#51: Provide a gradle plugin

build.gradle.kts

@@ -4,6 +4,7 @@
 plugins {
     java
     `maven-publish`
+    `java-gradle-plugin`
     id("com.diffplug.spotless") version "6.12.0"
     id("org.jetbrains.kotlin.jvm") version "1.8.10"
     id("org.jlleitschuh.gradle.ktlint") version "11.2.0"
@@ -22,9 +23,11 @@ java.sourceCompatibility = JavaVersion.VERSION_17
 
 dependencies {
     implementation("org.camunda.bpm.model:camunda-bpmn-model:7.18.0")
-    compileOnly("org.apache.maven.plugin-tools:maven-plugin-annotations:3.7.1")
     implementation("org.freemarker:freemarker:2.3.32")
+    implementation("org.slf4j:slf4j-api:2.0.7")
     dokkaHtmlPlugin("org.jetbrains.dokka:kotlin-as-java-plugin:1.7.20")
+    testImplementation("org.junit.jupiter:junit-jupiter-api:5.9.2")
+    testImplementation("org.junit.jupiter:junit-jupiter-engine:5.9.2")
 }
 
 publishing {
@@ -58,3 +61,12 @@ configure<com.diffplug.gradle.spotless.SpotlessExtension> {
         ktlint()
     }
 }
+
+gradlePlugin {
+    plugins {
+        create("CamundaBpmnDocumentationGenerator") {
+            id = "info.novatec.cbdg"
+            implementationClass = "info.novatec.cbdg.plugin.CamundaBpmnDocumentationGenerator"
+        }
+    }
+}

src/main/kotlin/info/novatec/cbdg/plugin/CamundaBpmnDocumentationGenerator.kt

@@ -0,0 +1,36 @@
+package info.novatec.cbdg.plugin
+
+import info.novatec.docu.generator.DocuGenerator
+import org.gradle.api.Plugin
+import org.gradle.api.Project
+import org.gradle.api.provider.Property
+import org.slf4j.LoggerFactory
+import java.io.File
+
+interface CamundaBpmnDocumentationGeneratorConfiguration {
+    val templateFile: Property<File>
+    val camundaBpmnDir: Property<File>
+    val resultOutputDir: Property<File>
+    val bpmnDiagramImageDir: Property<File>?
+}
+
+class CamundaBpmnDocumentationGenerator : Plugin<Project> {
+
+    override fun apply(project: Project) {
+        val configuration = project.extensions.create("cbdg", CamundaBpmnDocumentationGeneratorConfiguration::class.java)
+        configuration.templateFile.convention(project.layout.buildDirectory.file("resources/main/templates/default.ftl").get().asFile)
+        configuration.camundaBpmnDir.convention(project.layout.buildDirectory.dir("resources/main/bpmn").get().asFile)
+        configuration.resultOutputDir.convention(project.layout.buildDirectory.dir("cbdg/html").get().asFile)
+        configuration.bpmnDiagramImageDir?.convention(project.layout.buildDirectory.dir("resources/main/images").get().asFile)
+
+        project.task("generate").doLast {
+            DocuGenerator.parseAndGenerate(
+                LoggerFactory.getLogger(CamundaBpmnDocumentationGenerator::class.java),
+                configuration.templateFile.get(),
+                configuration.camundaBpmnDir.get(),
+                configuration.resultOutputDir.get(),
+                configuration.bpmnDiagramImageDir?.get()
+            )
+        }
+    }
+}

src/main/kotlin/info/novatec/docu/generator/DocuGenerator.kt

@@ -0,0 +1,56 @@
+package info.novatec.docu.generator
+
+import info.novatec.cbdg.FreeMarkerService
+import info.novatec.docu.parser.main.BpmnParser
+import org.slf4j.Logger
+import java.io.File
+import java.io.FileNotFoundException
+import java.io.FileOutputStream
+import java.nio.file.Files
+import java.nio.file.StandardCopyOption
+import kotlin.io.path.Path
+import kotlin.io.path.createDirectories
+import kotlin.io.path.exists
+
+object DocuGenerator {
+
+    fun parseAndGenerate(
+        log: Logger,
+        templateFile: File,
+        camundaBpmnDir: File,
+        resultOutputDir: File,
+        bpmnDiagramImageDir: File? = null
+    ) {
+        if (templateFile.name.equals("default.ftl")) {
+            FileOutputStream(templateFile, false).use {
+                javaClass.classLoader.getResourceAsStream("templates/default.ftl")
+                    ?.transferTo(it) ?: throw FileNotFoundException("templates/default.ftl don't exist.")
+            }
+        }
+
+        camundaBpmnDir.listFiles()?.forEach {
+            log.info("Generating documentation for file ${it.absolutePath}")
+            log.info("Using template ${templateFile.absolutePath}")
+
+            val imageSrcPath = Path("${bpmnDiagramImageDir?.absolutePath}/${it.nameWithoutExtension}.png")
+            val imageTargetPath = Path("${resultOutputDir.absolutePath}/images/${it.nameWithoutExtension}.png")
+            imageTargetPath.parent.createDirectories()
+            if (imageSrcPath.exists()) {
+                Files.copy(imageSrcPath, imageTargetPath, StandardCopyOption.REPLACE_EXISTING)
+            }
+
+            val bpmnObject = BpmnParser.parseBpmnFile(it, "${it.nameWithoutExtension}.png")
+            FreeMarkerService.writeTemplate(
+                bpmnObject,
+                templateFile.name,
+                "${resultOutputDir.absolutePath}/${it.nameWithoutExtension}.html"
+            ) {
+                setDirectoryForTemplateLoading(templateFile.parentFile)
+            }
+            log.info("Output report into path ${resultOutputDir.absolutePath}")
+        } ?: throw FileNotFoundException("${camundaBpmnDir.absolutePath} don't exist.")
+        resultOutputDir.listFiles()?.forEach {
+            log.info("Output: " + it.absolutePath)
+        } ?: throw FileNotFoundException("${resultOutputDir.absolutePath} don't exist.")
+    }
+}

src/test/kotlin/info/novatec/cbdg/plugin/CamundaBpmnDocumentationGeneratorTest.kt

@@ -0,0 +1,20 @@
+package info.novatec.cbdg.plugin
+
+import org.gradle.api.Project
+import org.gradle.testfixtures.ProjectBuilder
+import org.junit.jupiter.api.Assertions.assertNotNull
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Test
+
+class CamundaBpmnDocumentationGeneratorTest {
+
+    @Test
+    fun greetingTest() {
+        val project: Project = ProjectBuilder.builder().build()
+
+        project.getPluginManager().apply("info.novatec.cbdg")
+
+        assertTrue(project.getPluginManager().hasPlugin("info.novatec.cbdg"))
+        assertNotNull(project.getTasks().getByName("generate"))
+    }
+}