#!/usr/bin/env groovy

/*
 * Copyright (C) 2019 - present Instructure, Inc.
 *
 * This file is part of Canvas.
 *
 * Canvas is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Affero General Public License as published by the Free
 * Software Foundation, version 3 of the License.
 *
 * Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Affero General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

library "canvas-builds-library@${env.CANVAS_BUILDS_REFSPEC}"
loadLocalLibrary('local-lib', 'build/new-jenkins/library')

@groovy.transform.Field
def partitions = []
@groovy.transform.Field
def changedTests = ''
@groovy.transform.Field
def fscStatus = null
final static FSC_TIMEOUT = commitMessageFlag('fsc-timeout') as Integer ?: 20

def isPlugin() {
  return env.GERRIT_PROJECT == 'canvas-lms' ? '0' : '1'
}

def getDockerWorkDir() {
  if (env.GERRIT_PROJECT == 'qti_migration_tool') {
    return "/usr/src/app/vendor/${env.GERRIT_PROJECT}"
  }

  return env.GERRIT_PROJECT == 'canvas-lms' ? '/usr/src/app' : "/usr/src/app/gems/plugins/${env.GERRIT_PROJECT}"
}

def getLocalWorkDir() {
  if (env.GERRIT_PROJECT == 'qti_migration_tool') {
    return "vendor/${env.GERRIT_PROJECT}"
  }

  return env.GERRIT_PROJECT == 'canvas-lms' ? '.' : "gems/plugins/${env.GERRIT_PROJECT}"
}

def getMaxNodes() {
  return commitMessageFlag('fsc-max-nodes').asType(Integer) ?: 10
}

def setupNode() {
  sh 'rm -vrf ./tmp'
  def refspecToCheckout = env.GERRIT_PROJECT == 'canvas-lms' ? env.GERRIT_REFSPEC : env.CANVAS_LMS_REFSPEC

  checkoutFromGit(gerritProjectUrl('canvas-lms'), refspec: refspecToCheckout, depth: 2)

  if (env.IS_PLUGIN == '1') {
    dir(env.LOCAL_WORKDIR) {
      checkoutFromGit(gerritProjectUrl(), refspec: env.GERRIT_REFSPEC, depth: 2)
    }
  }

  credentials.withStarlordCredentials { ->
    sh(script: 'build/new-jenkins/docker-compose-pull.sh', label: 'Pull Images')
  }
  sh(script: 'build/new-jenkins/docker-compose-build-up.sh', label: 'Start Containers')
}

def computeTestCount() {
  // oops, probably should have added an easier way to _count_ tests...
  sh 'rm -vrf $LOCAL_WORKDIR/tmp'
  sh 'mkdir -v $LOCAL_WORKDIR/tmp'
  sh 'chmod -vv 777 $LOCAL_WORKDIR/tmp'

  if (FORCE_FAILURE == '1') {
    changedTests = 'spec/force_failure_spec.rb'
  } else {
    sh '''
      docker run --volume $(pwd)/$LOCAL_WORKDIR/.git:$DOCKER_WORKDIR/.git \
                 --volume $(pwd)/$LOCAL_WORKDIR/tmp:$DOCKER_WORKDIR/tmp \
                 --env FSC_IGNORE_FILES \
                 -w=$DOCKER_WORKDIR \
                 $PATCHSET_TAG \
          bash -c "git config --global --add safe.directory $DOCKER_WORKDIR; flakey_spec_catcher --use-parent --list-child-specs --dry-run-quiet > $DOCKER_WORKDIR/tmp/test_list"
    '''

    changedTests = readFile("$env.LOCAL_WORKDIR/tmp/test_list").trim()
  }

  echo "raw result from catcher: \n====\n$changedTests\n===="

  if (changedTests.length() == 0) {
    echo 'no tests found to execute'

    return
  }

  def changedTestsArr = changedTests.split('\n').collect { changedTest ->
    "$DOCKER_WORKDIR/$changedTest"
  }

  def testCount = changedTestsArr.size()
  def weightedValues = changedTestsArr.collect { changedTest ->
    changedTest.contains('selenium') ? env.SELENIUM_RATIO.toInteger() : 1
  }

  def distributedFactor = env.TESTS_PER_NODE.toInteger()

  def i = 0
  def curPartition = []
  def curWeight = 0

  while (i < testCount) {
    curPartition.add(changedTestsArr[i])
    curWeight += weightedValues[i]

    if (curWeight >= distributedFactor) {
      partitions.add(curPartition)

      curPartition = []
      curWeight = 0
    }

    i++
  }

  if (curPartition.size() > 0) {
    partitions.add(curPartition)
  }

  echo "expected nodes to run on for $testCount tests: ${partitions.size()}"
}

def executeFlakeySpecCatcher() {
  try {
    sh 'build/new-jenkins/rspec-flakey-spec-catcher.sh'
  } catch (org.jenkinsci.plugins.workflow.steps.FlowInterruptedException e) {
    if (e.causes[0] instanceof org.jenkinsci.plugins.workflow.steps.TimeoutStepExecution.ExceededTimeout) {
      echo 'Failing the build due to timeouts'
      fscStatus = 'timeout'
      throw e
    } else if (e.causes[0] instanceof jenkins.model.CauseOfInterruption.UserInterruption) {
      echo 'Build aborted'
      fscStatus = 'aborted'
    } else {
      throw e
    }
  } finally {
    sh """
    rm -vrf tmp && mkdir -p tmp
    docker cp flakey-spec-catcher_canvas_1:/usr/src/app/tmp/fsc.out tmp/fsc-${env.NODE_NUMBER}.out || true
    """
    archiveArtifacts artifacts: "tmp/fsc-${env.NODE_NUMBER}.out", allowEmptyArchive: true
  }
}

def sendSlack(success) {
  def color = fscStatus == 'timeout' ? 'warning' : (success ? 'good' : 'danger')
  def jobInfo = "<https://gerrit.instructure.com/$env.GERRIT_CHANGE_NUMBER|Gerrit> | <$env.BUILD_URL|Jenkins>"
  def message = "$jobInfo\n$changedTests"
  if (fscStatus == 'timeout') {
    message = "Timeout Occurred!\n$message"
  }
  slackSend channel: '#flakey_spec_catcher_noisy', color: color, message: message
}

def cleanupFn(status) {
  if (fscStatus != 'aborted') {
    sendSlack(status == 'SUCCESS')
  }
}

pipeline {
  agent none
  options {
    ansiColor('xterm')
    timeout(time: FSC_TIMEOUT)
    timestamps()
  }

  environment {
    GERRIT_PORT = '29418'
    GERRIT_URL = "$GERRIT_HOST:$GERRIT_PORT"
    BUILD_REGISTRY_FQDN = configuration.buildRegistryFQDN()
    COMPOSE_FILE = 'docker-compose.new-jenkins.yml:docker-compose.new-jenkins-selenium.yml:docker-compose.new-jenkins-flakey-spec-catcher.yml'
    IS_PLUGIN = isPlugin()
    DOCKER_WORKDIR = getDockerWorkDir()
    LOCAL_WORKDIR = getLocalWorkDir()
    FORCE_FAILURE = commitMessageFlag('force-failure-fsc').asBooleanInteger()
    // fsc errors when running specs from gems.
    // until we figure out how to run them, we should ignore them
    FSC_IGNORE_FILES = 'gems/.*/spec/,spec/contracts/,spec/selenium/performance/'
    POSTGRES_PASSWORD = 'sekret'

    // Targeting 10 minutes / node, each node runs RSPEC_PROCESSES threads and
    // repeats each test FSC_REPEAT_FACTOR times.
    // Assumption: non-selenium tests take 500ms / test
    // Assumption: selenium tests take 500ms * SELENIUM_RATIO / test
    FSC_REPEAT_FACTOR = 10
    MAX_NODES = getMaxNodes()
    RSPEC_PROCESSES = 3
    SELENIUM_RATIO = 20
    TESTS_PER_NODE = 200
  }

  stages {
    stage('Environment') {
      steps {
        script {
          extendedStage('Runner').nodeRequirements(label: nodeLabel()).obeysAllowStages(false).execute {
            def postBuildHandler = [
              onStageEnded: { stageName, stageConfig, result ->
                cleanupFn(stageConfig.status())
              }
            ]

            extendedStage('Builder').hooks(postBuildHandler).obeysAllowStages(false).execute {
              stage('Setup') {
                setupNode()
              }

              stage('Compute Build Distribution') {
                computeTestCount()
              }

              stage('Run Flakey Spec Catcher') {
                if (partitions.size() == 0) {
                  return
                } else if (partitions.size() > env.MAX_NODES.toInteger()) {
                  error "Refusing to use more than ${env.MAX_NODES} nodes to catch flakey specs. Consider breaking this change into smaller pieces."

                  return
                }

                def stages = [:]

                stages['flakey set 00'] = {
                  withEnv([
                    "FSC_TESTS=${partitions[0].join(',')}",
                    'NODE_NUMBER=00'
                  ]) {
                    executeFlakeySpecCatcher()
                  }
                }

                for (int i = 1; i < partitions.size(); i++) {
                  // make sure to create a new index variable so this value gets
                  // captured by the lambda
                  def index = i
                  def nodeNumber = (index).toString().padLeft(2, '0')

                  stages["flakey set $nodeNumber"] = {
                    protectedNode(nodeLabel()) {
                      withEnv([
                        "FSC_TESTS=${partitions[index].join(',')}",
                        "NODE_NUMBER=$nodeNumber"
                      ]) {
                        setupNode()
                        executeFlakeySpecCatcher()
                      }
                    }
                  }
                }
                parallel(stages)
              }
            }
          }
        }
      }
    }
  }
}