class Heartbeat < Formula
  desc "Lightweight Shipper for Uptime Monitoring"
  homepage "https://www.elastic.co/products/beats/heartbeat"
  # Pinned at 6.2.x because of a licencing issue
  # See: https://github.com/Homebrew/homebrew-core/pull/28995
  url "https://github.com/elastic/beats/archive/v6.2.4.tar.gz"
  sha256 "87d863cf55863329ca80e76c3d813af2960492f4834d4fea919f1d4b49aaf699"
  head "https://github.com/elastic/beats.git"

  bottle do
    cellar :any_skip_relocation
    rebuild 1
    sha256 "41bc5429f96531dee4d989d5b5bf59c5183c3be8bf2218f3231d4b3e6b0e9a13" => :mojave
    sha256 "ad880a8fb097c0e9a3b61de9cd53b2cfefb6d19effdda945e4f2f3bde9daba50" => :high_sierra
    sha256 "b6c3d3d20c0154a66847ed9837247964c874eb559b5ad8bc451ba6b660cd0256" => :sierra
  end

  depends_on "go" => :build
  depends_on "python" => :build

  resource "virtualenv" do
    url "https://files.pythonhosted.org/packages/b1/72/2d70c5a1de409ceb3a27ff2ec007ecdd5cc52239e7c74990e32af57affe9/virtualenv-15.2.0.tar.gz"
    sha256 "1d7e241b431e7afce47e77f8843a276f652699d1fa4f93b9d8ce0076fd7b0b54"
  end

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

    xy = Language::Python.major_minor_version "python3"
    ENV.prepend_create_path "PYTHONPATH", buildpath/"vendor/lib/python#{xy}/site-packages"

    resource("virtualenv").stage do
      system "python3", *Language::Python.setup_install_args(buildpath/"vendor")
    end

    ENV.prepend_path "PATH", buildpath/"vendor/bin"

    cd "src/github.com/elastic/beats/heartbeat" do
      system "make"
      # prevent downloading binary wheels during python setup
      system "make", "PIP_INSTALL_COMMANDS=--no-binary :all", "python-env"
      system "make", "DEV_OS=darwin", "update"

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

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

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

  def post_install
    (var/"lib/heartbeat").mkpath
    (var/"log/heartbeat").mkpath
  end

  plist_options :manual => "heartbeat"

  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}/heartbeat</string>
        <key>RunAtLoad</key>
        <true/>
      </dict>
    </plist>
  EOS
  end

  test do
    require "socket"

    server = TCPServer.new(0)
    port = server.addr[1]
    server.close

    (testpath/"config/heartbeat.yml").write <<~EOS
      heartbeat.monitors:
      - type: tcp
        schedule: '@every 5s'
        hosts: ["localhost:#{port}"]
        check.send: "hello\\n"
        check.receive: "goodbye\\n"
      output.file:
        path: "#{testpath}/heartbeat"
        filename: heartbeat
        codec.format:
          string: '%{[monitor]}'
    EOS
    pid = fork do
      exec bin/"heartbeat", "-path.config", testpath/"config", "-path.data",
                            testpath/"data"
    end
    sleep 5

    begin
      assert_match "hello", pipe_output("nc -c -l #{port}", "goodbye\n", 0)
      sleep 5
      assert_match "\"status\":\"up\"", (testpath/"heartbeat/heartbeat").read
    ensure
      Process.kill "SIGINT", pid
      Process.wait pid
    end
  end
end