project> {
    String inputPath
    String outputPath

    void apply(Project project) {
        project.extensions.create('vdl', VdlConfiguration)

        def extractTask = project.task('extractVdl', type: Copy) {
            from {
                getVdlToolJarFiles(project, project.buildscript.configurations.classpath)
            }
            into { new File(project.buildDir, 'vdltool') }
        }
        def generateTask = project.task('generateVdl', type: Exec) {
        }
        def vdlTask = project.task('vdl') {
            group = "Build"
            description('Generates Java vdl source using the vdl tool')
        }
        def prepareTask = project.task('prepareVdl') {
            doLast {
                generateTask.environment(VDLPATH: project.vdl.inputPaths.join(":"))
                generateTask.commandLine('build/vdltool/vdl-' + getOsName(), '--builtin_vdlroot', 'generate', '--lang=java', "--java-out-dir=${project.vdl.outputPath}", 'all')
            }
        }
        def removeVdlRootTask = project.task('removeVdlRoot', type: Delete) {
            onlyIf { !project.vdl.generateVdlRoot }
            delete project.vdl.outputPath + '/io/v/v23/vdlroot/'
        }
        extractTask.dependsOn(prepareTask)
        generateTask.dependsOn(extractTask)
        removeVdlRootTask.dependsOn(generateTask)
        vdlTask.dependsOn(removeVdlRootTask)
        project.clean.delete(project.vdl.outputPath)

        if (project.plugins.hasPlugin('java')) {
            project.compileJava.dependsOn(vdlTask)
            project.sourceSets.main.java.srcDirs += project.vdl.outputPath
        }

        if (project.plugins.hasPlugin('com.android.library') || project.plugins.hasPlugin('com.android.application')) {
            project.tasks.'preBuild'.dependsOn(vdlTask)
            project.android.sourceSets.main.java.srcDirs += project.vdl.outputPath
        }
    }

    /**
     * Returns a list of {@link java.io.File} instances representing VDL binaries.
     */
    static List<File> getVdlToolJarFiles(Project project, FileCollection files) {
        List<File> result = new ArrayList<File>()

        for (File file : files.findAll({
            it.name.contains 'gradle-plugin'
        })) {
            project.zipTree(file).findAll({ it.name.startsWith("vdl-") }).each({
                result.add(project.resources.text.fromArchiveEntry(file, it.name).asFile())
            })
        }

        return result
    }

    private static isMacOsX() {
        return System.properties['os.name'].toLowerCase().contains("os x")
    }

    private static isLinux() {
        return System.properties['os.name'].toLowerCase().contains("linux")
    }

    static String getOsName() {
        if (isLinux()) {
            return "linux";
        } else if (isMacOsX()) {
            return "macosx";
        } else {
            throw new IllegalStateException("Unsupported operating system " + System.properties.'os.name')
        }
    }
}

class VdlConfiguration {
    String vanadiumRoot
    List<String> inputPaths = []
    String outputPath = "generated-src/vdl"
    String vdlToolPath = ""

    // If true, code generated for the vdlroot vdl package will be emitted.
    // Typically, users will want to leave this set to false as they will
    // already get the vdlroot package by depending on the :lib project.
    boolean generateVdlRoot = false;
}