class Metricbeat < Formula
  desc "Collect metrics from your systems and services"
  homepage "https://www.elastic.co/products/beats/metricbeat"
  url "https://github.com/elastic/beats.git",
      :tag      => "v6.8.5",
      :revision => "22b590e4e8dbb91bdcfe8689e59dcb04447eeef6"
  revision 1
  head "https://github.com/elastic/beats.git"

  bottle do
    cellar :any_skip_relocation
    sha256 "a7e57e0a45c199988abf82d7fefc1e0e29dfec3d36fc404c3f66f1589a9959e0" => :catalina
    sha256 "e2e5a236ae0051987d1e15907525ff035cbe93fd7a1f83cdc2157d1bdabc7fb8" => :mojave
    sha256 "6466e3abe58c3648d841a06ea1e11bd27af6ce38c568af4d9046701a30200d9d" => :high_sierra
  end

  depends_on "go" => :build
  # https://github.com/elastic/beats/pull/14798
  uses_from_macos "python@2" => :build # does not support Python 3

  # Newer virtualenvs are not compatible with Python 2.7.10 on high sierra, use an old version
  resource "virtualenv" do
    url "https://files.pythonhosted.org/packages/d4/0c/9840c08189e030873387a73b90ada981885010dd9aea134d6de30cd24cb8/virtualenv-15.1.0.tar.gz"
    sha256 "02f8102c2436bb03b3ee6dede1919d1dac8a427541652e5ec95171ec8adbc93a"
  end

  def install
    # remove non open source files
    rm_rf "x-pack"

    ENV["GOPATH"] = buildpath
    (buildpath/"src/github.com/elastic/beats").install buildpath.children

    ENV.prepend_create_path "PYTHONPATH", buildpath/"vendor/lib/python2.7/site-packages"

    resource("virtualenv").stage do
      system "python", *Language::Python.setup_install_args(buildpath/"vendor")
    end

    ENV.prepend_path "PATH", buildpath/"vendor/bin" # for virtualenv
    ENV.prepend_path "PATH", buildpath/"bin" # for mage (build tool)

    cd "src/github.com/elastic/beats/metricbeat" do
      # don't build docs because it would fail creating the combined OSS/x-pack
      # docs and we aren't installing them anyway
      inreplace "Makefile", "collect: assets collect-docs configs kibana imports",
                            "collect: assets configs kibana imports"

      system "make", "mage"
      # prevent downloading binary wheels during python setup
      system "make", "PIP_INSTALL_COMMANDS=--no-binary :all", "python-env"
      system "mage", "-v", "build"
      system "mage", "-v", "update"

      (etc/"metricbeat").install Dir["metricbeat.*", "fields.yml", "modules.d"]
      (libexec/"bin").install "metricbeat"
      prefix.install "_meta/kibana.generated"
    end

    prefix.install_metafiles buildpath/"src/github.com/elastic/beats"

    (bin/"metricbeat").write <<~EOS
      #!/bin/sh
      exec #{libexec}/bin/metricbeat \
        --path.config #{etc}/metricbeat \
        --path.data #{var}/lib/metricbeat \
        --path.home #{prefix} \
        --path.logs #{var}/log/metricbeat \
        "$@"
    EOS
  end

  plist_options :manual => "metricbeat"

  def plist; <<~EOS
    <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN"
    "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
    <plist version="1.0">
      <dict>
        <key>Label</key>
        <string>#{plist_name}</string>
        <key>Program</key>
        <string>#{opt_bin}/metricbeat</string>
        <key>RunAtLoad</key>
        <true/>
      </dict>
    </plist>
  EOS
  end

  test do
    (testpath/"config/metricbeat.yml").write <<~EOS
      metricbeat.modules:
      - module: system
        metricsets: ["load"]
        period: 1s
      output.file:
        enabled: true
        path: #{testpath}/data
        filename: metricbeat
    EOS

    (testpath/"logs").mkpath
    (testpath/"data").mkpath

    pid = fork do
      exec bin/"metricbeat", "-path.config", testpath/"config", "-path.data",
                             testpath/"data"
    end

    begin
      sleep 30
      assert_predicate testpath/"data/metricbeat", :exist?
    ensure
      Process.kill "SIGINT", pid
      Process.wait pid
    end
  end
end