#!groovy
import groovy.json.JsonOutput
import groovy.json.JsonSlurper

node {
    // pull request or feature branch
    if  (env.BRANCH_NAME != 'master') {
        checkout()
        build()
        unitTest()
        // test whether this is a regular branch build or a merged PR build
        if (!isPRMergeBuild()) {
            // maybe disabled for ChatOps
            // preview()
        }
    } // master branch / production
    else {
        checkout()
        build()
        allTests()
        preProduction()
        manualPromotion()
        production()
    }
}

def isPRMergeBuild() {
    return (env.BRANCH_NAME ==~ /^PR-\d+$/)
}

def checkout () {
    stage 'Checkout code'
    context="continuous-integration/jenkins/"
    context += isPRMergeBuild()?"branch/checkout":"pr-merge/checkout"
    setBuildStatus ("${context}", 'Checking out...', 'PENDING')
    checkout scm
    setBuildStatus ("${context}", 'Checking out completed', 'SUCCESS')
}

def build () {
    stage 'Build'
    // cache maven artifacts
    shareM2 '/tmp/m2repo'
    mvn 'clean install -DskipTests=true -Dmaven.javadoc.skip=true -Dcheckstyle.skip=true -B -V'
}


def unitTest() {
    stage 'Unit tests'
    mvn 'test -B -Dmaven.javadoc.skip=true -Dcheckstyle.skip=true'
    step([$class: 'JUnitResultArchiver', testResults: '**/target/surefire-reports/TEST-*.xml'])
    if (currentBuild.result == "UNSTABLE") {
        sh "exit 1"
    }
}

def allTests() {
    stage 'All tests'
    // don't skip anything
    mvn 'test -B'
    step([$class: 'JUnitResultArchiver', testResults: '**/target/surefire-reports/TEST-*.xml'])
    if (currentBuild.result == "UNSTABLE") {
        // input "Unit tests are failing, proceed?"
        sh "exit 1"
    }
}

def preview() {
    herokuApp = "${env.HEROKU_PREVIEW}"
    deployToStage("preview", herokuApp)
}

def preProduction() {
    herokuApp = "${env.HEROKU_PREPRODUCTION}"
    deployToStage("preproduction", herokuApp)
}

def manualPromotion() {
  stage 'Manual Promotion'
    // we need a first milestone step so that all jobs entering this stage are tracked an can be aborted if needed
    milestone 1
    // time out manual approval after ten minutes
    timeout(time: 10, unit: 'MINUTES') {
        input message: "Does Pre-Production look good?"
    }
    // this will kill any job which is still in the input step
    milestone 2
}

def production() {
    herokuApp = "${env.HEROKU_PRODUCTION}"
    deployToStage("production", herokuApp)
    step([$class: 'ArtifactArchiver', artifacts: '**/target/*.jar', fingerprint: true])
}

def deployToStage(stageName, herokuApp) {
    stage name: "Deploy to ${stageName}", concurrency: 1
    id = createDeployment(getBranch(), "${stageName}", "Deploying branch to ${stageName}")
    echo "Deployment ID for ${stageName}: ${id}"
    if (id != null) {
        setDeploymentStatus(id, "pending", "https://${herokuApp}.herokuapp.com/", "Pending deployment to ${stageName}");
        herokuDeploy "${herokuApp}"
        setDeploymentStatus(id, "success", "https://${herokuApp}.herokuapp.com/", "Successfully deployed to ${stageName}");
    }
}

def herokuDeploy (herokuApp) {
    withCredentials([[$class: 'StringBinding', credentialsId: 'HEROKU_API_KEY', variable: 'HEROKU_API_KEY']]) {
        mvn "heroku:deploy -DskipTests=true -Dmaven.javadoc.skip=true -B -V -D heroku.appName=${herokuApp}"
    }
}

def mvn(args) {
    // point to settings.xml with cached .m2 directory and proceed in case of test failures
    sh "${tool 'Maven 3.x'}/bin/mvn -s settings.xml ${args} -Dmaven.test.failure.ignore"
}

def shareM2(file) {
    // Set up a shared Maven repo so we don't need to download all dependencies on every build.
    writeFile file: 'settings.xml',
    text: "<settings><localRepository>${file}</localRepository></settings>"
}

def getRepoSlug() {
    tokens = "${env.JOB_NAME}".tokenize('/')
    org = tokens[tokens.size()-3]
    repo = tokens[tokens.size()-2]
    return "${org}/${repo}"
}

def getBranch() {
    tokens = "${env.JOB_NAME}".tokenize('/')
    branch = tokens[tokens.size()-1]
    return "${branch}"
}

def createDeployment(ref, environment, description) {
    withCredentials([[$class: 'StringBinding', credentialsId: 'GITHUB_TOKEN', variable: 'GITHUB_TOKEN']]) {
        def payload = JsonOutput.toJson(["ref": "${ref}", "description": "${description}", "environment": "${environment}", "required_contexts": []])
        def apiUrl = "https://octodemo.com/api/v3/repos/${getRepoSlug()}/deployments"
        def response = sh(returnStdout: true, script: "curl -s -H \"Authorization: Token ${env.GITHUB_TOKEN}\" -H \"Accept: application/json\" -H \"Content-type: application/json\" -X POST -d '${payload}' ${apiUrl}").trim()
        def jsonSlurper = new JsonSlurper()
        def data = jsonSlurper.parseText("${response}")
        return data.id
    }
}

void setDeploymentStatus(deploymentId, state, targetUrl, description) {
    withCredentials([[$class: 'StringBinding', credentialsId: 'GITHUB_TOKEN', variable: 'GITHUB_TOKEN']]) {
        def payload = JsonOutput.toJson(["state": "${state}", "target_url": "${targetUrl}", "description": "${description}"])
        def apiUrl = "https://octodemo.com/api/v3/repos/${getRepoSlug()}/deployments/${deploymentId}/statuses"
        def response = sh(returnStdout: true, script: "curl -s -H \"Authorization: Token ${env.GITHUB_TOKEN}\" -H \"Accept: application/json\" -H \"Content-type: application/json\" -X POST -d '${payload}' ${apiUrl}").trim()
    }
}

void setBuildStatus(context, message, state) {
// partially hard coded URL because of https://issues.jenkins-ci.org/browse/JENKINS-36961, adjust to your own GitHub instance
    step([
      $class: "GitHubCommitStatusSetter",
      contextSource: [$class: "ManuallyEnteredCommitContextSource", context: context],
      errorHandlers: [[$class: "ChangingBuildStatusErrorHandler", result: "UNSTABLE"]],
      reposSource: [$class: "ManuallyEnteredRepositorySource", url: "https://github.com/${getRepoSlug()}"],
      statusResultSource: [ $class: "ConditionalStatusResultSource", results: [[$class: "AnyBuildResult", message: message, state: state]] ]
  ]);
}