/*
 * Licensed to Elasticsearch under one or more contributor
 * license agreements. See the NOTICE file distributed with
 * this work for additional information regarding copyright
 * ownership. Elasticsearch licenses this file to you under
 * the Apache License, Version 2.0 (the "License"); you may
 * not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */


import org.elasticsearch.gradle.LoggedExec

/**
 * This is a dummy project which does a local checkout of the previous
 * wire compat version's branch, and builds a snapshot. This allows backcompat
 * tests to test against the next unreleased version, closest to this version,
 * without relying on snapshots.
 */
String bwcVersion
boolean enabled = true
if (project.name == 'bwc-stable-snapshot') {
  /* bwc-stable is only used if the last version is on a stable branch instead
   * of a bugfix branch */
  enabled = indexCompatVersions[-1].bugfix == 0
  bwcVersion = indexCompatVersions[-1]
} else if (project.name == 'bwc-release-snapshot') {
  if (indexCompatVersions[-1].bugfix == 0) {
    /* The last version is on a stable branch so it is handled by the bwc-stable
     * project. This project will instead handle the version before that which
     * *should* be on a stable branch. */
    bwcVersion = indexCompatVersions[-2]
  } else {
    // The last version is on a release branch so it is handled by this project
    bwcVersion = indexCompatVersions[-1]
  }
} else {
  throw new InvalidUserDataException("Unsupport project name ${project.name}")
}

if (enabled) {
  apply plugin: 'distribution'
  // Not published so no need to assemble
  tasks.remove(assemble)
  build.dependsOn.remove('assemble')

  def (String major, String minor, String bugfix) = bwcVersion.split('\\.')
  def (String currentMajor, String currentMinor, String currentBugfix) = version.split('\\.')
  String bwcBranch
  if (project.name == 'bwc-stable-snapshot') {
    bwcBranch = "${major}.x"
  } else {
    bwcBranch = "${major}.${minor}"
  }
  File checkoutDir = file("${buildDir}/bwc/checkout-${bwcBranch}")

  task createClone(type: LoggedExec) {
    onlyIf { checkoutDir.exists() == false }
    commandLine = ['git', 'clone', rootDir, checkoutDir]
  }

  task findUpstream(type: LoggedExec) {
    dependsOn createClone
    workingDir = checkoutDir
    commandLine = ['git', 'remote', '-v']
    doLast {
      project.ext.upstreamExists = false
      output.toString('UTF-8').eachLine {
        if (it.contains("upstream")) {
          project.ext.upstreamExists = true
        }
      }
    }
  }

  task addUpstream(type: LoggedExec) {
    dependsOn findUpstream
    onlyIf { project.ext.upstreamExists == false }
    workingDir = checkoutDir
    commandLine = ['git', 'remote', 'add', 'upstream', 'https://github.com/elastic/elasticsearch.git']
  }

  task fetchLatest(type: LoggedExec) {
    onlyIf { project.gradle.startParameter.isOffline() == false }
    dependsOn addUpstream
    workingDir = checkoutDir
    commandLine = ['git', 'fetch', '--all']
  }

  String buildMetadataKey = "bwc_refspec_${project.path.substring(1)}"
  task checkoutBwcBranch(type: LoggedExec) {
    String refspec = System.getProperty("tests.bwc.refspec", buildMetadata.get(buildMetadataKey, "upstream/${bwcBranch}"))
    dependsOn fetchLatest
    workingDir = checkoutDir
    commandLine = ['git', 'checkout', refspec]
    doFirst {
      println "Checking out elasticsearch ${refspec} for branch ${bwcBranch}"
    }
  }

  File buildMetadataFile = project.file("build/${project.name}/build_metadata")
  task writeBuildMetadata(type: LoggedExec) {
    dependsOn checkoutBwcBranch
    workingDir = checkoutDir
    commandLine = ['git', 'rev-parse', 'HEAD']
    ignoreExitValue = true
    ByteArrayOutputStream output = new ByteArrayOutputStream()
    standardOutput = output
    doLast {
      if (execResult.exitValue != 0) {
        output.toString('UTF-8').eachLine { line -> logger.error(line) }
        execResult.assertNormalExitValue()
      }
      project.mkdir(buildMetadataFile.parent)
      String commit = output.toString('UTF-8')
      buildMetadataFile.setText("${buildMetadataKey}=${commit}", 'UTF-8')
      println "Checked out elasticsearch commit ${commit}"
    }
  }

  File bwcDeb = file("${checkoutDir}/distribution/deb/build/distributions/elasticsearch-${bwcVersion}.deb")
  File bwcRpm = file("${checkoutDir}/distribution/rpm/build/distributions/elasticsearch-${bwcVersion}.rpm")
  File bwcZip = file("${checkoutDir}/distribution/zip/build/distributions/elasticsearch-${bwcVersion}.zip")
  task buildBwcVersion(type: GradleBuild) {
    dependsOn checkoutBwcBranch, writeBuildMetadata
    dir = checkoutDir
    tasks = [':distribution:deb:assemble', ':distribution:rpm:assemble', ':distribution:zip:assemble']
    startParameter.systemPropertiesArgs = ['build.snapshot': 'true']
    doLast {
      List missing = [bwcDeb, bwcRpm, bwcZip].grep { file ->
        false == file.exists() }
      if (false == missing.empty) {
        throw new InvalidUserDataException(
          "Building bwc version didn't generate expected files ${missing}")
      }
    }
  }

  artifacts {
    'default' file: bwcDeb, name: 'elasticsearch', type: 'deb', builtBy: buildBwcVersion
    'default' file: bwcRpm, name: 'elasticsearch', type: 'rpm', builtBy: buildBwcVersion
    'default' file: bwcZip, name: 'elasticsearch', type: 'zip', builtBy: buildBwcVersion
  }
}